Exploring the Antimicrobial Potential of New Selenium- N-Heterocyclic Carbene Complexes and Their Benzimidazolium Salts: Synthesis, Characterization, Biological Evaluation, and Docking Insights

Exploring the Antimicrobial Potential of New Selenium- N-Heterocyclic Carbene Complexes and Their Benzimidazolium Salts: Synthesis, Characterization, Biological Evaluation, and Docking Insights | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Exploring the Antimicrobial Potential of New Selenium- N-Heterocyclic Carbene Complexes and Their Benzimidazolium Salts: Synthesis, Characterization, Biological Evaluation, and Docking Insights Boutheina BOUALIA, Abd elkrim SANDELI, Houssem BOULEBD, Hüseyin KARCI, and 6 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-5034118/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 29 Dec, 2024 Read the published version in Chemical Papers → Version 1 posted 5 You are reading this latest preprint version Abstract The present work, describes the synthesis and antimicrobial evaluation of new selenium-NHC adducts ( 3a-e) and their corresponding benzimidazolium salts ( 2a-e) . Specific synthetic approaches were employed, resulting in compounds with satisfactory stability under humid and aerated conditions. Characterization by spectroscopic methods confirmed structural changes upon selenium incorporation. Biological evaluations revealed varying antimicrobial and antifungal activities among the synthesized compounds. The results indicated that the benzimidazolium salts exhibited significantly enhanced antimicrobial and antifungal activities compared to reference agents. For instance, compound 2a demonstrated an IC 50 value of 6.25 µg/mL against Candida albicans, which was comparable to the reference Caspofungin (6.25 µg/mL). Similarly, compound 2e demonstrated strong antibacterial activity against Staphylococcus aureus, with an IC 50 value of 0.8 µg/mL, significantly outperforming the reference Ampicillin (1.56 µg/mL). In contrast, the selenium-NHC adducts exhibited moderate to minimal activity, with compound 3e showing the highest IC 50 value of 25 µg/mL against Staphylococcus aureus, but failing to surpass the activity of the reference agent. To explore the potential mechanism of action, molecular docking studies were conducted against E. coli DNA gyrase and CYP51. The molecular docking results demonstrate that synthesized compounds exhibit significant binding affinity against both enzymes, indicating antibacterial and antifungal potential. These binding affinities suggest that these molecules could be effective dual-action antimicrobial agents. Selenium N-heterocyclic carbene Benzimidazolium Antimicrobial Structure-activity Docking Figures Figure 1 1. INTRODUCTION Due to their diverse range of biological activities, N -heterocyclic carbene metal complexes are gaining increasing significance in medicinal chemistry (Fatima et al., 2017; Haque et al., 2017). In recent years, research has primarily concentrated on the anticancer (Iqbal et al., 2013) and antibacterial (Asekunowo et al., 2017) applications of silver(I) and gold(I) NHC complexes. Conversely, selenium-based compounds have been examined and demonstrated promising antimicrobial activity (Dhau et al., 2014; Nguyen et al., 2014). Being an essential micronutrient (Rother & Quitzke, 2018; Solovyev, 2015), selenium is non-toxic to humans when present in low concentrations(Genchi et al., 2023; Sun et al., 2014; Zwolak & Zaporowska, 2012). This makes it a potential candidate for an adduct that can release selenium steadily into the biological system, acting as an effective pharmaceutical agent (Du et al., 2014). A key advantage of Se-NHC adducts lies in their potential for the targeted and effective delivery of selenium to biological sites, which remains a challenge in medicinal applications (Karthik et al., 2024). In medicinal chemistry, Selenium's compatibility with biological systems makes it particularly valuable for treating a range of illnesses, outperforming many other elements in the periodic table. For instance, selenium supplements are administered to address selenium deficiency, and selenium sulfide is a common ingredient in anti-dandruff shampoos (Cisnetti & Gautier, 2013; Huda et al., 2023; Khalifa et al., 2015). To date, several transition metal NHC compounds, such as those containing Au, Ag, or Ru, have shown great potential as antimicrobial and anticancer agents (Karci et al., 2024; Zou et al., 2018). However, these compounds often have limited biological safety and potential toxicity at higher concentrations (Bian et al., 2019; Mora et al., 2019). In contrast, Se-NHC adducts have shown similar antimicrobial and antioxidant activities at much lower concentrations, while also demonstrating biocompatibility (Nassar et al., 2023). Effectively delivering selenium within biological systems continues to be a significant challenge. To explore the potential of NHC donor ligands, researchers have recently designed and synthesized carbene adducts incorporating selenium (Doddi et al., 2019; Yaqoob et al., 2020). The incorporation of selenium in NHC frameworks has been shown to enhance bioactivity, as observed by Altaf et al., who reported superior anticancer and antimicrobial activities for selenium adducts compared to their ligands(Altaf et al., 2025a). The substituents at the N-position in N-heterocyclic carbenes (NHCs) play a significant role in determining their chemical properties and biological applications(Hassan et al., 2023). Altering these substituents enables researchers to achieve targeted electronic and steric properties, which is crucial in designing NHCs for specific reactivities in fields like catalysis and medicinal chemistry. Since their first synthesis from imidazolium salts, NHC complexes have become highly valuable for coordinating a wide range of metals and metalloids, with significant applications in drug development, catalysis, and more (Hopkinson et al., 2014; Kamal et al., 2023; Hayat et al., 2023; Kamal et al., 2022; Chang et al., 2024). The synthesis of NH-free carbene ligands and their metal compounds, especially with elements like silver and selenium, has thus become a significant area of research. In previous work, we synthesized benzimidazolium-based Ag-NHC carbene adducts and evaluated their biological potential, identifying several compounds with significant antibacterial activity (Sandeli et al., 2021). Expanding upon this, we aimed to develop Se-NHC carbene adducts derived from benzimidazolium, hypothesizing that selenium incorporation would enhance biological efficacy. In this study, we synthesized five azolium-based Se-NHC compounds and evaluated their in vitro antimicrobial activities against a range of microbial strains. By investigating the impact of different substituents on biological activity, we aimed to elucidate structure-activity relationships for these compounds. 2. EXPERIMENTAL 2.1 Chemistry 2.1.1 General All reactions for the preparation of starting material and benzimidazolium salts were carried out under an argon atmosphere in flame-dried glassware using standard Schlenk techniques. Selenium-NHC adducts were performed under reflux conditions. Nuclear Magnetic Resonance (NMR) Spectroscopy 1 H NMR and 13 C NMR spectra were recorded with a Varian As 400 Merkur spectrometer operating at 400 MHz ( 1 H), and 100 MHz ( 13 C) in CDCl 3 or DMSO- d 6 with tetramethylsilane as an internal reference. FT-IR spectra were recorded on the ATR unit in the range 400–4000 cm -1 on Perkin Elmer Spectrum 100. Melting points of the synthesized compounds were determined using a Kofler-type WME melting point apparatus (Scientific Apparatus for Research and Industry Laboratory Equipment, Model Nr.6809, vol 230, Amp.0.44, Watt 100). Mass spectroscopic measurements were performed at İnönü University Drug Administration and Research Center to determine the molecular weights and fragmentation patterns of the synthesized compounds. No further purification was done on the chemicals purchased from Merck, Sigma-Aldrich, and Fluka, ensuring the reproducibility and reliability of the experimental results. 2.1.2 General procedure for the synthesis of Benzimidazolium Salts (2a-e) Through minor adjustments to previously published methods described in the literature (Garrison & Youngs, 2005; Rahali et al., 2024), benzimidazolium salts can be achieved. The process involved dissolving 1-(2-(piperidine-1-yl)ethyl)-1H-benzo[d]imidazole (1 equivalent) and an equivalent amount of alkyl halide derivative in degassed toluene (4-5 mL). The reaction mixture was stirred at 80 °C for 2 days under argon. Upon completion of the reaction, the solvent was evaporated under vacuum, and diethyl ether (50 mL) was added to yield a solid powder, which was then filtered. The solid was washed with diethyl ether (3 × 20 mL) and dried under vacuum. The crude product was recrystallized from a dichloromethane /diethyl ether mixture (1:3, v/v) at room temperature and thoroughly dried under vacuum to yield pure products suitable for experimental analysis. 1-benzhydryl-3-(2-(piperidin-1-yl)ethyl)-1 H -benzo[d]imidazol-3-ium bromide (2a) 1 H NMR (400 MHz, DMSO- d 6 , TMS, 25 °C): δ (ppm) = 9.20 (s, 1H, NC H N); 8.18 (d, J = 5.1 Hz, 1H, C H -Ar); 7.78 (d, J = 5.2 Hz, 1H, C H -Ar); 7.69-7.58 (m, 2H, C H -Ar); 7.56-7.34 (m, 10H, CH-Ar); 7.63 (d, 1H, J = 6.8 Hz, CH-Ar); 5.72 (s, H, Ph-C H -Ph); 4.70-4.57 (br s, 2H, C H 2 -N(piperidine)); 2.70-2.52 (br s, 2H, C H 2 -N(bezimidazole)); 2.40-2.13 (br s, 4H, 2CH 2 , C H 2 -N-C H 2 piperidine); 1.39-1.11 (br s, 6H, 3CH 2 , C H 2 -C H 2 -C H 2 piperidine). 13 C NMR (100 MHz, DMSO- d 6 , TMS, 25 °C): δ (ppm) = 142.7 (N C HN); 136.6 (2Cq); 131.8 (C, CH); 129.7 (4C, CH); 128.8 (4C, CH); 127.3 (2C, CH); 127.2 (2C, CH); 114.7 (C, CH); 114.4 (C, CH); 65.3 (C, Ph- C H-Ph); 55.4 (C, C H 2 -N(piperidine)); 54.9 (2C, C H 2 -N- C H 2 piperidine); 45.0 (C, C H 2 -N(bezimidazole)); 25.9 (2C, C H 2 -CH 2 - C H 2 piperidine); 24.0 (C, CH 2 - C H 2 -CH 2 piperidine ). Elemental analysis; calcd (%) for C 27 H 30 BrN 3 (M.w.= 476.46 g/mol): C 68.06, H 6.35, N 8.82; found (%): C 68.26, H 6.16, N 8.74; HRMS (ESI) C 27 H 30 N 3 + m/z calcd [M+H] + 396.2434, found 396.2411. 1-(3,5-di-tert-butylbenzyl)-3-(2-(piperidin-1-yl)ethyl)-1 H -benzo[d]imidazol-3-ium bromide (2b) 1 H NMR (400 MHz, CDCl 3 , TMS, 25 °C): δ (ppm) = 10.98 (s, 1H, NC H N); 7.79 (d, J = 7.5 Hz, 1H, C H -Ar);7.70-7.37 (m, 6H, C H -Ar); 5.69 (s, H, Ph-C H -Ph); 4.75-4.67 (br s, 2H, C H 2 -N(piperidine)); 2.90-2.82 (br s, 2H, C H 2 -N(bezimidazole)); 2.48-2.38 (br s, 4H, 2CH 2 , C H 2 -N-C H 2 piperidine); 1.29-1.24 (br s, 6H, 3CH 2 , C H 2 -C H 2 -C H 2 piperidine). 13 C NMR (100 MHz, CDCl 3 , TMS, 25 °C): δ (ppm) = 152.1 (2Cq); 143.2 (N C HN); 131.7 (C, Cq); 131.7 (C, Cq); 131.0 (C, Cq); 126.8 (C, CH-Ar); 126.8 (C, CH-Ar); 123.2 (C, CH-Ar); 122.6 (2C, CH-Ar); 113.5 (C, CH); 113.3 (C, CH); 56.7 (C, N- C H 2 -C 6 H 2 ( t -bu) 2 ); 54.4 (2C, C H 2 -N- C H 2 piperidine); 52.0 (C, C H 2 -N(piperidine); 44.9 (C, C H 2 -N(bezimidazole)); 34.9 (2Cq, C t -bu); 31.3 (9C, C H 3 ); 25.9 (2C, C H 2 -CH 2 - C H 2 piperidine); 23.9 (C, CH 2 - C H 2 -CH 2 piperidine ). Elemental analysis; calcd (%) for C 29 H 42 BrN 3 (M.w.= 512.58 g/mol): C 67.95, H 8.26, N 8.20; found (%): C 67.82, H 8.32, N 8.08; HRMS (ESI) C 29 H 42 N 3 + m/z calcd [M+H] + 432.3323, found 432.3308. 1-isopentyl-3-(2-(piperidin-1-yl)ethyl)-1 H -benzo[d]imidazol-3-ium bromide (2c) 1 H NMR (400 MHz, CDCl 3 , TMS, 25 °C): δ (ppm) = 11.06 (s, 1H, NC H N); 7.90 -7.79 (m, 1H, CH-Ar); 7.70 (d, J = 22.4 Hz, 2H, C H -Ar); 7.69 (d, J = 2.1 Hz, 1H, C H -Ar); 4.81-4.70 (br s, 2H, C H 2 -N(piperidine)); 4.69-4.58 (br s, 2H, N-C H 2 -CH 2 -CH(CH 3 ) 2 ); 2.92-2.82 (br s, 2H, C H 2 -N(bezimidazole)); 2.60-2.42 (br s, 4H, 2CH 2 , C H 2 -N-C H 2 piperidine); 2.05-1.90 (br s, 2H, C H 2 -CH-(CH 3 ) 2 ); 1.80-1.66 (m, 1H, CH, CH 3 -C H -CH 3 ); 1.56-1.36 (br s, 6H, 3CH 2 , C H 2 -C H 2 -C H 2 piperidine); 1.06 (s, 3H, C H 3 ); 1.04 (s, 3H, C H 3 ). 13 C NMR (100 MHz, CDCl 3 , TMS, 25 °C): δ (ppm) = 143.1 (N C HN); 131.5 (C, Cq); 131.0 (C, Cq); 126.9 (2C, C H-Ar); 129.0 (C, C H-Ar); 128.1 (C, C H-Ar); 113.7 (C, C H); 112.8 (C, C H); 56.9 (C, C H 2 -N(piperidine)); 54.5 (2C, C H 2 -N- C H 2 piperidine); 45.9 (C, N- C H 2 -CH 2 -CH(CH 3 ) 2 ); 44.9 (C, C H 2 -N(bezimidazole); 37.9 (C, N-CH 2 - C H 2 -CH(CH 3 ) 2 ); 26.0 (2C, C H 2 -CH 2 - C H 2 piperidine); 25.6 (C, CH 3 - C H-CH 3 ); 24.0 (C, CH 2 - C H 2 -CH 2 piperidine ); 22.3 (2C, C H 3 ). Elemental analysis; calcd (%) for C 19 H 30 BrN 3 (M.w.= 380.37 g/mol): C 60.00, H 7.95, N 11.05; found (%): C 60.12, H 7.75, N 11.30; HRMS (ESI) C 19 H 30 N 3 + m/z calcd [M+H] + 300.2434, found 300.2414. 1-(benzyloxymethyl)-3-(2-(piperidin-1-yl)ethyl)-1 H -benzo[d]imidazol-3-ium chloride (2d) 1 H NMR (400 MHz, DMSO- d 6 , TMS, 25 °C): δ (ppm) = 10.34 (s, 1H, NC H N); 8.33-8.19 (m, 1H, C H -Ar); 8.18-8.04 (m, 1H, C H -Ar); 7.78-7.68 (m, 1H, C H -Ar); 7.42-7.21 (m, 5H, C H -Ar); 6.08 (s, 2H, O-C H 2 -Ph); 5.76 (br s, 2H, O- C H 2 -N(bezimidazole)); 4.78-4.67 (br s, 2H, C H 2 -N(piperidine)); 2.00-1.30 (br s, 6H, 3CH 2 , C H 2 -C H 2 -C H 2 piperidine). 13 C NMR (100 MHz, DMSO- d 6 , TMS, 25 °C): δ (ppm) = 137.0 (NC H N); 131.7 (C, Cq); 128.7 (2C, CH); 128.4 (C, CH); 128.3 (C, CH); 127.4 (C, CH-Ar); 127.2 (C, CH-Ar); 114.5 (C, CH); 114.4 (C, CH); 76.9 (C, O- C H 2 -N); 71.5 (C, Ph- C H 2 -O); 55.4 (C, C H 2 -N(piperidine); 52.9 (2C, C H 2 -N- C H 2 piperidine); 49.0 (C, C H 2 -N(bezimidazole); 22.7 (C, CH 2 - C H 2 -CH 2 piperidine ). Elemental analysis; calcd (%) for C 22 H 28 ClN 3 O (M.w.= 385.93 g/mol): C 68.47, H 7.31, N 10.89; found (%): C 68.35, H 7.46, N 10.70; HRMS (ESI) C 22 H 28 N 3 O+ m/z calcd [M+H] + 350.2227, found 350.2206. 1-(3,5-dimethylbenzyl)-3-(2-(piperidin-1-yl)ethyl)-1 H -benzo[d]imidazol-3-ium bromide (2e) 1 H NMR (400 MHz, CDCl 3 , TMS, 25 °C): δ (ppm) = 11.03 (s, 1H, NCHN); 7.76 (d, J = 6.7 Hz, 1H, CH-Ar); 7.62 (d, J = 7.4 Hz, 2H, CH-Ar); 7.23 (d, J = 5.1 Hz, 1H, CH-Ar); 7.06 (s, 2H, C H -Ar); 6.96 (s, H, C H -Ar); 5.72 (s, H, N-C H 2 -Ph); 4.75-4.66 (br s, 2H, C H 2 -N(piperidine)); 2.89-2.77 (br s, 2H, C H 2 -N(bezimidazole)); 2.51-2.37 (br s, 4H, 2CH 2 , C H 2 -N-C H 2 piperidine); 2.26 (s, 6H, 2C H 3 ); 1.49-1.30 (br s, 6H, 3CH 2 , C H 2 -C H 2 -C H 2 piperidine). 13 C NMR (100 MHz, CDCl 3 , TMS, 25 °C): δ (ppm) = 143.4 (N C HN); 139.1 (2C, Cq); 132.5 (C, Cq); 131.5 (C, Cq); 131.0 (C, Cq); 130.9 (C, Cq); 129.0 (C, CH-Ar); 128.2 (C, CH-Ar); 126.8 (C, CH-Ar); 126.2 (2C, CH-Ar); 113.5 (C, CH); 113.1 (C, CH); 56.5 (C, C H 2 -N(piperidine)); 54.4 (2C, C H 2 -N- C H 2 piperidine); 51.2 (C, N- C H 2 -C 6 H 3 (CH 3 ) 2 ); 44.9 (C, C H 2 -N(bezimidazole); 25.9 (2C, C H 2 -CH 2 - C H 2 piperidine); 24.0 (C, CH 2 - C H 2 -CH 2 piperidine ); 21.2 (2C, C H 3 ). Elemental analysis; calcd (%) for C 23 H 30 BrN 3 (M.w.= 428.41 g/mol): C 64.48, H 7.06, N 9.81; found (%): C 64.50, H 7.16, N 9.95; HRMS (ESI) C 23 H 30 N 3 + m/z calcd [M+H] + 348.2434, found 348.2414. 2.1.3 General procedure for the synthesis of selenium-NHC compounds (3a-e) Selenium-NHC adducts were obtained by reacting selenium metal with benzimidazolium salts at the carbene carbon site, using a mild base such as K 2 CO 3 or Na 2 CO 3 as a catalyst (Iqbal et al., 2016; Tian et al., 2014) . A mixture of benzimidazolium salts (1 equivalent) and selenium metal (1 equivalent) with potassium carbonate (1.5 equivalent) in methanol at 80°C for 2 days. This process facilitated the formation of selenium-based N-heterocyclic carbene (Se-NHC) adducts, resulting in a black solid. This process automatically converts the salts into selenium-NHC adducts. The solid product was then dissolved in dichloromethane (CH₂Cl₂) and purified through flash column chromatography on silica gel. After evaporation of the solvent in the open air, the product was recrystallized from a CHCl₃/Et₂O mixture, yielding the pure Se-NHC adducts as a solid. 1-benzhydryl-3-(2-(piperidin-1-yl)ethyl)-1 H -benzo[d]imidazole-2(3H)-selenone (3a) 1 H NMR (400 MHz, CDCl 3 , TMS, 25 °C): δ (ppm) = 8.24-8.17 (m, 1H, C H -Ar); 7.38-7.28 (m, 10H, C H -Ar); 7.16 (t, J = 15.8 Hz, 1 H , CH-Ar); 6.93 (t, J = 7.2 Hz, 1H, C H -Ar); 6.73 (d, J = 7.9 Hz, 1H, C H -Ar); 4.69-4.58 (br s, 2H, C H 2 -N(piperidine)); 2.83-2.74 (br s, 2H, C H 2 -N(bezimidazole)); 2.66-2.50 (br s, 4H, 2CH 2 , C H 2 -N-C H 2 piperidine); 1.66-1.37 (br s, 6H, 3CH 2 , C H 2 -C H 2 -C H 2 piperidine). 13 C NMR (100 MHz, CDCl 3 , TMS, 25 °C): δ (ppm) = 167.9 (C=Se); 137.4 (2Cq); 133.6 (C, Cq); 132.3 (C, Cq);128.5 (4C, CH); 128.5 (4C, CH); 127.9 (2C, CH); 112.6 (C, CH); 109.8 (C, CH); 65.3 (C, Ph- C H-Ph); 55.4 (C, C H 2 -N(piperidine)); 54.9 (2C, C H 2 -N- C H 2 piperidine); 45.0 (C, C H 2 -N(bezimidazole)); 25.9 (2C, C H 2 -CH 2 - C H 2 piperidine); 24.0 (C, CH 2 - C H 2 -CH 2 piperidine ). Elemental analysis; calcd (%) for C 27 H 29 N 3 Se (M.w.= 474.49 g/mol): C 68.34, H 6.16, N 8.86; found (%): C 68.25, H 6.22, N 08.79; HRMS (ESI) m/z (C 27 H 30 N 3 Se + ) calcd [M+H] + 476.1527, found 476.1544. 1-(3,5-di-tert-butylbenzyl)-3-(2-(piperidin-1-yl)ethyl)-1 H -benzo[d]imidazole-2(3H)-selenone (3b) 1 H NMR (400 MHz, CDCl 3 , TMS, 25 °C): δ (ppm) = 7.47 (d, J = 6.7 Hz, 1 H , CH-Ar); 7.40 (d, J = 5.7 Hz, 2H, C H -Ar); 7.21-7.10 (m, 4H, C H -Ar); 6.99 (s, 1H, C H -Ar); 5.57 (s, H, Ph-C H -Ph); 4.50-4.40 (br s, 2H, C H 2 -N(piperidine)); 2.64-2.54 (br s, 2H, C H 2 -N(bezimidazole)); 2.38-2.29 (br s, 4H, 2CH 2 , C H 2 -N-C H 2 piperidine); 1.35-1.20 (br s, 6H, 3CH 2 , C H 2 -C H 2 -C H 2 piperidine); 1.11 (s, 6C, C H 3 ). 13 C NMR (100 MHz, CDCl 3 , TMS, 25 °C): δ (ppm) = 166.3 ( C =Se); 150.8 (2Cq); 135.6 (C, Cq); 133.5 (C, Cq); 132.6 (C, Cq); 123.6 (C, C H-Ar); 123.5 (C, C H-Ar); 123.4 (C, C H-Ar); 121.4 (2C, CH-Ar); 111.1 (C, C H); 110.9 (C, C H); 56.4 (C, N- C H 2 -C 6 H 2 ( t -bu) 2 ); 54.8 (2C, C H 2 -N- C H 2 piperidine); 49.5 (C, C H 2 -N(piperidine); 44.5 (C, C H 2 -N(bezimidazole); 34.8 (2Cq, C t- bu); 31.8 (C, C H 3 ); 31.6 (2C, C H 3 ); 26.0 (2C, C H 2 -CH 2 - C H 2 piperidine); 24.3 (C, CH 2 - C H 2 -CH 2 piperidine ). Elemental analysis; calcd (%) for C 29 H 41 N 3 Se (M.w.= 510.62 g/mol): C 68.21, H 8.09, N 8.23; found (%): C 68.32, H 8.12, N 08.01; HRMS (ESI) m/z C 29 H 42 N 3 Se + calcd [M+H] + 512.2466, found 512.2465. 1-isopentyl-3-(2-(piperidin-1-yl)ethyl)-1 H -benzo[d]imidazole-2(3H)-selenone (3c) 1H NMR (400 MHz, CDCl 3 , TMS, 25 °C): δ (ppm) = 7.39-7.31 (m, 1H, C H -Ar); 4.62-4.55 (br s, 2H, C H 2 -N(piperidine)); 4.49-4.38 (br s, 2H, N-C H 2 -CH 2 -CH(CH 3 ) 2 ); 2.78-2.68 (br s, 2H, C H 2 -N(bezimidazole)); 2.62-2.50 (br s, 4H, 2CH 2 , C H 2 -N-C H 2 piperidine); 1.83-1.73 (br s, 1H, CH, CH 3 -C H -CH 3 ); 1.65-1.39 (br s, 6H, 3CH 2 , C H 2 -C H 2 -C H 2 piperidine); 1.05 (s, 3H, C H 3 ); 1.03 (s, 3H, C H 3 ). 13 C NMR (100 MHz, CDCl 3 , TMS, 25 °C): δ (ppm) = 165.5 ( C =Se); 133.3 (C, Cq); 132.8 (C, Cq); 128.7 (C, CH-Ar); 127.1 (C, CH-Ar); 123.1 (2C, CH-Ar); 109.9 (C, CH); 109.4 (C, CH); 56.1 (C, C H 2 -N(piperidine); 54.9 (2C, C H 2 -N- C H 2 piperidine); 45.2 (C, N- C H 2 -CH 2 -CH(CH 3 ) 2 ); 44.3 (C, C H 2 -N(bezimidazole); 36.6 (C, N-CH 2 - C H 2 -CH(CH 3 ) 2 ); 26.1 (2C, C H 2 -CH 2 - C H 2 piperidine); 26.0 (C, CH 3 - C H-CH 3 ); 24.2 (C, CH 2 - C H 2 -CH 2 piperidine ); 22.5 (2C, C H 3 ). Elemental analysis; calcd (%) for C 19 H 29 N 3 Se (M.w.= 378.42 g/mol): C 60.30, H 7.72, N 11.10; found (%): C 60.42, H 7.80, N 11.00; HRMS (ESI) C 19 H 29 N 3 Se+ m/z calcd [M+H] + 380.1527, found 380.1554. 1-(benzyloxymethyl)-3-(2-(piperidin-1-yl)ethyl)-1 H -benzo[d]imidazole-2(3H)-selenone (3d) 1 H NMR (400 MHz, CDCl 3 , TMS, 25 °C): δ (ppm) = 7.63-7.52 (m, 2H, CH-Ar); 7.27 (s, 5H, CH-Ar); 5.99 (s, 2H, O-C H 2 -Ph); 4.68-4.61 (br s, 2H, O- C H 2 -N(bezimidazole)); 4.57-4.44 (br s, 2H, C H 2 -N(piperidine)); 2.72-2.69 (br s, 2H, C H 2 -N(bezimidazole)); 2.49-2.32 (br s, 4H, 2CH 2 , C H 2 -N-C H 2 piperidine); 1.49-1.28 (br s, 6H, 3CH 2 , C H 2 -C H 2 -C H 2 piperidine). 13 C NMR (100 MHz, DMSO- d 6 , TMS, 25 °C): δ (ppm) = 167.1 (C=Se); 137.8 (C, Cq; 134.7 (C, Cq); 132.6 (C, Cq); 128.6 (2C, CH); 128.0 (C, CH); 127.9 (2C, CH); 124.0 (C, CH-Ar); 123.9 (C, CH-Ar); 111.9 (C, CH); 111.9 (C, CH); 75.6 (C, O- C H 2 -N); 71.5 (C, Ph- C H 2 -O); 56.1 (C, C H 2 -N(piperidine); 54.8(2C, C H 2 -N- C H 2 piperidine); 44.2 (C, C H 2 -N(bezimidazole); 26.0 (2C, C H 2 -CH 2 - C H 2 piperidine); 24.3 (C, CH 2 - C H 2 -CH 2 piperidine). Elemental analysis; calcd (%) for C 22 H 27 N 3 OSe (M.w.= 428.42 g/mol): C 61.78, H 6.35, N 9.81; found (%): C 61.73, H 6.46, N 9.92; HRMS (ESI) C 22 H 27 N 3 OSe+ m/z calcd [M+H] + 430.1319, found 430.1347. 1-(3,5-dimethylbenzyl)-3-(2-(piperidin-1-yl)ethyl)-1 H -benzo[d]imidazole-2(3H)-selenone (3e) 1 H NMR (400 MHz, CDCl 3 , TMS, 25 °C): δ (ppm) = 7.35 (d, J = 7.1 Hz, 1H, C H -Ar); 7.24-7.18 (m, 1H, C H -Ar); 7.18-7.10 (m, 2H, C H -Ar); 7.94 (s, 2H, CH-Ar); 6.89 (s, H, C H -Ar); 5.29 (s, H, N-CH 2 -Ph); 4.67-4.57 (br s, 2H, C H 2 -N(piperidine); 2.85-2.73 (br s, 2H, C H 2 -N(bezimidazole)); 2.64-2.52 (br s, 4H, 2CH 2 , C H 2 -N-C H 2 piperidine); 2.25 (s, 6H, 2C H 3 ); 1.67-1.37 (br s, 6H, 3CH 2 , C H 2 -C H 2 -C H 2 piperidine). 13 C NMR (100 MHz, CDCl 3 , TMS, 25 °C): δ (ppm) = 167.1 (C=Se); 138.8 (2C, Cq); 135.2 (C, Cq); 133.4 (C, Cq); 133.0 (C, Cq); 129.5 (C, CH-Ar); 127.1 (C, CH-Ar); 125.1 (2C, CH-Ar); 123.2 (C, CH-Ar); 110.3 (C, CH); 109.8 (C, CH); 56.1 (C, C H 2 -N(piperidine)); 54.7 (2C, C H 2 -N- C H 2 piperidine); 50.3 (C, N- C H 2 -C 6 H 3 (CH 3 ) 2 ); 44.7 (C, C H 2 -N(bezimidazole)); 26.0 (2C, C H 2 -CH 2 - C H 2 piperidine); 24.4 (C, CH 2 - C H 2 -CH 2 piperidine); 21.3 (2C, C H 3 ). Elemental analysis; calcd (%) for C 23 H 29 N 3 Se (M.w.= 426.45 g/mol): C 64.78, H 6.85, N 9.85; found (%): C 64.60, H 6.96, N 9.72; HRMS (ESI) C 23 H 29 N 3 Se+ m/z calcd [M+H] + 427.1528, found 428.1549. 2.2 Biological assays 2.2.1. Materials The antimicrobial activity experiments were conducted in the Laboratory of the Department of Medical Genetics at the School of Medicine, Inonu University. The study utilized various chemical materials including peptone, glucose, pure water, tryptone, NaCl, dimethyl sulfoxide (DMSO), yeast extract, and agar, all sourced from PanReac AppliChem and Fisher Scientific. The equipment used in the study comprised a Denovix DS-11 FX+ (UV, Blue, Red, Green) Spectrophotometer/Fluorometer, an Allsheng AMR-100 Microplate Reader, a Daihan WIS 20 Shaking Incubator, a Nüve EN 120 Incubator, a Nüve NF 800R Cooled Centrifuge, and a Sigma 1-14 Microcentrifuge. 2.2.2. Methods Antimicrobial activity Disc Diffusion Test The disc diffusion method was used to evaluate the compounds' effectiveness in inhibiting bacterial and fungal growth. The bacterial strains tested included Pseudomonas aeruginosa (ATCC 27853), Escherichia coli (ATCC 25922), and Staphylococcus aureus (ATCC 29213), while the fungal strains were Candida glabrata (ATCC 2001) and Candida albicans (SC5314/ATCC MYA-2876) (Khan et al., 2023) . To obtain a concentration of 80 μg/μL, 8 mg of each compound was dissolved in 100% DMSO. For the assay, 800 μg of the compound was applied per disc. Test bacteria (approximately 1x108 cells) were inoculated in sterilized LB broth media, and yeast (approximately 1x107 cells) in YPD broth media. These cultures were gently mixed and transferred to a Petri dish under aseptic conditions. The compound-loaded disc was placed on the 90 mm diameter Petri dish and incubated at 37°C for 24 hours. A disc containing only DMSO served as the negative control, while ampicillin (800 μg per disc) and caspofungin (800 μg per disc) were used as standard antibacterial and antifungal agents, respectively. The antibacterial and antifungal activity of the compounds was indicated by the diameter of the clear inhibition zone, measured in millimeters. IC 50 Test The same fungi and bacteria species used in the disc diffusion test were subjected to the IC 50 test. IC 50 analyses were performed using the BMD (Broth Microdilution) test, as described in EUCAST EDef 7.3.2 (Arendrup et al., 2020) for yeasts and CLSI M07 (Wikler, 2006) for bacteria within different mediums mentioned in these documents. Briefly, the stock solution of chemically synthesized powdered compounds used in antifungal and antimicrobial tests was prepared in 100% DMSO. Serial dilutions were made in flat bottom 96-well plates, in YPD (Yeast Peptone Dextrose) medium (2% peptone, 2% glucose, 1% yeast extract) pH 6,5 for yeasts, and LB (Luria-Bertani) broth medium (1% tryptone, 1% NaCl, 0.5% yeast extract, pH 7.0) for bacteria. In sterile water, yeast (1-5x10 5 CFU / ml) and bacteria (1x10 6 CFU / ml) cell solutions (inoculums) were prepared and added in equal volumes to 96-well plates containing different concentrations of the compounds to obtain the required cell density and concentrations of chemical compounds tested. After adding the cell solutions, the final concentrations of the compounds were between 0.8 and 800 mg / L, and the cell concentrations required for the test were 0.5-2.5x10 5 CFU / ml in yeasts and 5x10 5 CFU / ml in bacteria in the final step. Plates were incubated for 24 hours at 37 ° C for yeasts and 16-18 hours at 37°C for bacteria, and the IC 50 was determined spectrophotometrically at 600 nm after incubation. The IC 50 value was measured as the lowest drug concentration causing at least 50% or more reduction in growth compared to the control (no drug) group. 2.3 Molecular docking This molecular docking study aims to predict the antibacterial ( E. coli ) and antifungal activities of synthesized benzimidazolium salts (compounds 2a-e) and their corresponding selenium N-heterocyclic carbene derivatives (compounds 3a-e). Each compound was structurally optimized using the MMFF94 force field as implemented in AVOGADRO software (Hanwell et al., 2012) . The optimized structures were then used as ligands in molecular docking simulations. To rationalize the antibacterial activity, the compounds were docked against DNA gyrase, specifically E. coli topoisomerase II DNA gyrase B. The X-ray crystallographic structure of this enzyme, complexed with the antibiotic ligand Clorobiocin (CBN), was retrieved from the Protein Data Bank (PDB ID: 1KZN) (Hanwell et al., 2012) . For evaluating antifungal activity, the compounds were docked against the enzyme CYP51, with the structure obtained from PDB (PDB ID: 1EA1) (Podust et al., 2001) . The protein structures were preprocessed by removing all solvent molecules and co-crystallized ligands using Discovery Studio Visualizer software. (Biovia, 2017) Then the protein structures were corrected by Swiss-PdbViewer software (Guex & Peitsch, 1997) . Docking simulations were performed using AutoDock Vina, as implemented in the PyRx software. (Guex & Peitsch, 1997) . The search centers (SC) and box dimensions (BD) for the docking experiments were set as follows: For DNA gyrase (PDB ID: 1KZN): SC: X = 19, Y = 26, Z = 35; BD: X = 25, Y = 25, Z = 25. For CYP51 (PDB ID: 1EA1): SC: X = -20, Y = -0.8, Z = 71; BD: X = 42.23, Y = 36.48, Z = 40.96 Visualization and analysis of the docking results were carried out using Discovery Studio Visualizer (Biovia, 2017) . 3. RESULTS AND DISCUSSION 3.1 Chemistry Efforts were undertaken to synthesize benzimidazolium salts ( 2a-e ) and the corresponding selenium-NHC adducts ( 3a-e ) by slightly modifying previously published methods (Engl et al., 2015; Steiner et al., 2005; Tian et al., 2014). The literature indicates that the synthesis of these compounds has been executed using various approaches, some of which include standard procedures. Synthesis of the benzimidazolium salts 2a–e Benzimidazolium salts 2a-e were synthesized through a two-step N -alkylation process, as illustrated in the diagram. The initial compound 1, was formed by the first N -alkylation of 1 H -benzo[d]imidazole with 1-(2-chloroethyl)piperidine hydrochloride. The second N -alkylation involved reacting 1-(2-(piperidine-1-yl)ethyl)-1 H -benzo[d]imidazole 1 with various aryl/benzyl halide derivatives in toluene at 80°C to produce the five benzimidazolium salts 2a-e All the synthesized benzimidazolium salts 2a-e , as outlined in Scheme 1 , were successfully produced with satisfactory yields. The benzimidazolium salts spectroscopic data align well with previously reported data for similar salts found in the literature (Sandeli et al., 2021; Siciliano et al., 2011; Younas et al., 2023). All of the salts ( 2a-e ) demonstrated stability to air and moisture and were kept for further use. A summary of the physical and selected spectroscopic details of these benzimidazolium salts is presented in Table 1 Table 1 Physical data and yield for benzimidazolium salts 2a-e. Code Chemical Formula Molecular Weight (g/mol) Melting Point ◦C Physical Appearance Yield (%) 2a C 27 H 30 BrN 3 476.46 264 Brown solid 65 2b C 29 H 42 BrN 3 512.58 266 White solid 70 2c C 19 H 30 BrN 3 380.37 200 White solid 91 2d C 22 H 28 ClN 3 O 385.93 222 White solid 90 2e C 23 H 30 BrN 3 428.41 192 White solid 91 Preparation of selenium-NHC compounds 3a-e The selenium N -heterocyclic carbene adducts ( 3a-e ) were produced by treating benzimidazolium salts with selenium, using a mild base such as K 2 CO 3 leading to the formation of the anticipated selenium Se-NHC adducts 3a-e through an in situ deprotonation process. This reaction was carried out at 80°C in methanol, as outlined in (Scheme 2 ). The production of selenium-NHC compounds 3a-e resulted in black solids that are highly yield-efficient and dissolve in halogenated solvents. The newly synthesized Se–NHC compounds 3a-e, illustrated in Scheme 2 , were produced with satisfactory yields. The spectroscopic characteristics of these compounds align with previously reported data for similar Se-NHC compounds found in literature references(Kamal et al., 2022; Haque et al., 2018; Iqbal et al., 2016; Kamal et al., 2019). They were also found to be stable to air and moisture. Summaries of their physical properties and select spectroscopic data are presented in Table 02 . Table 2 Physical data and yield for Se-NHC complexes 3a-e. Code Chemical Formula Molecular Weight (g/mol) Melting Point ◦C Physical Appearance Yield (%) 3a C 27 H 29 N 3 Se 474.49 190 Beige solid 74 3b C 29 H 41 N 3 Se 510.62 154 Pale Yellow 75 3c C 19 H 29 N 3 Se 378.42 200 Yellow solid 73 3d C 22 H 27 N 3 OSe 428.42 60–62 Brown solid 74 3e C 23 H 29 N 3 Se 426.45 132 Yellow solid 64 Initial indications of successfully synthesizing the desired compounds, as illustrated in Schemes 1 and 2 , were identified through their solubility properties, physical states, and melting points (mp). Notable differences in these characteristics were observed between the benzimidazolium salts and their selenium-NHC compounds. These findings confirm the successful synthesis and isolation of benzimidazolium salts and selenium-NHC adducts achieved with good to excellent yields. The compounds were obtained with yields ranging from 64–94% and demonstrated stability in the presence of moisture and air. The yields of the synthesized products were calculated based on the isolated product weights relative to the theoretical maximum yield. The melting points (m.p) and physical appearances of the synthesized compounds verify their purity and identity. In the solid-state state, Variations in melting points (m.p) suggest differences in molecular packing and intermolecular interactions. Benzimidazolium salts (2a-e ) exhibited melting points (m.p) between 192–266°C, whereas the selenium-NHC adducts ( 3a-e ) had (m.p) ranging from 60–200°C, These differences reflect the organic nature of the benzimidazolium salts and the coordination of selenium, which introduces an inorganic character to the selenium-NHC adducts. The appearance of the benzimidazolium salts 2a-e initially formed as white solids in the reaction medium, was influenced by the type of alkyl chain substituted on the nitrogen atoms of the benzimidazole group. In contrast, the selenium-NHC adducts 3a-e first appeared as a sticky brown, yellow, and beige material, which, upon recrystallization, yielded a thick light yellow fluid that eventually turned colorless with further recrystallization. Both the salts and selenium-NHC adducts ( 3a-e ) were observed to be soluble in non-polar solvents like chloroform and dichloromethane. All benzimidazolium salts and their corresponding selenium-NHC adducts were characterized using a variety of analytical techniques. To identify changes before and after selenium incorporation into the carbene carbon, FT-IR spectra were recorded. Comparing the spectral features of the compounds pre- and post-incorporation revealed distinct changes that provided preliminary evidence of successful metal integration into the organic framework. Notably, significant spectral variations were observed in the 1000–1600 cm − 1 region when comparing the salts with the Se-NHC adducts. FT-IR data showed that the benzimidazolium salts exhibited a characteristic ν(CN) band, with values of 1554, 1558, 1561, 1563, and 1561 cm⁻¹ for salts 2a–e, respectively. In addition, the salts showed absorption bands corresponding to ν(N-C), ν(C = C), and ν(C-H), with specific values as follows: 2a: 1336, 1458, and 2930 cm⁻¹; 2b: 1336, 1504, and 2922 cm⁻¹; 2c: 1344, 1428, and 2930 cm⁻¹; 2d: 1336, 1443, and 2945 cm⁻¹; and 2e: 1338, 1428, and 2930 cm⁻¹, respectively. In contrast, the selenium compounds exhibited a characteristic ν(CN) band, with values of 1226, 1195, 1204, 1475, and 1195 cm⁻¹ for compounds 3a–e, respectively. They also showed ν(N-C), ν(C = C), and ν(C-H) bands at the following values: 3a: 1324, 1454, and 2948 cm⁻¹; 3b: 1344, 1481, and 2938 cm⁻¹; 3c: 1344, 1440, and 2938 cm⁻¹; 3d: 1336, 1443, and 2938 cm⁻¹; and 3e: 1328, 1481, and 2930 cm⁻¹, respectively. These observations confirmed the successful formation of the Se-NHC adducts and highlighted the impact of selenium incorporation on the spectral properties of the salts. The observed shifts in ν(CN), along with changes in the ν(N-C), ν(C = C), and ν(C-H) bands, clearly indicate successful formation of the Se-NHC adducts. Notably, compound 2d displayed an additional ν(C = O) band at 1100 cm⁻¹. For compound 3d, a ν(C = O) band was observed at 1077 cm⁻¹. The notable changes in the spectral properties between the benzimidazolium salts and the selenium derivatives highlight the impact of selenium incorporation, likely due to altered electronic interactions and changes in the molecular structure. These findings corroborate the structural modifications expected upon the formation of the selenium-NHC adducts and provide strong evidence for the successful synthesis of the target compounds. Additionally, 1 H and 13 C NMR spectra of salts ( 2a-e ) and Se-NHC adducts ( 3a-e ) were recorded in deuterated chloroform, considering their solubility characteristics. The 1 H NMR spectra of the benzimidazolium salts (2a–e) showed characteristic signals confirming the presence of key structural features. The highly deshielded NC H N proton (the acidic proton C2-H of the benzimidazole ring) appeared as a singlet between δ 9.20–11.06 ppm, with variations attributed to electronic effects from different substituents, indicating salt formation. Aromatic protons of the benzimidazole core and appended phenyl rings resonated as multiplets and doublets between δ = 7.06–8.33 ppm, with coupling constants in the range of J = 2.1–7.5 Hz and J = 2.1–7.5Hz. In salt 2a, the Ph-CH-Ph proton appeared as a singlet at δ 5.72 ppm, while substituent-specific signals, such as piperidine CH 2 groups, were observed as broad singlets in the δ = 4.70–4.57 ppm range. Benzylic CH 2 protons attached to the benzimidazole nitrogen resonated at δ = 2.70–2.52 ppm, whereas the piperidine CH 2 -N-CH 2 methylene protons appeared as broad singlets between δ = 2.40–2.13 ppm. Aliphatic regions also displayed signals from CH 2 , CH 3 , and tert-butyl groups between δ = 1.39–1.11 ppm, indicating the presence of bulky substituents. For salts with isopropyl groups, such as 2c, distinct methyl singlets were observed at δ 1.06 and 1.04 ppm. In the selenium-NHC adducts (3a–e), the disappearance of the NC H N proton from δ = 9.20–11.06 ppm confirmed carbene formation and coordination with selenium. The aromatic protons of the benzimidazole framework and substituent phenyl rings resonated between δ = 6.73–8.24 ppm, with multiplets and doublets reflecting minor shifts compared to their precursors. Signals for substituents, such as piperidine CH 2 groups, appeared as broad singlets in the δ = 4.69–4.50 ppm range, while CH 2 -N(benzimidazole) protons were observed between δ = 2.85–2.68 ppm. Aliphatic CH 2 , CH 3 , and isopropyl protons remained in their expected ranges, with notable singlets for CH 3 groups near δ = 1.05 ppm and broad singlets for piperidine CH 2 protons at δ = 1.67–1.37 ppm. Overall, the formation of the selenium-NHC bond is evidenced by the absence of the deshielded NCHN proton, while the integrity of aromatic and aliphatic substituents is maintained, as shown by consistent chemical shifts. The 13 C NMR analysis of the benzimidazolium salts ( 2a-e ) revealed characteristic peaks that confirm their structures. The highly deshielded N C HN carbons (C2 of the benzimidazole core) appeared consistently in the range of δ = 142–143 ppm, while quaternary aromatic carbons resonated around δ = 136–139 ppm. The aromatic CH carbons were observed between δ = 114–132 ppm, indicative of the benzimidazole framework. Aliphatic carbons from substituents, such as piperidine, benzyl, and tert-butyl groups, appeared in their expected regions: δ = 44–76 ppm for methylene carbons and δ = 22–37 ppm for alkyl chains or methyl groups. For example, C H 2 -N(piperidine) groups consistently appeared at δ = 54–56 ppm, while the CH 2 -N(benzimidazole) carbons were slightly downfield at δ = 44–45 ppm, reflecting the electron-withdrawing effect of the nitrogen atom. Substituent effects were evident, with benzylic CH 2 carbons resonating at δ = 65–71 ppm and tert-butyl quaternary carbons around δ = 34–37 ppm. Notable variations in chemical shifts were observed depending on the substituents, particularly in the aliphatic region. For the selenium-NHC adducts ( 3a-e ), the formation of the carbene-selenium bond was confirmed by the appearance of a characteristic C = Se peak in the range of δ = 165–167 ppm, alongside a downfield shift of the N C HN carbon from δ 142–143 ppm in the benzimidazolium salts to δ = 150–152 ppm in the adducts. These shifts are consistent with the strong deshielding effect of selenium coordination. The aromatic carbons in the benzimidazole framework remained largely unchanged, resonating between δ = 110–135 ppm, highlighting the preservation of the core structure. Similarly, aliphatic carbons, such as those from piperidine substituents, were observed in their expected regions (e.g., δ = 44–56 ppm for CH 2 groups), indicating minimal structural perturbation in the substituent environment upon adduct formation. Substituents such as tert-butyl or methyl groups caused slight shielding of adjacent carbons, leading to subtle upfield shifts. Overall, the selenium coordination is clearly reflected in the downfield shifts of the carbene carbon and the appearance of the C = Se signal, while the substituent effects and core structural integrity were corroborated by consistent chemical shifts across aromatic and aliphatic regions. The mass spectrometry (HRMS-ESI) results provided detailed insights into the molecular weights of the synthesized benzimidazolium salts and selenium-NHC adducts. For the benzimidazolium salts ( 2a-e ), the calculated [M + H] + values were as follows: m/z = 396.2434 ( 2a ), 432.3373 ( 2b ), 300.2434 ( 2c ), 350.2227 ( 2d ), and m/z = 348.2434 ( 2e ), with corresponding found values of m/z = 396.2411, 432.3308, 300.2414, 350.2206, and m/z = 348.2414, respectively. These findings closely matched the theoretical values, confirming the accurate molecular weights of the synthesized salts. Similarly, the Selenium-NHC adducts ( 3a-e ) exhibited calculated [M + H] + values of m/z = 475.1527 ( 3a ), 511.2466 ( 3b ), 379.1527 ( 3c ), 429.1319 ( 3d ), and m/z = 427.1527 ( 3e ). The experimental mass spectra revealed found values of m/z = 476.1544, 512.2465, 380.1554, 430.13477, and m/z = 428.1549, respectively. These results confirmed the successful formation of the selenium-NHC adducts with good agreement between the calculated and observed molecular weights. The accurate determination of molecular weights through mass spectrometry underscored the precision and reliability of the synthetic methods employed. These data provide essential confirmation of the chemical identities and purity of both the benzimidazolium salts and selenium-NHC adducts, essential for further investigations into their properties and potential applications. 3.2 Biological evaluation The synthesized benzimidazolium salts ( 2a-e ) and their selenium–NHC adducts (3a-e ) were tested for antifungal and antimicrobial activities against a variety of bacteria and yeasts. Caspofungin served as the control for yeast testing, and Ampicillin was used as the control for bacteria. The inhibition zone values and IC50 values for the benzimidazolium salts and their corresponding selenium-NHC adducts, in comparison to the reference antimicrobial agents, are detailed in the provided Table 3 and Table 4 respectively. Table 3 Antifungal and antibacterial inhibition zone values. Compounds Anti-Fungal Anti-Bacterial C. albicans a C. glabrata a E. coli a P. aeruginosa a S. aureus a Benzimida-zolium Salts 2a 15,17 ± 0,24 14,67 ± 0,40 11,97 ± 0,12 10,27 ± 0,17 20,75 ± 0,35 2b 7,45 ± 0,07 8,13 ± 0,11 11,70 ± 0,22 7,13 ± 0,25 20,40 ± 0,43 2c 8,93 ± 0,09 9,12 ± 0,21 12,28 ± 0,26 NA 23,75 ± 0,25 2d 8,08 ± 0,06 7,28 ± 0,15 12,70 ± 0,57 6,67 ± 0,09 19,43 ± 0,74 2e 12,15 ± 0,15 8,83 ± 0,12 13,44 ± 0,10 12,17 ± 0,05 27,05 ± 0,19 Selenium-NHC complexes 3a NA NA NA NA NA 3b 10,00 ± 0,41 10,57 ± 0,51 NA NA 8,63 ± 0,39 3c 8,57 ± 0,31 NA NA NA 8,88 ± 0,19 3d 10,13 ± 0,10 8,99 ± 0,07 NA NA NA 3e 11,70 ± 0,16 9,15 ± 0,08 NA NA 11,77 ± 0,17 Ampicillin b - - 14,27 ± 0,61 12,43 ± 0,42 15,33 ± 0,21 Caspofungin b 14,30 ± 0,15 20,57 ± 0,61 - - - a : Tested microorganism b : Reference drugs NA: Not Active (no inhibition zone) Based on the inhibition zone measurements, the synthesized benzimidazolium salts 2a-e and selenium-NHC adducts 3a-e exhibited varying degrees of antimicrobial and antifungal activities against the tested microorganisms. For Candida albicans , the reference Caspofungin displayed an inhibition zone of 14.30 ± 0.15 mm. Among the benzimidazolium salts, compound 2a showed the highest inhibition with a zone of 15.17 ± 0.24 mm, indicating a significant antifungal effect. The other benzimidazolium salts showed lower inhibition zones: 2b (7.45 ± 0.07 mm), 2c (8.93 ± 0.09 mm), 2d (8.08 ± 0.06 mm), and 2e (12.15 ± 0.15 mm). In contrast, the selenium-NHC adducts demonstrated moderate antifungal activity, with 3e (11.70 ± 0.16 mm) being the most effective, followed by 3b (10.00 ± 0.41 mm), 3d (10.13 ± 0.10 mm), and 3c (8.57 ± 0.31 mm). Complex 3a showed no activity. Table 4 Antifungal and antibacterial IC50 values. Compounds Anti-Fungal Anti-Bacterial C. albicans a C. glabrata a E. coli a P. aeruginosa a S. aureus a Benzimida-zolium Salts 2a 6,25 6,25 50 100 1,56 2b 400 200 100 400 3,12 2c 200 200 25 800 0,8 2d 200 400 25 800 3,12 2e 25 200 12,5 25 0,8 Selenium-NHC complexes 3a 800 800 400 800 800 3b 100 100 800 800 200 3c 200 800 NA NA 200 3d 100 200 800 NA 400 3e 50 100 NA 800 25 Ampicillin b - - 6,25 100 1,56 Caspofungin b 6,25 1,56 - - - a : Tested microorganism b : Reference drugs NA: Not Active (IC50 > 800 µg/ml) Against the pathogenic yeast Candida albicans , among the benzimidazolium salts, 2a was found to be the most effective salt, with an IC 50 value of 6.25 µg/mL against C. albicans yeast strain. This benzimidazolium salt exhibited antifungal activity with strong toxicity, comparable to the control group, Caspofungin, at the same IC 50 value. The other compounds showed varying activities as follows: 2e benzimidazolium salt had an IC 50 value of 25 µg/mL, 2c and 2d shared the same IC 50 value of 200 µg/mL, 2b exhibited an IC 50 value of 400 µg/mL. These compounds demonstrated lower antifungal activity with lower toxicity at higher doses. The most effective Se-NHC complex against Candida albicans yeasts was the 3e complex, with an IC 50 value of 50 µg/mL. This value, being higher than the control group Caspofungin, exhibited relatively low toxicity and relatively low antifungal activity. The other Se-NHC adducts demonstrated the following activities: 3b and 3d complexes had an IC 50 value of 100 µg/mL, 3c complex exhibited an IC 50 value of 200 µg/mL, 3a complex showed an IC 50 value of 800 µg/mL. These higher IC 50 values indicated lower toxicity and weak antifungal activity. In the case of Candida glabrata , the reference Caspofungin showed an inhibition zone of 20.57 ± 0.61 mm. Among the benzimidazolium salts, compound 2a exhibited the highest activity with an inhibition zone of 14.67 ± 0.40 mm. The other salts had lower activities: 2b (8.13 ± 0.11 mm), 2c (9.12 ± 0.21 mm), 2d (7.28 ± 0.15 mm), and 2e (8.83 ± 0.12 mm). Selenium-NHC adducts showed moderate inhibition, with 3b (10.57 ± 0.51 mm) being the most effective, followed by 3d (8.99 ± 0.07 mm) and 3e (9.15 ± 0.08 mm). Compounds 3a and 3c showed no activity. Against the pathogenic yeast Candida glabrata , the 2a benzimidazolium salt was identified as the most effective salt with an IC 50 value of 6.25 µg/mL. The 2a benzimidazolium salt exhibited antifungal activity with relatively low toxicity, despite having a higher IC 50 value compared to the control group, Caspofungin.The other compounds demonstrated the following activities: 2b , 2c , and 2e had the same IC 50 value of 200 µg/mL, 2d had an IC 50 value of 400 µg/mL. These compounds displayed lower antifungal activity with reduced toxicity. The most effective Se-NHC complex against C. glabrata was the 3e complex, with an IC 50 value of 50 µg/mL. This value, higher than that of the control group Caspofungin, indicated relatively low toxicity and moderate antifungal activity. The other Se-NHC adducts showed the following activities: 3b had an IC 50 value of 100 µg/mL, 3d had an IC 50 value of 200 µg/mL, 3a and 3c exhibited higher IC 50 values of 800 µg/mL, with lower toxicity and weak antifungal activity. For Escherichia coli , the reference Ampicillin showed an inhibition zone of 14.27 ± 0.61 mm. Benzimidazolium salts displayed notable antibacterial activity, with compound 2e showing the highest inhibition zone of 13.44 ± 0.10 mm. The other salts exhibited zones as follows: 2a (11.97 ± 0.12 mm), 2b (11.70 ± 0.22 mm), 2c (12.28 ± 0.26 mm), and 2d (12.70 ± 0.57 mm). The selenium-NHC adducts were ineffective against E. coli , as all tested compounds ( 3a-e ) showed no activity. Against E. coli , the 2e benzimidazolium salt demonstrated the best activity, with an IC 50 value of 12.5 µg/mL. This value, being higher than that of the control group Ampicillin, exhibited relatively low toxicity and moderate antibacterial activity. The other benzimidazolium salts showed the following IC 50 values: 2c and 2d shared an IC 50 value of 25 µg/mL, 2a had an IC 50 value of 50 µg/mL, 2b exhibited an IC 50 value of 100 µg/mL. These compounds showed lower antibacterial activity with reduced toxicity. Among the Se-NHC complexes, the 3a complex showed the best activity against E. coli , with an IC 50 value of 400 µg/mL. This value, higher than the control group Ampicillin, indicated low toxicity and weak antibacterial activity. The 3b and 3d Se-NHC complexes had IC 50 values of 800 µg/mL, displaying weak antibacterial activity with reduced toxicity. The 3c and 3e Se-NHC complexes showed no toxicity against E. coli. Against Pseudomonas aeruginosa , the reference Ampicillin exhibited an inhibition zone of 12.43 ± 0.42 mm. The benzimidazolium salts showed some activity, with compound 2e displaying the highest inhibition zone of 12.17 ± 0.05 mm. The other salts showed lower activity: 2a (10.27 ± 0.17 mm), 2b (7.13 ± 0.25 mm), 2d (6.67 ± 0.09 mm), and 2c showed no activity. None of the selenium-NHC adducts ( 3a-e ) demonstrated significant activity against P. aeruginosa . This may caused by presence of an outer membrane that acts as a permeability barrier, which can limit the uptake of selenium-NHC adducts or possessing efficient efflux pumps that can actively expel selenium-NHC adducts by E.coli and P. aeruginosa . Against P. aeruginosa , the 2e benzimidazolium salt exhibited the best activity, with an IC 50 value of 25 µg/mL. This value, although higher than the control group Ampicillin, demonstrated relatively low toxicity and moderate antibacterial activity. The other benzimidazolium salts showed the following IC 50 values: 2a had an IC 50 value of 100 µg/mL, 2b exhibited an IC 50 value of 400 µg/mL, 2c and 2d had IC 50 values of 800 µg/mL. These compounds displayed lower antibacterial activity with reduced toxicity. Among the Se-NHC adducts, the 3a , 3b , and 3e complexes showed IC 50 values of 800 µg/mL against P. aeruginosa , indicating weak antibacterial activity with low toxicity. The 3c and 3d Se-NHC complexes exhibited no toxicity against P. aeruginosa . For Staphylococcus aureus , benzimidazolium salts showed strong antibacterial activity, with compound 2e exhibiting the highest inhibition zone of 27.05 ± 0.19 mm. The other salts showed the following inhibition zones: 2a (20.75 ± 0.35 mm), 2b (20.40 ± 0.43 mm), 2c (23.75 ± 0.25 mm), and 2d (19.43 ± 0.74 mm). Selenium-NHC adducts showed much lower activity, with 3e (11.77 ± 0.17 mm) being the most effective, followed by 3b (8.63 ± 0.39 mm) and 3c (8.88 ± 0.19 mm). Compounds 3a and 3d showed no activity. Against S. aureus , the 2c and 2e benzimidazolium salts demonstrated the best activity, with an IC 50 value of 0.8 µg/mL. These values, lower than the control group Ampicillin, indicated high toxicity and strong antibacterial activity. The 2a benzimidazolium salt showed an IC 50 value of 1.56 µg/mL, with toxicity comparable to the control drug. The 2b and 2d salts exhibited IC 50 values of 3.12 µg/mL, showing lower antibacterial activity with reduced toxicity compared to the control group. Among the Se-NHC complexes, the 3e complex displayed the best activity against S. aureus, with an IC 50 value of 25 µg/mL. This value, being higher than that of the control group Ampicillin, demonstrated low toxicity and weak antibacterial activity. The other Se-NHC adducts showed the following IC 50 values: 3b and 3c : 200 µg/mL, 3d : 400 µg/mL, 3a : 800 µg/mL. These higher IC 50 values reflected weaker antibacterial activity with reduced toxicity. In summary, benzimidazolium salts generally exhibited strong antimicrobial and antifungal activities across various strains, with compounds 2c and 2e consistently showing the highest activities. These compounds often outperformed the selenium-NHC adducts and the reference antimicrobial agents. The selenium-NHC adducts demonstrated moderate to low activity, with none surpassing the reference agents. The superior activity of benzimidazolium salts, particularly compounds 2c and 2e , suggests their potential as effective antimicrobial agents for further development. 3.3 Molecular docking The synthesized compounds 2a-e and 3a-e were evaluated for their binding affinities against DNA gyrase B (PDB ID: 1KZN) and CYP51 (PDB ID: 1EA1) using AutoDock Vina, with the binding energies presented in Table 5 . Molecule 2a , which exhibited significant interactions with both targets, showed a binding energy of -8.1 kcal/mol against 1KZN and − 10.0 kcal/mol against 1EA1. These values suggest strong binding affinities, consistent with the detailed interaction analysis. Table 5 Autodock Vina binding energies of the synthesized compound against 1KZN and 1EA1 in (kcal/mol). Compounds Code Binding affinity (kcal/mol) 1KZN 1EA1 Benzimidazolium Salts 2a-e 2a -8.1 -10 2b -7.9 -9.7 2c -7 -7.7 2d -7.7 -8.9 2e -7.8 -8.5 Selenium-NHC complexes 3a-e 3a -7.5 -10.2 3b -7.6 -8.9 3c -6.4 -7.8 3d -7.5 -8.8 3e -7.5 -9 Ampicillin a -7.2 Ciprofloxacin a -7.2 [a] Reference drugs. As shown in Fig. 1 Molecule 2a exhibits several key interactions with DNA gyrase B enzyme, indicative of a stable and potentially inhibitory binding. The ligand forms carbon-hydrogen bonds with ASN46, ASP49, and GLU42, with bond lengths of approximately 3.40 Å, 3.02 Å, and 3.41 Å, respectively. These interactions involve the ligand acting as the hydrogen donor, contributing to the binding affinity through specific interactions with these amino acid residues. An electrostatic pi-anion interaction is observed between the ligand's pi-orbitals and the carboxylate group of GLU50 at a distance of about 3.55 Å. Hydrophobic interactions further enhance the ligand's binding stability, with pi-alkyl interactions occurring with ILE90 and ILE78, at distances of approximately 4.73 Å, 5.40 Å, and 5.03 Å. Overall, these binding interactions suggest that 2a forms a stable complex with the enzyme, potentially leading to effective inhibition. The combination of hydrogen bonding, electrostatic, and hydrophobic interactions provides a comprehensive understanding of the 2a ligand's binding mechanism, supporting its potential as a therapeutic agent. These findings support the potential of this molecule as a promising candidate for further development as an antibacterial agent targeting DNA gyrase B in E. coli . The ligand 2a forms several key interactions with the enzyme CYP51 Fig. 1 . A carbon-hydrogen bond with GLN72 is observed, with a bond length of approximately 3.44 Å, where the ligand acts as the hydrogen donor. An electrostatic pi-cation interaction occurs between ARG96 and the ligand's aromatic system, at a distance of about 4.77 Å. Hydrophobic interactions include a pi-sigma interaction with ALA256 (around 3.99 Å), a pi-sulfur interaction with CYS394 (approximately 4.94 Å), and a pi-pi T-shaped interaction with TYR76 (about 4.88 Å). Additional alkyl and pi-alkyl interactions are seen with LEU324 (4.47 Å), MET79 (4.91 Å), LEU321 (4.98 Å), and ALA256 (4.10 Å). The interaction profile of 2a with CYP51 indicates multiple binding interactions that stabilize the complex. These interactions suggest that molecule 2a could effectively inhibit CYP51, supporting its observed antifungal activity and providing a basis for further optimization. Overall, the data from the docking studies and interaction analyses underscore the potential of these compounds, especially 2a , as antibacterial agents which is in agreement with the antibacterial assays against E. colia and P. aeruginosa . Further optimization and development of these molecules could lead to effective therapeutic options for treating infections caused by E. coli and fungal pathogens. 4. CONCLUSION This study successfully synthesized a series of benzimidazolium salts ( 2a-e ) and selenium-NHC adducts ( 3a-e ). The resulting compounds exhibited satisfactory yields and demonstrated notable stability under humid and aerated conditions. Comprehensive characterization via FT-IR, ¹H NMR, ¹³C NMR, and mass spectrometry confirmed their molecular structures and purity. Biological evaluations revealed that the benzimidazolium salts exhibited potent antimicrobial activities, particularly against Candida species and Staphylococcus aureus. Notably, compounds 2d and 2e showed the highest inhibition zones, outperforming the selenium-NHC adducts, which demonstrated moderate to low activity. This finding suggests that the structural characteristics of the benzimidazolium salts enhance their efficacy as antimicrobial agent. The molecular docking studies revealed that the synthesized compounds, particularly molecule 2a, have significant binding interactions with DNA gyrase B and CYP51, suggesting a potential mechanism for their antibacterial and antifungal activities. The strong binding energies and diverse interactions, including hydrogen bonds and hydrophobic contacts, indicate that these compounds could serve as effective inhibitors. The promising results with binding energies superior to reference drugs Ampicillin and Caspofungin underscore their potential for therapeutic development as dual-action antimicrobial agents. The enhanced biological activity of the benzimidazolium salts may be attributed to their structural features, although the exact mechanism requires further investigation. The promising IC 50 values and inhibition zones observed for specific compounds, combined with favorable docking results, suggest their potential for therapeutic development. Future studies should focus on elucidating the precise mechanisms underlying their activity, particularly for the benzimidazolium salts, and validating their efficacy in vivo to pave the way for the development of novel antimicrobial therapies. Declarations CONFLICT OF INTEREST The authors declare that there are no conflicts of interest. ACKNOWLEDGEMENTS The authors greatly acknowledge financial support from the İnönü University Research Fund (İÜ-BAP: FBG-2021-2562) for this work. 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Schemes Schemes 1 and 2 are available in the Supplementary Files section Supplementary Files GA.png Graphical abstract Scheme1.png Scheme 1 Synthetic route and structure of benzimidazolium salts 2a-e Scheme2.png Scheme 2 Synthetic route and structure of Se-NHC compounds 3a-e. Cite Share Download PDF Status: Published Journal Publication published 29 Dec, 2024 Read the published version in Chemical Papers → Version 1 posted Editorial decision: Accept 15 Dec, 2024 Reviewers agreed at journal 11 Dec, 2024 Reviewers invited by journal 11 Dec, 2024 Editor assigned by journal 11 Dec, 2024 First submitted to journal 10 Dec, 2024 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. 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SANDELI","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAABE0lEQVRIiWNgGAWjYBACCSA+AGEmMB5IYGBm4AezC4jTwgDWItkAYhvg18IA18IA1GIANgGPFsn2sw8P3WCokzdnTz5w4AGDtb3x+dWJHx4YMMjzix3AqkWaJ93gcA7DYcOdPc8SgA5LZza78XazBNBhhjNnJ2DVIseQxgDUcoBxw40cA6CWw2xmN85uAGlJMLiNQwv/M5CWOvsNN/I/gLTwGM84u/kHPi3SEmBbmBOBtoBC7LCEAX/vNry2SM4A2WJwOHnDmWdAhxmkG0jc4N1mkWAggdMvEufTmD/nVNTZbjie/PDhjwpre/7+s5tv/qiwkeeXxq4FAgyQGRJglRK41GID/AdIUT0KRsEoGAUjAAAAlpNioPTAAPUAAAAASUVORK5CYII=","orcid":"https://orcid.org/0009-0009-8590-567X","institution":"Pharmaceutical Sciences Research Center: Centre de Recherche en Sciences Pharmaceutiques","correspondingAuthor":true,"prefix":"","firstName":"Abd","middleName":"elkrim","lastName":"SANDELI","suffix":""},{"id":389089057,"identity":"9f0d58f8-c028-4363-8d26-e9763710b882","order_by":2,"name":"Houssem BOULEBD","email":"","orcid":"","institution":"Université Constantine 1: Universite Constantine 1","correspondingAuthor":false,"prefix":"","firstName":"Houssem","middleName":"","lastName":"BOULEBD","suffix":""},{"id":389089058,"identity":"b24e3700-b49c-4e99-b92a-bcd87d465016","order_by":3,"name":"Hüseyin KARCI","email":"","orcid":"","institution":"Inonu University: Inonu Universitesi","correspondingAuthor":false,"prefix":"","firstName":"Hüseyin","middleName":"","lastName":"KARCI","suffix":""},{"id":389089059,"identity":"5f2398f0-1f7b-4f32-8473-cfac6e2f7f23","order_by":4,"name":"Muhammed DUNDAR","email":"","orcid":"","institution":"Inonu University: Inonu Universitesi","correspondingAuthor":false,"prefix":"","firstName":"Muhammed","middleName":"","lastName":"DUNDAR","suffix":""},{"id":389089060,"identity":"252562b2-7260-4948-90fb-bd8ecd493e3b","order_by":5,"name":"İlknur ÖZDEMIR","email":"","orcid":"","institution":"Inonu University: Inonu Universitesi","correspondingAuthor":false,"prefix":"","firstName":"İlknur","middleName":"","lastName":"ÖZDEMIR","suffix":""},{"id":389089061,"identity":"5c09b011-2dea-4508-88b3-cc750503fbd3","order_by":6,"name":"Nevin Gürbüz","email":"","orcid":"","institution":"Inonu University: Inonu Universitesi","correspondingAuthor":false,"prefix":"","firstName":"Nevin","middleName":"","lastName":"Gürbüz","suffix":""},{"id":389089062,"identity":"6402d2cc-07a5-4dfb-a643-ac7a1ed06a1b","order_by":7,"name":"Ahmet Koç","email":"","orcid":"","institution":"Inonu University: Inonu Universitesi","correspondingAuthor":false,"prefix":"","firstName":"Ahmet","middleName":"","lastName":"Koç","suffix":""},{"id":389089063,"identity":"73c0318b-5af0-4f3e-b5d8-3022a0f17fca","order_by":8,"name":"Rafik MENACER","email":"","orcid":"","institution":"Pharmaceutical Sciences Research Center: Centre de Recherche en Sciences Pharmaceutiques","correspondingAuthor":false,"prefix":"","firstName":"Rafik","middleName":"","lastName":"MENACER","suffix":""},{"id":389089064,"identity":"63c43215-aafe-4ac6-a1fc-6b2de500dfc6","order_by":9,"name":"İsmail ÖZDEMIR","email":"","orcid":"","institution":"Inonu University: Inonu Universitesi","correspondingAuthor":false,"prefix":"","firstName":"İsmail","middleName":"","lastName":"ÖZDEMIR","suffix":""}],"badges":[],"createdAt":"2024-09-04 22:43:27","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-5034118/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-5034118/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1007/s11696-024-03866-9","type":"published","date":"2024-12-29T15:57:51+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":71507755,"identity":"2c94883c-fb60-4b21-8ff5-204448561ab5","added_by":"auto","created_at":"2024-12-16 10:02:21","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":174788,"visible":true,"origin":"","legend":"\u003cp\u003eBinding pose of compound \u003cstrong\u003e2a\u003c/strong\u003eagainst (a) 1KZN and (b) 1EA1\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-5034118/v1/915d068ed661bbb0956b269c.png"},{"id":72640674,"identity":"b239f4fb-3459-49e9-8a9f-6864d8536090","added_by":"auto","created_at":"2024-12-30 16:08:25","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1782175,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-5034118/v1/0e27172e-ff98-451d-9c02-b6aba90cdb7b.pdf"},{"id":71507088,"identity":"8b2ac983-a7f1-48f9-a268-0b6860ee743f","added_by":"auto","created_at":"2024-12-16 09:54:21","extension":"png","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":183039,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eGraphical abstract\u003c/strong\u003e\u003c/p\u003e","description":"","filename":"GA.png","url":"https://assets-eu.researchsquare.com/files/rs-5034118/v1/8b08ea6c99d898e0ea55a527.png"},{"id":71507089,"identity":"722c938f-967e-41cb-9b24-4d1972d6b29c","added_by":"auto","created_at":"2024-12-16 09:54:21","extension":"png","order_by":2,"title":"","display":"","copyAsset":false,"role":"supplement","size":52219,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eScheme 1\u003c/strong\u003e Synthetic route and structure of benzimidazolium salts 2a-e\u003c/p\u003e","description":"","filename":"Scheme1.png","url":"https://assets-eu.researchsquare.com/files/rs-5034118/v1/7f217e4693b73a1fc7455005.png"},{"id":71507756,"identity":"ff4968d9-5789-47e9-943c-96586e5d68dc","added_by":"auto","created_at":"2024-12-16 10:02:21","extension":"png","order_by":3,"title":"","display":"","copyAsset":false,"role":"supplement","size":41977,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eScheme 2\u003c/strong\u003e Synthetic route and structure of Se-NHC compounds \u003cstrong\u003e3a-e\u003c/strong\u003e.\u003c/p\u003e","description":"","filename":"Scheme2.png","url":"https://assets-eu.researchsquare.com/files/rs-5034118/v1/1fa556f51e85b1214d6443ec.png"}],"financialInterests":"","formattedTitle":"Exploring the Antimicrobial Potential of New Selenium- N-Heterocyclic Carbene Complexes and Their Benzimidazolium Salts: Synthesis, Characterization, Biological Evaluation, and Docking Insights","fulltext":[{"header":"1. INTRODUCTION","content":"\u003cp\u003eDue to their diverse range of biological activities, \u003cem\u003eN\u003c/em\u003e-heterocyclic carbene metal complexes are gaining increasing significance in medicinal chemistry (Fatima et al., 2017; Haque et al., 2017). In recent years, research has primarily concentrated on the anticancer (Iqbal et al., 2013) and antibacterial (Asekunowo et al., 2017) applications of silver(I) and gold(I) NHC complexes. Conversely, selenium-based compounds have been examined and demonstrated promising antimicrobial activity (Dhau et al., 2014; Nguyen et al., 2014). Being an essential micronutrient (Rother \u0026amp; Quitzke, 2018; Solovyev, 2015), selenium is non-toxic to humans when present in low concentrations(Genchi et al., 2023; Sun et al., 2014; Zwolak \u0026amp; Zaporowska, 2012). This makes it a potential candidate for an adduct that can release selenium steadily into the biological system, acting as an effective pharmaceutical agent (Du et al., 2014). A key advantage of Se-NHC adducts lies in their potential for the targeted and effective delivery of selenium to biological sites, which remains a challenge in medicinal applications (Karthik et al., 2024). In medicinal chemistry, Selenium's compatibility with biological systems makes it particularly valuable for treating a range of illnesses, outperforming many other elements in the periodic table. For instance, selenium supplements are administered to address selenium deficiency, and selenium sulfide is a common ingredient in anti-dandruff shampoos (Cisnetti \u0026amp; Gautier, 2013; Huda et al., 2023; Khalifa et al., 2015).\u003c/p\u003e \u003cp\u003eTo date, several transition metal NHC compounds, such as those containing Au, Ag, or Ru, have shown great potential as antimicrobial and anticancer agents (Karci et al., 2024; Zou et al., 2018). However, these compounds often have limited biological safety and potential toxicity at higher concentrations (Bian et al., 2019; Mora et al., 2019). In contrast, Se-NHC adducts have shown similar antimicrobial and antioxidant activities at much lower concentrations, while also demonstrating biocompatibility (Nassar et al., 2023). Effectively delivering selenium within biological systems continues to be a significant challenge. To explore the potential of NHC donor ligands, researchers have recently designed and synthesized carbene adducts incorporating selenium (Doddi et al., 2019; Yaqoob et al., 2020). The incorporation of selenium in NHC frameworks has been shown to enhance bioactivity, as observed by Altaf et al., who reported superior anticancer and antimicrobial activities for selenium adducts compared to their ligands(Altaf et al., 2025a).\u003c/p\u003e \u003cp\u003eThe substituents at the N-position in N-heterocyclic carbenes (NHCs) play a significant role in determining their chemical properties and biological applications(Hassan et al., 2023). Altering these substituents enables researchers to achieve targeted electronic and steric properties, which is crucial in designing NHCs for specific reactivities in fields like catalysis and medicinal chemistry. Since their first synthesis from imidazolium salts, NHC complexes have become highly valuable for coordinating a wide range of metals and metalloids, with significant applications in drug development, catalysis, and more (Hopkinson et al., 2014; Kamal et al., 2023; Hayat et al., 2023; Kamal et al., 2022; Chang et al., 2024). The synthesis of NH-free carbene ligands and their metal compounds, especially with elements like silver and selenium, has thus become a significant area of research.\u003c/p\u003e \u003cp\u003eIn previous work, we synthesized benzimidazolium-based Ag-NHC carbene adducts and evaluated their biological potential, identifying several compounds with significant antibacterial activity (Sandeli et al., 2021). Expanding upon this, we aimed to develop Se-NHC carbene adducts derived from benzimidazolium, hypothesizing that selenium incorporation would enhance biological efficacy. In this study, we synthesized five azolium-based Se-NHC compounds and evaluated their in vitro antimicrobial activities against a range of microbial strains. By investigating the impact of different substituents on biological activity, we aimed to elucidate structure-activity relationships for these compounds.\u003c/p\u003e"},{"header":"2. EXPERIMENTAL","content":"\u003cp\u003e\u003cstrong\u003e2.1 Chemistry\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e2.1.1 General\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAll reactions for the preparation of starting material and benzimidazolium salts were carried out under an argon atmosphere in flame-dried glassware using standard Schlenk techniques. Selenium-NHC adducts were performed under reflux conditions. Nuclear Magnetic Resonance (NMR) Spectroscopy \u003csup\u003e1\u003c/sup\u003eH NMR and \u003csup\u003e13\u003c/sup\u003eC NMR spectra were recorded with a Varian As 400 Merkur spectrometer operating at 400 MHz (\u003csup\u003e1\u003c/sup\u003eH), and 100 MHz (\u003csup\u003e13\u003c/sup\u003eC) in CDCl\u003csub\u003e3\u003c/sub\u003e or DMSO-\u003cem\u003ed\u003csup\u003e6\u003c/sup\u003e\u003c/em\u003e with tetramethylsilane as an internal reference. FT-IR spectra were recorded on the ATR unit in the range 400\u0026ndash;4000 cm\u003csup\u003e-1\u003c/sup\u003e on Perkin Elmer Spectrum 100. Melting points of the synthesized compounds were determined using a Kofler-type WME melting point apparatus (Scientific Apparatus for Research and Industry Laboratory Equipment, Model Nr.6809, vol 230, Amp.0.44, Watt 100). Mass spectroscopic measurements were performed at İn\u0026ouml;n\u0026uuml; University Drug Administration and Research Center to determine the molecular weights and fragmentation patterns of the synthesized compounds. No further purification was done on the chemicals purchased from Merck, Sigma-Aldrich, and Fluka, ensuring the reproducibility and reliability of the experimental results.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e2.1.2 General procedure for the synthesis of Benzimidazolium Salts (2a-e)\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThrough minor adjustments to previously published methods described in the literature (Garrison \u0026amp; Youngs, 2005; Rahali et al., 2024), benzimidazolium salts can be achieved. The process involved dissolving 1-(2-(piperidine-1-yl)ethyl)-1H-benzo[d]imidazole (1 equivalent) and an equivalent amount of alkyl halide derivative in degassed toluene (4-5 mL). The reaction mixture was stirred at 80 \u0026deg;C for 2 days under argon. Upon completion of the reaction, the solvent was evaporated under vacuum, and diethyl ether (50 mL) was added to yield a solid powder, which was then filtered. The solid was washed with diethyl ether (3 \u0026times; 20 mL) and dried under vacuum. The crude product was recrystallized from a dichloromethane /diethyl ether mixture (1:3, v/v) at room temperature and thoroughly dried under vacuum to yield pure products suitable for experimental analysis.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e1-benzhydryl-3-(2-(piperidin-1-yl)ethyl)-1\u003cem\u003eH\u003c/em\u003e-benzo[d]imidazol-3-ium bromide (2a)\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003csup\u003e1\u003c/sup\u003eH NMR (400 MHz, DMSO-\u003cem\u003ed\u003csup\u003e6\u003c/sup\u003e\u003c/em\u003e, TMS, 25 \u0026deg;C): \u0026delta; (ppm) = 9.20 (s, 1H, NC\u003cu\u003eH\u003c/u\u003eN); 8.18 (d, \u003cem\u003eJ\u003c/em\u003e = 5.1 Hz, 1H, C\u003cu\u003eH\u003c/u\u003e-Ar); 7.78 (d, \u003cem\u003eJ\u0026nbsp;\u003c/em\u003e= 5.2 Hz, 1H, C\u003cu\u003eH\u003c/u\u003e-Ar); \u0026nbsp;7.69-7.58 (m, 2H, C\u003cu\u003eH\u003c/u\u003e-Ar); 7.56-7.34 (m, 10H, CH-Ar); 7.63 (d, 1H, \u003cem\u003eJ\u003c/em\u003e = 6.8 Hz, CH-Ar); 5.72 (s, H, Ph-C\u003cu\u003eH\u003c/u\u003e-Ph); 4.70-4.57 (br s, 2H, \u003cstrong\u003e\u003cu\u003eC\u003c/u\u003e\u003c/strong\u003eH\u003csub\u003e2\u003c/sub\u003e-N(piperidine)); 2.70-2.52 (br s, 2H, \u003cstrong\u003e\u003cu\u003eC\u003c/u\u003e\u003c/strong\u003eH\u003csub\u003e2\u003c/sub\u003e-N(bezimidazole)); 2.40-2.13 (br s, 4H, 2CH\u003csub\u003e2\u003c/sub\u003e, C\u003cu\u003eH\u003csub\u003e2\u003c/sub\u003e\u003c/u\u003e-N-C\u003cu\u003eH\u003csub\u003e2\u0026nbsp;\u003c/sub\u003e\u003c/u\u003epiperidine); 1.39-1.11 (br s, 6H, 3CH\u003csub\u003e2\u003c/sub\u003e, C\u003cu\u003eH\u003csub\u003e2\u003c/sub\u003e\u003c/u\u003e-C\u003cu\u003eH\u003csub\u003e2\u003c/sub\u003e\u003c/u\u003e-C\u003cu\u003eH\u003csub\u003e2\u003c/sub\u003e\u003c/u\u003e\u003csub\u003e\u0026nbsp;\u003c/sub\u003epiperidine).\u0026nbsp;\u003csup\u003e13\u003c/sup\u003eC NMR (100 MHz, DMSO-\u003cem\u003ed\u003c/em\u003e\u003csup\u003e6\u003c/sup\u003e, TMS, 25 \u0026deg;C): \u0026delta; (ppm) = 142.7 (N\u003cstrong\u003e\u003cu\u003eC\u003c/u\u003e\u003c/strong\u003eHN); 136.6 (2Cq); 131.8 (C, CH); 129.7 (4C, CH); 128.8 (4C, CH); 127.3 (2C, CH); 127.2 (2C, CH); 114.7 (C, CH); 114.4 (C, CH); 65.3 (C, Ph-\u003cstrong\u003e\u003cu\u003eC\u003c/u\u003e\u003c/strong\u003eH-Ph); 55.4 (C, \u003cstrong\u003e\u003cu\u003eC\u003c/u\u003e\u003c/strong\u003eH\u003csub\u003e2\u003c/sub\u003e-N(piperidine)); 54.9 (2C, \u003cstrong\u003e\u003cu\u003eC\u003c/u\u003e\u003c/strong\u003eH\u003csub\u003e2\u003c/sub\u003e-N-\u003cstrong\u003e\u003cu\u003eC\u003c/u\u003e\u003c/strong\u003eH\u003csub\u003e2\u0026nbsp;\u003c/sub\u003epiperidine); 45.0 (C, \u003cstrong\u003e\u003cu\u003eC\u003c/u\u003e\u003c/strong\u003eH\u003csub\u003e2\u003c/sub\u003e-N(bezimidazole)); 25.9 (2C, \u003cstrong\u003e\u003cu\u003eC\u003c/u\u003e\u003c/strong\u003eH\u003csub\u003e2\u003c/sub\u003e-CH\u003csub\u003e2\u003c/sub\u003e-\u003cstrong\u003e\u003cu\u003eC\u003c/u\u003e\u003c/strong\u003eH\u003csub\u003e2\u0026nbsp;\u003c/sub\u003epiperidine); 24.0 (C, CH\u003csub\u003e2\u003c/sub\u003e-\u003cstrong\u003e\u003cu\u003eC\u003c/u\u003e\u003c/strong\u003eH\u003csub\u003e2\u003c/sub\u003e-CH\u003csub\u003e2\u0026nbsp;\u003c/sub\u003epiperidine\u003csub\u003e\u0026nbsp;\u003c/sub\u003e). Elemental analysis; calcd (%) for C\u003csub\u003e27\u003c/sub\u003eH\u003csub\u003e30\u003c/sub\u003eBrN\u003csub\u003e3\u003c/sub\u003e (M.w.= 476.46 g/mol): C 68.06, H 6.35, N 8.82; found (%): C 68.26, H 6.16, N 8.74; HRMS (ESI) C\u003csub\u003e27\u003c/sub\u003eH\u003csub\u003e30\u003c/sub\u003eN\u003csub\u003e3\u003c/sub\u003e+ \u0026nbsp; m/z calcd [M+H]\u003csup\u003e+\u003c/sup\u003e 396.2434, found 396.2411.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e1-(3,5-di-tert-butylbenzyl)-3-(2-(piperidin-1-yl)ethyl)-1\u003cem\u003eH\u003c/em\u003e-benzo[d]imidazol-3-ium bromide (2b)\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003csup\u003e1\u003c/sup\u003eH NMR (400 MHz, CDCl\u003csub\u003e3\u003c/sub\u003e, TMS, 25 \u0026deg;C): \u0026delta; (ppm) = \u0026nbsp;10.98 (s, 1H, NC\u003cu\u003eH\u003c/u\u003eN); 7.79 (d, \u003cem\u003eJ\u003c/em\u003e = 7.5 Hz, 1H, C\u003cu\u003eH\u003c/u\u003e-Ar);7.70-7.37 (m, 6H, C\u003cu\u003eH\u003c/u\u003e-Ar); 5.69 (s, H, Ph-C\u003cu\u003eH\u003c/u\u003e-Ph); 4.75-4.67 (br s, 2H, \u003cstrong\u003e\u003cu\u003eC\u003c/u\u003e\u003c/strong\u003eH\u003csub\u003e2\u003c/sub\u003e-N(piperidine)); 2.90-2.82 (br s, 2H, \u003cstrong\u003e\u003cu\u003eC\u003c/u\u003e\u003c/strong\u003eH\u003csub\u003e2\u003c/sub\u003e-N(bezimidazole)); 2.48-2.38 (br s, 4H, 2CH\u003csub\u003e2\u003c/sub\u003e, C\u003cu\u003eH\u003csub\u003e2\u003c/sub\u003e\u003c/u\u003e-N-C\u003cu\u003eH\u003csub\u003e2\u0026nbsp;\u003c/sub\u003e\u003c/u\u003epiperidine); 1.29-1.24 (br s, 6H, 3CH\u003csub\u003e2\u003c/sub\u003e, C\u003cu\u003eH\u003csub\u003e2\u003c/sub\u003e\u003c/u\u003e-C\u003cu\u003eH\u003csub\u003e2\u003c/sub\u003e\u003c/u\u003e-C\u003cu\u003eH\u003csub\u003e2\u003c/sub\u003e\u003c/u\u003e\u003csub\u003e\u0026nbsp;\u003c/sub\u003epiperidine).\u0026nbsp;\u003csup\u003e13\u003c/sup\u003eC NMR (100 MHz, CDCl\u003csub\u003e3\u003c/sub\u003e, TMS, 25 \u0026deg;C): \u0026delta; (ppm) = 152.1 (2Cq); 143.2 (N\u003cstrong\u003e\u003cu\u003eC\u003c/u\u003e\u003c/strong\u003eHN); 131.7 (C, Cq); 131.7 (C, Cq); 131.0 (C, Cq); 126.8 (C, CH-Ar); 126.8 (C, CH-Ar); 123.2 (C, CH-Ar); 122.6 (2C, CH-Ar); 113.5 (C, CH); 113.3 (C, CH); 56.7 (C, N-\u003cstrong\u003e\u003cu\u003eC\u003c/u\u003e\u003c/strong\u003eH\u003csub\u003e2\u003c/sub\u003e-C\u003csub\u003e6\u003c/sub\u003eH\u003csub\u003e2\u003c/sub\u003e(\u003cem\u003et\u003c/em\u003e-bu)\u003csub\u003e2\u003c/sub\u003e); 54.4 (2C, \u003cstrong\u003e\u003cu\u003eC\u003c/u\u003e\u003c/strong\u003eH\u003csub\u003e2\u003c/sub\u003e-N-\u003cstrong\u003e\u003cu\u003eC\u003c/u\u003e\u003c/strong\u003eH\u003csub\u003e2\u0026nbsp;\u003c/sub\u003epiperidine); 52.0 (C, \u003cstrong\u003e\u003cu\u003eC\u003c/u\u003e\u003c/strong\u003eH\u003csub\u003e2\u003c/sub\u003e-N(piperidine); 44.9 (C, \u003cstrong\u003e\u003cu\u003eC\u003c/u\u003e\u003c/strong\u003eH\u003csub\u003e2\u003c/sub\u003e-N(bezimidazole)); 34.9 (2Cq, \u003cstrong\u003e\u003cu\u003eC\u003c/u\u003e\u003c/strong\u003e \u003cem\u003et\u003c/em\u003e-bu); 31.3 (9C, \u003cstrong\u003e\u003cu\u003eC\u003c/u\u003e\u003c/strong\u003eH\u003csub\u003e3\u003c/sub\u003e); 25.9 (2C, \u003cstrong\u003e\u003cu\u003eC\u003c/u\u003e\u003c/strong\u003eH\u003csub\u003e2\u003c/sub\u003e-CH\u003csub\u003e2\u003c/sub\u003e-\u003cstrong\u003e\u003cu\u003eC\u003c/u\u003e\u003c/strong\u003eH\u003csub\u003e2\u0026nbsp;\u003c/sub\u003epiperidine); 23.9 (C, CH\u003csub\u003e2\u003c/sub\u003e-\u003cstrong\u003e\u003cu\u003eC\u003c/u\u003e\u003c/strong\u003eH\u003csub\u003e2\u003c/sub\u003e-CH\u003csub\u003e2\u0026nbsp;\u003c/sub\u003epiperidine\u003csub\u003e\u0026nbsp;\u003c/sub\u003e). Elemental analysis; calcd (%) for C\u003csub\u003e29\u003c/sub\u003eH\u003csub\u003e42\u003c/sub\u003eBrN\u003csub\u003e3\u003c/sub\u003e (M.w.= 512.58 g/mol): C 67.95, H 8.26, N 8.20; found (%): C 67.82, H 8.32, N 8.08; HRMS (ESI) C\u003csub\u003e29\u003c/sub\u003eH\u003csub\u003e42\u003c/sub\u003eN\u003csub\u003e3\u003c/sub\u003e+ m/z calcd [M+H]\u003csup\u003e+\u003c/sup\u003e 432.3323, found 432.3308.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e1-isopentyl-3-(2-(piperidin-1-yl)ethyl)-1\u003cem\u003eH\u003c/em\u003e-benzo[d]imidazol-3-ium bromide (2c)\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003csup\u003e1\u003c/sup\u003eH NMR (400 MHz, CDCl\u003csub\u003e3\u003c/sub\u003e, TMS, 25 \u0026deg;C): \u0026delta; (ppm) = 11.06 (s, 1H, NC\u003cu\u003eH\u003c/u\u003eN); 7.90 -7.79 (m, 1H, CH-Ar); 7.70 (d, J = 22.4 Hz, 2H, C\u003cu\u003eH\u003c/u\u003e-Ar); 7.69 (d, J = 2.1 Hz, 1H, C\u003cu\u003eH\u003c/u\u003e-Ar); 4.81-4.70 (br s, 2H, \u003cstrong\u003e\u003cu\u003eC\u003c/u\u003e\u003c/strong\u003eH\u003csub\u003e2\u003c/sub\u003e-N(piperidine)); 4.69-4.58 (br s, 2H, N-C\u003cu\u003eH\u003csub\u003e2\u003c/sub\u003e\u003c/u\u003e-CH\u003csub\u003e2\u003c/sub\u003e-CH(CH\u003csub\u003e3\u003c/sub\u003e)\u003csub\u003e2\u003c/sub\u003e); \u0026nbsp;2.92-2.82 (br s, 2H, \u003cstrong\u003e\u003cu\u003eC\u003c/u\u003e\u003c/strong\u003eH\u003csub\u003e2\u003c/sub\u003e-N(bezimidazole)); 2.60-2.42 (br s, 4H, 2CH\u003csub\u003e2\u003c/sub\u003e, C\u003cu\u003eH\u003csub\u003e2\u003c/sub\u003e\u003c/u\u003e-N-C\u003cu\u003eH\u003csub\u003e2\u0026nbsp;\u003c/sub\u003e\u003c/u\u003epiperidine); 2.05-1.90 (br s, 2H, C\u003cu\u003eH\u003csub\u003e2\u003c/sub\u003e\u003c/u\u003e-CH-(CH\u003csub\u003e3\u003c/sub\u003e)\u003csub\u003e2\u003c/sub\u003e); \u0026nbsp;1.80-1.66 (m, 1H, CH, CH\u003csub\u003e3\u003c/sub\u003e-C\u003cu\u003eH\u003c/u\u003e-CH\u003csub\u003e3\u003c/sub\u003e); 1.56-1.36 (br s, 6H, 3CH\u003csub\u003e2\u003c/sub\u003e, C\u003cu\u003eH\u003csub\u003e2\u003c/sub\u003e\u003c/u\u003e-C\u003cu\u003eH\u003csub\u003e2\u003c/sub\u003e\u003c/u\u003e-C\u003cu\u003eH\u003csub\u003e2\u003c/sub\u003e\u003c/u\u003e\u003csub\u003e\u0026nbsp;\u003c/sub\u003epiperidine); 1.06 (s, 3H, C\u003cu\u003eH\u003csub\u003e3\u003c/sub\u003e\u003c/u\u003e); 1.04 (s, 3H, C\u003cu\u003eH\u003csub\u003e3\u003c/sub\u003e\u003c/u\u003e).\u0026nbsp;\u003csup\u003e13\u003c/sup\u003eC NMR (100 MHz, CDCl\u003csub\u003e3\u003c/sub\u003e, TMS, 25 \u0026deg;C): \u0026delta; (ppm) = 143.1 (N\u003cstrong\u003e\u003cu\u003eC\u003c/u\u003e\u003c/strong\u003eHN); 131.5 (C, Cq); 131.0 (C, Cq); 126.9 (2C, \u003cu\u003eC\u003c/u\u003eH-Ar); 129.0 (C, \u003cu\u003eC\u003c/u\u003eH-Ar); 128.1 (C, \u003cu\u003eC\u003c/u\u003eH-Ar); 113.7 (C, \u003cu\u003eC\u003c/u\u003eH); \u0026nbsp;112.8 (C, \u003cu\u003eC\u003c/u\u003eH); 56.9 (C, \u003cstrong\u003e\u003cu\u003eC\u003c/u\u003e\u003c/strong\u003eH\u003csub\u003e2\u003c/sub\u003e-N(piperidine)); 54.5 (2C, \u003cstrong\u003e\u003cu\u003eC\u003c/u\u003e\u003c/strong\u003eH\u003csub\u003e2\u003c/sub\u003e-N-\u003cstrong\u003e\u003cu\u003eC\u003c/u\u003e\u003c/strong\u003eH\u003csub\u003e2\u0026nbsp;\u003c/sub\u003epiperidine); 45.9 (C, N-\u003cstrong\u003e\u003cu\u003eC\u003c/u\u003e\u003c/strong\u003eH\u003csub\u003e2\u003c/sub\u003e-CH\u003csub\u003e2\u003c/sub\u003e-CH(CH\u003csub\u003e3\u003c/sub\u003e)\u003csub\u003e2\u003c/sub\u003e); 44.9 (C, \u003cstrong\u003e\u003cu\u003eC\u003c/u\u003e\u003c/strong\u003eH\u003csub\u003e2\u003c/sub\u003e-N(bezimidazole); 37.9 (C, N-CH\u003csub\u003e2\u003c/sub\u003e-\u003cstrong\u003e\u003cu\u003eC\u003c/u\u003e\u003c/strong\u003eH\u003csub\u003e2\u003c/sub\u003e-CH(CH\u003csub\u003e3\u003c/sub\u003e)\u003csub\u003e2\u003c/sub\u003e); 26.0 (2C, \u003cstrong\u003e\u003cu\u003eC\u003c/u\u003e\u003c/strong\u003eH\u003csub\u003e2\u003c/sub\u003e-CH\u003csub\u003e2\u003c/sub\u003e-\u003cstrong\u003e\u003cu\u003eC\u003c/u\u003e\u003c/strong\u003eH\u003csub\u003e2\u0026nbsp;\u003c/sub\u003epiperidine); 25.6 (C, CH\u003csub\u003e3\u003c/sub\u003e-\u003cstrong\u003e\u003cu\u003eC\u003c/u\u003e\u003c/strong\u003eH-CH\u003csub\u003e3\u003c/sub\u003e); 24.0 (C, CH\u003csub\u003e2\u003c/sub\u003e-\u003cstrong\u003e\u003cu\u003eC\u003c/u\u003e\u003c/strong\u003eH\u003csub\u003e2\u003c/sub\u003e-CH\u003csub\u003e2\u0026nbsp;\u003c/sub\u003epiperidine\u003csub\u003e\u0026nbsp;\u003c/sub\u003e); 22.3 (2C, \u003cstrong\u003e\u003cu\u003eC\u003c/u\u003e\u003c/strong\u003eH\u003csub\u003e3\u003c/sub\u003e). Elemental analysis; calcd (%) for C\u003csub\u003e19\u003c/sub\u003eH\u003csub\u003e30\u003c/sub\u003eBrN\u003csub\u003e3\u003c/sub\u003e (M.w.= 380.37 g/mol): C 60.00, H 7.95, N 11.05; found (%): C 60.12, H 7.75, N 11.30; HRMS (ESI) C\u003csub\u003e19\u003c/sub\u003eH\u003csub\u003e30\u003c/sub\u003eN\u003csub\u003e3\u0026nbsp;\u003c/sub\u003e+ m/z calcd [M+H]\u003csup\u003e+\u003c/sup\u003e 300.2434, found 300.2414.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e1-(benzyloxymethyl)-3-(2-(piperidin-1-yl)ethyl)-1\u003cem\u003eH\u003c/em\u003e-benzo[d]imidazol-3-ium chloride (2d)\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003csup\u003e1\u003c/sup\u003eH NMR (400 MHz, DMSO-\u003cem\u003ed\u003csup\u003e6\u003c/sup\u003e\u003c/em\u003e, TMS, 25 \u0026deg;C): \u0026delta; (ppm) = 10.34 (s, 1H, NC\u003cu\u003eH\u003c/u\u003eN); 8.33-8.19 (m, 1H, C\u003cu\u003eH\u003c/u\u003e-Ar); 8.18-8.04 (m, 1H, C\u003cu\u003eH\u003c/u\u003e-Ar); 7.78-7.68 (m, 1H, C\u003cu\u003eH\u003c/u\u003e-Ar); 7.42-7.21 (m, 5H, C\u003cu\u003eH\u003c/u\u003e-Ar); 6.08 (s, 2H, O-C\u003cu\u003eH\u003csub\u003e2\u003c/sub\u003e\u003c/u\u003e-Ph); 5.76 (br s, 2H, O-\u003cstrong\u003e\u003cu\u003eC\u003c/u\u003e\u003c/strong\u003eH\u003csub\u003e2\u003c/sub\u003e-N(bezimidazole)); 4.78-4.67 (br s, 2H, \u003cstrong\u003e\u003cu\u003eC\u003c/u\u003e\u003c/strong\u003eH\u003csub\u003e2\u003c/sub\u003e-N(piperidine)); 2.00-1.30 (br s, 6H, 3CH\u003csub\u003e2\u003c/sub\u003e, C\u003cu\u003eH\u003csub\u003e2\u003c/sub\u003e\u003c/u\u003e-C\u003cu\u003eH\u003csub\u003e2\u003c/sub\u003e\u003c/u\u003e-C\u003cu\u003eH\u003csub\u003e2\u003c/sub\u003e\u003c/u\u003e\u003csub\u003e\u0026nbsp;\u003c/sub\u003epiperidine). \u003csup\u003e13\u003c/sup\u003eC NMR (100 MHz, DMSO-\u003cem\u003ed\u003csup\u003e6\u003c/sup\u003e\u003c/em\u003e, TMS, 25 \u0026deg;C): \u0026delta; (ppm) = 137.0 (NC\u003cstrong\u003e\u003cu\u003eH\u003c/u\u003e\u003c/strong\u003eN); 131.7 (C, Cq); 128.7 (2C, CH); 128.4 (C, CH); 128.3 (C, CH); 127.4 (C, CH-Ar); 127.2 (C, CH-Ar); 114.5 (C, CH); 114.4 (C, CH);\u0026nbsp;76.9 (C, O-\u003cstrong\u003e\u003cu\u003eC\u003c/u\u003e\u003c/strong\u003eH\u003csub\u003e2\u003c/sub\u003e-N); 71.5 (C, Ph-\u003cstrong\u003e\u003cu\u003eC\u003c/u\u003e\u003c/strong\u003eH\u003csub\u003e2\u003c/sub\u003e-O); 55.4 (C, \u003cstrong\u003e\u003cu\u003eC\u003c/u\u003e\u003c/strong\u003eH\u003csub\u003e2\u003c/sub\u003e-N(piperidine); 52.9 (2C, \u003cstrong\u003e\u003cu\u003eC\u003c/u\u003e\u003c/strong\u003eH\u003csub\u003e2\u003c/sub\u003e-N-\u003cstrong\u003e\u003cu\u003eC\u003c/u\u003e\u003c/strong\u003eH\u003csub\u003e2\u0026nbsp;\u003c/sub\u003epiperidine); 49.0 (C, \u003cstrong\u003e\u003cu\u003eC\u003c/u\u003e\u003c/strong\u003eH\u003csub\u003e2\u003c/sub\u003e-N(bezimidazole); 22.7 (C, CH\u003csub\u003e2\u003c/sub\u003e-\u003cstrong\u003e\u003cu\u003eC\u003c/u\u003e\u003c/strong\u003eH\u003csub\u003e2\u003c/sub\u003e-CH\u003csub\u003e2\u0026nbsp;\u003c/sub\u003epiperidine\u003csub\u003e\u0026nbsp;\u003c/sub\u003e).\u0026nbsp;Elemental analysis; calcd (%) for C\u003csub\u003e22\u003c/sub\u003eH\u003csub\u003e28\u003c/sub\u003eClN\u003csub\u003e3\u003c/sub\u003eO (M.w.= 385.93 g/mol):\u0026nbsp;C 68.47, H 7.31, N 10.89; found (%): C 68.35, H 7.46, N 10.70; HRMS (ESI) C\u003csub\u003e22\u003c/sub\u003eH\u003csub\u003e28\u003c/sub\u003eN\u003csub\u003e3\u003c/sub\u003eO+ m/z calcd [M+H]\u003csup\u003e+\u003c/sup\u003e 350.2227, found 350.2206.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e1-(3,5-dimethylbenzyl)-3-(2-(piperidin-1-yl)ethyl)-1\u003cem\u003eH\u003c/em\u003e-benzo[d]imidazol-3-ium bromide (2e)\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;\u003csup\u003e1\u003c/sup\u003eH NMR (400 MHz, CDCl\u003csub\u003e3\u003c/sub\u003e, TMS, 25 \u0026deg;C): \u0026delta; (ppm) = 11.03 \u0026nbsp;(s, 1H, NCHN); 7.76 (d,\u003cem\u003e\u0026nbsp;J\u003c/em\u003e = 6.7 Hz, 1H, CH-Ar); 7.62 (d, \u003cem\u003eJ\u0026nbsp;\u003c/em\u003e= 7.4 Hz, 2H, CH-Ar); 7.23 (d, \u003cem\u003eJ\u003c/em\u003e = 5.1 Hz, 1H, CH-Ar); 7.06 (s, 2H, C\u003cu\u003eH\u003c/u\u003e-Ar); 6.96 (s, H, C\u003cu\u003eH\u003c/u\u003e-Ar); 5.72 (s, H, N-C\u003cu\u003eH\u003csub\u003e2\u003c/sub\u003e\u003c/u\u003e-Ph); 4.75-4.66 (br s, 2H, \u003cstrong\u003e\u003cu\u003eC\u003c/u\u003e\u003c/strong\u003eH\u003csub\u003e2\u003c/sub\u003e-N(piperidine)); 2.89-2.77 (br s, 2H, \u003cstrong\u003e\u003cu\u003eC\u003c/u\u003e\u003c/strong\u003eH\u003csub\u003e2\u003c/sub\u003e-N(bezimidazole)); 2.51-2.37 (br s, 4H, 2CH\u003csub\u003e2\u003c/sub\u003e, C\u003cu\u003eH\u003csub\u003e2\u003c/sub\u003e\u003c/u\u003e-N-C\u003cu\u003eH\u003csub\u003e2\u0026nbsp;\u003c/sub\u003e\u003c/u\u003epiperidine); 2.26 (s, 6H, 2C\u003cu\u003eH\u003csub\u003e3\u003c/sub\u003e\u003c/u\u003e); 1.49-1.30 (br s, 6H, 3CH\u003csub\u003e2\u003c/sub\u003e, C\u003cu\u003eH\u003csub\u003e2\u003c/sub\u003e\u003c/u\u003e-C\u003cu\u003eH\u003csub\u003e2\u003c/sub\u003e\u003c/u\u003e-C\u003cu\u003eH\u003csub\u003e2\u003c/sub\u003e\u003c/u\u003e\u003csub\u003e\u0026nbsp;\u003c/sub\u003epiperidine). \u003csup\u003e13\u003c/sup\u003eC NMR (100 MHz, CDCl\u003csub\u003e3\u003c/sub\u003e, TMS, 25 \u0026deg;C): \u0026delta; (ppm) = 143.4 (N\u003cstrong\u003e\u003cu\u003eC\u003c/u\u003e\u003c/strong\u003eHN); 139.1 (2C, Cq); 132.5 (C, Cq); 131.5 \u0026nbsp;(C, Cq); 131.0 (C, Cq); 130.9 (C, Cq); 129.0 (C, CH-Ar); 128.2 (C, CH-Ar); 126.8 (C, CH-Ar); 126.2 (2C, CH-Ar); \u0026nbsp;113.5 (C, CH); \u0026nbsp;113.1 (C, CH); 56.5 (C, \u003cstrong\u003e\u003cu\u003eC\u003c/u\u003e\u003c/strong\u003eH\u003csub\u003e2\u003c/sub\u003e-N(piperidine)); 54.4 (2C, \u003cstrong\u003e\u003cu\u003eC\u003c/u\u003e\u003c/strong\u003eH\u003csub\u003e2\u003c/sub\u003e-N-\u003cstrong\u003e\u003cu\u003eC\u003c/u\u003e\u003c/strong\u003eH\u003csub\u003e2\u0026nbsp;\u003c/sub\u003epiperidine); 51.2 (C, N-\u003cstrong\u003e\u003cu\u003eC\u003c/u\u003e\u003c/strong\u003eH\u003csub\u003e2\u003c/sub\u003e-C\u003csub\u003e6\u003c/sub\u003eH\u003csub\u003e3\u003c/sub\u003e(CH\u003csub\u003e3\u003c/sub\u003e)\u003csub\u003e2\u003c/sub\u003e); 44.9 (C, \u003cstrong\u003e\u003cu\u003eC\u003c/u\u003e\u003c/strong\u003eH\u003csub\u003e2\u003c/sub\u003e-N(bezimidazole); 25.9 (2C, \u003cstrong\u003e\u003cu\u003eC\u003c/u\u003e\u003c/strong\u003eH\u003csub\u003e2\u003c/sub\u003e-CH\u003csub\u003e2\u003c/sub\u003e-\u003cstrong\u003e\u003cu\u003eC\u003c/u\u003e\u003c/strong\u003eH\u003csub\u003e2\u0026nbsp;\u003c/sub\u003epiperidine); 24.0 (C, CH\u003csub\u003e2\u003c/sub\u003e-\u003cstrong\u003e\u003cu\u003eC\u003c/u\u003e\u003c/strong\u003eH\u003csub\u003e2\u003c/sub\u003e-CH\u003csub\u003e2\u0026nbsp;\u003c/sub\u003epiperidine\u003csub\u003e\u0026nbsp;\u003c/sub\u003e); 21.2 (2C, \u003cstrong\u003e\u003cu\u003eC\u003c/u\u003e\u003c/strong\u003eH\u003csub\u003e3\u003c/sub\u003e). Elemental analysis; calcd (%) for C\u003csub\u003e23\u003c/sub\u003eH\u003csub\u003e30\u003c/sub\u003eBrN\u003csub\u003e3\u003c/sub\u003e (M.w.= 428.41 g/mol):\u0026nbsp;C 64.48, H 7.06, N 9.81; found (%): C 64.50, H 7.16, N 9.95; HRMS (ESI) C\u003csub\u003e23\u003c/sub\u003eH\u003csub\u003e30\u003c/sub\u003eN\u003csub\u003e3\u003c/sub\u003e+ \u003csub\u003e\u0026nbsp;\u003c/sub\u003em/z calcd [M+H]\u003csup\u003e+\u003c/sup\u003e 348.2434, found 348.2414.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e2.1.3 General procedure for the synthesis of selenium-NHC compounds (3a-e)\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eSelenium-NHC adducts were obtained by reacting selenium metal with benzimidazolium salts at the carbene carbon site, using a mild base such as K\u003csub\u003e2\u003c/sub\u003eCO\u003csub\u003e3\u003c/sub\u003e or Na\u003csub\u003e2\u003c/sub\u003eCO\u003csub\u003e3\u003c/sub\u003e as a catalyst \u003cspan lang=\"FR\"\u003e(Iqbal et al., 2016; Tian et al., 2014)\u003c/span\u003e. A mixture of benzimidazolium salts (1 equivalent) and selenium metal (1 equivalent) with potassium carbonate (1.5 equivalent) in methanol at 80\u0026deg;C for 2 days. This process facilitated the formation of selenium-based N-heterocyclic carbene (Se-NHC) adducts, resulting in a black solid. This process automatically converts the salts into selenium-NHC\u0026nbsp;adducts. The solid product was then dissolved in dichloromethane (CH₂Cl₂) and purified through flash column chromatography on silica gel. After evaporation of the solvent in the open air, the product was recrystallized from a CHCl₃/Et₂O mixture, yielding the pure Se-NHC adducts as a solid.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e1-benzhydryl-3-(2-(piperidin-1-yl)ethyl)-1\u003cem\u003eH\u003c/em\u003e-benzo[d]imidazole-2(3H)-selenone\u0026nbsp;\u003c/strong\u003e\u003cstrong\u003e(3a)\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003csup\u003e1\u003c/sup\u003eH NMR (400 MHz, CDCl\u003csub\u003e3\u003c/sub\u003e, TMS, 25 \u0026deg;C): \u0026delta; (ppm) = 8.24-8.17 (m, 1H, C\u003cu\u003eH\u003c/u\u003e-Ar); 7.38-7.28 (m, 10H, C\u003cu\u003eH\u003c/u\u003e-Ar); 7.16 (t, \u003cem\u003eJ\u0026nbsp;\u003c/em\u003e= 15.8 Hz, 1\u003cu\u003eH\u003c/u\u003e, CH-Ar); 6.93 (t, \u003cem\u003eJ\u003c/em\u003e = 7.2 Hz, 1H, C\u003cu\u003eH\u003c/u\u003e-Ar); 6.73 (d, \u003cem\u003eJ\u003c/em\u003e = 7.9 Hz, 1H, C\u003cu\u003eH\u003c/u\u003e-Ar); 4.69-4.58 (br s, 2H, C\u003cu\u003eH\u003csub\u003e2\u003c/sub\u003e\u003c/u\u003e-N(piperidine)); 2.83-2.74 (br s, 2H, C\u003cu\u003eH\u003csub\u003e2\u003c/sub\u003e\u003c/u\u003e-N(bezimidazole)); 2.66-2.50 (br s, 4H, 2CH\u003csub\u003e2\u003c/sub\u003e, C\u003cu\u003eH\u003csub\u003e2\u003c/sub\u003e\u003c/u\u003e-N-C\u003cu\u003eH\u003csub\u003e2\u0026nbsp;\u003c/sub\u003e\u003c/u\u003epiperidine); 1.66-1.37 (br s, 6H, 3CH\u003csub\u003e2\u003c/sub\u003e, C\u003cu\u003eH\u003csub\u003e2\u003c/sub\u003e\u003c/u\u003e-C\u003cu\u003eH\u003csub\u003e2\u003c/sub\u003e\u003c/u\u003e-C\u003cu\u003eH\u003csub\u003e2\u003c/sub\u003e\u003c/u\u003e\u003csub\u003e\u0026nbsp;\u003c/sub\u003epiperidine). \u003csup\u003e13\u003c/sup\u003eC NMR (100 MHz, CDCl\u003csub\u003e3\u003c/sub\u003e, TMS, 25 \u0026deg;C): \u0026delta; (ppm) = 167.9 (C=Se); 137.4 (2Cq); 133.6 (C, Cq); 132.3 (C, Cq);128.5 (4C, CH); 128.5 (4C, CH); 127.9 (2C, CH); 112.6 (C, CH); \u0026nbsp;109.8 (C, CH); 65.3 (C, Ph-\u003cu\u003eC\u003c/u\u003eH-Ph);\u0026nbsp;55.4 (C, \u003cstrong\u003e\u003cu\u003eC\u003c/u\u003e\u003c/strong\u003eH\u003csub\u003e2\u003c/sub\u003e-N(piperidine)); 54.9 (2C, \u003cstrong\u003e\u003cu\u003eC\u003c/u\u003e\u003c/strong\u003eH\u003csub\u003e2\u003c/sub\u003e-N-\u003cstrong\u003e\u003cu\u003eC\u003c/u\u003e\u003c/strong\u003eH\u003csub\u003e2\u0026nbsp;\u003c/sub\u003epiperidine); 45.0 (C, \u003cstrong\u003e\u003cu\u003eC\u003c/u\u003e\u003c/strong\u003eH\u003csub\u003e2\u003c/sub\u003e-N(bezimidazole)); 25.9 (2C, \u003cstrong\u003e\u003cu\u003eC\u003c/u\u003e\u003c/strong\u003eH\u003csub\u003e2\u003c/sub\u003e-CH\u003csub\u003e2\u003c/sub\u003e-\u003cstrong\u003e\u003cu\u003eC\u003c/u\u003e\u003c/strong\u003eH\u003csub\u003e2\u0026nbsp;\u003c/sub\u003epiperidine); 24.0 (C, CH\u003csub\u003e2\u003c/sub\u003e-\u003cstrong\u003e\u003cu\u003eC\u003c/u\u003e\u003c/strong\u003eH\u003csub\u003e2\u003c/sub\u003e-CH\u003csub\u003e2\u0026nbsp;\u003c/sub\u003epiperidine\u003csub\u003e\u0026nbsp;\u003c/sub\u003e).\u0026nbsp;Elemental analysis; calcd (%) for C\u003csub\u003e27\u003c/sub\u003eH\u003csub\u003e29\u003c/sub\u003eN\u003csub\u003e3\u003c/sub\u003eSe (M.w.= 474.49 g/mol):\u0026nbsp;C 68.34, H 6.16, N 8.86; found (%): C 68.25, H 6.22, N 08.79; HRMS (ESI) m/z (C\u003csub\u003e27\u003c/sub\u003eH\u003csub\u003e30\u003c/sub\u003eN\u003csub\u003e3\u003c/sub\u003eSe\u003csup\u003e+\u003c/sup\u003e) calcd [M+H]\u003csup\u003e+\u003c/sup\u003e 476.1527, found 476.1544.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e1-(3,5-di-tert-butylbenzyl)-3-(2-(piperidin-1-yl)ethyl)-1\u003cem\u003eH\u003c/em\u003e-benzo[d]imidazole-2(3H)-selenone\u0026nbsp;\u003c/strong\u003e\u003cstrong\u003e(3b)\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003csup\u003e1\u003c/sup\u003eH NMR (400 MHz, CDCl\u003csub\u003e3\u003c/sub\u003e, TMS, 25 \u0026deg;C): \u0026delta; (ppm) = \u0026nbsp; 7.47 (d, \u003cem\u003eJ\u003c/em\u003e = 6.7 Hz, 1\u003cu\u003eH\u003c/u\u003e, CH-Ar); 7.40 (d,\u003cem\u003e\u0026nbsp;J\u003c/em\u003e = 5.7 Hz, 2H, C\u003cu\u003eH\u003c/u\u003e-Ar); 7.21-7.10 (m, 4H, C\u003cu\u003eH\u003c/u\u003e-Ar); 6.99 (s, 1H, C\u003cu\u003eH\u003c/u\u003e-Ar); 5.57 (s, H, Ph-C\u003cu\u003eH\u003c/u\u003e-Ph); 4.50-4.40 (br s, 2H, \u003cstrong\u003e\u003cu\u003eC\u003c/u\u003e\u003c/strong\u003eH\u003csub\u003e2\u003c/sub\u003e-N(piperidine)); 2.64-2.54 (br s, 2H, \u003cstrong\u003e\u003cu\u003eC\u003c/u\u003e\u003c/strong\u003eH\u003csub\u003e2\u003c/sub\u003e-N(bezimidazole)); 2.38-2.29 (br s, 4H, 2CH\u003csub\u003e2\u003c/sub\u003e, C\u003cu\u003eH\u003csub\u003e2\u003c/sub\u003e\u003c/u\u003e-N-C\u003cu\u003eH\u003csub\u003e2\u0026nbsp;\u003c/sub\u003e\u003c/u\u003epiperidine); 1.35-1.20 (br s, 6H, 3CH\u003csub\u003e2\u003c/sub\u003e, C\u003cu\u003eH\u003csub\u003e2\u003c/sub\u003e\u003c/u\u003e-C\u003cu\u003eH\u003csub\u003e2\u003c/sub\u003e\u003c/u\u003e-C\u003cu\u003eH\u003csub\u003e2\u003c/sub\u003e\u003c/u\u003e\u003csub\u003e\u0026nbsp;\u003c/sub\u003epiperidine); 1.11 (s, 6C, C\u003cu\u003eH\u003csub\u003e3\u003c/sub\u003e\u003c/u\u003e). \u003csup\u003e13\u003c/sup\u003eC NMR (100 MHz, CDCl\u003csub\u003e3\u003c/sub\u003e, TMS, 25 \u0026deg;C): \u0026delta; (ppm) = 166.3 (\u003cstrong\u003e\u003cu\u003eC\u003c/u\u003e\u003c/strong\u003e=Se); 150.8 (2Cq); 135.6 \u0026nbsp;(C, Cq); 133.5 (C, Cq); 132.6 (C, Cq); 123.6 (C, \u003cu\u003eC\u003c/u\u003eH-Ar); 123.5 (C, \u003cu\u003eC\u003c/u\u003eH-Ar); 123.4 (C, \u003cu\u003eC\u003c/u\u003eH-Ar); 121.4 (2C, CH-Ar); 111.1 (C, \u003cu\u003eC\u003c/u\u003eH); \u0026nbsp;110.9 (C, \u003cu\u003eC\u003c/u\u003eH); 56.4 (C, N-\u003cstrong\u003e\u003cu\u003eC\u003c/u\u003e\u003c/strong\u003eH\u003csub\u003e2\u003c/sub\u003e-C\u003csub\u003e6\u003c/sub\u003eH\u003csub\u003e2\u003c/sub\u003e(\u003cem\u003et\u003c/em\u003e-bu)\u003csub\u003e2\u003c/sub\u003e); 54.8 (2C, \u003cstrong\u003e\u003cu\u003eC\u003c/u\u003e\u003c/strong\u003eH\u003csub\u003e2\u003c/sub\u003e-N-\u003cstrong\u003e\u003cu\u003eC\u003c/u\u003e\u003c/strong\u003eH\u003csub\u003e2\u0026nbsp;\u003c/sub\u003epiperidine); 49.5 (C, \u003cstrong\u003e\u003cu\u003eC\u003c/u\u003e\u003c/strong\u003eH\u003csub\u003e2\u003c/sub\u003e-N(piperidine); 44.5 (C, \u003cstrong\u003e\u003cu\u003eC\u003c/u\u003e\u003c/strong\u003eH\u003csub\u003e2\u003c/sub\u003e-N(bezimidazole); 34.8 (2Cq, \u003cu\u003eC\u003c/u\u003e \u003cem\u003et-\u003c/em\u003ebu); 31.8 (C, \u003cstrong\u003e\u003cu\u003eC\u003c/u\u003e\u003c/strong\u003eH\u003csub\u003e3\u003c/sub\u003e); 31.6 (2C, \u003cstrong\u003e\u003cu\u003eC\u003c/u\u003e\u003c/strong\u003eH\u003csub\u003e3\u003c/sub\u003e); 26.0 (2C, \u003cstrong\u003e\u003cu\u003eC\u003c/u\u003e\u003c/strong\u003eH\u003csub\u003e2\u003c/sub\u003e-CH\u003csub\u003e2\u003c/sub\u003e-\u003cstrong\u003e\u003cu\u003eC\u003c/u\u003e\u003c/strong\u003eH\u003csub\u003e2\u0026nbsp;\u003c/sub\u003epiperidine); 24.3 (C, CH\u003csub\u003e2\u003c/sub\u003e-\u003cstrong\u003e\u003cu\u003eC\u003c/u\u003e\u003c/strong\u003eH\u003csub\u003e2\u003c/sub\u003e-CH\u003csub\u003e2\u0026nbsp;\u003c/sub\u003epiperidine\u003csub\u003e\u0026nbsp;\u003c/sub\u003e). Elemental analysis; calcd (%) for C\u003csub\u003e29\u003c/sub\u003eH\u003csub\u003e41\u003c/sub\u003eN\u003csub\u003e3\u003c/sub\u003eSe (M.w.= 510.62 g/mol):\u0026nbsp;C 68.21, H 8.09, N 8.23; found (%): C 68.32, H 8.12, N 08.01; HRMS (ESI) m/z C\u003csub\u003e29\u003c/sub\u003eH\u003csub\u003e42\u003c/sub\u003eN\u003csub\u003e3\u003c/sub\u003eSe\u003csup\u003e+\u003c/sup\u003e calcd [M+H]\u003csup\u003e+\u003c/sup\u003e 512.2466, found 512.2465.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e1-isopentyl-3-(2-(piperidin-1-yl)ethyl)-1\u003cem\u003eH\u003c/em\u003e-benzo[d]imidazole-2(3H)-selenone (3c)\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e1H NMR (400 MHz, CDCl\u003csub\u003e3\u003c/sub\u003e, TMS, 25 \u0026deg;C): \u0026delta; (ppm) = 7.39-7.31 (m, 1H, C\u003cu\u003eH\u003c/u\u003e-Ar); 4.62-4.55 (br s, 2H, \u003cstrong\u003e\u003cu\u003eC\u003c/u\u003e\u003c/strong\u003eH\u003csub\u003e2\u003c/sub\u003e-N(piperidine)); 4.49-4.38 (br s, 2H, N-C\u003cu\u003eH\u003csub\u003e2\u003c/sub\u003e\u003c/u\u003e-CH\u003csub\u003e2\u003c/sub\u003e-CH(CH\u003csub\u003e3\u003c/sub\u003e)\u003csub\u003e2\u003c/sub\u003e); 2.78-2.68 (br s, 2H, \u003cstrong\u003e\u003cu\u003eC\u003c/u\u003e\u003c/strong\u003eH\u003csub\u003e2\u003c/sub\u003e-N(bezimidazole)); 2.62-2.50 (br s, 4H, 2CH\u003csub\u003e2\u003c/sub\u003e, C\u003cu\u003eH\u003csub\u003e2\u003c/sub\u003e\u003c/u\u003e-N-C\u003cu\u003eH\u003csub\u003e2\u0026nbsp;\u003c/sub\u003e\u003c/u\u003epiperidine); 1.83-1.73 (br s, 1H, CH, CH\u003csub\u003e3\u003c/sub\u003e-C\u003cu\u003eH\u003c/u\u003e-CH\u003csub\u003e3\u003c/sub\u003e); 1.65-1.39 (br s, 6H, 3CH\u003csub\u003e2\u003c/sub\u003e, C\u003cu\u003eH\u003csub\u003e2\u003c/sub\u003e\u003c/u\u003e-C\u003cu\u003eH\u003csub\u003e2\u003c/sub\u003e\u003c/u\u003e-C\u003cu\u003eH\u003csub\u003e2\u003c/sub\u003e\u003c/u\u003e\u003csub\u003e\u0026nbsp;\u003c/sub\u003epiperidine); 1.05 (s, 3H, C\u003cu\u003eH\u003csub\u003e3\u003c/sub\u003e\u003c/u\u003e); 1.03 (s, 3H, C\u003cu\u003eH\u003csub\u003e3\u003c/sub\u003e\u003c/u\u003e). \u003csup\u003e13\u003c/sup\u003eC NMR (100 MHz, CDCl\u003csub\u003e3\u003c/sub\u003e, TMS, 25 \u0026deg;C): \u0026delta; (ppm) = 165.5 (\u003cstrong\u003e\u003cu\u003eC\u003c/u\u003e\u003c/strong\u003e=Se); 133.3 (C, Cq); 132.8 (C, Cq); 128.7 (C, CH-Ar); 127.1 (C, CH-Ar); 123.1 (2C, CH-Ar); 109.9 (C, CH); 109.4 (C, CH); 56.1 (C, \u003cstrong\u003e\u003cu\u003eC\u003c/u\u003e\u003c/strong\u003eH\u003csub\u003e2\u003c/sub\u003e-N(piperidine); 54.9 (2C, \u003cstrong\u003e\u003cu\u003eC\u003c/u\u003e\u003c/strong\u003eH\u003csub\u003e2\u003c/sub\u003e-N-\u003cstrong\u003e\u003cu\u003eC\u003c/u\u003e\u003c/strong\u003eH\u003csub\u003e2\u0026nbsp;\u003c/sub\u003epiperidine); 45.2 (C, N-\u003cstrong\u003e\u003cu\u003eC\u003c/u\u003e\u003c/strong\u003eH\u003csub\u003e2\u003c/sub\u003e-CH\u003csub\u003e2\u003c/sub\u003e-CH(CH\u003csub\u003e3\u003c/sub\u003e)\u003csub\u003e2\u003c/sub\u003e); 44.3 (C, \u003cstrong\u003e\u003cu\u003eC\u003c/u\u003e\u003c/strong\u003eH\u003csub\u003e2\u003c/sub\u003e-N(bezimidazole); 36.6 (C, N-CH\u003csub\u003e2\u003c/sub\u003e-\u003cstrong\u003e\u003cu\u003eC\u003c/u\u003e\u003c/strong\u003eH\u003csub\u003e2\u003c/sub\u003e-CH(CH\u003csub\u003e3\u003c/sub\u003e)\u003csub\u003e2\u003c/sub\u003e); 26.1 (2C, \u003cstrong\u003e\u003cu\u003eC\u003c/u\u003e\u003c/strong\u003eH\u003csub\u003e2\u003c/sub\u003e-CH\u003csub\u003e2\u003c/sub\u003e-\u003cstrong\u003e\u003cu\u003eC\u003c/u\u003e\u003c/strong\u003eH\u003csub\u003e2\u0026nbsp;\u003c/sub\u003epiperidine); 26.0 (C, CH\u003csub\u003e3\u003c/sub\u003e-\u003cstrong\u003e\u003cu\u003eC\u003c/u\u003e\u003c/strong\u003eH-CH\u003csub\u003e3\u003c/sub\u003e); 24.2 (C, CH\u003csub\u003e2\u003c/sub\u003e-\u003cstrong\u003e\u003cu\u003eC\u003c/u\u003e\u003c/strong\u003eH\u003csub\u003e2\u003c/sub\u003e-CH\u003csub\u003e2\u0026nbsp;\u003c/sub\u003epiperidine\u003csub\u003e\u0026nbsp;\u003c/sub\u003e); 22.5 (2C, \u003cstrong\u003e\u003cu\u003eC\u003c/u\u003e\u003c/strong\u003eH\u003csub\u003e3\u003c/sub\u003e). Elemental analysis; calcd (%) for C\u003csub\u003e19\u003c/sub\u003eH\u003csub\u003e29\u003c/sub\u003eN\u003csub\u003e3\u003c/sub\u003eSe (M.w.= 378.42 g/mol):\u0026nbsp;C 60.30, H 7.72, N 11.10; found (%): C 60.42, H 7.80, N 11.00; HRMS (ESI) C\u003csub\u003e19\u003c/sub\u003eH\u003csub\u003e29\u003c/sub\u003eN\u003csub\u003e3\u003c/sub\u003eSe+ m/z calcd [M+H]\u003csup\u003e+\u003c/sup\u003e 380.1527, found 380.1554.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e1-(benzyloxymethyl)-3-(2-(piperidin-1-yl)ethyl)-1\u003cem\u003eH\u003c/em\u003e-benzo[d]imidazole-2(3H)-selenone (3d)\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003csup\u003e1\u003c/sup\u003eH NMR (400 MHz, CDCl\u003csub\u003e3\u003c/sub\u003e, TMS, 25 \u0026deg;C): \u0026delta; (ppm) = 7.63-7.52 (m, 2H, CH-Ar); 7.27 (s, \u0026nbsp; 5H, CH-Ar); 5.99 (s, 2H, O-C\u003cu\u003eH\u003csub\u003e2\u003c/sub\u003e\u003c/u\u003e-Ph); 4.68-4.61 (br s, 2H, O-\u003cstrong\u003e\u003cu\u003eC\u003c/u\u003e\u003c/strong\u003eH\u003csub\u003e2\u003c/sub\u003e-N(bezimidazole)); 4.57-4.44 (br s, 2H, \u003cstrong\u003e\u003cu\u003eC\u003c/u\u003e\u003c/strong\u003eH\u003csub\u003e2\u003c/sub\u003e-N(piperidine)); 2.72-2.69 (br s, 2H, \u003cstrong\u003e\u003cu\u003eC\u003c/u\u003e\u003c/strong\u003eH\u003csub\u003e2\u003c/sub\u003e-N(bezimidazole)); 2.49-2.32 (br s, 4H, 2CH\u003csub\u003e2\u003c/sub\u003e, C\u003cu\u003eH\u003csub\u003e2\u003c/sub\u003e\u003c/u\u003e-N-C\u003cu\u003eH\u003csub\u003e2\u0026nbsp;\u003c/sub\u003e\u003c/u\u003epiperidine); 1.49-1.28 (br s, 6H, 3CH\u003csub\u003e2\u003c/sub\u003e, C\u003cu\u003eH\u003csub\u003e2\u003c/sub\u003e\u003c/u\u003e-C\u003cu\u003eH\u003csub\u003e2\u003c/sub\u003e\u003c/u\u003e-C\u003cu\u003eH\u003csub\u003e2\u003c/sub\u003e\u003c/u\u003e\u003csub\u003e\u0026nbsp;\u003c/sub\u003epiperidine). \u003csup\u003e13\u003c/sup\u003eC NMR (100 MHz, DMSO-\u003cem\u003ed\u003csup\u003e6\u003c/sup\u003e\u003c/em\u003e, TMS, 25 \u0026deg;C): \u0026delta; (ppm) = 167.1 (C=Se); 137.8 (C, Cq; 134.7 (C, Cq); 132.6 (C, Cq); 128.6 (2C, CH); 128.0 (C, CH); 127.9 (2C, CH); 124.0 (C, CH-Ar); 123.9 (C, CH-Ar); \u0026nbsp; 111.9 (C, CH); \u0026nbsp;111.9 (C, CH); 75.6 (C, O-\u003cstrong\u003e\u003cu\u003eC\u003c/u\u003e\u003c/strong\u003eH\u003csub\u003e2\u003c/sub\u003e-N); 71.5 (C, Ph-\u003cstrong\u003e\u003cu\u003eC\u003c/u\u003e\u003c/strong\u003eH\u003csub\u003e2\u003c/sub\u003e-O); 56.1 (C, \u003cstrong\u003e\u003cu\u003eC\u003c/u\u003e\u003c/strong\u003eH\u003csub\u003e2\u003c/sub\u003e-N(piperidine); 54.8(2C, \u003cstrong\u003e\u003cu\u003eC\u003c/u\u003e\u003c/strong\u003eH\u003csub\u003e2\u003c/sub\u003e-N-\u003cstrong\u003e\u003cu\u003eC\u003c/u\u003e\u003c/strong\u003eH\u003csub\u003e2\u0026nbsp;\u003c/sub\u003epiperidine); 44.2 (C, \u003cstrong\u003e\u003cu\u003eC\u003c/u\u003e\u003c/strong\u003eH\u003csub\u003e2\u003c/sub\u003e-N(bezimidazole); 26.0 (2C, \u003cstrong\u003e\u003cu\u003eC\u003c/u\u003e\u003c/strong\u003eH\u003csub\u003e2\u003c/sub\u003e-CH\u003csub\u003e2\u003c/sub\u003e-\u003cstrong\u003e\u003cu\u003eC\u003c/u\u003e\u003c/strong\u003eH\u003csub\u003e2\u0026nbsp;\u003c/sub\u003epiperidine); 24.3 (C, CH\u003csub\u003e2\u003c/sub\u003e-\u003cstrong\u003e\u003cu\u003eC\u003c/u\u003e\u003c/strong\u003eH\u003csub\u003e2\u003c/sub\u003e-CH\u003csub\u003e2\u0026nbsp;\u003c/sub\u003epiperidine). Elemental analysis; calcd (%) for C\u003csub\u003e22\u003c/sub\u003eH\u003csub\u003e27\u003c/sub\u003eN\u003csub\u003e3\u003c/sub\u003eOSe (M.w.= 428.42 g/mol):\u0026nbsp;C 61.78, H 6.35, N 9.81; found (%): C 61.73, H 6.46, N 9.92; HRMS (ESI) C\u003csub\u003e22\u003c/sub\u003eH\u003csub\u003e27\u003c/sub\u003eN\u003csub\u003e3\u003c/sub\u003eOSe+ m/z calcd [M+H]\u003csup\u003e+\u003c/sup\u003e 430.1319, found 430.1347.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e1-(3,5-dimethylbenzyl)-3-(2-(piperidin-1-yl)ethyl)-1\u003cem\u003eH\u003c/em\u003e-benzo[d]imidazole-2(3H)-selenone (3e)\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003csup\u003e1\u003c/sup\u003eH NMR (400 MHz, CDCl\u003csub\u003e3\u003c/sub\u003e, TMS, 25 \u0026deg;C): \u0026delta; (ppm) = 7.35 (d, J = 7.1 Hz, 1H, C\u003cu\u003eH\u003c/u\u003e-Ar); 7.24-7.18 (m, 1H, C\u003cu\u003eH\u003c/u\u003e-Ar); 7.18-7.10 (m, 2H, C\u003cu\u003eH\u003c/u\u003e-Ar); 7.94 (s, 2H, CH-Ar); 6.89 (s, H, C\u003cu\u003eH\u003c/u\u003e-Ar); 5.29 (s, H, N-CH\u003csub\u003e2\u003c/sub\u003e-Ph); 4.67-4.57 (br s, 2H, \u003cstrong\u003e\u003cu\u003eC\u003c/u\u003e\u003c/strong\u003eH\u003csub\u003e2\u003c/sub\u003e-N(piperidine); 2.85-2.73 (br s, 2H, \u003cstrong\u003e\u003cu\u003eC\u003c/u\u003e\u003c/strong\u003eH\u003csub\u003e2\u003c/sub\u003e-N(bezimidazole)); 2.64-2.52 (br s, 4H, 2CH\u003csub\u003e2\u003c/sub\u003e, C\u003cu\u003eH\u003csub\u003e2\u003c/sub\u003e\u003c/u\u003e-N-C\u003cu\u003eH\u003csub\u003e2\u0026nbsp;\u003c/sub\u003e\u003c/u\u003epiperidine); 2.25 (s, 6H, 2C\u003cu\u003eH\u003csub\u003e3\u003c/sub\u003e\u003c/u\u003e); 1.67-1.37 (br s, 6H, 3CH\u003csub\u003e2\u003c/sub\u003e, C\u003cu\u003eH\u003csub\u003e2\u003c/sub\u003e\u003c/u\u003e-C\u003cu\u003eH\u003csub\u003e2\u003c/sub\u003e\u003c/u\u003e-C\u003cu\u003eH\u003csub\u003e2\u003c/sub\u003e\u003c/u\u003e\u003csub\u003e\u0026nbsp;\u003c/sub\u003epiperidine).\u0026nbsp;\u003csup\u003e13\u003c/sup\u003eC NMR (100 MHz, CDCl\u003csub\u003e3\u003c/sub\u003e, TMS, 25 \u0026deg;C): \u0026delta; (ppm) = 167.1 (C=Se); 138.8 (2C, Cq); 135.2 \u0026nbsp;(C, Cq); 133.4 (C, Cq); 133.0 (C, Cq); 129.5 (C, CH-Ar); 127.1 (C, CH-Ar); 125.1 (2C, CH-Ar); 123.2 (C, CH-Ar); \u0026nbsp;110.3 (C, CH); \u0026nbsp;109.8 (C, CH); 56.1 (C, \u003cstrong\u003e\u003cu\u003eC\u003c/u\u003e\u003c/strong\u003eH\u003csub\u003e2\u003c/sub\u003e-N(piperidine)); 54.7 (2C, \u003cstrong\u003e\u003cu\u003eC\u003c/u\u003e\u003c/strong\u003eH\u003csub\u003e2\u003c/sub\u003e-N-\u003cstrong\u003e\u003cu\u003eC\u003c/u\u003e\u003c/strong\u003eH\u003csub\u003e2\u0026nbsp;\u003c/sub\u003epiperidine); 50.3 (C, N-\u003cstrong\u003e\u003cu\u003eC\u003c/u\u003e\u003c/strong\u003eH\u003csub\u003e2\u003c/sub\u003e-C\u003csub\u003e6\u003c/sub\u003eH\u003csub\u003e3\u003c/sub\u003e(CH\u003csub\u003e3\u003c/sub\u003e)\u003csub\u003e2\u003c/sub\u003e); 44.7 (C, \u003cstrong\u003e\u003cu\u003eC\u003c/u\u003e\u003c/strong\u003eH\u003csub\u003e2\u003c/sub\u003e-N(bezimidazole)); 26.0 (2C, \u003cstrong\u003e\u003cu\u003eC\u003c/u\u003e\u003c/strong\u003eH\u003csub\u003e2\u003c/sub\u003e-CH\u003csub\u003e2\u003c/sub\u003e-\u003cstrong\u003e\u003cu\u003eC\u003c/u\u003e\u003c/strong\u003eH\u003csub\u003e2\u0026nbsp;\u003c/sub\u003epiperidine); 24.4 (C, CH\u003csub\u003e2\u003c/sub\u003e-\u003cstrong\u003e\u003cu\u003eC\u003c/u\u003e\u003c/strong\u003eH\u003csub\u003e2\u003c/sub\u003e-CH\u003csub\u003e2\u0026nbsp;\u003c/sub\u003epiperidine); 21.3 (2C, \u003cstrong\u003e\u003cu\u003eC\u003c/u\u003e\u003c/strong\u003eH\u003csub\u003e3\u003c/sub\u003e). Elemental analysis; calcd (%) for C\u003csub\u003e23\u003c/sub\u003eH\u003csub\u003e29\u003c/sub\u003eN\u003csub\u003e3\u003c/sub\u003eSe (M.w.= 426.45 g/mol):\u0026nbsp;C 64.78, H 6.85, N 9.85; found (%): C 64.60, H 6.96, N 9.72; HRMS (ESI) C\u003csub\u003e23\u003c/sub\u003eH\u003csub\u003e29\u003c/sub\u003eN\u003csub\u003e3\u003c/sub\u003eSe+ m/z calcd [M+H]\u003csup\u003e+\u003c/sup\u003e 427.1528, found 428.1549.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e2.2 Biological assays\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e2.2.1. Materials\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe antimicrobial activity experiments were conducted in the Laboratory of the Department of Medical Genetics at the School of Medicine, Inonu University. The study utilized various chemical materials including peptone, glucose, pure water, tryptone, NaCl, dimethyl sulfoxide (DMSO), yeast extract, and agar, all sourced from PanReac AppliChem and Fisher Scientific. The equipment used in the study comprised a Denovix DS-11 FX+ (UV, Blue, Red, Green) Spectrophotometer/Fluorometer, an Allsheng AMR-100 Microplate Reader, a Daihan WIS 20 Shaking Incubator, a N\u0026uuml;ve EN 120 Incubator, a N\u0026uuml;ve NF 800R Cooled Centrifuge, and a Sigma 1-14 Microcentrifuge.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e2.2.2. Methods\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAntimicrobial activity\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eDisc Diffusion Test\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe disc diffusion method was used to evaluate the compounds\u0026apos; effectiveness in inhibiting bacterial and fungal growth. The bacterial strains tested included \u003cem\u003ePseudomonas aeruginosa\u003c/em\u003e (ATCC 27853), \u003cem\u003eEscherichia coli\u003c/em\u003e (ATCC 25922), and \u003cem\u003eStaphylococcus aureus\u003c/em\u003e (ATCC 29213), while the fungal strains were \u003cem\u003eCandida glabrata\u003c/em\u003e (ATCC 2001) and \u003cem\u003eCandida albicans\u003c/em\u003e (SC5314/ATCC MYA-2876) \u003cspan lang=\"FR\"\u003e(Khan et al., 2023)\u003c/span\u003e. To obtain a concentration of 80 \u0026mu;g/\u0026mu;L, 8 mg of each compound was dissolved in 100% DMSO. For the assay, 800 \u0026mu;g of the compound was applied per disc. Test bacteria (approximately 1x108 cells) were inoculated in sterilized LB broth media, and yeast (approximately 1x107 cells) in YPD broth media. These cultures were gently mixed and transferred to a Petri dish under aseptic conditions. The compound-loaded disc was placed on the 90 mm diameter Petri dish and incubated at 37\u0026deg;C for 24 hours. A disc containing only DMSO served as the negative control, while ampicillin (800 \u0026mu;g per disc) and \u003cem\u003ecaspofungin\u003c/em\u003e (800 \u0026mu;g per disc) were used as standard antibacterial and antifungal agents, respectively. The antibacterial and antifungal activity of the compounds was indicated by the diameter of the clear inhibition zone, measured in millimeters.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eIC\u003csub\u003e50\u003c/sub\u003e Test\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe same fungi and bacteria species used in the disc diffusion test were subjected to the IC\u003csub\u003e50\u003c/sub\u003e test. IC\u003csub\u003e50\u003c/sub\u003e analyses were performed using the BMD (Broth Microdilution) test, as described in EUCAST EDef 7.3.2 (Arendrup et al., 2020)\u0026nbsp;for yeasts and CLSI M07 (Wikler, 2006)\u0026nbsp;for bacteria within different mediums mentioned in these documents. Briefly, the stock solution of chemically synthesized powdered compounds used in antifungal and antimicrobial tests was prepared in 100% DMSO. Serial dilutions were made in flat bottom 96-well plates, in YPD (Yeast Peptone Dextrose) medium (2% peptone, 2% glucose, 1% yeast extract) pH 6,5 \u0026nbsp;for yeasts, and LB (Luria-Bertani) broth medium (1% tryptone, 1% NaCl, 0.5% yeast extract, pH 7.0) \u0026nbsp;for bacteria. In sterile water, yeast (1-5x10\u003csup\u003e5\u003c/sup\u003e CFU / ml) and bacteria (1x10\u003csup\u003e6\u003c/sup\u003e CFU / ml) cell solutions (inoculums) were prepared and added in equal volumes to 96-well plates containing different concentrations of the compounds to obtain the required cell density and concentrations of chemical compounds tested. After adding the cell solutions, the final concentrations of the compounds were between 0.8 and 800 mg / L, and the cell concentrations required for the test were 0.5-2.5x10\u003csup\u003e5\u0026nbsp;\u003c/sup\u003eCFU / ml in yeasts and 5x10\u003csup\u003e5\u0026nbsp;\u003c/sup\u003eCFU / ml in bacteria in the final step. Plates were incubated for 24 hours at 37 \u0026deg; C for yeasts and 16-18 hours at 37\u0026deg;C for bacteria, and the IC\u003csub\u003e50\u003c/sub\u003e was determined spectrophotometrically at 600 nm after incubation. The IC\u003csub\u003e50\u003c/sub\u003e value was measured as the lowest drug concentration causing at least 50% or more reduction in growth compared to the control (no drug) group.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e2.3 Molecular docking\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis molecular docking study aims to predict the antibacterial (\u003cem\u003eE. coli\u003c/em\u003e) and antifungal activities of synthesized benzimidazolium salts (compounds 2a-e) and their corresponding selenium N-heterocyclic carbene derivatives (compounds 3a-e). Each compound was structurally optimized using the MMFF94 force field as implemented in AVOGADRO software\u003cspan lang=\"FR\"\u003e(Hanwell et al., 2012)\u003c/span\u003e. The optimized structures were then used as ligands in molecular docking simulations.\u003c/p\u003e\n\u003cp\u003eTo rationalize the antibacterial activity, the compounds were docked against DNA gyrase, specifically \u003cem\u003eE. coli\u003c/em\u003e topoisomerase II DNA gyrase B. The X-ray crystallographic structure of this enzyme, complexed with the antibiotic ligand Clorobiocin (CBN), was retrieved from the Protein Data Bank (PDB ID: 1KZN) \u003cspan lang=\"FR\"\u003e(Hanwell et al., 2012)\u003c/span\u003e. For evaluating antifungal activity, the compounds were docked against the enzyme CYP51, with the structure obtained from PDB (PDB ID: 1EA1) \u003cspan lang=\"FR\"\u003e(Podust et al., 2001)\u003c/span\u003e. The protein structures were preprocessed by removing all solvent molecules and co-crystallized ligands using Discovery Studio Visualizer software. \u003cspan lang=\"FR\"\u003e(Biovia, 2017)\u003c/span\u003e Then the protein structures were corrected by Swiss-PdbViewer software \u003cspan lang=\"FR\"\u003e(Guex \u0026amp; Peitsch, 1997)\u003c/span\u003e. Docking simulations were performed using AutoDock Vina, as implemented in the PyRx software.\u003cspan lang=\"FR\"\u003e(Guex \u0026amp; Peitsch, 1997)\u003c/span\u003e. The search centers (SC) and box dimensions (BD) for the docking experiments were set as follows: For DNA gyrase (PDB ID: 1KZN): SC: X = 19, Y = 26, Z = 35; BD: X = 25, Y = 25, Z = 25. For CYP51 (PDB ID: 1EA1): SC: X = -20, Y = -0.8, Z = 71; BD: X = 42.23, Y = 36.48, Z = 40.96 Visualization and analysis of the docking results were carried out using Discovery Studio Visualizer \u003cspan lang=\"FR\"\u003e(Biovia, 2017)\u003c/span\u003e.\u003c/p\u003e"},{"header":"3. RESULTS AND DISCUSSION","content":"\u003cdiv id=\"Sec22\" class=\"Section2\"\u003e \u003ch2\u003e3.1 Chemistry\u003c/h2\u003e \u003cp\u003eEfforts were undertaken to synthesize benzimidazolium salts (\u003cb\u003e2a-e\u003c/b\u003e) and the corresponding selenium-NHC adducts (\u003cb\u003e3a-e\u003c/b\u003e) by slightly modifying previously published methods (Engl et al., 2015; Steiner et al., 2005; Tian et al., 2014). The literature indicates that the synthesis of these compounds has been executed using various approaches, some of which include standard procedures.\u003c/p\u003e \u003cp\u003e \u003cb\u003eSynthesis of the benzimidazolium salts 2a\u0026ndash;e\u003c/b\u003e \u003c/p\u003e \u003cp\u003eBenzimidazolium salts \u003cb\u003e2a-e\u003c/b\u003e were synthesized through a two-step \u003cem\u003eN\u003c/em\u003e-alkylation process, as illustrated in the diagram. The initial compound 1, was formed by the first \u003cem\u003eN\u003c/em\u003e-alkylation of 1\u003cem\u003eH\u003c/em\u003e-benzo[d]imidazole with 1-(2-chloroethyl)piperidine hydrochloride. The second \u003cem\u003eN\u003c/em\u003e-alkylation involved reacting 1-(2-(piperidine-1-yl)ethyl)-1\u003cem\u003eH\u003c/em\u003e-benzo[d]imidazole 1 with various aryl/benzyl halide derivatives in toluene at 80\u0026deg;C to produce the five benzimidazolium salts \u003cb\u003e2a-e\u003c/b\u003e\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eAll the synthesized benzimidazolium salts \u003cb\u003e2a-e\u003c/b\u003e, as outlined in Scheme \u003cspan refid=\"Sch1\" class=\"InternalRef\"\u003e1\u003c/span\u003e, were successfully produced with satisfactory yields. The benzimidazolium salts spectroscopic data align well with previously reported data for similar salts found in the literature (Sandeli et al., 2021; Siciliano et al., 2011; Younas et al., 2023). All of the salts (\u003cb\u003e2a-e\u003c/b\u003e) demonstrated stability to air and moisture and were kept for further use. A summary of the physical and selected spectroscopic details of these benzimidazolium salts is presented in Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003ePhysical data and yield for benzimidazolium salts 2a-e.\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"6\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cem\u003eCode\u003c/em\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cem\u003eChemical Formula\u003c/em\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u003cem\u003eMolecular Weight (g/mol)\u003c/em\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u003cem\u003eMelting Point ◦C\u003c/em\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u003cem\u003ePhysical Appearance\u003c/em\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003e\u003cem\u003eYield (%)\u003c/em\u003e\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e2a\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eC\u003csub\u003e27\u003c/sub\u003eH\u003csub\u003e30\u003c/sub\u003eBrN\u003csub\u003e3\u003c/sub\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e476.46\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e264\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eBrown solid\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e65\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e2b\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eC\u003csub\u003e29\u003c/sub\u003eH\u003csub\u003e42\u003c/sub\u003eBrN\u003csub\u003e3\u003c/sub\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e512.58\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e266\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eWhite solid\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e70\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e2c\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eC\u003csub\u003e19\u003c/sub\u003eH\u003csub\u003e30\u003c/sub\u003eBrN\u003csub\u003e3\u003c/sub\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e380.37\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e200\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eWhite solid\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e91\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e2d\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eC\u003csub\u003e22\u003c/sub\u003eH\u003csub\u003e28\u003c/sub\u003eClN\u003csub\u003e3\u003c/sub\u003eO\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e385.93\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e222\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eWhite solid\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e90\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e2e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eC\u003csub\u003e23\u003c/sub\u003eH\u003csub\u003e30\u003c/sub\u003eBrN\u003csub\u003e3\u003c/sub\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e428.41\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e192\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eWhite solid\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e91\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003e \u003cb\u003ePreparation of selenium-NHC compounds 3a-e\u003c/b\u003e \u003c/p\u003e \u003cp\u003eThe selenium \u003cem\u003eN\u003c/em\u003e-heterocyclic carbene adducts (\u003cb\u003e3a-e\u003c/b\u003e) were produced by treating benzimidazolium salts with selenium, using a mild base such as K\u003csub\u003e2\u003c/sub\u003eCO\u003csub\u003e3\u003c/sub\u003e leading to the formation of the anticipated selenium Se-NHC adducts \u003cb\u003e3a-e\u003c/b\u003e through an in situ deprotonation process. This reaction was carried out at 80\u0026deg;C in methanol, as outlined in (Scheme \u003cspan refid=\"Sch2\" class=\"InternalRef\"\u003e2\u003c/span\u003e). The production of selenium-NHC compounds \u003cb\u003e3a-e\u003c/b\u003e resulted in black solids that are highly yield-efficient and dissolve in halogenated solvents.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eThe newly synthesized Se\u0026ndash;NHC compounds 3a-e, illustrated in Scheme \u003cspan refid=\"Sch2\" class=\"InternalRef\"\u003e2\u003c/span\u003e, were produced with satisfactory yields. The spectroscopic characteristics of these compounds align with previously reported data for similar Se-NHC compounds found in literature references(Kamal et al., 2022; Haque et al., 2018; Iqbal et al., 2016; Kamal et al., 2019). They were also found to be stable to air and moisture. Summaries of their physical properties and select spectroscopic data are presented in Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e02\u003c/span\u003e.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003ePhysical data and yield for Se-NHC complexes 3a-e.\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"6\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cem\u003eCode\u003c/em\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cem\u003eChemical Formula\u003c/em\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u003cem\u003eMolecular Weight (g/mol)\u003c/em\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u003cem\u003eMelting Point ◦C\u003c/em\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u003cem\u003ePhysical Appearance\u003c/em\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003e\u003cem\u003eYield (%)\u003c/em\u003e\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e3a\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eC\u003csub\u003e27\u003c/sub\u003eH\u003csub\u003e29\u003c/sub\u003eN\u003csub\u003e3\u003c/sub\u003eSe\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e474.49\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e190\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eBeige solid\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e74\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e3b\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eC\u003csub\u003e29\u003c/sub\u003eH\u003csub\u003e41\u003c/sub\u003eN\u003csub\u003e3\u003c/sub\u003eSe\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e510.62\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e154\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003ePale Yellow\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e75\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e3c\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eC\u003csub\u003e19\u003c/sub\u003eH\u003csub\u003e29\u003c/sub\u003eN\u003csub\u003e3\u003c/sub\u003eSe\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e378.42\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e200\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eYellow solid\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e73\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e3d\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eC\u003csub\u003e22\u003c/sub\u003eH\u003csub\u003e27\u003c/sub\u003eN\u003csub\u003e3\u003c/sub\u003eOSe\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e428.42\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e60\u0026ndash;62\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eBrown solid\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e74\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e3e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eC\u003csub\u003e23\u003c/sub\u003eH\u003csub\u003e29\u003c/sub\u003eN\u003csub\u003e3\u003c/sub\u003eSe\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e426.45\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e132\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eYellow solid\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e64\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eInitial indications of successfully synthesizing the desired compounds, as illustrated in Schemes \u003cspan refid=\"Sch1\" class=\"InternalRef\"\u003e1\u003c/span\u003e and \u003cspan refid=\"Sch2\" class=\"InternalRef\"\u003e2\u003c/span\u003e, were identified through their solubility properties, physical states, and melting points (mp). Notable differences in these characteristics were observed between the benzimidazolium salts and their selenium-NHC compounds.\u003c/p\u003e \u003cp\u003eThese findings confirm the successful synthesis and isolation of benzimidazolium salts and selenium-NHC adducts achieved with good to excellent yields. The compounds were obtained with yields ranging from 64\u0026ndash;94% and demonstrated stability in the presence of moisture and air. The yields of the synthesized products were calculated based on the isolated product weights relative to the theoretical maximum yield. The melting points (m.p) and physical appearances of the synthesized compounds verify their purity and identity. In the solid-state state, Variations in melting points (m.p) suggest differences in molecular packing and intermolecular interactions. Benzimidazolium salts \u003cb\u003e(2a-e\u003c/b\u003e) exhibited melting points (m.p) between 192\u0026ndash;266\u0026deg;C, whereas the selenium-NHC adducts (\u003cb\u003e3a-e\u003c/b\u003e) had (m.p) ranging from 60\u0026ndash;200\u0026deg;C, These differences reflect the organic nature of the benzimidazolium salts and the coordination of selenium, which introduces an inorganic character to the selenium-NHC adducts.\u003c/p\u003e \u003cp\u003eThe appearance of the benzimidazolium salts \u003cb\u003e2a-e\u003c/b\u003e initially formed as white solids in the reaction medium, was influenced by the type of alkyl chain substituted on the nitrogen atoms of the benzimidazole group. In contrast, the selenium-NHC adducts \u003cb\u003e3a-e\u003c/b\u003e first appeared as a sticky brown, yellow, and beige material, which, upon recrystallization, yielded a thick light yellow fluid that eventually turned colorless with further recrystallization. Both the salts and selenium-NHC adducts (\u003cb\u003e3a-e\u003c/b\u003e) were observed to be soluble in non-polar solvents like chloroform and dichloromethane.\u003c/p\u003e \u003cp\u003eAll benzimidazolium salts and their corresponding selenium-NHC adducts were characterized using a variety of analytical techniques. To identify changes before and after selenium incorporation into the carbene carbon, FT-IR spectra were recorded. Comparing the spectral features of the compounds pre- and post-incorporation revealed distinct changes that provided preliminary evidence of successful metal integration into the organic framework. Notably, significant spectral variations were observed in the 1000\u0026ndash;1600 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e region when comparing the salts with the Se-NHC adducts. FT-IR data showed that the benzimidazolium salts exhibited a characteristic ν(CN) band, with values of 1554, 1558, 1561, 1563, and 1561 cm⁻\u0026sup1; for salts 2a\u0026ndash;e, respectively. In addition, the salts showed absorption bands corresponding to ν(N-C), ν(C\u0026thinsp;=\u0026thinsp;C), and ν(C-H), with specific values as follows: 2a: 1336, 1458, and 2930 cm⁻\u0026sup1;; 2b: 1336, 1504, and 2922 cm⁻\u0026sup1;; 2c: 1344, 1428, and 2930 cm⁻\u0026sup1;; 2d: 1336, 1443, and 2945 cm⁻\u0026sup1;; and 2e: 1338, 1428, and 2930 cm⁻\u0026sup1;, respectively. In contrast, the selenium compounds exhibited a characteristic ν(CN) band, with values of 1226, 1195, 1204, 1475, and 1195 cm⁻\u0026sup1; for compounds 3a\u0026ndash;e, respectively. They also showed ν(N-C), ν(C\u0026thinsp;=\u0026thinsp;C), and ν(C-H) bands at the following values: 3a: 1324, 1454, and 2948 cm⁻\u0026sup1;; 3b: 1344, 1481, and 2938 cm⁻\u0026sup1;; 3c: 1344, 1440, and 2938 cm⁻\u0026sup1;; 3d: 1336, 1443, and 2938 cm⁻\u0026sup1;; and 3e: 1328, 1481, and 2930 cm⁻\u0026sup1;, respectively. These observations confirmed the successful formation of the Se-NHC adducts and highlighted the impact of selenium incorporation on the spectral properties of the salts. The observed shifts in ν(CN), along with changes in the ν(N-C), ν(C\u0026thinsp;=\u0026thinsp;C), and ν(C-H) bands, clearly indicate successful formation of the Se-NHC adducts. Notably, compound 2d displayed an additional ν(C\u0026thinsp;=\u0026thinsp;O) band at 1100 cm⁻\u0026sup1;. For compound 3d, a ν(C\u0026thinsp;=\u0026thinsp;O) band was observed at 1077 cm⁻\u0026sup1;. The notable changes in the spectral properties between the benzimidazolium salts and the selenium derivatives highlight the impact of selenium incorporation, likely due to altered electronic interactions and changes in the molecular structure. These findings corroborate the structural modifications expected upon the formation of the selenium-NHC adducts and provide strong evidence for the successful synthesis of the target compounds.\u003c/p\u003e \u003cp\u003eAdditionally, \u003csup\u003e1\u003c/sup\u003eH and \u003csup\u003e13\u003c/sup\u003eC NMR spectra of salts (\u003cb\u003e2a-e\u003c/b\u003e) and Se-NHC adducts (\u003cb\u003e3a-e\u003c/b\u003e) were recorded in deuterated chloroform, considering their solubility characteristics. The \u003csup\u003e1\u003c/sup\u003eH NMR spectra of the benzimidazolium salts (2a\u0026ndash;e) showed characteristic signals confirming the presence of key structural features. The highly deshielded NC\u003cspan type=\"Underline\" class=\"Underline\" name=\"Emphasis\"\u003eH\u003c/span\u003eN proton (the acidic proton C2-H of the benzimidazole ring) appeared as a singlet between δ 9.20\u0026ndash;11.06 ppm, with variations attributed to electronic effects from different substituents, indicating salt formation. Aromatic protons of the benzimidazole core and appended phenyl rings resonated as multiplets and doublets between δ\u0026thinsp;=\u0026thinsp;7.06\u0026ndash;8.33 ppm, with coupling constants in the range of \u003cem\u003eJ\u003c/em\u003e\u0026thinsp;=\u0026thinsp;2.1\u0026ndash;7.5 Hz and \u003cem\u003eJ\u003c/em\u003e\u0026thinsp;=\u0026thinsp;2.1\u0026ndash;7.5Hz. In salt 2a, the Ph-CH-Ph proton appeared as a singlet at δ 5.72 ppm, while substituent-specific signals, such as piperidine CH\u003csub\u003e2\u003c/sub\u003e groups, were observed as broad singlets in the δ\u0026thinsp;=\u0026thinsp;4.70\u0026ndash;4.57 ppm range. Benzylic CH\u003csub\u003e2\u003c/sub\u003e protons attached to the benzimidazole nitrogen resonated at δ\u0026thinsp;=\u0026thinsp;2.70\u0026ndash;2.52 ppm, whereas the piperidine CH\u003csub\u003e2\u003c/sub\u003e -N-CH\u003csub\u003e2\u003c/sub\u003e methylene protons appeared as broad singlets between δ\u0026thinsp;=\u0026thinsp;2.40\u0026ndash;2.13 ppm. Aliphatic regions also displayed signals from CH\u003csub\u003e2\u003c/sub\u003e, CH\u003csub\u003e3\u003c/sub\u003e, and tert-butyl groups between δ\u0026thinsp;=\u0026thinsp;1.39\u0026ndash;1.11 ppm, indicating the presence of bulky substituents. For salts with isopropyl groups, such as 2c, distinct methyl singlets were observed at δ 1.06 and 1.04 ppm.\u003c/p\u003e \u003cp\u003eIn the selenium-NHC adducts (3a\u0026ndash;e), the disappearance of the NC\u003cspan type=\"Underline\" class=\"Underline\" name=\"Emphasis\"\u003eH\u003c/span\u003eN proton from δ\u0026thinsp;=\u0026thinsp;9.20\u0026ndash;11.06 ppm confirmed carbene formation and coordination with selenium. The aromatic protons of the benzimidazole framework and substituent phenyl rings resonated between δ\u0026thinsp;=\u0026thinsp;6.73\u0026ndash;8.24 ppm, with multiplets and doublets reflecting minor shifts compared to their precursors. Signals for substituents, such as piperidine CH\u003csub\u003e2\u003c/sub\u003e groups, appeared as broad singlets in the δ\u0026thinsp;=\u0026thinsp;4.69\u0026ndash;4.50 ppm range, while CH\u003csub\u003e2\u003c/sub\u003e-N(benzimidazole) protons were observed between δ\u0026thinsp;=\u0026thinsp;2.85\u0026ndash;2.68 ppm. Aliphatic CH\u003csub\u003e2\u003c/sub\u003e, CH\u003csub\u003e3\u003c/sub\u003e, and isopropyl protons remained in their expected ranges, with notable singlets for CH\u003csub\u003e3\u003c/sub\u003e groups near δ\u0026thinsp;=\u0026thinsp;1.05 ppm and broad singlets for piperidine CH\u003csub\u003e2\u003c/sub\u003e protons at δ\u0026thinsp;=\u0026thinsp;1.67\u0026ndash;1.37 ppm. Overall, the formation of the selenium-NHC bond is evidenced by the absence of the deshielded NCHN proton, while the integrity of aromatic and aliphatic substituents is maintained, as shown by consistent chemical shifts.\u003c/p\u003e \u003cp\u003eThe \u003csup\u003e13\u003c/sup\u003eC NMR analysis of the benzimidazolium salts (\u003cb\u003e2a-e\u003c/b\u003e) revealed characteristic peaks that confirm their structures. The highly deshielded N\u003cspan type=\"Underline\" class=\"Underline\" name=\"Emphasis\"\u003eC\u003c/span\u003eHN carbons (C2 of the benzimidazole core) appeared consistently in the range of δ\u0026thinsp;=\u0026thinsp;142\u0026ndash;143 ppm, while quaternary aromatic carbons resonated around δ\u0026thinsp;=\u0026thinsp;136\u0026ndash;139 ppm. The aromatic CH carbons were observed between δ\u0026thinsp;=\u0026thinsp;114\u0026ndash;132 ppm, indicative of the benzimidazole framework. Aliphatic carbons from substituents, such as piperidine, benzyl, and tert-butyl groups, appeared in their expected regions: δ\u0026thinsp;=\u0026thinsp;44\u0026ndash;76 ppm for methylene carbons and δ\u0026thinsp;=\u0026thinsp;22\u0026ndash;37 ppm for alkyl chains or methyl groups. For example, \u003cspan type=\"Underline\" class=\"Underline\" name=\"Emphasis\"\u003eC\u003c/span\u003eH\u003csub\u003e2\u003c/sub\u003e-N(piperidine) groups consistently appeared at δ\u0026thinsp;=\u0026thinsp;54\u0026ndash;56 ppm, while the CH\u003csub\u003e2\u003c/sub\u003e-N(benzimidazole) carbons were slightly downfield at δ\u0026thinsp;=\u0026thinsp;44\u0026ndash;45 ppm, reflecting the electron-withdrawing effect of the nitrogen atom. Substituent effects were evident, with benzylic CH\u003csub\u003e2\u003c/sub\u003e carbons resonating at δ\u0026thinsp;=\u0026thinsp;65\u0026ndash;71 ppm and tert-butyl quaternary carbons around δ\u0026thinsp;=\u0026thinsp;34\u0026ndash;37 ppm. Notable variations in chemical shifts were observed depending on the substituents, particularly in the aliphatic region. For the selenium-NHC adducts (\u003cb\u003e3a-e\u003c/b\u003e), the formation of the carbene-selenium bond was confirmed by the appearance of a characteristic C\u0026thinsp;=\u0026thinsp;Se peak in the range of δ\u0026thinsp;=\u0026thinsp;165\u0026ndash;167 ppm, alongside a downfield shift of the N\u003cspan type=\"Underline\" class=\"Underline\" name=\"Emphasis\"\u003eC\u003c/span\u003eHN carbon from δ 142\u0026ndash;143 ppm in the benzimidazolium salts to δ\u0026thinsp;=\u0026thinsp;150\u0026ndash;152 ppm in the adducts. These shifts are consistent with the strong deshielding effect of selenium coordination. The aromatic carbons in the benzimidazole framework remained largely unchanged, resonating between δ\u0026thinsp;=\u0026thinsp;110\u0026ndash;135 ppm, highlighting the preservation of the core structure. Similarly, aliphatic carbons, such as those from piperidine substituents, were observed in their expected regions (e.g., δ\u0026thinsp;=\u0026thinsp;44\u0026ndash;56 ppm for CH\u003csub\u003e2\u003c/sub\u003e groups), indicating minimal structural perturbation in the substituent environment upon adduct formation. Substituents such as tert-butyl or methyl groups caused slight shielding of adjacent carbons, leading to subtle upfield shifts. Overall, the selenium coordination is clearly reflected in the downfield shifts of the carbene carbon and the appearance of the C\u0026thinsp;=\u0026thinsp;Se signal, while the substituent effects and core structural integrity were corroborated by consistent chemical shifts across aromatic and aliphatic regions.\u003c/p\u003e \u003cp\u003eThe mass spectrometry (HRMS-ESI) results provided detailed insights into the molecular weights of the synthesized benzimidazolium salts and selenium-NHC adducts. For the benzimidazolium salts (\u003cb\u003e2a-e\u003c/b\u003e), the calculated [M\u0026thinsp;+\u0026thinsp;H]\u003csup\u003e+\u003c/sup\u003e values were as follows: m/z\u0026thinsp;=\u0026thinsp;396.2434 (\u003cb\u003e2a\u003c/b\u003e), 432.3373 (\u003cb\u003e2b\u003c/b\u003e), 300.2434 (\u003cb\u003e2c\u003c/b\u003e), 350.2227 (\u003cb\u003e2d\u003c/b\u003e), and m/z\u0026thinsp;=\u0026thinsp;348.2434 (\u003cb\u003e2e\u003c/b\u003e), with corresponding found values of m/z\u0026thinsp;=\u0026thinsp;396.2411, 432.3308, 300.2414, 350.2206, and m/z\u0026thinsp;=\u0026thinsp;348.2414, respectively. These findings closely matched the theoretical values, confirming the accurate molecular weights of the synthesized salts. Similarly, the Selenium-NHC adducts (\u003cb\u003e3a-e\u003c/b\u003e) exhibited calculated [M\u0026thinsp;+\u0026thinsp;H]\u003csup\u003e+\u003c/sup\u003e values of m/z\u0026thinsp;=\u0026thinsp;475.1527 (\u003cb\u003e3a\u003c/b\u003e), 511.2466 (\u003cb\u003e3b\u003c/b\u003e), 379.1527 (\u003cb\u003e3c\u003c/b\u003e), 429.1319 (\u003cb\u003e3d\u003c/b\u003e), and m/z\u0026thinsp;=\u0026thinsp;427.1527 (\u003cb\u003e3e\u003c/b\u003e). The experimental mass spectra revealed found values of m/z\u0026thinsp;=\u0026thinsp;476.1544, 512.2465, 380.1554, 430.13477, and m/z\u0026thinsp;=\u0026thinsp;428.1549, respectively. These results confirmed the successful formation of the selenium-NHC adducts with good agreement between the calculated and observed molecular weights. The accurate determination of molecular weights through mass spectrometry underscored the precision and reliability of the synthetic methods employed. These data provide essential confirmation of the chemical identities and purity of both the benzimidazolium salts and selenium-NHC adducts, essential for further investigations into their properties and potential applications.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec23\" class=\"Section2\"\u003e \u003ch2\u003e3.2 Biological evaluation\u003c/h2\u003e \u003cp\u003eThe synthesized benzimidazolium salts (\u003cb\u003e2a-e\u003c/b\u003e) and their selenium\u0026ndash;NHC adducts \u003cb\u003e(3a-e\u003c/b\u003e) were tested for antifungal and antimicrobial activities against a variety of bacteria and yeasts. \u003cem\u003eCaspofungin\u003c/em\u003e served as the control for yeast testing, and Ampicillin was used as the control for bacteria. The inhibition zone values and IC50 values for the benzimidazolium salts and their corresponding selenium-NHC adducts, in comparison to the reference antimicrobial agents, are detailed in the provided Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e and Table\u0026nbsp;\u003cspan refid=\"Tab4\" class=\"InternalRef\"\u003e4\u003c/span\u003e respectively.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab3\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 3\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eAntifungal and antibacterial inhibition zone values.\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"7\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"2\" morerows=\"1\" nameend=\"c2\" namest=\"c1\" rowspan=\"2\"\u003e \u003cp\u003eCompounds\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c4\" namest=\"c3\"\u003e \u003cp\u003e\u003cem\u003eAnti-Fungal\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c7\" namest=\"c5\"\u003e \u003cp\u003e\u003cem\u003eAnti-Bacterial\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u003cem\u003eC.\u003c/em\u003e\u003c/p\u003e \u003cp\u003e\u003cem\u003ealbicans\u003c/em\u003e\u003csup\u003e\u003cem\u003ea\u003c/em\u003e\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u003cem\u003eC.\u003c/em\u003e\u003c/p\u003e \u003cp\u003e\u003cem\u003eglabrata\u003c/em\u003e\u003csup\u003e\u003cem\u003ea\u003c/em\u003e\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u003cem\u003eE. coli\u003c/em\u003e\u003csup\u003e\u003cem\u003ea\u003c/em\u003e\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e\u003cem\u003eP. aeruginosa\u003c/em\u003e\u003csup\u003e\u003cem\u003ea\u003c/em\u003e\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e\u003cem\u003eS. aureus\u003c/em\u003e\u003csup\u003e\u003cem\u003ea\u003c/em\u003e\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"4\" rowspan=\"5\"\u003e \u003cp\u003e\u003cb\u003eBenzimida-zolium\u003c/b\u003e\u003c/p\u003e \u003cp\u003e\u003cb\u003eSalts\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003e2a\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e15,17\u0026thinsp;\u0026plusmn;\u0026thinsp;0,24\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e14,67\u0026thinsp;\u0026plusmn;\u0026thinsp;0,40\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e11,97\u0026thinsp;\u0026plusmn;\u0026thinsp;0,12\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e10,27\u0026thinsp;\u0026plusmn;\u0026thinsp;0,17\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e20,75\u0026thinsp;\u0026plusmn;\u0026thinsp;0,35\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003e2b\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e7,45\u0026thinsp;\u0026plusmn;\u0026thinsp;0,07\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e8,13\u0026thinsp;\u0026plusmn;\u0026thinsp;0,11\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e11,70\u0026thinsp;\u0026plusmn;\u0026thinsp;0,22\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e7,13\u0026thinsp;\u0026plusmn;\u0026thinsp;0,25\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e20,40\u0026thinsp;\u0026plusmn;\u0026thinsp;0,43\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003e2c\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e8,93\u0026thinsp;\u0026plusmn;\u0026thinsp;0,09\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e9,12\u0026thinsp;\u0026plusmn;\u0026thinsp;0,21\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e12,28\u0026thinsp;\u0026plusmn;\u0026thinsp;0,26\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eNA\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e23,75\u0026thinsp;\u0026plusmn;\u0026thinsp;0,25\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003e2d\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e8,08\u0026thinsp;\u0026plusmn;\u0026thinsp;0,06\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e7,28\u0026thinsp;\u0026plusmn;\u0026thinsp;0,15\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e12,70\u0026thinsp;\u0026plusmn;\u0026thinsp;0,57\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e6,67\u0026thinsp;\u0026plusmn;\u0026thinsp;0,09\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e19,43\u0026thinsp;\u0026plusmn;\u0026thinsp;0,74\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003e2e\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e12,15\u0026thinsp;\u0026plusmn;\u0026thinsp;0,15\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e8,83\u0026thinsp;\u0026plusmn;\u0026thinsp;0,12\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e13,44\u0026thinsp;\u0026plusmn;\u0026thinsp;0,10\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e12,17\u0026thinsp;\u0026plusmn;\u0026thinsp;0,05\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e27,05\u0026thinsp;\u0026plusmn;\u0026thinsp;0,19\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"4\" rowspan=\"5\"\u003e \u003cp\u003e\u003cb\u003eSelenium-NHC\u003c/b\u003e\u003c/p\u003e \u003cp\u003e\u003cb\u003ecomplexes\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003e3a\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eNA\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eNA\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eNA\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eNA\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003eNA\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003e3b\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e10,00\u0026thinsp;\u0026plusmn;\u0026thinsp;0,41\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e10,57\u0026thinsp;\u0026plusmn;\u0026thinsp;0,51\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eNA\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eNA\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e8,63\u0026thinsp;\u0026plusmn;\u0026thinsp;0,39\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003e3c\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e8,57\u0026thinsp;\u0026plusmn;\u0026thinsp;0,31\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eNA\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eNA\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eNA\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e8,88\u0026thinsp;\u0026plusmn;\u0026thinsp;0,19\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003e3d\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e10,13\u0026thinsp;\u0026plusmn;\u0026thinsp;0,10\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e8,99\u0026thinsp;\u0026plusmn;\u0026thinsp;0,07\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eNA\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eNA\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003eNA\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003e3e\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e11,70\u0026thinsp;\u0026plusmn;\u0026thinsp;0,16\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e9,15\u0026thinsp;\u0026plusmn;\u0026thinsp;0,08\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eNA\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eNA\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e11,77\u0026thinsp;\u0026plusmn;\u0026thinsp;0,17\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003eAmpicillin\u003c/b\u003e\u003csup\u003e\u003cb\u003eb\u003c/b\u003e\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e14,27\u0026thinsp;\u0026plusmn;\u0026thinsp;0,61\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e12,43\u0026thinsp;\u0026plusmn;\u0026thinsp;0,42\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e15,33\u0026thinsp;\u0026plusmn;\u0026thinsp;0,21\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003eCaspofungin\u003c/b\u003e \u003csup\u003e\u003cb\u003eb\u003c/b\u003e\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e14,30\u0026thinsp;\u0026plusmn;\u0026thinsp;0,15\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e20,57\u0026thinsp;\u0026plusmn;\u0026thinsp;0,61\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"7\"\u003e\u003csup\u003ea\u003c/sup\u003e: Tested microorganism\u003c/td\u003e\u003c/tr\u003e \u003ctr\u003e\u003ctd colspan=\"7\"\u003e\u003csup\u003eb\u003c/sup\u003e: Reference drugs\u003c/td\u003e\u003c/tr\u003e \u003ctr\u003e\u003ctd colspan=\"7\"\u003eNA: Not Active (no inhibition zone)\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eBased on the inhibition zone measurements, the synthesized benzimidazolium salts \u003cb\u003e2a-e\u003c/b\u003e and selenium-NHC adducts \u003cb\u003e3a-e\u003c/b\u003e exhibited varying degrees of antimicrobial and antifungal activities against the tested microorganisms.\u003c/p\u003e \u003cp\u003eFor \u003cem\u003eCandida albicans\u003c/em\u003e, the reference \u003cem\u003eCaspofungin\u003c/em\u003e displayed an inhibition zone of 14.30\u0026thinsp;\u0026plusmn;\u0026thinsp;0.15 mm. Among the benzimidazolium salts, compound \u003cb\u003e2a\u003c/b\u003e showed the highest inhibition with a zone of 15.17\u0026thinsp;\u0026plusmn;\u0026thinsp;0.24 mm, indicating a significant antifungal effect. The other benzimidazolium salts showed lower inhibition zones: \u003cb\u003e2b\u003c/b\u003e (7.45\u0026thinsp;\u0026plusmn;\u0026thinsp;0.07 mm), \u003cb\u003e2c\u003c/b\u003e (8.93\u0026thinsp;\u0026plusmn;\u0026thinsp;0.09 mm), \u003cb\u003e2d\u003c/b\u003e (8.08\u0026thinsp;\u0026plusmn;\u0026thinsp;0.06 mm), and \u003cb\u003e2e\u003c/b\u003e (12.15\u0026thinsp;\u0026plusmn;\u0026thinsp;0.15 mm). In contrast, the selenium-NHC adducts demonstrated moderate antifungal activity, with \u003cb\u003e3e\u003c/b\u003e (11.70\u0026thinsp;\u0026plusmn;\u0026thinsp;0.16 mm) being the most effective, followed by \u003cb\u003e3b\u003c/b\u003e (10.00\u0026thinsp;\u0026plusmn;\u0026thinsp;0.41 mm), 3d (10.13\u0026thinsp;\u0026plusmn;\u0026thinsp;0.10 mm), and \u003cb\u003e3c\u003c/b\u003e (8.57\u0026thinsp;\u0026plusmn;\u0026thinsp;0.31 mm). Complex 3a showed no activity.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab4\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 4\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eAntifungal and antibacterial IC50 values.\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"7\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"2\" morerows=\"1\" nameend=\"c2\" namest=\"c1\" rowspan=\"2\"\u003e \u003cp\u003eCompounds\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c4\" namest=\"c3\"\u003e \u003cp\u003e\u003cem\u003eAnti-Fungal\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c7\" namest=\"c5\"\u003e \u003cp\u003e\u003cem\u003eAnti-Bacterial\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u003cem\u003eC.\u003c/em\u003e\u003c/p\u003e \u003cp\u003e\u003cem\u003ealbicans\u003c/em\u003e\u003csup\u003e\u003cem\u003ea\u003c/em\u003e\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u003cem\u003eC.\u003c/em\u003e\u003c/p\u003e \u003cp\u003e\u003cem\u003eglabrata\u003c/em\u003e\u003csup\u003e\u003cem\u003ea\u003c/em\u003e\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u003cem\u003eE. coli\u003c/em\u003e\u003csup\u003e\u003cem\u003ea\u003c/em\u003e\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e\u003cem\u003eP. aeruginosa\u003c/em\u003e\u003csup\u003e\u003cem\u003ea\u003c/em\u003e\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e\u003cem\u003eS. aureus\u003c/em\u003e\u003csup\u003e\u003cem\u003ea\u003c/em\u003e\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"4\" rowspan=\"5\"\u003e \u003cp\u003e\u003cb\u003eBenzimida-zolium\u003c/b\u003e\u003c/p\u003e \u003cp\u003e\u003cb\u003eSalts\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003e2a\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e6,25\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e6,25\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e50\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e100\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e1,56\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003e2b\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e400\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e200\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e100\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e400\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e3,12\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003e2c\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e200\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e200\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e25\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e800\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0,8\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003e2d\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e200\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e400\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e25\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e800\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e3,12\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003e2e\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e25\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e200\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e12,5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e25\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0,8\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"4\" rowspan=\"5\"\u003e \u003cp\u003e\u003cb\u003eSelenium-NHC\u003c/b\u003e\u003c/p\u003e \u003cp\u003e\u003cb\u003ecomplexes\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003e3a\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e800\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e800\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e400\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e800\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e800\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003e3b\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e100\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e100\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e800\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e800\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e200\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003e3c\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e200\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e800\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eNA\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eNA\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e200\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003e3d\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e100\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e200\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e800\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eNA\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e400\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003e3e\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e50\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e100\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eNA\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e800\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e25\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003eAmpicillin\u003c/b\u003e\u003csup\u003e\u003cb\u003eb\u003c/b\u003e\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e6,25\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e100\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e1,56\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003eCaspofungin\u003c/b\u003e \u003csup\u003e\u003cb\u003eb\u003c/b\u003e\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e6,25\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1,56\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"7\"\u003e\u003csup\u003ea\u003c/sup\u003e: Tested microorganism\u003c/td\u003e\u003c/tr\u003e \u003ctr\u003e\u003ctd colspan=\"7\"\u003e\u003csup\u003eb\u003c/sup\u003e: Reference drugs\u003c/td\u003e\u003c/tr\u003e \u003ctr\u003e\u003ctd colspan=\"7\"\u003eNA: Not Active (IC50\u0026thinsp;\u0026gt;\u0026thinsp;800 \u0026micro;g/ml)\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eAgainst the pathogenic yeast \u003cem\u003eCandida albicans\u003c/em\u003e, among the benzimidazolium salts, \u003cb\u003e2a\u003c/b\u003e was found to be the most effective salt, with an IC\u003csub\u003e50\u003c/sub\u003e value of 6.25 \u0026micro;g/mL against \u003cem\u003eC. albicans\u003c/em\u003e yeast strain. This benzimidazolium salt exhibited antifungal activity with strong toxicity, comparable to the control group, Caspofungin, at the same IC\u003csub\u003e50\u003c/sub\u003e value. The other compounds showed varying activities as follows: \u003cb\u003e2e\u003c/b\u003e benzimidazolium salt had an IC\u003csub\u003e50\u003c/sub\u003e value of 25 \u0026micro;g/mL, \u003cb\u003e2c\u003c/b\u003e and \u003cb\u003e2d\u003c/b\u003e shared the same IC\u003csub\u003e50\u003c/sub\u003e value of 200 \u0026micro;g/mL, \u003cb\u003e2b\u003c/b\u003e exhibited an IC\u003csub\u003e50\u003c/sub\u003e value of 400 \u0026micro;g/mL. These compounds demonstrated lower antifungal activity with lower toxicity at higher doses. The most effective Se-NHC complex against \u003cem\u003eCandida albicans\u003c/em\u003e yeasts was the \u003cb\u003e3e\u003c/b\u003e complex, with an IC\u003csub\u003e50\u003c/sub\u003e value of 50 \u0026micro;g/mL. This value, being higher than the control group Caspofungin, exhibited relatively low toxicity and relatively low antifungal activity. The other Se-NHC adducts demonstrated the following activities: \u003cb\u003e3b\u003c/b\u003e and \u003cb\u003e3d\u003c/b\u003e complexes had an IC\u003csub\u003e50\u003c/sub\u003e value of 100 \u0026micro;g/mL, \u003cb\u003e3c\u003c/b\u003e complex exhibited an IC\u003csub\u003e50\u003c/sub\u003e value of 200 \u0026micro;g/mL, \u003cb\u003e3a\u003c/b\u003e complex showed an IC\u003csub\u003e50\u003c/sub\u003e value of 800 \u0026micro;g/mL. These higher IC\u003csub\u003e50\u003c/sub\u003e values indicated lower toxicity and weak antifungal activity.\u003c/p\u003e \u003cp\u003eIn the case of \u003cem\u003eCandida glabrata\u003c/em\u003e, the reference Caspofungin showed an inhibition zone of 20.57\u0026thinsp;\u0026plusmn;\u0026thinsp;0.61 mm. Among the benzimidazolium salts, compound \u003cb\u003e2a\u003c/b\u003e exhibited the highest activity with an inhibition zone of 14.67\u0026thinsp;\u0026plusmn;\u0026thinsp;0.40 mm. The other salts had lower activities: \u003cb\u003e2b\u003c/b\u003e (8.13\u0026thinsp;\u0026plusmn;\u0026thinsp;0.11 mm), \u003cb\u003e2c\u003c/b\u003e (9.12\u0026thinsp;\u0026plusmn;\u0026thinsp;0.21 mm), \u003cb\u003e2d\u003c/b\u003e (7.28\u0026thinsp;\u0026plusmn;\u0026thinsp;0.15 mm), and \u003cb\u003e2e\u003c/b\u003e (8.83\u0026thinsp;\u0026plusmn;\u0026thinsp;0.12 mm). Selenium-NHC adducts showed moderate inhibition, with \u003cb\u003e3b\u003c/b\u003e (10.57\u0026thinsp;\u0026plusmn;\u0026thinsp;0.51 mm) being the most effective, followed by \u003cb\u003e3d\u003c/b\u003e (8.99\u0026thinsp;\u0026plusmn;\u0026thinsp;0.07 mm) and \u003cb\u003e3e\u003c/b\u003e (9.15\u0026thinsp;\u0026plusmn;\u0026thinsp;0.08 mm). Compounds \u003cb\u003e3a\u003c/b\u003e and \u003cb\u003e3c\u003c/b\u003e showed no activity.\u003c/p\u003e \u003cp\u003eAgainst the pathogenic yeast \u003cem\u003eCandida glabrata\u003c/em\u003e, the \u003cb\u003e2a\u003c/b\u003e benzimidazolium salt was identified as the most effective salt with an IC\u003csub\u003e50\u003c/sub\u003e value of 6.25 \u0026micro;g/mL. The \u003cb\u003e2a\u003c/b\u003e benzimidazolium salt exhibited antifungal activity with relatively low toxicity, despite having a higher IC\u003csub\u003e50\u003c/sub\u003e value compared to the control group, Caspofungin.The other compounds demonstrated the following activities: \u003cb\u003e2b\u003c/b\u003e, \u003cb\u003e2c\u003c/b\u003e, and \u003cb\u003e2e\u003c/b\u003e had the same IC\u003csub\u003e50\u003c/sub\u003e value of 200 \u0026micro;g/mL, \u003cb\u003e2d\u003c/b\u003e had an IC\u003csub\u003e50\u003c/sub\u003e value of 400 \u0026micro;g/mL. These compounds displayed lower antifungal activity with reduced toxicity. The most effective Se-NHC complex against \u003cem\u003eC. glabrata\u003c/em\u003e was the \u003cb\u003e3e\u003c/b\u003e complex, with an IC\u003csub\u003e50\u003c/sub\u003e value of 50 \u0026micro;g/mL. This value, higher than that of the control group Caspofungin, indicated relatively low toxicity and moderate antifungal activity. The other Se-NHC adducts showed the following activities: \u003cb\u003e3b\u003c/b\u003e had an IC\u003csub\u003e50\u003c/sub\u003e value of 100 \u0026micro;g/mL, \u003cb\u003e3d\u003c/b\u003e had an IC\u003csub\u003e50\u003c/sub\u003e value of 200 \u0026micro;g/mL, \u003cb\u003e3a\u003c/b\u003e and \u003cb\u003e3c\u003c/b\u003e exhibited higher IC\u003csub\u003e50\u003c/sub\u003e values of 800 \u0026micro;g/mL, with lower toxicity and weak antifungal activity.\u003c/p\u003e \u003cp\u003eFor \u003cem\u003eEscherichia coli\u003c/em\u003e, the reference \u003cem\u003eAmpicillin\u003c/em\u003e showed an inhibition zone of 14.27\u0026thinsp;\u0026plusmn;\u0026thinsp;0.61 mm. Benzimidazolium salts displayed notable antibacterial activity, with compound \u003cb\u003e2e\u003c/b\u003e showing the highest inhibition zone of 13.44\u0026thinsp;\u0026plusmn;\u0026thinsp;0.10 mm. The other salts exhibited zones as follows: \u003cb\u003e2a\u003c/b\u003e (11.97\u0026thinsp;\u0026plusmn;\u0026thinsp;0.12 mm), \u003cb\u003e2b\u003c/b\u003e (11.70\u0026thinsp;\u0026plusmn;\u0026thinsp;0.22 mm), \u003cb\u003e2c\u003c/b\u003e (12.28\u0026thinsp;\u0026plusmn;\u0026thinsp;0.26 mm), and \u003cb\u003e2d\u003c/b\u003e (12.70\u0026thinsp;\u0026plusmn;\u0026thinsp;0.57 mm). The selenium-NHC adducts were ineffective against \u003cem\u003eE. coli\u003c/em\u003e, as all tested compounds (\u003cb\u003e3a-e\u003c/b\u003e) showed no activity.\u003c/p\u003e \u003cp\u003eAgainst \u003cem\u003eE. coli\u003c/em\u003e, the \u003cb\u003e2e\u003c/b\u003e benzimidazolium salt demonstrated the best activity, with an IC\u003csub\u003e50\u003c/sub\u003e value of 12.5 \u0026micro;g/mL. This value, being higher than that of the control group Ampicillin, exhibited relatively low toxicity and moderate antibacterial activity. The other benzimidazolium salts showed the following IC\u003csub\u003e50\u003c/sub\u003e values: \u003cb\u003e2c\u003c/b\u003e and \u003cb\u003e2d\u003c/b\u003e shared an IC\u003csub\u003e50\u003c/sub\u003e value of 25 \u0026micro;g/mL, \u003cb\u003e2a\u003c/b\u003e had an IC\u003csub\u003e50\u003c/sub\u003e value of 50 \u0026micro;g/mL, \u003cb\u003e2b\u003c/b\u003e exhibited an IC\u003csub\u003e50\u003c/sub\u003e value of 100 \u0026micro;g/mL. These compounds showed lower antibacterial activity with reduced toxicity. Among the Se-NHC complexes, the \u003cb\u003e3a\u003c/b\u003e complex showed the best activity against \u003cem\u003eE. coli\u003c/em\u003e, with an IC\u003csub\u003e50\u003c/sub\u003e value of 400 \u0026micro;g/mL. This value, higher than the control group Ampicillin, indicated low toxicity and weak antibacterial activity. The \u003cb\u003e3b\u003c/b\u003e and \u003cb\u003e3d\u003c/b\u003e Se-NHC complexes had IC\u003csub\u003e50\u003c/sub\u003e values of 800 \u0026micro;g/mL, displaying weak antibacterial activity with reduced toxicity. The \u003cb\u003e3c\u003c/b\u003e and \u003cb\u003e3e\u003c/b\u003e Se-NHC complexes showed no toxicity against E. coli.\u003c/p\u003e \u003cp\u003eAgainst \u003cem\u003ePseudomonas aeruginosa\u003c/em\u003e, the reference \u003cem\u003eAmpicillin\u003c/em\u003e exhibited an inhibition zone of 12.43\u0026thinsp;\u0026plusmn;\u0026thinsp;0.42 mm. The benzimidazolium salts showed some activity, with compound \u003cb\u003e2e\u003c/b\u003e displaying the highest inhibition zone of 12.17\u0026thinsp;\u0026plusmn;\u0026thinsp;0.05 mm. The other salts showed lower activity: \u003cb\u003e2a\u003c/b\u003e (10.27\u0026thinsp;\u0026plusmn;\u0026thinsp;0.17 mm), \u003cb\u003e2b\u003c/b\u003e (7.13\u0026thinsp;\u0026plusmn;\u0026thinsp;0.25 mm), \u003cb\u003e2d\u003c/b\u003e (6.67\u0026thinsp;\u0026plusmn;\u0026thinsp;0.09 mm), and \u003cb\u003e2c\u003c/b\u003e showed no activity. None of the selenium-NHC adducts (\u003cb\u003e3a-e\u003c/b\u003e) demonstrated significant activity against \u003cem\u003eP. aeruginosa\u003c/em\u003e. This may caused by presence of an outer membrane that acts as a permeability barrier, which can limit the uptake of selenium-NHC adducts or possessing efficient efflux pumps that can actively expel selenium-NHC adducts by \u003cem\u003eE.coli\u003c/em\u003e and \u003cem\u003eP. aeruginosa\u003c/em\u003e.\u003c/p\u003e \u003cp\u003eAgainst \u003cem\u003eP. aeruginosa\u003c/em\u003e, the \u003cb\u003e2e\u003c/b\u003e benzimidazolium salt exhibited the best activity, with an IC\u003csub\u003e50\u003c/sub\u003e value of 25 \u0026micro;g/mL. This value, although higher than the control group Ampicillin, demonstrated relatively low toxicity and moderate antibacterial activity. The other benzimidazolium salts showed the following IC\u003csub\u003e50\u003c/sub\u003e values: \u003cb\u003e2a\u003c/b\u003e had an IC\u003csub\u003e50\u003c/sub\u003e value of 100 \u0026micro;g/mL, \u003cb\u003e2b\u003c/b\u003e exhibited an IC\u003csub\u003e50\u003c/sub\u003e value of 400 \u0026micro;g/mL, \u003cb\u003e2c\u003c/b\u003e and \u003cb\u003e2d\u003c/b\u003e had IC\u003csub\u003e50\u003c/sub\u003e values of 800 \u0026micro;g/mL. These compounds displayed lower antibacterial activity with reduced toxicity. Among the Se-NHC adducts, the \u003cb\u003e3a\u003c/b\u003e, \u003cb\u003e3b\u003c/b\u003e, and \u003cb\u003e3e\u003c/b\u003e complexes showed IC\u003csub\u003e50\u003c/sub\u003e values of 800 \u0026micro;g/mL against \u003cem\u003eP. aeruginosa\u003c/em\u003e, indicating weak antibacterial activity with low toxicity. The \u003cb\u003e3c\u003c/b\u003e and \u003cb\u003e3d\u003c/b\u003e Se-NHC complexes exhibited no toxicity against \u003cem\u003eP. aeruginosa\u003c/em\u003e.\u003c/p\u003e \u003cp\u003eFor \u003cem\u003eStaphylococcus aureus\u003c/em\u003e, benzimidazolium salts showed strong antibacterial activity, with compound 2e exhibiting the highest inhibition zone of 27.05\u0026thinsp;\u0026plusmn;\u0026thinsp;0.19 mm. The other salts showed the following inhibition zones: \u003cb\u003e2a\u003c/b\u003e (20.75\u0026thinsp;\u0026plusmn;\u0026thinsp;0.35 mm), \u003cb\u003e2b\u003c/b\u003e (20.40\u0026thinsp;\u0026plusmn;\u0026thinsp;0.43 mm), \u003cb\u003e2c\u003c/b\u003e (23.75\u0026thinsp;\u0026plusmn;\u0026thinsp;0.25 mm), and \u003cb\u003e2d\u003c/b\u003e (19.43\u0026thinsp;\u0026plusmn;\u0026thinsp;0.74 mm). Selenium-NHC adducts showed much lower activity, with \u003cb\u003e3e\u003c/b\u003e (11.77\u0026thinsp;\u0026plusmn;\u0026thinsp;0.17 mm) being the most effective, followed by \u003cb\u003e3b\u003c/b\u003e (8.63\u0026thinsp;\u0026plusmn;\u0026thinsp;0.39 mm) and \u003cb\u003e3c\u003c/b\u003e (8.88\u0026thinsp;\u0026plusmn;\u0026thinsp;0.19 mm). Compounds \u003cb\u003e3a\u003c/b\u003e and \u003cb\u003e3d\u003c/b\u003e showed no activity.\u003c/p\u003e \u003cp\u003eAgainst \u003cem\u003eS. aureus\u003c/em\u003e, the \u003cb\u003e2c\u003c/b\u003e and \u003cb\u003e2e\u003c/b\u003e benzimidazolium salts demonstrated the best activity, with an IC\u003csub\u003e50\u003c/sub\u003e value of 0.8 \u0026micro;g/mL. These values, lower than the control group Ampicillin, indicated high toxicity and strong antibacterial activity. The 2a benzimidazolium salt showed an IC\u003csub\u003e50\u003c/sub\u003e value of 1.56 \u0026micro;g/mL, with toxicity comparable to the control drug. The \u003cb\u003e2b\u003c/b\u003e and \u003cb\u003e2d\u003c/b\u003e salts exhibited IC\u003csub\u003e50\u003c/sub\u003e values of 3.12 \u0026micro;g/mL, showing lower antibacterial activity with reduced toxicity compared to the control group. Among the Se-NHC complexes, the \u003cb\u003e3e\u003c/b\u003e complex displayed the best activity against S. aureus, with an IC\u003csub\u003e50\u003c/sub\u003e value of 25 \u0026micro;g/mL. This value, being higher than that of the control group Ampicillin, demonstrated low toxicity and weak antibacterial activity. The other Se-NHC adducts showed the following IC\u003csub\u003e50\u003c/sub\u003e values: \u003cb\u003e3b\u003c/b\u003e and \u003cb\u003e3c\u003c/b\u003e: 200 \u0026micro;g/mL, \u003cb\u003e3d\u003c/b\u003e: 400 \u0026micro;g/mL, \u003cb\u003e3a\u003c/b\u003e: 800 \u0026micro;g/mL. These higher IC\u003csub\u003e50\u003c/sub\u003e values reflected weaker antibacterial activity with reduced toxicity.\u003c/p\u003e \u003cp\u003eIn summary, benzimidazolium salts generally exhibited strong antimicrobial and antifungal activities across various strains, with compounds \u003cb\u003e2c\u003c/b\u003e and \u003cb\u003e2e\u003c/b\u003e consistently showing the highest activities. These compounds often outperformed the selenium-NHC adducts and the reference antimicrobial agents. The selenium-NHC adducts demonstrated moderate to low activity, with none surpassing the reference agents. The superior activity of benzimidazolium salts, particularly compounds \u003cb\u003e2c\u003c/b\u003e and \u003cb\u003e2e\u003c/b\u003e, suggests their potential as effective antimicrobial agents for further development.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec24\" class=\"Section2\"\u003e \u003ch2\u003e3.3 Molecular docking\u003c/h2\u003e \u003cp\u003eThe synthesized compounds \u003cb\u003e2a-e\u003c/b\u003e and \u003cb\u003e3a-e\u003c/b\u003e were evaluated for their binding affinities against DNA gyrase B (PDB ID: 1KZN) and CYP51 (PDB ID: 1EA1) using AutoDock Vina, with the binding energies presented in Table\u0026nbsp;\u003cspan refid=\"Tab5\" class=\"InternalRef\"\u003e5\u003c/span\u003e. Molecule \u003cb\u003e2a\u003c/b\u003e, which exhibited significant interactions with both targets, showed a binding energy of -8.1 kcal/mol against 1KZN and \u0026minus;\u0026thinsp;10.0 kcal/mol against 1EA1. These values suggest strong binding affinities, consistent with the detailed interaction analysis.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab5\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 5\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eAutodock Vina binding energies of the synthesized compound against 1KZN and 1EA1 in (kcal/mol).\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"4\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eCompounds\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eCode\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c4\" namest=\"c3\"\u003e \u003cp\u003eBinding affinity (kcal/mol)\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1KZN\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1EA1\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"4\" rowspan=\"5\"\u003e \u003cp\u003eBenzimidazolium\u003c/p\u003e \u003cp\u003eSalts 2a-e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2a\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-8.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e-10\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2b\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-7.9\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e-9.7\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2c\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e-7.7\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2d\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-7.7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e-8.9\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-7.8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e-8.5\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"4\" rowspan=\"5\"\u003e \u003cp\u003eSelenium-NHC complexes\u003c/p\u003e \u003cp\u003e3a-e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e3a\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-7.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e-10.2\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e3b\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-7.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e-8.9\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e3c\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-6.4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e-7.8\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e3d\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-7.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e-8.8\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e3e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-7.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e-9\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e \u003cp\u003eAmpicillin\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-7.2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e \u003cp\u003eCiprofloxacin\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e-7.2\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003e[a] Reference drugs.\u003c/p\u003e \u003cp\u003eAs shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e Molecule \u003cb\u003e2a\u003c/b\u003e exhibits several key interactions with DNA gyrase B enzyme, indicative of a stable and potentially inhibitory binding. The ligand forms carbon-hydrogen bonds with ASN46, ASP49, and GLU42, with bond lengths of approximately 3.40 \u0026Aring;, 3.02 \u0026Aring;, and 3.41 \u0026Aring;, respectively. These interactions involve the ligand acting as the hydrogen donor, contributing to the binding affinity through specific interactions with these amino acid residues. An electrostatic pi-anion interaction is observed between the ligand's pi-orbitals and the carboxylate group of GLU50 at a distance of about 3.55 \u0026Aring;. Hydrophobic interactions further enhance the ligand's binding stability, with pi-alkyl interactions occurring with ILE90 and ILE78, at distances of approximately 4.73 \u0026Aring;, 5.40 \u0026Aring;, and 5.03 \u0026Aring;.\u003c/p\u003e \u003cp\u003eOverall, these binding interactions suggest that \u003cb\u003e2a\u003c/b\u003e forms a stable complex with the enzyme, potentially leading to effective inhibition. The combination of hydrogen bonding, electrostatic, and hydrophobic interactions provides a comprehensive understanding of the \u003cb\u003e2a\u003c/b\u003e ligand's binding mechanism, supporting its potential as a therapeutic agent. These findings support the potential of this molecule as a promising candidate for further development as an antibacterial agent targeting DNA gyrase B in \u003cem\u003eE. coli\u003c/em\u003e.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eThe ligand \u003cb\u003e2a\u003c/b\u003e forms several key interactions with the enzyme CYP51 Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e. A carbon-hydrogen bond with GLN72 is observed, with a bond length of approximately 3.44 \u0026Aring;, where the ligand acts as the hydrogen donor. An electrostatic pi-cation interaction occurs between ARG96 and the ligand's aromatic system, at a distance of about 4.77 \u0026Aring;. Hydrophobic interactions include a pi-sigma interaction with ALA256 (around 3.99 \u0026Aring;), a pi-sulfur interaction with CYS394 (approximately 4.94 \u0026Aring;), and a pi-pi T-shaped interaction with TYR76 (about 4.88 \u0026Aring;). Additional alkyl and pi-alkyl interactions are seen with LEU324 (4.47 \u0026Aring;), MET79 (4.91 \u0026Aring;), LEU321 (4.98 \u0026Aring;), and ALA256 (4.10 \u0026Aring;). The interaction profile of 2a with CYP51 indicates multiple binding interactions that stabilize the complex. These interactions suggest that molecule 2a could effectively inhibit CYP51, supporting its observed antifungal activity and providing a basis for further optimization. Overall, the data from the docking studies and interaction analyses underscore the potential of these compounds, especially \u003cb\u003e2a\u003c/b\u003e, as antibacterial agents which is in agreement with the antibacterial assays against \u003cem\u003eE. colia\u003c/em\u003e and \u003cem\u003eP. aeruginosa\u003c/em\u003e. Further optimization and development of these molecules could lead to effective therapeutic options for treating infections caused by \u003cem\u003eE. coli\u003c/em\u003e and fungal pathogens.\u003c/p\u003e \u003c/div\u003e"},{"header":"4. CONCLUSION","content":"\u003cp\u003eThis study successfully synthesized a series of benzimidazolium salts (\u003cb\u003e2a-e\u003c/b\u003e) and selenium-NHC adducts (\u003cb\u003e3a-e\u003c/b\u003e). The resulting compounds exhibited satisfactory yields and demonstrated notable stability under humid and aerated conditions. Comprehensive characterization via FT-IR, \u0026sup1;H NMR, \u0026sup1;\u0026sup3;C NMR, and mass spectrometry confirmed their molecular structures and purity. Biological evaluations revealed that the benzimidazolium salts exhibited potent antimicrobial activities, particularly against Candida species and Staphylococcus aureus. Notably, compounds 2d and 2e showed the highest inhibition zones, outperforming the selenium-NHC adducts, which demonstrated moderate to low activity. This finding suggests that the structural characteristics of the benzimidazolium salts enhance their efficacy as antimicrobial agent. The molecular docking studies revealed that the synthesized compounds, particularly molecule 2a, have significant binding interactions with DNA gyrase B and CYP51, suggesting a potential mechanism for their antibacterial and antifungal activities. The strong binding energies and diverse interactions, including hydrogen bonds and hydrophobic contacts, indicate that these compounds could serve as effective inhibitors. The promising results with binding energies superior to reference drugs \u003cem\u003eAmpicillin\u003c/em\u003e and \u003cem\u003eCaspofungin\u003c/em\u003e underscore their potential for therapeutic development as dual-action antimicrobial agents. The enhanced biological activity of the benzimidazolium salts may be attributed to their structural features, although the exact mechanism requires further investigation. The promising IC\u003csub\u003e50\u003c/sub\u003e values and inhibition zones observed for specific compounds, combined with favorable docking results, suggest their potential for therapeutic development. Future studies should focus on elucidating the precise mechanisms underlying their activity, particularly for the benzimidazolium salts, and validating their efficacy in vivo to pave the way for the development of novel antimicrobial therapies.\u003c/p\u003e "},{"header":"Declarations","content":"\u003cp\u003e \u003ch2\u003eCONFLICT OF INTEREST\u003c/h2\u003e \u003cp\u003eThe authors declare that there are no conflicts of interest.\u003c/p\u003e \u003c/p\u003e\u003ch2\u003eACKNOWLEDGEMENTS\u003c/h2\u003e \u003cp\u003eThe authors greatly acknowledge financial support from the İn\u0026ouml;n\u0026uuml; University Research Fund (İ\u0026Uuml;-BAP: FBG-2021-2562) for this work.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eAltaf, A., Jamil, F., Yaqoob, M., Adnan Iqbal, M., Sadique, S., Manahil, S., Nasir Malik, S., Sohail Shoukat, U., khalid, M., Ullah Zia, S., Nadeem, H., \u0026amp; Tauseef Haider, M. (2025a). 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Anticancer metal-N-heterocyclic carbene complexes of gold, platinum and palladium. \u003cem\u003eCurrent Opinion in Chemical Biology\u003c/em\u003e, \u003cem\u003e43\u003c/em\u003e, 30\u0026ndash;36.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eZwolak, I., \u0026amp; Zaporowska, H. (2012). Selenium interactions and toxicity: a review: selenium interactions and toxicity. \u003cem\u003eCell Biology and Toxicology\u003c/em\u003e, \u003cem\u003e28\u003c/em\u003e, 31\u0026ndash;46.\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"},{"header":"Schemes","content":"\u003cp\u003eSchemes 1 and 2 are available in the Supplementary Files section\u003c/p\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"chemical-papers","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"chpa","sideBox":"Learn more about [Chemical Papers](http://link.springer.com/journal/11696)","snPcode":"11696","submissionUrl":"https://www.editorialmanager.com/CHPA/default.aspx","title":"Chemical Papers","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"Selenium, N-heterocyclic carbene, Benzimidazolium, Antimicrobial, Structure-activity, Docking","lastPublishedDoi":"10.21203/rs.3.rs-5034118/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-5034118/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eThe present work, describes the synthesis and antimicrobial evaluation of new selenium-NHC adducts (\u003cstrong\u003e3a-e) \u003c/strong\u003eand their corresponding benzimidazolium salts (\u003cstrong\u003e2a-e)\u003c/strong\u003e. Specific synthetic approaches were employed, resulting in compounds with satisfactory stability under humid and aerated conditions. Characterization by spectroscopic methods confirmed structural changes upon selenium incorporation. Biological evaluations revealed varying antimicrobial and antifungal activities among the synthesized compounds. The results indicated that the benzimidazolium salts exhibited significantly enhanced antimicrobial and antifungal activities compared to reference agents. For instance, compound 2a demonstrated an IC\u003csub\u003e50\u003c/sub\u003e value of 6.25 µg/mL against Candida albicans, which was comparable to the reference Caspofungin (6.25 µg/mL).\u003c/p\u003e\n\u003cp\u003eSimilarly, compound 2e demonstrated strong antibacterial activity against Staphylococcus aureus, with an IC\u003csub\u003e50\u003c/sub\u003e value of 0.8 µg/mL, significantly outperforming the reference Ampicillin (1.56 µg/mL). In contrast, the selenium-NHC adducts exhibited moderate to minimal activity, with compound 3e showing the highest IC\u003csub\u003e50\u003c/sub\u003e value of 25 µg/mL against Staphylococcus aureus, but failing to surpass the activity of the reference agent. To explore the potential mechanism of action, molecular docking studies were conducted against \u003cem\u003eE. coli\u003c/em\u003e DNA gyrase and CYP51. The molecular docking results demonstrate that synthesized compounds exhibit significant binding affinity against both enzymes, indicating antibacterial and antifungal potential. These binding affinities suggest that these molecules could be effective dual-action antimicrobial agents.\u003c/p\u003e","manuscriptTitle":"Exploring the Antimicrobial Potential of New Selenium- N-Heterocyclic Carbene Complexes and Their Benzimidazolium Salts: Synthesis, Characterization, Biological Evaluation, and Docking Insights","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2024-12-16 09:54:16","doi":"10.21203/rs.3.rs-5034118/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Accept","date":"2024-12-16T03:44:30+00:00","index":"","fulltext":""},{"type":"reviewerAgreed","content":"","date":"2024-12-11T14:35:22+00:00","index":0,"fulltext":""},{"type":"reviewersInvited","content":"","date":"2024-12-11T14:07:14+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2024-12-11T13:50:31+00:00","index":"","fulltext":""},{"type":"submitted","content":"Chemical Papers","date":"2024-12-10T08:53:44+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"chemical-papers","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"chpa","sideBox":"Learn more about [Chemical Papers](http://link.springer.com/journal/11696)","snPcode":"11696","submissionUrl":"https://www.editorialmanager.com/CHPA/default.aspx","title":"Chemical Papers","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false}}],"origin":"","ownerIdentity":"6bb7ed2b-b1c1-4576-a525-b08a3ba87fd9","owner":[],"postedDate":"December 16th, 2024","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[],"tags":[],"updatedAt":"2024-12-30T16:03:33+00:00","versionOfRecord":{"articleIdentity":"rs-5034118","link":"https://doi.org/10.1007/s11696-024-03866-9","journal":{"identity":"chemical-papers","isVorOnly":false,"title":"Chemical Papers"},"publishedOn":"2024-12-29 15:57:51","publishedOnDateReadable":"December 29th, 2024"},"versionCreatedAt":"2024-12-16 09:54:16","video":"","vorDoi":"10.1007/s11696-024-03866-9","vorDoiUrl":"https://doi.org/10.1007/s11696-024-03866-9","workflowStages":[]},"version":"v1","identity":"rs-5034118","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-5034118","identity":"rs-5034118","version":["v1"]},"buildId":"qtupq5eGEP_6zYnWcrvyt","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}