Green Synthesis and Characterization of Vanadium Oxide (V₂O₅) Nanoparticles Using Parmentiera cereifera Leaf Extract: A Sustainable Biogenic Route with Biomedical Implications

Green Synthesis and Characterization of Vanadium Oxide (V₂O₅) Nanoparticles Using Parmentiera cereifera Leaf Extract: A Sustainable Biogenic Route with Biomedical Implications | 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 Green Synthesis and Characterization of Vanadium Oxide (V₂O₅) Nanoparticles Using Parmentiera cereifera Leaf Extract: A Sustainable Biogenic Route with Biomedical Implications P. Naveen¹, Gopi Mamidi², A. Indira Priyadarsini This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8174388/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 12 You are reading this latest preprint version Abstract Background: Green nanotechnology offers a sustainable alternative to conventional synthesis of metal and metal-oxide nanomaterials by eliminating toxic reagents and reducing environmental burdens [ 1 – 3 ]. Vanadium pentoxide (V₂O₅) holds exceptional catalytic and biomedical potential, yet its green synthesis remains largely unexplored. Parmentiera cereifera —a phenolic and flavonoid-rich plant—has never been utilized for nanoparticle fabrication. This study reports the first biogenic synthesis of V₂O₅ nanoparticles using P. cereifera leaf extract, establishing an unexplored metal–plant system with biomedical relevance. To the best of our knowledge, no literature reports exist on vanadium nanoparticle synthesis using any Bignoniaceae species, highlighting the novelty of this work. Methods: The aqueous extract of P. cereifera was employed as a natural reducing and stabilizing agent for converting NH₄VO₃ into V₂O₅ nanoparticles at 70°C under near-neutral conditions. Characterization included UV–Vis, FTIR, XRD, SEM, TEM, EDX, and zeta potential analyses. Biological activities—α-amylase inhibition, MTT cytotoxicity, and antimicrobial assays—were evaluated using standard protocols [ 12 – 15 ]. Green metrics such as atom economy, energy consumption, and E-factor were assessed against sol–gel and hydrothermal methods [ 16 – 21 ]. Results: A distinct absorption band at ~ 320 nm and V–O/V = O FTIR peaks confirmed nanoparticle formation. XRD indicated the orthorhombic V₂O₅ phase (JCPDS 41-1426) with crystallite size of ~ 45 ± 5 nm. SEM/TEM showed quasi-spherical nanoparticles (20–60 nm), supported by a zeta potential of − 28.4 mV, indicating excellent colloidal stability. The nanoparticles demonstrated strong α-amylase inhibition (IC₅₀ ≈ 38.4 µg mL⁻¹), selective cytotoxicity toward A549 cancer cells, and broad-spectrum antimicrobial activity against Staphylococcus aureus , E. coli , and Candida albicans [ 31 – 34 ]. The dual bioactivity profile identified in this work has not been previously reported for any green-synthesized V₂O₅ system, indicating biomedical novelty. A > 60% reduction in chemical usage, reaction temperature, and energy demand confirmed high sustainability over conventional synthesis. Conclusions: This work identifies P. cereifera as a new biogenic resource for scalable V₂O₅ nanomaterial synthesis and introduces a reproducible pathway aligned with circular bioeconomy principles. The phytochemical-mediated mechanism produced structurally stable, functionally active nanoparticles with strong biomedical potential. Future work should involve molecular-level mechanistic studies, nanocomposite fabrication, and in vivo validation. Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 Figure 10 Figure 11 1. Introduction Nanotechnology has revolutionized modern materials science by enabling the controlled design of matter at the atomic and molecular scale, giving rise to structures with novel optical, catalytic, and electronic properties that are otherwise inaccessible at the bulk level [ 1 , 2 ]. Among various classes of nanomaterials, metal and metal oxide nanoparticles (NPs) are of particular interest due to their broad applicability in catalysis, sensing, environmental remediation, and healthcare [ 3 – 5 ]. However, most conventional synthesis strategies—such as chemical precipitation, sol–gel processing, and hydrothermal growth—rely on harsh chemical reagents, organic solvents, and high energy inputs [ 6 – 8 ]. These processes often yield secondary waste and toxic byproducts that are inconsistent with the principles of environmental sustainability. To overcome these challenges, green nanotechnology has emerged as an environmentally responsible approach emphasizing non-toxic reagents, low-temperature synthesis, and renewable biological resources [ 9 – 11 ]. In this context, plant-mediated synthesis represents one of the most promising subfields, using extracts rich in natural metabolites as multifunctional agents that simultaneously reduce and stabilize nanoparticles [ 12 – 14 ]. The method is attractive for its cost-effectiveness, scalability, and inherent biocompatibility, as it eliminates the need for hazardous reducing agents such as hydrazine or sodium borohydride [ 15 , 16 ].Plant extracts contain an abundance of phytochemicals —including polyphenols, flavonoids, alkaloids, terpenoids, saponins, and reducing sugars—that feature electron-donating functional groups such as hydroxyl (–OH), carboxyl (–COOH), and carbonyl (–C = O) moieties [ 17 – 19 ]. These groups donate electrons to metal ions, driving the reduction process, and subsequently act as capping ligands , preventing nanoparticle agglomeration [ 20 , 21 ]. The resulting nanoparticles are surface-functionalized with biomolecular coatings that enhance aqueous stability, biocompatibility, and biological performance [ 22 , 23 ]. 1.1. Vanadium oxide nanoparticles and their significance Among transition metal oxides, vanadium oxides (V₂O₅, VO₂, V₂O₃) occupy a unique position due to their multiple oxidation states (V³⁺/V⁴⁺/V⁵⁺) and pronounced redox reversibility [ 24 – 26 ]. Vanadium pentoxide (V₂O₅) , in particular, crystallizes in an orthorhombic layered structure composed of VO₅ square pyramids sharing corners and edges, resulting in anisotropic electronic and ionic transport properties [ 27 ]. This structure makes V₂O₅ a versatile material with demonstrated performance in catalysis , lithium-ion batteries , electrochromic devices , and gas sensors [ 28 – 30 ]. Recent research has also revealed promising biological properties of vanadium-based materials, such as antidiabetic , anticancer , antioxidant , and antimicrobial effects [ 31 – 34 ]. Vanadium ions exhibit insulin-mimetic behavior, enhancing glucose uptake and glycogen synthesis in muscle cells [ 35 ]. At the cellular level, V₂O₅ nanoparticles are known to generate reactive oxygen species (ROS) , disrupt mitochondrial function, and induce apoptosis in cancer cells [ 36 – 38 ]. These dual catalytic and biomedical attributes make vanadium oxides uniquely suited for multifunctional nanomaterial platforms [ 39 , 40 ]. Despite their potential, the chemical synthesis of V₂O₅ typically involves high-temperature calcination, concentrated acids, or organic solvents, which compromise product safety for biomedical use and generate hazardous waste [ 41 , 42 ]. To realize the full potential of V₂O₅ nanoparticles in sustainable applications, it is imperative to develop green synthesis routes that utilize renewable plant biomolecules as reducing and stabilizing agents [ 43 – 45 ]. 1.2. Parmentiera cereifera as an untapped biogenic resource Parmentiera cereifera Seem. (family Bignoniaceae), commonly called the Candle Tree, is a perennial tropical species native to Central America and now cultivated widely across humid regions. Phytochemical screening of its leaves and fruits reveals a rich composition of phenolic acids (gallic, caffeic, ferulic) , flavonoids (quercetin, rutin, catechin) , tannins , terpenoids , and saponins —molecules that exhibit strong antioxidant and reducing capacities [ 46 – 49 ]. These compounds readily donate electrons from hydroxyl and carbonyl groups, making the plant extract a potent bio-reducing system for metal ions under ambient conditions. The presence of these phytochemicals also imparts antioxidant and antimicrobial functionality to the resulting nanostructures, supporting applications in nanomedicine and environmental remediation [ 50 – 52 ]. Despite this favorable chemistry, P. cereifera has never been reported as a plant source for nanoparticle synthesis, making it a scientifically intriguing and ecologically valuable biomass candidate for green nanotechnology. Its aqueous extractability, high phytochemical yield, and abundance in tropical regions provide an opportunity for low-cost, renewable nanomaterial production. 1.3. Rationale and Novelty of the Present Work Although several medicinal and aromatic plants—such as Azadirachta indica , Aloe vera , and Moringa oleifera —have been successfully utilized for the biosynthesis of metallic and metal-oxide nanoparticles [ 53 – 55 ], studies on vanadium-based nanostructures remain limited , and none have employed Parmentiera cereifera for such synthesis. This research represents the first report on the green synthesis of vanadium oxide (V₂O₅) nanoparticles using aqueous leaf extract of P. cereifera . The novelty and scientific contribution of this study can be summarized as follows: Unexplored Biomass Source : P. cereifera is introduced for the first time as a biofactory for nanomaterial synthesis , exploiting its rich matrix of phenolics, flavonoids, and terpenoids for vanadium reduction and stabilization. New Metal–Plant System : The combination of P. cereifera phytochemicals and vanadium precursor (NH₄VO₃) yields a unique biogenic V₂O₅ system that operates under neutral pH and low temperature (~ 70°C) without chemical surfactants. Mechanistic Elucidation : The work proposes a mechanistic model explaining how specific functional groups (–OH, –COOH, –C = O) donate electrons to VO₃⁻ ions, initiating reduction and promoting nucleation of orthorhombic V₂O₅ nanoparticles. Sustainability Integration : The study quantitatively evaluates energy efficiency, E-factor, atom economy , and carbon emission reduction , establishing clear sustainability metrics compared with conventional hydrothermal and sol–gel synthesis. Functional Validation : The synthesized nanoparticles were tested for α-amylase inhibition , anticancer activity , and antimicrobial efficacy , demonstrating the dual functional and biomedical relevance of the biogenic V₂O₅ material. This multi-dimensional novelty integrates green chemistry , biomass valorization , and functional material design , thereby positioning P. cereifera as a new and sustainable resource in the expanding domain of biogenic transition-metal nanomaterials . 1.4. Objective of the Study The present study aims to: develop an eco-friendly route for synthesizing V₂O₅ nanoparticles using aqueous leaf extract of P. cereifera ; perform comprehensive physicochemical characterization (UV–Vis, FTIR, XRD, SEM, TEM, EDX, and zeta potential analyses); elucidate the phytochemical reduction mechanism; assess representative biological activities (antidiabetic, anticancer, antimicrobial); and evaluate the environmental sustainability of the process in comparison with conventional methods. Through this integrated approach, the study not only introduces P. cereifera as a novel nanobiotechnological resource but also reinforces the principles of circular bioeconomy and green materials innovation. 2. Materials and Methods 2.1. Chemicals and reagents Ammonium metavanadate (NH₄VO₃, ≥ 99.5%), dinitrosalicylic acid (DNS), α-amylase (porcine pancreas, EC 3.2.1.1), starch (soluble), acarbose (≥ 98%), 3-(4,5-dimethyl-thiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), dimethyl sulfoxide (DMSO), ciprofloxacin, and fluconazole were procured from Sigma-Aldrich (USA). All solvents were of analytical grade (Merck, India) and used without further purification. Nutrient agar (NA) and Sabouraud dextrose agar (SDA) media were purchased from HiMedia, Mumbai. Deionized (DI) water (18.2 MΩ cm) was used throughout all preparations. Microbial strains Staphylococcus aureus (ATCC 25923), Escherichia coli (ATCC 25922), and Candida albicans (ATCC 10231) were obtained from the Microbial Type Culture Collection (MTCC), Chandigarh. Human lung adenocarcinoma (A549) and embryonic kidney (HEK-293) cell lines were sourced from the National Centre for Cell Science (NCCS), Pune, India. 2.2. Collection and Authentication of Plant Material Fresh, mature leaves of Parmentiera cereifera Seem. were collected from cultivated specimens growing in an authenticated botanical garden during July 2025, corresponding to the active vegetative phase. The species, originally native to Central America and now widely cultivated in tropical regions, was selected due to its high phytochemical richness and reported antioxidant potential. The collected material was taxonomically identified and authenticated by a qualified botanist. A voucher specimen (No. PC-2025-01) was prepared and deposited in the departmental herbarium of the host institution for future reference. After collection, the leaves were washed thoroughly with running tap water followed by deionized (DI) water to remove impurities. The cleaned leaves were shade-dried at 28 ± 2°C for ten days, pulverized using a stainless-steel grinder, and stored in airtight amber containers at 4°C until extraction. 2.3. Preparation of aqueous leaf extract Ten grams of the powdered leaf material were mixed with 200 mL of DI water in a 500 mL Erlenmeyer flask and heated at 80°C for 2 h under continuous stirring (400 rpm). After cooling to room temperature, the mixture was filtered through Whatman No. 1 paper followed by 0.45 µm membrane filtration. The filtrate was stored at 4°C for further use. The pH of the extract was 6.8 ± 0.1. Phytochemical screening confirmed the presence of phenolics, flavonoids, tannins, saponins, and terpenoids following standard qualitative assays [ 2 ]. Total phenolic content (TPC) was quantified by the Folin–Ciocalteu method and expressed as mg gallic acid equivalents (GAE) g⁻¹ extract [ 3 ]; total flavonoid content (TFC) was determined by the aluminium chloride method and expressed as mg quercetin equivalents g⁻¹ extract [ 4 ]. The high phenolic and flavonoid contents indicated strong reducing potential of the extract. 2.4. Green synthesis of V₂O₅ nanoparticles A 0.04 M aqueous solution of ammonium metavanadate (NH₄VO₃) was freshly prepared as the vanadium precursor. Equal volumes (50 mL each) of the NH₄VO₃ solution and the P. cereifera leaf extract were mixed in a 250 mL round-bottom flask. The initial pH of the reaction mixture was 7.1 ± 0.1, corresponding to the near-neutral pH of the extract. Preliminary optimization experiments revealed that nanoparticle formation was most efficient under slightly neutral to mildly alkaline conditions (pH 7–8). Under highly acidic conditions, incomplete reduction of vanadate species occurred, whereas strongly alkaline pH (> 9) led to rapid precipitation and particle aggregation. The reaction mixture was magnetically stirred at 70 ± 2°C for 90 min. During the reaction, the color gradually changed from pale yellow to deep orange and finally to reddish-brown, signifying the reduction of vanadate ions (VO₃⁻ → V₂O₅ NPs) by phytochemical electron donors present in the extract [ 5 , 6 ]. The final pH after completion of the reaction decreased slightly to 6.8 ± 0.1, indicating proton consumption during reduction and complexation processes. After cooling, the reaction suspension was centrifuged at 10 000 rpm for 15 min to separate the nanoparticle pellet. The pellet was washed twice with deionized water and once with ethanol to remove unbound organic residues. The washed product was dried in a hot-air oven at 80°C overnight, yielding a fine brown powder corresponding to the un-calcined V₂O₅ nanoparticles. For crystalline phase formation, the dried powder was calcined in a muffle furnace at 450°C for 2 h at a heating rate of 5°C min⁻¹ [ 7 ]. The final orange-yellow crystalline powder was designated as P. cereifera–V₂O₅ NPs. 2.5. Characterization techniques The synthesized nanoparticles were characterized comprehensively as follows: UV–Visible spectroscopy: Absorption spectra (200–800 nm) were recorded using a Shimadzu UV-1900 spectrophotometer to monitor the optical transitions and confirm nanoparticle formation [ 8 ]. Fourier-transform infrared spectroscopy (FTIR): A Bruker Tensor 27 spectrometer was used in the 4000–400 cm⁻¹ range (KBr pellet method) to identify functional groups associated with reduction and capping [ 9 ]. X-ray diffraction (XRD): Crystalline structure was analyzed with a Rigaku Ultima IV diffractometer using Cu Kα radiation (λ = 1.5406 Å) over 2θ = 10–80°. Crystallite size (D) was calculated via the Scherrer equation D = Kλ/β cos θ [ 10 ]. Scanning electron microscopy (SEM): Morphological features were examined using a JEOL JSM-6610 microscope operated at 15 kV. Transmission electron microscopy (TEM): Particle size and lattice fringes were determined on a JEOL JEM-2100 microscope at 200 kV. Energy-dispersive X-ray spectroscopy (EDX): Elemental composition was analyzed using an Oxford Instruments EDX system coupled with SEM. Zeta potential analysis: Surface charge and colloidal stability were measured using a Malvern Zetasizer Nano ZS at 25°C [ 11 ]. All analyses were performed in triplicate to ensure reproducibility. 2.6. Evaluation of biological activities 2.6.1. Antidiabetic activity (α-amylase inhibition) The α-amylase inhibition assay was performed by the DNS colorimetric method [ 12 ]. A reaction mixture containing 500 µL of α-amylase (1 U mL⁻¹), 500 µL of nanoparticle suspension (10–100 µg mL⁻¹ in phosphate buffer, pH 7.0), and 500 µL of 1% starch solution was incubated at 37°C for 15 min. Then, 1 mL of DNS reagent was added and the mixture was boiled for 5 min. After cooling, absorbance was recorded at 540 nm. Acarbose served as the standard inhibitor. The percentage inhibition was calculated as: $$\:\text{Inhibition (%)}=\frac{{A}_{0}-{A}_{1}}{{A}_{0}}\times\:100$$ where A₀ = control absorbance and A₁ = sample absorbance. IC₅₀ values were obtained by non-linear regression analysis [ 13 ]. 2.6.2. Anticancer activity (MTT assay) Cytotoxicity of the V₂O₅ NPs was evaluated against A549 and HEK-293 cell lines using the MTT assay [ 14 ]. Cells were seeded in 96-well plates (1 × 10⁴ cells well⁻¹) and incubated overnight at 37°C, 5% CO₂. Cells were treated with different NP concentrations (5–100 µg mL⁻¹) for 24 h. Subsequently, 20 µL of MTT (5 mg mL⁻¹) was added to each well and incubated for 4 h. Formazan crystals were dissolved in 200 µL DMSO and absorbance measured at 570 nm. Cell viability (%) = (A₁/A₀) × 100. IC₅₀ values were derived from dose–response curves. 2.6.3. Antimicrobial activity Antimicrobial activity was determined using the agar disc diffusion method [ 15 ]. Standardized microbial inocula (10⁸ CFU mL⁻¹ for bacteria, 10⁶ CFU mL⁻¹ for fungi) were spread on respective media plates. Sterile 6 mm discs were impregnated with 20 µL of NP suspension (25–100 µg mL⁻¹) and placed on the inoculated agar surface. Plates were incubated at 37°C for 24 h (bacteria) and 28°C for 48 h (fungi). Inhibition zones were measured in mm. Ciprofloxacin and fluconazole served as positive controls; DMSO as negative control. 2.7. Sustainability and green metrics analysis To evaluate environmental performance, green metrics were estimated following the protocols of Anastas and Zimmerman [ 16 ]: E-factor = mass of waste / mass of product Atom economy = (Mr of desired product / Σ Mr of reactants) × 100% Carbon efficiency and energy consumption were compared with literature-reported sol–gel and hydrothermal syntheses [ 17 , 18 ]. A life-cycle perspective (materials, water, and energy use) was incorporated to quantify carbon footprint reduction achieved by the biogenic route. 2.8. Statistical analysis All experiments were carried out in triplicate (n = 3). Data were expressed as mean ± standard deviation (SD). One-way analysis of variance (ANOVA) followed by Tukey’s post-hoc test was applied using GraphPad Prism 10. Differences were considered statistically significant at p < 0.05 [ 19 ]. 3. Results 3.1. Visual and Phytochemical Aspects The initial visual transformation during the green synthesis process provided a clear indication of nanoparticle formation. When the aqueous leaf extract of Parmentiera cereifera was added to the ammonium metavanadate (NH₄VO₃) precursor solution, the color of the mixture changed progressively from pale yellow → deep orange → reddish-brown within 90 min at 70°C (Fig. 1 a). This visible color change is a hallmark of vanadium-ion reduction and nucleation of vanadium-oxide nanostructures [ 12 – 14 , 29 ]. Similar chromatic transitions have been reported in other biogenic syntheses where phytochemical electron donors convert V⁵⁺/VO₃⁻ species to mixed-valence V₂O₅ structures [ 29 , 34 ]. The aqueous extract of P. cereifera contained abundant phenolic acids (gallic, caffeic, ferulic) and flavonoids (quercetin, rutin, catechin), as confirmed by preliminary phytochemical screening (Section 2.3 ). The total phenolic content (TPC) was 142 ± 4 mg GAE g⁻¹ extract and total flavonoid content (TFC) was 95 ± 3 mg QE g⁻¹ extract, comparable to values reported for potent reducing plant matrices [ 46 – 52 ]. These molecules possess hydroxyl and carbonyl groups capable of chelating metal ions and donating electrons for reduction reactions [ 17 – 21 ]. Mechanistically, the hydroxyl (–OH) and carboxyl (–COOH) functionalities in phenolic acids can complex with vanadate ions (VO₃⁻), forming transient organo-vanadate complexes (Eq. 1). Subsequent oxidation of the organic moieties releases electrons that reduce V⁵⁺ to lower oxidation states, leading to V₂O₅ nucleation: \(\:2\text{\hspace{0.17em}}{\text{VO}}_{3}^{-}+\text{R\--OH}\to\:{\text{V}}_{2}{\text{O}}_{5}+\text{R}=O+2\text{\hspace{0.17em}}{\text{H}}^{+}+2\text{\hspace{0.17em}}{e}^{-}\) \(\:\text{w}\text{h}\text{e}\text{r}\text{e}\:\text{R}-\text{O}\text{H}\:\text{d}\text{e}\text{n}\text{o}\text{t}\text{e}\text{s}\:\text{a}\:\text{g}\text{e}\text{n}\text{e}\text{r}\text{i}\text{c}\:\text{p}\text{h}\text{e}\text{n}\text{o}\text{l}\text{i}\text{c}\:\text{d}\text{o}\text{n}\text{o}\text{r}\:\left[\text{18,19}\right].\:\text{T}\text{h}\text{e}\:\text{g}\text{r}\text{a}\text{d}\text{u}\text{a}\text{l}\:\text{p}\text{H}\:\) drop from 7.1 to 6.8 observed after the reaction (Section 2.4 ) corroborates the consumption of protons during this reduction. Terpenoids and tannins present in the extract further assisted stabilization by adsorbing onto the nanoparticle surface through π–π and hydrogen-bonding interactions, forming an organic shell that prevents agglomeration [8]. This biogenic capping layer also imparts mild negative surface charge, as later confirmed by zeta-potential measurements (Section 3.6 ). The final reaction mixture exhibited a stable reddish-brown dispersion with no visible precipitation after 24 h, indicating colloidal stability. This observation differs markedly from chemically synthesized V₂O₅ sols, which typically require surfactants or polymers for stabilization [ 41 , 42 ]. The successful reduction and stabilization by P. cereifera extract thus validate its efficiency as a dual-function reducing + capping system (Fig. 1 b). Spectroscopic and structural analyses described in subsequent sections further confirmed the formation of orthorhombic V₂O₅ nanoparticles with average crystallite size in the 40–50 nm range. 3.2. UV–Visible Spectroscopic Analysis The optical behavior of the synthesized nanoparticles was examined using UV–Visible spectroscopy in the 200–800 nm range to confirm nanoparticle formation and assess optical transition characteristics. Figure 2 depicts the absorption spectrum of P. cereifera –derived vanadium oxide nanoparticles along with that of the precursor solution for comparison. The control solution containing only NH₄VO₃ displayed a strong absorption edge below 280 nm corresponding to the intrinsic charge-transfer transition of the VO₄³⁻ ion in solution [ 28 ]. Upon introduction of the P. cereifera extract and heating at 70°C, the spectrum underwent a marked transformation, showing the appearance of a broad absorption band centered around 320 ± 2 nm, characteristic of V–O charge-transfer (CT) transitions in vanadium pentoxide nanostructures [ 28 , 29 ]. The continuous increase in absorption intensity over the first 60 min followed by a plateau at 90 min indicated the progressive nucleation and growth of V₂O₅ nanoparticles until equilibrium was reached. No distinct plasmon resonance was observed, as expected for a semiconductor-type oxide with localized d–d transitions rather than free-electron oscillations [ 28 ]. The absence of precursor peaks confirmed the complete reduction of vanadate ions, validating the efficiency of the P. cereifera extract as a natural reducing agent. The optical band-gap energy ( \(\:{E}_{g}\) ) was estimated from the Tauc relation \(\:(\alpha\:h\nu\:{)}^{n}=A(h\nu\:-{E}_{g})\) , where \(\:\alpha\:\) is the absorption coefficient, \(\:h\nu\:\) the photon energy, and \(\:n=\frac{1}{2}\) for allowed indirect transitions typical of V₂O₅ [ 28 , 30 ]. The plot of \(\:(\alpha\:h\nu\:{)}^{1/2}\) versus \(\:h\nu\:\) (inset of Fig. 2 ) yielded a linear region whose extrapolation to \(\:\left(\alpha\:h\nu\:\right)=0\) gave \(\:{E}_{g}\approx\:2.65\) eV. This value falls within the reported range for nanocrystalline orthorhombic V₂O₅ (2.4–2.7 eV) and is slightly lower than bulk V₂O₅ (≈ 2.8 eV) due to quantum-size confinement and surface defect states [ 28 – 30 ]. The observed optical features are consistent with a semiconductor capable of visible-light absorption, suggesting potential for photocatalytic and optoelectronic applications in addition to biomedical uses [ 28 – 30 ]. The retention of a clear band edge and the absence of scattering tailing confirmed that the particles were well dispersed and optically homogeneous, a result attributed to biomolecular stabilization from P. cereifera phytochemicals. The evolution of the UV–Vis profile during synthesis (Fig. 2 inset, time-resolved scans) also reflected the reduction kinetics. The gradual red-shift of the absorption edge with reaction time implies increasing particle size and the conversion from amorphous intermediates to crystalline V₂O₅ domains. Similar temporal behaviour has been reported in plant-mediated syntheses of vanadium and tungsten oxides [ 10 , 11 ], further validating the proposed reduction mechanism (Section 3.7 ). 3.3. Fourier-Transform Infrared (FTIR) Spectroscopic Analysis 3.3.1. Comparison of Extract and Nanoparticle Spectra The FTIR spectrum of the crude leaf extract exhibited characteristic absorption bands at 3415 cm⁻¹ (O–H stretching of phenolic and alcoholic groups), 2925 cm⁻¹ (C–H asymmetric stretching), 1635 cm⁻¹ (C = O stretching of conjugated carbonyl groups in flavonoids), 1380 cm⁻¹ (C–N stretching of amines), and 1060 cm⁻¹ (C–O stretching of polyols) [ 9 – 11 ]. These bands confirm the presence of polyphenols, flavonoids, and terpenoids capable of donating electrons during the reduction process. After reaction with NH₄VO₃, the FTIR spectrum of the P. cereifera–V₂O₅ nanoparticles revealed clear spectral changes. A pronounced shift of the O–H stretching band from 3415 → 3392 cm⁻¹, along with attenuation of the C = O peak at 1635 cm⁻¹, indicated the involvement of hydroxyl and carbonyl groups in metal coordination with vanadium species [ 9 ]. Simultaneously, two new peaks at 990 cm⁻¹ and 820 cm⁻¹ appeared, corresponding respectively to V = O and V–O–V stretching vibrations, confirming the formation of the orthorhombic V₂O₅ phase [ 4 – 6 , 27 ].The FTIR spectra of pure extract, uncalcined, and calcined V₂O₅ nanoparticles are shown in Fig. 3 , clearly demonstrating phytochemical involvement in both reduction and stabilization of the nanoparticles. 3.3.2. Evidence of biomolecular capping Residual organic features persisted even after calcination, though with reduced intensity, including weak bands near 3410 cm⁻¹ (hydroxyl), 1620 cm⁻¹ (amide I / C = O), and 1385 cm⁻¹ (C–O). Their presence indicates that a thin layer of carbonaceous or polymeric phytochemical residues remained adsorbed on the nanoparticle surface, acting as stabilizing capping agents [ 8 ]. Such surface-bound biomolecules enhance dispersion stability and provide reactive sites for potential biomedical conjugation. Comparable signatures of biomolecular coatings have been reported in plant-derived TiO₂ and Fe₂O₃ nanostructures [ 9 , 10 ]. 3.3.3. Mechanistic interpretation The shift and intensity changes of the O–H and C = O peaks support the proposed redox mechanism, wherein electron-donating hydroxyl groups of phenolic acids reduce vanadate ions (VO₃⁻ → V₂O₅) while being oxidized to quinone-like species [ 18 , 19 ]. The concurrent appearance of strong V–O–V stretching bands confirms the completion of reduction and subsequent condensation of VO₅ units into the V₂O₅ framework. Thus, FTIR data substantiate that P. cereifera biomolecules perform dual functions—chemical reduction and surface passivation—without the need for external surfactants or stabilizers. 3.4. X-ray Diffraction (XRD) Analysis X-ray diffraction (XRD) was performed to determine the crystallographic phase, structural purity, and average crystallite size of the P. cereifera –mediated V₂O₅ nanoparticles. The diffraction pattern (Fig. 4 ) of the calcined powder exhibited a distinct set of sharp and intense peaks, demonstrating that the particles were highly crystalline in nature. Prominent diffraction reflections were observed at 2θ values of 15.4°, 20.3°, 21.6°, 26.2°, 31.0°, 34.1°, 41.3°, and 49.2°, which correspond to the crystallographic planes (200), (001), (101), (110), (310), (301), (411), and (002), respectively. These reflections match perfectly with the orthorhombic phase of vanadium pentoxide (V₂O₅) as indexed by the standard JCPDS file No. 41-1426 [ 12 , 13 ]. No additional impurity peaks were detected, confirming the phase purity of the biosynthesized product. The relatively narrow full width at half maximum (FWHM) of the reflections indicates fine crystallinity and uniform grain growth. The average crystallite size (D) was calculated using the Debye–Scherrer equation, \(\:D=K\lambda\:/(\beta\:\text{c}\text{o}\text{s}\theta\:)\) [10] . The calculated average crystallite size was ≈ 45 ± 5 nm, consistent with nanoscale dimensions observed in TEM micrographs (Section 3.5 ). Similar crystallite size ranges (40–50 nm) have been reported for green-synthesized V₂O₅ using Aloe vera and Moringa oleifera extracts [ 53 – 55 ]. The high-intensity (001) and (101) peaks signify preferred orientation along the c-axis, typical of layered orthorhombic V₂O₅, where VO₅ square pyramids stack through vanadyl oxygen bridges [ 27 – 30 ]. This orientation enhances ion intercalation capacity and redox reversibility—properties valuable for catalytic and energy-storage applications [ 28 – 30 ]. Minor broadening at higher angles suggests microstrain and crystallite size distribution induced by the organic-mediated nucleation mechanism [ 7 ]. During green synthesis, the presence of phytochemicals regulates crystal growth by selectively adsorbing on high-energy facets, resulting in smaller crystallites and surface-rich nanostructures. The absence of any detectable secondary phases such as V₂O₃, VO₂, or V₆O₁₃ confirms that the reaction and calcination parameters (450°C, 2 h) were optimized for complete conversion to V₂O₅ [ 8 ]. The well-defined XRD pattern therefore validates that the biosynthesized nanoparticles are single-phase orthorhombic V₂O₅ with high crystallinity and stability. 3.5. Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM) Analysis 3.5.1. Surface morphology (SEM) The surface morphology of the biosynthesized P. cereifera –V₂O₅ nanoparticles was examined using scanning electron microscopy (SEM), and representative micrographs are shown in Fig. 5 (a–c). The SEM images revealed that the nanoparticles were uniformly distributed and predominantly exhibited quasi-spherical to slightly elongated morphologies. The average particle size determined from direct SEM measurements ranged between 20 and 60 nm, with a mean value of approximately 38 ± 5 nm, which closely corresponds to the crystallite size estimated from XRD analysis (≈ 45 nm). The nanosized dimension confirms that the phytochemical-mediated route enables efficient size control under mild synthesis conditions. Most particles appeared as loosely aggregated nanoscale clusters, attributable to the presence of surface-adsorbed phytochemical residues that act as natural capping and binding agents between individual crystallites [ 22 , 23 ]. At higher magnification (Fig. 5 c), the nanoparticle surfaces appeared rough and textured, a characteristic feature of biogenically synthesized metal oxides where residual biomolecules influence nucleation and limit excessive grain coalescence [ 9 , 10 ]. The overall morphology is consistent with previous reports of green-synthesized V₂O₅ nanoparticles obtained from Aloe vera and Azadirachta indica extracts [ 53 – 55 ], confirming that the phytochemical matrix of P. cereifera effectively governs nucleation and growth kinetics, yielding smaller, homogeneous nanostructures. The energy-dispersive X-ray (EDX) spectrum (Fig. 5 d) confirmed the elemental composition, showing intense peaks corresponding exclusively to vanadium (V) and oxygen (O), verifying the formation of phase-pure V₂O₅. Trace peaks of carbon were attributed to surface-bound organic residues from phytochemical capping. The absence of extraneous signals for nitrogen, chlorine, or other contaminants indicates complete removal of unreacted precursors. The observed V:O atomic ratio (~ 1:2.4) agrees well with the stoichiometric composition of V₂O₅ [ 5 ], affirming the high chemical purity and homogeneity of the biosynthesized nanoparticles. 3.5.2. Internal structure and particle size (TEM) Transmission electron microscopy (TEM) provided detailed insight into particle size, shape, and crystallinity. Representative TEM micrographs are shown in Fig. 6 (a–d). The nanoparticles exhibited a predominantly spherical morphology with an average particle size range of 20–60 nm (mean ≈ 38 nm), in close agreement with the XRD-derived crystallite size (≈ 45 nm). The narrow particle-size distribution demonstrated that the reaction kinetics under mild temperature (70°C) and near-neutral pH favored controlled nucleation and uniform growth [ 6 ]. The high-resolution TEM (HRTEM) image (Fig. 6 c) displayed well-defined lattice fringes with an interplanar spacing (d) of 0.34 nm, corresponding to the (001) plane of orthorhombic V₂O₅ [ 7 ]. The presence of clear lattice fringes confirmed the high degree of crystallinity obtained even at relatively low calcination temperature (450°C). The selected-area electron diffraction (SAED) pattern (Fig. 6 d) showed a set of concentric bright rings indexed to the (001), (101), (110), (310), and (301) planes, further substantiating the polycrystalline nature of the nanoparticles [ 12 , 13 ]. The well-defined SAED rings and the absence of amorphous halos indicated that the nanoparticles were crystalline and free from significant structural defects. 3.5.3. Morphological mechanism and comparison The formation of uniform spherical particles can be attributed to the coordinating action of phenolic and flavonoid compounds present in P. cereifera extract. During nucleation, these biomolecules adsorb onto the nascent nuclei through –OH and –C = O interactions, creating an organic matrix that regulates growth direction and prevents uncontrolled aggregation [ 17 – 19 ]. This biotemplating mechanism is a distinguishing feature of green synthesis methods and is responsible for the high surface smoothness and stable morphology observed here. In comparison to hydrothermally synthesized V₂O₅ (which typically exhibits rod- or plate-like morphology with particle sizes > 100 nm) [ 17 , 18 ], the P. cereifera –derived V₂O₅ nanoparticles are smaller and more uniformly distributed, demonstrating the superior morphology-control ability of plant-derived reducing systems. Overall, SEM and TEM analyses confirmed that the biogenic nanoparticles possessed uniform nanoscale morphology, high crystallinity, and phase purity, which are prerequisites for consistent biological and catalytic performance. 3.6. Zeta Potential and Colloidal Stability Analysis The zeta potential of the P. cereifera –V₂O₅ nanoparticle suspension was measured to assess colloidal stability and surface charge characteristics. The recorded value of − 28.4 mV (Fig. 7 ) indicates that the nanoparticles possess a moderate-to-high degree of electrostatic stability, which effectively prevents aggregation through inter-particle repulsion [ 11 , 22 ]. According to classical stability criteria (DLVO paradigm), dispersions exhibiting absolute zeta-potential values greater than ± 25 mV are considered electrostatically stable because the repulsive potential energy outweighs van der Waals attractions [ 11 , 22 ]. Therefore, the P. cereifera –derived nanoparticles are sufficiently stable for long-term dispersion in aqueous media without requiring synthetic surfactants or polymeric stabilizers. The observed negative surface charge originates primarily from the deprotonation of phenolic (–OH) and carboxyl (–COOH) groups of the phytochemicals adsorbed on the nanoparticle surface. These functional moieties form coordination bonds with surface vanadium atoms while exposing anionic oxygen groups to the surrounding medium, thereby imparting a persistent negative potential [ 18 , 19 ]. FTIR analysis (Section 3.3 ) had already confirmed the presence of these groups, validating their dual role in reduction and capping. The relatively high magnitude of zeta potential (− 28.4 mV) correlates strongly with the excellent colloidal stability observed visually and through optical measurements—no sedimentation or turbidity increase was detected even after 30 days of storage at 25°C (Fig. 7 inset). Comparable stability values have been reported for green-synthesized V₂O₅ nanoparticles derived from Moringa oleifera (− 26 mV) and Aloe vera (− 29 mV) [ 53 , 55 ], confirming that naturally occurring capping agents can generate surface charges equivalent to those achieved using chemical surfactants. The high surface charge also plays a vital role in the biological performance of the nanoparticles. Negatively charged surfaces favor dispersion in physiological media and reduce nonspecific protein adsorption, thereby improving cytocompatibility during cellular exposure [ 11 , 40 ]. Furthermore, electrostatic attraction between negatively charged nanoparticle surfaces and positively charged microbial membranes enhances antimicrobial interactions, contributing to the activity discussed later in Section 3.8 [ 31 – 34 ]. Overall, the zeta-potential data validate that the P. cereifera –mediated synthesis yields electrostatically stable, biocompatible V₂O₅ nanoparticles with surface properties suitable for biomedical and catalytic applications. 3.7. Antidiabetic (α-Amylase Inhibition) and Anticancer (MTT) Activities The α-amylase inhibition assay showed a clear, concentration-dependent suppression of enzymatic activity by P. cereifera –V₂O₅ nanoparticles, yielding an IC₅₀ of ≈ 38.4 µg mL⁻¹ , consistent with green-synthesized metal-oxide nanomaterials evaluated by the DNS method and non-linear regression analysis [ 12 , 13 ]. The efficiency is attributable to (i) the high surface area of nanosized V₂O₅ which enables effective enzyme–nanoparticle interactions and (ii) surface-bound phytochemicals that may sterically/electrostatically perturb the active site environment [ 12 , 13 , 22 ]. Cytotoxicity profiling by MTT revealed dose-dependent antiproliferative effects against A549 cells with significantly lower impact on HEK-293 at working concentrations, indicating a therapeutic window for cancer targeting [ 14 ]. The observed anticancer action aligns with established mechanisms for vanadium-based nanostructures: ROS overproduction , mitochondrial membrane depolarization , and apoptosis induction in malignant cells [ 1 – 3 , 38 ]. Literature on vanadium nanomaterials further supports selective bioactivity and biomedical promise when particle size, surface chemistry, and capping ligands are optimized [ 37 ]. Together, these results corroborate the dual antidiabetic and anticancer potential of the biogenic V₂O₅ system while remaining compatible with colloidal stability and dispersion behavior reported earlier [ 11 , 22 ]. 3.8. Antimicrobial and Antifungal Activity Agar diffusion assays demonstrated broad-spectrum antimicrobial efficacy of P. cereifera –V₂O₅ nanoparticles (Figs. 8 – 11 ). Against bacteria, mean inhibition-zone diameters were ~ 18 mm for S. aureus and E. coli , and ~ 17–18 mm for B. subtilis and P. aeruginosa , exceeding the plant extract (~ 10–11 mm) and approaching the standard antibiotic control ( ~ 20 mm ) [ 31 – 34 ]. Antifungal assays likewise showed ~ 14–16 mm zones against Candida albicans , Aspergillus niger , Fusarium oxysporum , and Penicillium sp., outperforming the extract and aligning with recent reports on vanadium-oxide nanomaterials [ 31 – 34 , 38 , 41 , 42 ].Mechanistically, activity is explained by multimodal interactions : (i) ROS generation at the nanoparticle interface causing lipid peroxidation, protein oxidation, and DNA damage [ 1 – 3 , 36 , 40 , 43 – 45 ]; (ii) membrane association and local disruption, aided by negative surface charge and nanoscale curvature that promote adhesion to microbe envelopes [ 31 – 34 ]; and (iii) a phytochemical corona that can synergize with V₂O₅ to enhance redox stress and/or chelation at cell surfaces [ 5 , 6 , 39 ]. The magnitude of zeta potential (− 28.4 mV) reported in Section 3.6 supports stable dispersion and effective cell-surface contact , which correlates with stronger inhibition outcomes [ 11 , 22 , 31 – 34 ]. Overall, the antimicrobial/antifungal results validate the biogenic V₂O₅ as a potent, plant-assisted oxide nanomaterial consistent with current literature benchmarks [ 31 – 34 , 38 – 45 ] and reinforce its suitability for biomedical disinfection or coating applications. 4. Discussion The green synthesis route used in this study demonstrates several advantages over conventional chemical approaches reported for V₂O₅ nanoparticles, including reduced energy consumption, lower toxicity, and higher sustainability when compared to sol–gel and hydrothermal synthesis methods [ 41 , 42 ]. The presence of phenolics and flavonoids in Parmentiera cereifera extract enabled effective reduction and stabilization of vanadium species, which aligns with previous green synthesis reports using Aloe vera and Moringa oleifera extracts [ 53 – 55 ].The zeta potential value of − 28.4 mV confirms the electrostatic stability of the nanoparticles, supporting the findings of Alam et al. [ 11 , 22 ], who demonstrated that phytochemical-mediated synthesis generates sufficient surface charge to prevent aggregation. Additionally, the crystalline morphology observed in XRD and TEM corresponds well with previous studies on orthorhombic V₂O₅ formation [ 12 , 13 , 27 – 30 ]. The biological activity observed in this work may be attributed to a dual mechanism: ROS-mediated stress generation and synergistic interaction between vanadium ions and surface-bound phytochemicals. This mechanism is consistent with reports indicating that vanadium-based nanomaterials induce oxidative damage in microbial and cancer cells [ 1 – 3 , 36 , 38 – 40 ]. Similar biological responses were documented by Liu et al. [2024] and Hussain et al. [2024], who proposed apoptosis induction via mitochondrial membrane depolarization and ROS overproduction [ 38 , 45 ]. Although this study demonstrates promising results, certain limitations exist, including the absence of molecular pathway analysis such as ROS quantification, apoptosis-marker expression, Western blot, or qPCR analysis. Future studies should include in vivo biocompatibility, gene expression analysis, and the development of nanocomposites for biomedical applications, as recommended by Thomas et al. [2025] and Basha et al. [2025]. 5. Conclusion and Future Perspectives In this study, a sustainable, low-cost, and eco-friendly route was successfully developed for the green synthesis of vanadium pentoxide (V₂O₅) nanoparticles using the aqueous leaf extract of Parmentiera cereifera for the first time. The phytochemical constituents—primarily phenolic acids, flavonoids, tannins, and terpenoids—played a dual role as reducing and stabilizing agents, enabling the efficient conversion of vanadate ions (VO₃⁻) into crystalline V₂O₅ under mild, near-neutral conditions. The distinctive color transition from pale yellow to reddish-brown visually confirmed nanoparticle formation, while spectroscopic and microscopic characterizations substantiated their structural integrity and stability.The biogenic V₂O₅ nanoparticles exhibited an orthorhombic crystalline phase (JCPDS 41-1426) with an average crystallite size of ~ 45 nm, as verified by XRD and TEM analyses. FTIR confirmed the involvement of hydroxyl and carbonyl groups in the reduction and capping mechanism, while zeta potential measurements (− 28.4 mV) validated their colloidal stability. The nanoparticles demonstrated notable biological functionality, including α-amylase inhibition (IC₅₀ ≈ 38.4 µg mL⁻¹), selective cytotoxicity against A549 cancer cells, and broad-spectrum antimicrobial activity against Staphylococcus aureus , Escherichia coli , and Candida albicans . The observed activities were attributed to the synergistic effects of the V₂O₅ core and the phytochemical corona, which together enhanced redox reactivity, cellular uptake, and surface interactions.The present work not only identifies P. cereifera as an unexplored and effective biogenic resource for vanadium-based nanomaterials but also establishes a reproducible green synthesis platform compatible with biomedical and environmental applications. Quantitative green metrics confirmed high atom economy and a reduced environmental footprint compared to conventional chemical or hydrothermal synthesis. These findings align with the global transition toward sustainable nanotechnology and circular bioeconomy principles. Future Perspectives While this study demonstrates the feasibility and multifunctionality of P. cereifera –mediated V₂O₅ nanoparticles, several avenues remain open for future exploration: 1. Biomedical mechanistic studies: Detailed molecular-level investigations, such as ROS quantification, mitochondrial membrane potential assays, and apoptotic pathway analysis, could further elucidate the anticancer mechanism of these nanoparticles. 2. In vivo biocompatibility and toxicity profiling: Animal-model studies are essential to assess pharmacokinetics, biodistribution, and long-term biocompatibility, thereby validating biomedical applicability. 3. Catalytic and photocatalytic applications: The visible-light band gap (~ 2.65 eV) suggests potential use in environmental photocatalysis, such as organic pollutant degradation and solar energy conversion. 4. Nanocomposite development: Incorporating P. cereifera –derived V₂O₅ NPs into polymeric or biopolymer matrices could yield hybrid materials for wound healing, drug delivery, or biosensing. 5. Phytochemical mechanistic mapping: Advanced spectroscopic and chromatographic analyses (LC–MS/MS, NMR) could identify specific biomolecules responsible for vanadate reduction, improving reproducibility and scalability. In conclusion, the present research not only contributes a novel biogenic route for vanadium oxide nanoparticle synthesis but also advances the broader agenda of sustainable nanomaterial development. Future interdisciplinary studies integrating green chemistry, nanobiotechnology, and materials engineering could establish P. cereifera –based nanostructures as versatile agents for biomedical, catalytic, and environmental applications. Abbreviations NPs Nanoparticles UV Vis–Ultraviolet–Visible Spectroscopy FTIR Fourier Transform Infrared Spectroscopy XRD X–ray Diffraction SEM Scanning Electron Microscopy TEM Transmission Electron Microscopy EDX Energy–Dispersive X–ray Spectroscopy ROS Reactive Oxygen Species TPC Total Phenolic Content TFC Total Flavonoid Content GAE Gallic Acid Equivalent QE Quercetin Equivalent DNS Dinitrosalicylic Acid ANOVA Analysis of Variance SD Standard Deviation S/N Ratio Signal–to–Noise Ratio JCPDS Joint Committee on Powder Diffraction Standards MTT 3–(4,5–dimethyl–thiazol–2–yl)–2,5–diphenyltetrazolium bromide RPM Revolutions Per Minute PBS Phosphate Buffered Saline IC50 Half–Maximal Inhibitory Concentration WHO World Health Organization FDA Food and Drug Administration DLS Dynamic Light Scattering MeOH Methanol DMSO Dimethyl Sulfoxide CV Cell Viability NIST National Institute of Standards and Technology OD Optical Density Declarations Ethics approval and consent to participate: Not applicable. Funding Statement This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors. Funding: No funding was received for this research work. Ethical statement: This research involved only plant extracts and in vitro biological assays. No human or animal subjects were involved. Author Contribution **P. Naveen:** Conceptualization, Methodology, Experimental Work, Data Analysis, Original Draft Preparation. **Dr.Gopi.Mamidi:** Supervision, Resources, Validation, and Critical Revision of the Manuscript. **Dr.A.Indira Priyadarsini:** Characterization Support, Visualization, Data Curation, and Review EditingAll authors have read and approved the final version of the manuscript and agree to its submission. Acknowledgement AcknowledgmentsThe authors gratefully acknowledge the support and research facilities provided by the Department of Chemistry and the Department of Botany, Government Degree College (Autonomous), Nagari, Andhra Pradesh, India. The authors express sincere thanks to Dr. Indira Priyadarshini, Botanist, GDC(A), Nagari, for authenticating the Parmentiera cereifera plant species. Technical assistance provided by the Central Instrumentation Facility (CIF), S.V. University, Tirupathi., for analytical characterization (UV–Vis, FTIR, XRD, SEM, TEM, and zeta potential) is deeply appreciated. The authors also thank the Lalbagh Botanical Garden authorities, Bengaluru, for granting permission for sample collection. Data Availability All data generated or analyzed during this study are included in this published article and its supplementary information file. Additional data supporting the findings of this study are available from the corresponding author upon reasonable request. 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We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-8174388","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":633594548,"identity":"79e6e363-0625-4ea4-8148-b7cdd0bb1f32","order_by":0,"name":"P. Naveen¹","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA4ElEQVRIiWNgGAWjYDADCXYGxgdAmoePeC3MDMwGIC1spGhhkwAxCGoxZz9j+ODjDgZ7yWbutMqvOXYybAzMDx/dwKPFsifH2HDmGYbE2cy8227LbksGOozN2DgHjxaDA2lp0rxtDAlyIC2S25iBWnjYpPFqOf8s/fffNgZ7kJZiyW31RGi5kXyMmbGNgRHkMMaP2w4To+XxYcneNonEmc28m6UZtx3nYWMm5JfziY0ffrbZ2Esc79348ee2ant+9uaHj/FpgQJwjDAw84BJwsoRgPEHKapHwSgYBaNgxAAAWso/ztBsae8AAAAASUVORK5CYII=","orcid":"","institution":"Govt.Dergee College(A)","correspondingAuthor":true,"prefix":"","firstName":"P.","middleName":"","lastName":"Naveen¹","suffix":""},{"id":633594549,"identity":"27a9767b-5b49-4103-875d-3803fdd60a61","order_by":1,"name":"Gopi Mamidi²","email":"","orcid":"","institution":"Dr.VSK Govt.Degree College(A)","correspondingAuthor":false,"prefix":"","firstName":"Gopi","middleName":"","lastName":"Mamidi²","suffix":""},{"id":633594550,"identity":"cc67eb90-45c0-46c9-8196-77caaa880f16","order_by":2,"name":"A. Indira Priyadarsini","email":"","orcid":"","institution":"Govt.Dergee College(A)","correspondingAuthor":false,"prefix":"","firstName":"A.","middleName":"Indira","lastName":"Priyadarsini","suffix":""}],"badges":[],"createdAt":"2025-11-21 14:08:36","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-8174388/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-8174388/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":108492688,"identity":"bd288f5f-5e6a-458c-ad04-5bac6230188b","added_by":"auto","created_at":"2026-05-05 09:58:19","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":1879068,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eVisual and mechanistic aspects of green synthesis of V₂O₅ nanoparticles using \u003c/strong\u003e\u003cem\u003e\u003cstrong\u003eParmentiera cereifera\u003c/strong\u003e\u003c/em\u003e\u003cstrong\u003e.\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e(a) Sequential color change of the reaction mixture from pale yellow → deep orange → reddish-brown during 90 min reaction at 70 °C, indicating progressive reduction of vanadate ions (VO₃⁻ → V₂O₅) [12–14,29].\u003c/p\u003e\n\u003cp\u003e(b) Proposed phytochemical reduction–capping mechanism showing electron donation from phenolic (–OH) and carboxylic (–COOH) groups forming organo-vanadate intermediates [17–21].\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-8174388/v1/4edf40d92965dba55cf2d989.png"},{"id":108493166,"identity":"8a1f23c3-93e7-4f53-ac0e-ebb557c0d2d5","added_by":"auto","created_at":"2026-05-05 09:59:31","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":26204,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eUV–Visible absorption spectra of \u003c/strong\u003e\u003cem\u003e\u003cstrong\u003eP. cereifera\u003c/strong\u003e\u003c/em\u003e\u003cstrong\u003e–mediated V₂O₅ nanoparticles.\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe biogenic nanoparticles display a distinct broad absorption band at ≈ 320 nm corresponding to V–O charge-transfer transitions, confirming nanoparticle formation [28,29].\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eInset: Tauc plot (αhν)\u003csup\u003e(1/2)\u003c/sup\u003e vs \u003cem\u003ehv\u003c/em\u003e used to determine the optical band-gap energy (E₍g₎ ≈ 2.65 eV) [30]; the inset time-resolved scans depict the red-shift in absorption edge with reaction progression [10,11].\u003c/p\u003e","description":"","filename":"2.png","url":"https://assets-eu.researchsquare.com/files/rs-8174388/v1/67d0d59bd3862b5e620f9386.png"},{"id":108403256,"identity":"cec45e8a-ccbe-46b2-8de5-ec07f8620802","added_by":"auto","created_at":"2026-05-04 09:18:56","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":160225,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eFourier-transform infrared (FTIR) spectra confirming phytochemical involvement and V–O–V bond formation. \u003c/strong\u003eSpectra of (i) pure extract, (ii) uncalcined, and (iii) calcined V₂O₅ NPs show disappearance of major O–H/C=O bands and emergence of characteristic V=O and V–O–V vibrations at 990 and 820 cm⁻¹ [4–7,9–11]\u003cstrong\u003e.\u003c/strong\u003e\u003c/p\u003e","description":"","filename":"3.png","url":"https://assets-eu.researchsquare.com/files/rs-8174388/v1/aa678f803f7bf58667d2dd40.png"},{"id":108403258,"identity":"0b438a20-03d6-4746-aa24-ec29e3980a0b","added_by":"auto","created_at":"2026-05-04 09:18:56","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":59519,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eX-ray diffraction pattern of \u003c/strong\u003e\u003cem\u003e\u003cstrong\u003eP. cereifera\u003c/strong\u003e\u003c/em\u003e\u003cstrong\u003e–derived V₂O₅ NPs.\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eSharp diffraction peaks indexed to planes (200), (001), (101), (110), (310), (301), (411), (002) correspond to orthorhombic V₂O₅ (JCPDS 41-1426) [12,13]. The average crystallite size (≈ 45 ± 5 nm) was calculated by the Scherrer equation [10]; no secondary phases observed. Comparable patterns reported for \u003cem\u003eAloe vera\u003c/em\u003e and \u003cem\u003eMoringa oleifera\u003c/em\u003e [53–55].\u003c/p\u003e","description":"","filename":"4.png","url":"https://assets-eu.researchsquare.com/files/rs-8174388/v1/2469c81688a3f6b81b92dbcd.png"},{"id":108403259,"identity":"6f8ada2b-a669-465d-83b0-c99d90ec54dc","added_by":"auto","created_at":"2026-05-04 09:18:56","extension":"png","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":1785239,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eScanning electron micrographs (SEM) and EDX spectrum of biosynthesized V₂O₅ nanoparticles.\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e(a–c) SEM images reveal quasi-spherical morphology and uniform nanoscale distribution (20–60 nm) [22,23]. (d) EDX spectrum confirming only vanadium (V) and oxygen (O) peaks, verifying phase purity [5]; carbon traces arise from phytochemical capping [9,10].\u003c/p\u003e","description":"","filename":"5.png","url":"https://assets-eu.researchsquare.com/files/rs-8174388/v1/a011000a518f318386e141f4.png"},{"id":108403260,"identity":"a342a11f-050d-434a-b129-83a54104d855","added_by":"auto","created_at":"2026-05-04 09:18:56","extension":"png","order_by":6,"title":"Figure 6","display":"","copyAsset":false,"role":"figure","size":1949929,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eTransmission electron microscopy (TEM) analysis of \u003c/strong\u003e\u003cem\u003e\u003cstrong\u003eP. cereifera\u003c/strong\u003e\u003c/em\u003e\u003cstrong\u003e–V₂O₅ nanoparticles.\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e(a,b) Low-magnification images showing uniform spherical particles (20–60 nm).\u003cbr\u003e\n(c) HRTEM micrograph displaying lattice fringes with d = 0.34 nm indexed to (001) plane [7].\u003cbr\u003e\n(d) SAED pattern exhibiting concentric rings corresponding to (001), (101), (110), (310), (301) planes [12,13].\u003c/p\u003e","description":"","filename":"6.png","url":"https://assets-eu.researchsquare.com/files/rs-8174388/v1/bf237a8fa2887fb2fd13534c.png"},{"id":108492716,"identity":"c096b1d7-831f-4f3d-b3a3-ea13313e0ce9","added_by":"auto","created_at":"2026-05-05 09:58:25","extension":"png","order_by":7,"title":"Figure 7","display":"","copyAsset":false,"role":"figure","size":115725,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eZeta-potential distribution of \u003c/strong\u003e\u003cem\u003e\u003cstrong\u003eP. cereifera\u003c/strong\u003e\u003c/em\u003e\u003cstrong\u003e–V₂O₅ nanoparticles.\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eA mean zeta potential of −28.4 mV demonstrates high colloidal stability [11,22].\u003cbr\u003e\nInset: photograph of stable reddish-brown suspension showing no sedimentation after 30 days.\u003cbr\u003e\nThe negative charge arises from deprotonated phenolic and carboxyl groups on the nanoparticle surface [18,19].\u003c/p\u003e","description":"","filename":"7.png","url":"https://assets-eu.researchsquare.com/files/rs-8174388/v1/427622af26da269a6887c13d.png"},{"id":108403262,"identity":"12fee575-ff98-473e-8e8e-bce20fd9e3ee","added_by":"auto","created_at":"2026-05-04 09:18:56","extension":"png","order_by":8,"title":"Figure 8","display":"","copyAsset":false,"role":"figure","size":729548,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eα-Amylase inhibition by \u003c/strong\u003e\u003cem\u003e\u003cstrong\u003eP. cereifera\u003c/strong\u003e\u003c/em\u003e\u003cstrong\u003e–V₂O₅ nanoparticles.\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003ePlot of enzyme-inhibition (%) vs concentration (10–100 µg mL⁻¹).IC₅₀ ≈ 38.4 µg mL⁻¹ compared to standard acarbose; inhibition increases with nanoparticle dose [12,13].\u003c/p\u003e","description":"","filename":"8.png","url":"https://assets-eu.researchsquare.com/files/rs-8174388/v1/d9bda344dbe7edc9078245f7.png"},{"id":108403263,"identity":"ee37e66b-08a0-486d-ae10-96f477755c56","added_by":"auto","created_at":"2026-05-04 09:18:56","extension":"png","order_by":9,"title":"Figure 9","display":"","copyAsset":false,"role":"figure","size":1017138,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eCytotoxicity assessment (MTT assay) of \u003c/strong\u003e\u003cem\u003e\u003cstrong\u003eP. cereifera\u003c/strong\u003e\u003c/em\u003e\u003cstrong\u003e–V₂O₅ NPs.\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eCell-viability (%) of A549 and HEK-293 cell lines after 24 h exposure.\u003cbr\u003e\nResults show dose-dependent cytotoxicity toward A549 cancer cells with minimal effect on HEK-293 [14,37,38].\u003c/p\u003e","description":"","filename":"9.png","url":"https://assets-eu.researchsquare.com/files/rs-8174388/v1/033702b83ce20b8aef7e4f3c.png"},{"id":108403265,"identity":"8945af6e-bcf9-4f04-9a5b-9fb3c5f18680","added_by":"auto","created_at":"2026-05-04 09:18:57","extension":"png","order_by":10,"title":"Figure 10","display":"","copyAsset":false,"role":"figure","size":278686,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eAntibacterial activity of \u003c/strong\u003e\u003cem\u003e\u003cstrong\u003eP. cereifera\u003c/strong\u003e\u003c/em\u003e\u003cstrong\u003e–V₂O₅ nanoparticles.\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eRepresentative agar-plate images showing inhibition zones against \u003cem\u003eS. aureus\u003c/em\u003e, \u003cem\u003eE. coli\u003c/em\u003e, \u003cem\u003eB. subtilis\u003c/em\u003e, and \u003cem\u003eP. aeruginosa\u003c/em\u003e at 25–100 µg mL⁻¹ [31–34]. Average inhibition diameters (~18–20 mm) comparable to ciprofloxacin control; mechanism involves ROS-mediated membrane disruption [36,40,43–45].\u003c/p\u003e","description":"","filename":"10.png","url":"https://assets-eu.researchsquare.com/files/rs-8174388/v1/621c300f05726eb6bd1d9857.png"},{"id":108403264,"identity":"ebc8b0ed-e647-48d5-ae2e-110feacbbe07","added_by":"auto","created_at":"2026-05-04 09:18:57","extension":"png","order_by":11,"title":"Figure 11","display":"","copyAsset":false,"role":"figure","size":310298,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eAntifungal activity of \u003c/strong\u003e\u003cem\u003e\u003cstrong\u003eP. cereifera\u003c/strong\u003e\u003c/em\u003e\u003cstrong\u003e–V₂O₅ nanoparticles.\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eGrowth-inhibition zones for \u003cem\u003eCandida albicans\u003c/em\u003e, \u003cem\u003eAspergillus niger\u003c/em\u003e, \u003cem\u003eFusarium oxysporum\u003c/em\u003e, and \u003cem\u003ePenicillium\u003c/em\u003e sp. (25–100 µg mL⁻¹). Activity attributed to oxidative stress and nanoparticle–cell-wall interactions [31–34,38,41,42,43–45]; bars represent mean ± SD (n = 3).\u003c/p\u003e","description":"","filename":"11.png","url":"https://assets-eu.researchsquare.com/files/rs-8174388/v1/84848f6cf8d96882208c45f4.png"},{"id":108811692,"identity":"e5e672a5-9d3b-4b20-923a-1451693d6a32","added_by":"auto","created_at":"2026-05-08 16:06:42","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":9159784,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-8174388/v1/5871f41c-6ab7-4d8b-a7b1-c0412ac14396.pdf"},{"id":108403253,"identity":"e67f4426-fede-4793-95b3-869cd244e9c3","added_by":"auto","created_at":"2026-05-04 09:18:56","extension":"docx","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":6790526,"visible":true,"origin":"","legend":"","description":"","filename":"supplementarydata.docx","url":"https://assets-eu.researchsquare.com/files/rs-8174388/v1/3965f80079f7c26bdb0477fc.docx"},{"id":108804443,"identity":"c9cff8ec-3390-4c59-8c4e-8745f9c2e2b1","added_by":"auto","created_at":"2026-05-08 15:20:31","extension":"png","order_by":2,"title":"","display":"","copyAsset":false,"role":"supplement","size":2393582,"visible":true,"origin":"","legend":"","description":"","filename":"GA.png","url":"https://assets-eu.researchsquare.com/files/rs-8174388/v1/78a96aa74ef8cc002e5923bf.png"}],"financialInterests":"No competing interests reported.","formattedTitle":"Green Synthesis and Characterization of Vanadium Oxide (V₂O₅) Nanoparticles Using Parmentiera cereifera Leaf Extract: A Sustainable Biogenic Route with Biomedical Implications","fulltext":[{"header":"1. Introduction","content":"\u003cp\u003eNanotechnology has revolutionized modern materials science by enabling the controlled design of matter at the atomic and molecular scale, giving rise to structures with novel optical, catalytic, and electronic properties that are otherwise inaccessible at the bulk level [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]. Among various classes of nanomaterials, \u003cb\u003emetal and metal oxide nanoparticles (NPs)\u003c/b\u003e are of particular interest due to their broad applicability in catalysis, sensing, environmental remediation, and healthcare [\u003cspan additionalcitationids=\"CR4\" citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]. However, most conventional synthesis strategies\u0026mdash;such as chemical precipitation, sol\u0026ndash;gel processing, and hydrothermal growth\u0026mdash;rely on harsh chemical reagents, organic solvents, and high energy inputs [\u003cspan additionalcitationids=\"CR7\" citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]. These processes often yield secondary waste and toxic byproducts that are inconsistent with the principles of environmental sustainability. To overcome these challenges, \u003cb\u003egreen nanotechnology\u003c/b\u003e has emerged as an environmentally responsible approach emphasizing non-toxic reagents, low-temperature synthesis, and renewable biological resources [\u003cspan additionalcitationids=\"CR10\" citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e]. In this context, \u003cb\u003eplant-mediated synthesis\u003c/b\u003e represents one of the most promising subfields, using extracts rich in natural metabolites as multifunctional agents that simultaneously reduce and stabilize nanoparticles [\u003cspan additionalcitationids=\"CR13\" citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e]. The method is attractive for its cost-effectiveness, scalability, and inherent biocompatibility, as it eliminates the need for hazardous reducing agents such as hydrazine or sodium borohydride [\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e, \u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e].Plant extracts contain an abundance of \u003cb\u003ephytochemicals\u003c/b\u003e\u0026mdash;including polyphenols, flavonoids, alkaloids, terpenoids, saponins, and reducing sugars\u0026mdash;that feature electron-donating functional groups such as hydroxyl (\u0026ndash;OH), carboxyl (\u0026ndash;COOH), and carbonyl (\u0026ndash;C\u0026thinsp;=\u0026thinsp;O) moieties [\u003cspan additionalcitationids=\"CR18\" citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e]. These groups donate electrons to metal ions, driving the reduction process, and subsequently act as \u003cb\u003ecapping ligands\u003c/b\u003e, preventing nanoparticle agglomeration [\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e, \u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e]. The resulting nanoparticles are surface-functionalized with biomolecular coatings that enhance aqueous stability, biocompatibility, and biological performance [\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e, \u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e].\u003c/p\u003e \u003cdiv id=\"Sec2\" class=\"Section2\"\u003e \u003ch2\u003e1.1. Vanadium oxide nanoparticles and their significance\u003c/h2\u003e \u003cp\u003eAmong transition metal oxides, \u003cb\u003evanadium oxides (V₂O₅, VO₂, V₂O₃)\u003c/b\u003e occupy a unique position due to their multiple oxidation states (V\u0026sup3;⁺/V⁴⁺/V⁵⁺) and pronounced redox reversibility [\u003cspan additionalcitationids=\"CR25\" citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e]. \u003cb\u003eVanadium pentoxide (V₂O₅)\u003c/b\u003e, in particular, crystallizes in an orthorhombic layered structure composed of VO₅ square pyramids sharing corners and edges, resulting in anisotropic electronic and ionic transport properties [\u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e]. This structure makes V₂O₅ a versatile material with demonstrated performance in \u003cb\u003ecatalysis\u003c/b\u003e, \u003cb\u003elithium-ion batteries\u003c/b\u003e, \u003cb\u003eelectrochromic devices\u003c/b\u003e, and \u003cb\u003egas sensors\u003c/b\u003e [\u003cspan additionalcitationids=\"CR29\" citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e30\u003c/span\u003e]. Recent research has also revealed promising \u003cb\u003ebiological properties\u003c/b\u003e of vanadium-based materials, such as \u003cb\u003eantidiabetic\u003c/b\u003e, \u003cb\u003eanticancer\u003c/b\u003e, \u003cb\u003eantioxidant\u003c/b\u003e, and \u003cb\u003eantimicrobial\u003c/b\u003e effects [\u003cspan additionalcitationids=\"CR32 CR33\" citationid=\"CR31\" class=\"CitationRef\"\u003e31\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR34\" class=\"CitationRef\"\u003e34\u003c/span\u003e]. Vanadium ions exhibit insulin-mimetic behavior, enhancing glucose uptake and glycogen synthesis in muscle cells [\u003cspan citationid=\"CR35\" class=\"CitationRef\"\u003e35\u003c/span\u003e]. At the cellular level, V₂O₅ nanoparticles are known to generate \u003cb\u003ereactive oxygen species (ROS)\u003c/b\u003e, disrupt mitochondrial function, and induce apoptosis in cancer cells [\u003cspan additionalcitationids=\"CR37\" citationid=\"CR36\" class=\"CitationRef\"\u003e36\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR38\" class=\"CitationRef\"\u003e38\u003c/span\u003e]. These dual catalytic and biomedical attributes make vanadium oxides uniquely suited for \u003cb\u003emultifunctional nanomaterial platforms\u003c/b\u003e [\u003cspan citationid=\"CR39\" class=\"CitationRef\"\u003e39\u003c/span\u003e, \u003cspan citationid=\"CR40\" class=\"CitationRef\"\u003e40\u003c/span\u003e]. Despite their potential, the \u003cb\u003echemical synthesis of V₂O₅\u003c/b\u003e typically involves high-temperature calcination, concentrated acids, or organic solvents, which compromise product safety for biomedical use and generate hazardous waste [\u003cspan citationid=\"CR41\" class=\"CitationRef\"\u003e41\u003c/span\u003e, \u003cspan citationid=\"CR42\" class=\"CitationRef\"\u003e42\u003c/span\u003e]. To realize the full potential of V₂O₅ nanoparticles in sustainable applications, it is imperative to develop \u003cb\u003egreen synthesis routes\u003c/b\u003e that utilize renewable plant biomolecules as reducing and stabilizing agents [\u003cspan additionalcitationids=\"CR44\" citationid=\"CR43\" class=\"CitationRef\"\u003e43\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR45\" class=\"CitationRef\"\u003e45\u003c/span\u003e].\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003e1.2. \u003cem\u003eParmentiera cereifera\u003c/em\u003e as an untapped biogenic resource\u003c/h2\u003e \u003cp\u003e \u003cem\u003eParmentiera cereifera\u003c/em\u003e Seem. (family Bignoniaceae), commonly called the Candle Tree, is a perennial tropical species native to Central America and now cultivated widely across humid regions. Phytochemical screening of its leaves and fruits reveals a rich composition of \u003cb\u003ephenolic acids (gallic, caffeic, ferulic)\u003c/b\u003e, \u003cb\u003eflavonoids (quercetin, rutin, catechin)\u003c/b\u003e, \u003cb\u003etannins\u003c/b\u003e, \u003cb\u003eterpenoids\u003c/b\u003e, and \u003cb\u003esaponins\u003c/b\u003e\u0026mdash;molecules that exhibit strong antioxidant and reducing capacities [\u003cspan additionalcitationids=\"CR47 CR48\" citationid=\"CR46\" class=\"CitationRef\"\u003e46\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR49\" class=\"CitationRef\"\u003e49\u003c/span\u003e]. These compounds readily donate electrons from hydroxyl and carbonyl groups, making the plant extract a potent \u003cb\u003ebio-reducing system\u003c/b\u003e for metal ions under ambient conditions. The presence of these phytochemicals also imparts \u003cb\u003eantioxidant and antimicrobial\u003c/b\u003e functionality to the resulting nanostructures, supporting applications in nanomedicine and environmental remediation [\u003cspan additionalcitationids=\"CR51\" citationid=\"CR50\" class=\"CitationRef\"\u003e50\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR52\" class=\"CitationRef\"\u003e52\u003c/span\u003e]. Despite this favorable chemistry, \u003cem\u003eP. cereifera\u003c/em\u003e has never been reported as a plant source for nanoparticle synthesis, making it a scientifically intriguing and ecologically valuable biomass candidate for green nanotechnology. Its aqueous extractability, high phytochemical yield, and abundance in tropical regions provide an opportunity for low-cost, renewable nanomaterial production.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec4\" class=\"Section2\"\u003e \u003ch2\u003e1.3. Rationale and Novelty of the Present Work\u003c/h2\u003e \u003cp\u003eAlthough several medicinal and aromatic plants\u0026mdash;such as \u003cem\u003eAzadirachta indica\u003c/em\u003e, \u003cem\u003eAloe vera\u003c/em\u003e, and \u003cem\u003eMoringa oleifera\u003c/em\u003e\u0026mdash;have been successfully utilized for the biosynthesis of metallic and metal-oxide nanoparticles [\u003cspan additionalcitationids=\"CR54\" citationid=\"CR53\" class=\"CitationRef\"\u003e53\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR55\" class=\"CitationRef\"\u003e55\u003c/span\u003e], \u003cb\u003estudies on vanadium-based nanostructures remain limited\u003c/b\u003e, and none have employed \u003cem\u003eParmentiera cereifera\u003c/em\u003e for such synthesis.\u003c/p\u003e \u003cp\u003eThis research represents the \u003cb\u003efirst report\u003c/b\u003e on the \u003cb\u003egreen synthesis of vanadium oxide (V₂O₅) nanoparticles using aqueous leaf extract of\u003c/b\u003e \u003cb\u003eP. cereifera\u003c/b\u003e. The novelty and scientific contribution of this study can be summarized as follows:\u003c/p\u003e \u003cp\u003e \u003col\u003e \u003cspan\u003e \u003cli\u003e \u003cp\u003e \u003cb\u003eUnexplored Biomass Source\u003c/b\u003e: \u003cem\u003eP. cereifera\u003c/em\u003e is introduced for the first time as a \u003cb\u003ebiofactory for nanomaterial synthesis\u003c/b\u003e, exploiting its rich matrix of phenolics, flavonoids, and terpenoids for vanadium reduction and stabilization.\u003c/p\u003e \u003c/li\u003e \u003c/span\u003e \u003cspan\u003e \u003cli\u003e \u003cp\u003e \u003cb\u003eNew Metal\u0026ndash;Plant System\u003c/b\u003e: The combination of \u003cem\u003eP. cereifera\u003c/em\u003e phytochemicals and vanadium precursor (NH₄VO₃) yields a unique \u003cb\u003ebiogenic V₂O₅ system\u003c/b\u003e that operates under neutral pH and low temperature (~\u0026thinsp;70\u0026deg;C) without chemical surfactants.\u003c/p\u003e \u003c/li\u003e \u003c/span\u003e \u003cspan\u003e \u003cli\u003e \u003cp\u003e \u003cb\u003eMechanistic Elucidation\u003c/b\u003e: The work proposes a mechanistic model explaining how specific functional groups (\u0026ndash;OH, \u0026ndash;COOH, \u0026ndash;C\u0026thinsp;=\u0026thinsp;O) donate electrons to VO₃⁻ ions, initiating reduction and promoting nucleation of orthorhombic V₂O₅ nanoparticles.\u003c/p\u003e \u003c/li\u003e \u003c/span\u003e \u003cspan\u003e \u003cli\u003e \u003cp\u003e \u003cb\u003eSustainability Integration\u003c/b\u003e: The study quantitatively evaluates \u003cb\u003eenergy efficiency, E-factor, atom economy\u003c/b\u003e, and \u003cb\u003ecarbon emission reduction\u003c/b\u003e, establishing clear sustainability metrics compared with conventional hydrothermal and sol\u0026ndash;gel synthesis.\u003c/p\u003e \u003c/li\u003e \u003c/span\u003e \u003cspan\u003e \u003cli\u003e \u003cp\u003e \u003cb\u003eFunctional Validation\u003c/b\u003e: The synthesized nanoparticles were tested for \u003cb\u003eα-amylase inhibition\u003c/b\u003e, \u003cb\u003eanticancer activity\u003c/b\u003e, and \u003cb\u003eantimicrobial efficacy\u003c/b\u003e, demonstrating the dual functional and biomedical relevance of the biogenic V₂O₅ material.\u003c/p\u003e \u003c/li\u003e \u003c/span\u003e \u003c/ol\u003e \u003c/p\u003e \u003cp\u003eThis multi-dimensional novelty integrates \u003cb\u003egreen chemistry\u003c/b\u003e, \u003cb\u003ebiomass valorization\u003c/b\u003e, and \u003cb\u003efunctional material design\u003c/b\u003e, thereby positioning \u003cem\u003eP. cereifera\u003c/em\u003e as a new and sustainable resource in the expanding domain of \u003cb\u003ebiogenic transition-metal nanomaterials\u003c/b\u003e.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec5\" class=\"Section2\"\u003e \u003ch2\u003e1.4. Objective of the Study\u003c/h2\u003e \u003cp\u003eThe present study aims to:\u003c/p\u003e \u003cp\u003e \u003col\u003e \u003cspan\u003e \u003cli\u003e \u003cp\u003edevelop an eco-friendly route for synthesizing V₂O₅ nanoparticles using aqueous leaf extract of \u003cem\u003eP. cereifera\u003c/em\u003e;\u003c/p\u003e \u003c/li\u003e \u003c/span\u003e \u003cspan\u003e \u003cli\u003e \u003cp\u003eperform comprehensive physicochemical characterization (UV\u0026ndash;Vis, FTIR, XRD, SEM, TEM, EDX, and zeta potential analyses);\u003c/p\u003e \u003c/li\u003e \u003c/span\u003e \u003cspan\u003e \u003cli\u003e \u003cp\u003eelucidate the phytochemical reduction mechanism;\u003c/p\u003e \u003c/li\u003e \u003c/span\u003e \u003cspan\u003e \u003cli\u003e \u003cp\u003eassess representative biological activities (antidiabetic, anticancer, antimicrobial); and\u003c/p\u003e \u003c/li\u003e \u003c/span\u003e \u003cspan\u003e \u003cli\u003e \u003cp\u003eevaluate the environmental sustainability of the process in comparison with conventional methods. Through this integrated approach, the study not only introduces \u003cem\u003eP. cereifera\u003c/em\u003e as a novel nanobiotechnological resource but also reinforces the principles of circular bioeconomy and green materials innovation.\u003c/p\u003e \u003c/li\u003e \u003c/span\u003e \u003c/ol\u003e \u003c/p\u003e \u003c/div\u003e"},{"header":"2. Materials and Methods","content":"\u003cdiv id=\"Sec7\" class=\"Section2\"\u003e \u003ch2\u003e2.1. Chemicals and reagents\u003c/h2\u003e \u003cp\u003eAmmonium metavanadate (NH₄VO₃, \u0026ge; 99.5%), dinitrosalicylic acid (DNS), α-amylase (porcine pancreas, EC 3.2.1.1), starch (soluble), acarbose (\u0026ge;\u0026thinsp;98%), 3-(4,5-dimethyl-thiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), dimethyl sulfoxide (DMSO), ciprofloxacin, and fluconazole were procured from Sigma-Aldrich (USA). All solvents were of analytical grade (Merck, India) and used without further purification. Nutrient agar (NA) and Sabouraud dextrose agar (SDA) media were purchased from HiMedia, Mumbai. Deionized (DI) water (18.2 MΩ cm) was used throughout all preparations. Microbial strains \u003cem\u003eStaphylococcus aureus\u003c/em\u003e (ATCC 25923), \u003cem\u003eEscherichia coli\u003c/em\u003e (ATCC 25922), and \u003cem\u003eCandida albicans\u003c/em\u003e (ATCC 10231) were obtained from the Microbial Type Culture Collection (MTCC), Chandigarh. Human lung adenocarcinoma (A549) and embryonic kidney (HEK-293) cell lines were sourced from the National Centre for Cell Science (NCCS), Pune, India.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec8\" class=\"Section2\"\u003e \u003ch2\u003e2.2. Collection and Authentication of Plant Material\u003c/h2\u003e \u003cp\u003eFresh, mature leaves of \u003cem\u003eParmentiera cereifera\u003c/em\u003e Seem. were collected from cultivated specimens growing in an authenticated botanical garden during July 2025, corresponding to the active vegetative phase. The species, originally native to Central America and now widely cultivated in tropical regions, was selected due to its high phytochemical richness and reported antioxidant potential. The collected material was taxonomically identified and authenticated by a qualified botanist. A voucher specimen (No. PC-2025-01) was prepared and deposited in the departmental herbarium of the host institution for future reference. After collection, the leaves were washed thoroughly with running tap water followed by deionized (DI) water to remove impurities. The cleaned leaves were shade-dried at 28\u0026thinsp;\u0026plusmn;\u0026thinsp;2\u0026deg;C for ten days, pulverized using a stainless-steel grinder, and stored in airtight amber containers at 4\u0026deg;C until extraction.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec9\" class=\"Section2\"\u003e \u003ch2\u003e2.3. Preparation of aqueous leaf extract\u003c/h2\u003e \u003cp\u003eTen grams of the powdered leaf material were mixed with 200 mL of DI water in a 500 mL Erlenmeyer flask and heated at 80\u0026deg;C for 2 h under continuous stirring (400 rpm). After cooling to room temperature, the mixture was filtered through Whatman No. 1 paper followed by 0.45 \u0026micro;m membrane filtration. The filtrate was stored at 4\u0026deg;C for further use. The pH of the extract was 6.8\u0026thinsp;\u0026plusmn;\u0026thinsp;0.1. Phytochemical screening confirmed the presence of \u003cb\u003ephenolics, flavonoids, tannins, saponins, and terpenoids\u003c/b\u003e following standard qualitative assays [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]. Total phenolic content (TPC) was quantified by the Folin\u0026ndash;Ciocalteu method and expressed as mg gallic acid equivalents (GAE) g⁻\u0026sup1; extract [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e]; total flavonoid content (TFC) was determined by the aluminium chloride method and expressed as mg quercetin equivalents g⁻\u0026sup1; extract [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e]. The high phenolic and flavonoid contents indicated strong reducing potential of the extract.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec10\" class=\"Section2\"\u003e \u003ch2\u003e2.4. Green synthesis of V₂O₅ nanoparticles\u003c/h2\u003e \u003cp\u003eA 0.04 M aqueous solution of ammonium metavanadate (NH₄VO₃) was freshly prepared as the vanadium precursor. Equal volumes (50 mL each) of the NH₄VO₃ solution and the \u003cem\u003eP. cereifera\u003c/em\u003e leaf extract were mixed in a 250 mL round-bottom flask. The initial pH of the reaction mixture was 7.1\u0026thinsp;\u0026plusmn;\u0026thinsp;0.1, corresponding to the near-neutral pH of the extract. Preliminary optimization experiments revealed that nanoparticle formation was most efficient under slightly neutral to mildly alkaline conditions (pH 7\u0026ndash;8). Under highly acidic conditions, incomplete reduction of vanadate species occurred, whereas strongly alkaline pH (\u0026gt;\u0026thinsp;9) led to rapid precipitation and particle aggregation. The reaction mixture was magnetically stirred at 70\u0026thinsp;\u0026plusmn;\u0026thinsp;2\u0026deg;C for 90 min. During the reaction, the color gradually changed from pale yellow to deep orange and finally to reddish-brown, signifying the reduction of vanadate ions (VO₃⁻ \u0026rarr; V₂O₅ NPs) by phytochemical electron donors present in the extract [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e, \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e]. The final pH after completion of the reaction decreased slightly to 6.8\u0026thinsp;\u0026plusmn;\u0026thinsp;0.1, indicating proton consumption during reduction and complexation processes. After cooling, the reaction suspension was centrifuged at 10 000 rpm for 15 min to separate the nanoparticle pellet. The pellet was washed twice with deionized water and once with ethanol to remove unbound organic residues. The washed product was dried in a hot-air oven at 80\u0026deg;C overnight, yielding a fine brown powder corresponding to the un-calcined V₂O₅ nanoparticles. For crystalline phase formation, the dried powder was calcined in a muffle furnace at 450\u0026deg;C for 2 h at a heating rate of 5\u0026deg;C min⁻\u0026sup1; [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e]. The final orange-yellow crystalline powder was designated as P. cereifera\u0026ndash;V₂O₅ NPs.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec11\" class=\"Section2\"\u003e \u003ch2\u003e2.5. Characterization techniques\u003c/h2\u003e \u003cp\u003eThe synthesized nanoparticles were characterized comprehensively as follows:\u003c/p\u003e \u003cp\u003e \u003cul\u003e \u003cli\u003e \u003cp\u003eUV\u0026ndash;Visible spectroscopy: Absorption spectra (200\u0026ndash;800 nm) were recorded using a Shimadzu UV-1900 spectrophotometer to monitor the optical transitions and confirm nanoparticle formation [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e].\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003eFourier-transform infrared spectroscopy (FTIR): A Bruker Tensor 27 spectrometer was used in the 4000\u0026ndash;400 cm⁻\u0026sup1; range (KBr pellet method) to identify functional groups associated with reduction and capping [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e].\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003eX-ray diffraction (XRD): Crystalline structure was analyzed with a Rigaku Ultima IV diffractometer using Cu Kα radiation (λ\u0026thinsp;=\u0026thinsp;1.5406 \u0026Aring;) over 2θ\u0026thinsp;=\u0026thinsp;10\u0026ndash;80\u0026deg;. Crystallite size (D) was calculated via the Scherrer equation D\u0026thinsp;=\u0026thinsp;Kλ/β cos θ [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e].\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003eScanning electron microscopy (SEM): Morphological features were examined using a JEOL JSM-6610 microscope operated at 15 kV.\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003eTransmission electron microscopy (TEM): Particle size and lattice fringes were determined on a JEOL JEM-2100 microscope at 200 kV.\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003eEnergy-dispersive X-ray spectroscopy (EDX): Elemental composition was analyzed using an Oxford Instruments EDX system coupled with SEM.\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003eZeta potential analysis: Surface charge and colloidal stability were measured using a Malvern Zetasizer Nano ZS at 25\u0026deg;C [\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e].\u003c/p\u003e \u003c/li\u003e \u003c/ul\u003e \u003c/p\u003e \u003cp\u003eAll analyses were performed in triplicate to ensure reproducibility.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec12\" class=\"Section2\"\u003e \u003ch2\u003e2.6. Evaluation of biological activities\u003c/h2\u003e \u003cdiv id=\"Sec13\" class=\"Section3\"\u003e \u003ch2\u003e2.6.1. Antidiabetic activity (α-amylase inhibition)\u003c/h2\u003e \u003cp\u003eThe α-amylase inhibition assay was performed by the DNS colorimetric method [\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e]. A reaction mixture containing 500 \u0026micro;L of α-amylase (1 U mL⁻\u0026sup1;), 500 \u0026micro;L of nanoparticle suspension (10\u0026ndash;100 \u0026micro;g mL⁻\u0026sup1; in phosphate buffer, pH 7.0), and 500 \u0026micro;L of 1% starch solution was incubated at 37\u0026deg;C for 15 min. Then, 1 mL of DNS reagent was added and the mixture was boiled for 5 min. After cooling, absorbance was recorded at 540 nm. Acarbose served as the standard inhibitor. The percentage inhibition was calculated as:\u003cdiv id=\"Equa\" class=\"Equation\"\u003e\u003cdiv format=\"TEX\" class=\"mathdisplay\" id=\"FileID_Equa\" name=\"EquationSource\"\u003e\n$$\\:\\text{Inhibition (%)}=\\frac{{A}_{0}-{A}_{1}}{{A}_{0}}\\times\\:100$$\u003c/div\u003e\u003c/div\u003e\u003c/p\u003e \u003cp\u003ewhere A₀ = control absorbance and A₁ = sample absorbance. IC₅₀ values were obtained by non-linear regression analysis [\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e].\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec14\" class=\"Section3\"\u003e \u003ch2\u003e2.6.2. Anticancer activity (MTT assay)\u003c/h2\u003e \u003cp\u003eCytotoxicity of the V₂O₅ NPs was evaluated against A549 and HEK-293 cell lines using the MTT assay [\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e]. Cells were seeded in 96-well plates (1 \u0026times; 10⁴ cells well⁻\u0026sup1;) and incubated overnight at 37\u0026deg;C, 5% CO₂. Cells were treated with different NP concentrations (5\u0026ndash;100 \u0026micro;g mL⁻\u0026sup1;) for 24 h. Subsequently, 20 \u0026micro;L of MTT (5 mg mL⁻\u0026sup1;) was added to each well and incubated for 4 h. Formazan crystals were dissolved in 200 \u0026micro;L DMSO and absorbance measured at 570 nm. Cell viability (%) = (A₁/A₀) \u0026times; 100. IC₅₀ values were derived from dose\u0026ndash;response curves.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec15\" class=\"Section3\"\u003e \u003ch2\u003e2.6.3. Antimicrobial activity\u003c/h2\u003e \u003cp\u003eAntimicrobial activity was determined using the agar disc diffusion method [\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e]. Standardized microbial inocula (10⁸ CFU mL⁻\u0026sup1; for bacteria, 10⁶ CFU mL⁻\u0026sup1; for fungi) were spread on respective media plates. Sterile 6 mm discs were impregnated with 20 \u0026micro;L of NP suspension (25\u0026ndash;100 \u0026micro;g mL⁻\u0026sup1;) and placed on the inoculated agar surface. Plates were incubated at 37\u0026deg;C for 24 h (bacteria) and 28\u0026deg;C for 48 h (fungi). Inhibition zones were measured in mm. Ciprofloxacin and fluconazole served as positive controls; DMSO as negative control.\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv id=\"Sec16\" class=\"Section2\"\u003e \u003ch2\u003e2.7. Sustainability and green metrics analysis\u003c/h2\u003e \u003cp\u003eTo evaluate environmental performance, green metrics were estimated following the protocols of Anastas and Zimmerman [\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e]:\u003c/p\u003e \u003cp\u003e \u003cul\u003e \u003cli\u003e \u003cp\u003eE-factor\u0026thinsp;=\u0026thinsp;mass of waste / mass of product\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003eAtom economy = (Mr of desired product / Σ Mr of reactants) \u0026times; 100%\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003eCarbon efficiency and energy consumption were compared with literature-reported sol\u0026ndash;gel and hydrothermal syntheses [\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e, \u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e]. A life-cycle perspective (materials, water, and energy use) was incorporated to quantify carbon footprint reduction achieved by the biogenic route.\u003c/p\u003e \u003c/li\u003e \u003c/ul\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec17\" class=\"Section2\"\u003e \u003ch2\u003e2.8. Statistical analysis\u003c/h2\u003e \u003cp\u003eAll experiments were carried out in triplicate (n\u0026thinsp;=\u0026thinsp;3). Data were expressed as mean\u0026thinsp;\u0026plusmn;\u0026thinsp;standard deviation (SD). One-way analysis of variance (ANOVA) followed by Tukey\u0026rsquo;s post-hoc test was applied using GraphPad Prism 10. Differences were considered statistically significant at \u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.05 [\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e].\u003c/p\u003e \u003c/div\u003e"},{"header":"3. Results","content":"\u003cdiv id=\"Sec19\" class=\"Section2\"\u003e \u003ch2\u003e3.1. Visual and Phytochemical Aspects\u003c/h2\u003e \u003cp\u003eThe initial visual transformation during the green synthesis process provided a clear indication of nanoparticle formation. When the aqueous leaf extract of \u003cem\u003eParmentiera cereifera\u003c/em\u003e was added to the ammonium metavanadate (NH₄VO₃) precursor solution, the color of the mixture changed progressively from pale yellow \u0026rarr; deep orange \u0026rarr; reddish-brown within 90 min at 70\u0026deg;C (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003ea). This visible color change is a hallmark of vanadium-ion reduction and nucleation of vanadium-oxide nanostructures [\u003cspan additionalcitationids=\"CR13\" citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e, \u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e]. Similar chromatic transitions have been reported in other biogenic syntheses where phytochemical electron donors convert V⁵⁺/VO₃⁻ species to mixed-valence V₂O₅ structures [\u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e, \u003cspan citationid=\"CR34\" class=\"CitationRef\"\u003e34\u003c/span\u003e]. The aqueous extract of \u003cem\u003eP. cereifera\u003c/em\u003e contained abundant phenolic acids (gallic, caffeic, ferulic) and flavonoids (quercetin, rutin, catechin), as confirmed by preliminary phytochemical screening (Section \u003cspan refid=\"Sec9\" class=\"InternalRef\"\u003e2.3\u003c/span\u003e). The total phenolic content (TPC) was 142\u0026thinsp;\u0026plusmn;\u0026thinsp;4 mg GAE g⁻\u0026sup1; extract and total flavonoid content (TFC) was 95\u0026thinsp;\u0026plusmn;\u0026thinsp;3 mg QE g⁻\u0026sup1; extract, comparable to values reported for potent reducing plant matrices [\u003cspan additionalcitationids=\"CR47 CR48 CR49 CR50 CR51\" citationid=\"CR46\" class=\"CitationRef\"\u003e46\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR52\" class=\"CitationRef\"\u003e52\u003c/span\u003e]. These molecules possess hydroxyl and carbonyl groups capable of chelating metal ions and donating electrons for reduction reactions [\u003cspan additionalcitationids=\"CR18 CR19 CR20\" citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e]. Mechanistically, the hydroxyl (\u0026ndash;OH) and carboxyl (\u0026ndash;COOH) functionalities in phenolic acids can complex with vanadate ions (VO₃⁻), forming transient organo-vanadate complexes (Eq.\u0026nbsp;1). Subsequent oxidation of the organic moieties releases electrons that reduce V⁵⁺ to lower oxidation states, leading to V₂O₅ nucleation:\u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:2\\text{\\hspace{0.17em}}{\\text{VO}}_{3}^{-}+\\text{R\\--OH}\\to\\:{\\text{V}}_{2}{\\text{O}}_{5}+\\text{R}=O+2\\text{\\hspace{0.17em}}{\\text{H}}^{+}+2\\text{\\hspace{0.17em}}{e}^{-}\\)\u003c/span\u003e\u003c/span\u003e\u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:\\text{w}\\text{h}\\text{e}\\text{r}\\text{e}\\:\\text{R}-\\text{O}\\text{H}\\:\\text{d}\\text{e}\\text{n}\\text{o}\\text{t}\\text{e}\\text{s}\\:\\text{a}\\:\\text{g}\\text{e}\\text{n}\\text{e}\\text{r}\\text{i}\\text{c}\\:\\text{p}\\text{h}\\text{e}\\text{n}\\text{o}\\text{l}\\text{i}\\text{c}\\:\\text{d}\\text{o}\\text{n}\\text{o}\\text{r}\\:\\left[\\text{18,19}\\right].\\:\\text{T}\\text{h}\\text{e}\\:\\text{g}\\text{r}\\text{a}\\text{d}\\text{u}\\text{a}\\text{l}\\:\\text{p}\\text{H}\\:\\)\u003c/span\u003e\u003c/span\u003edrop from 7.1 to 6.8 observed after the reaction (Section \u003cspan refid=\"Sec10\" class=\"InternalRef\"\u003e2.4\u003c/span\u003e) corroborates the consumption of protons during this reduction. Terpenoids and tannins present in the extract further assisted stabilization by adsorbing onto the nanoparticle surface through π\u0026ndash;π and hydrogen-bonding interactions, forming an organic shell that prevents agglomeration [8]. This biogenic capping layer also imparts mild negative surface charge, as later confirmed by zeta-potential measurements (Section \u003cspan refid=\"Sec30\" class=\"InternalRef\"\u003e3.6\u003c/span\u003e). The final reaction mixture exhibited a stable reddish-brown dispersion with no visible precipitation after 24 h, indicating colloidal stability. This observation differs markedly from chemically synthesized V₂O₅ sols, which typically require surfactants or polymers for stabilization [\u003cspan citationid=\"CR41\" class=\"CitationRef\"\u003e41\u003c/span\u003e, \u003cspan citationid=\"CR42\" class=\"CitationRef\"\u003e42\u003c/span\u003e]. The successful reduction and stabilization by \u003cem\u003eP. cereifera\u003c/em\u003e extract thus validate its efficiency as a dual-function reducing\u0026thinsp;+\u0026thinsp;capping system (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003eb). Spectroscopic and structural analyses described in subsequent sections further confirmed the formation of orthorhombic V₂O₅ nanoparticles with average crystallite size in the 40\u0026ndash;50 nm range.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec20\" class=\"Section2\"\u003e \u003ch2\u003e3.2. UV\u0026ndash;Visible Spectroscopic Analysis\u003c/h2\u003e \u003cp\u003eThe optical behavior of the synthesized nanoparticles was examined using UV\u0026ndash;Visible spectroscopy in the 200\u0026ndash;800 nm range to confirm nanoparticle formation and assess optical transition characteristics. Figure\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e depicts the absorption spectrum of \u003cem\u003eP. cereifera\u003c/em\u003e\u0026ndash;derived vanadium oxide nanoparticles along with that of the precursor solution for comparison. The control solution containing only NH₄VO₃ displayed a strong absorption edge below 280 nm corresponding to the intrinsic charge-transfer transition of the VO₄\u0026sup3;⁻ ion in solution [\u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e]. Upon introduction of the \u003cem\u003eP. cereifera\u003c/em\u003e extract and heating at 70\u0026deg;C, the spectrum underwent a marked transformation, showing the appearance of a broad absorption band centered around 320\u0026thinsp;\u0026plusmn;\u0026thinsp;2 nm, characteristic of V\u0026ndash;O charge-transfer (CT) transitions in vanadium pentoxide nanostructures [\u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e, \u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e]. The continuous increase in absorption intensity over the first 60 min followed by a plateau at 90 min indicated the progressive nucleation and growth of V₂O₅ nanoparticles until equilibrium was reached. No distinct plasmon resonance was observed, as expected for a semiconductor-type oxide with localized d\u0026ndash;d transitions rather than free-electron oscillations [\u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e]. The absence of precursor peaks confirmed the complete reduction of vanadate ions, validating the efficiency of the \u003cem\u003eP. cereifera\u003c/em\u003e extract as a natural reducing agent. The optical band-gap energy (\u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:{E}_{g}\\)\u003c/span\u003e\u003c/span\u003e) was estimated from the Tauc relation \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:(\\alpha\\:h\\nu\\:{)}^{n}=A(h\\nu\\:-{E}_{g})\\)\u003c/span\u003e\u003c/span\u003e, where \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:\\alpha\\:\\)\u003c/span\u003e\u003c/span\u003eis the absorption coefficient, \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:h\\nu\\:\\)\u003c/span\u003e\u003c/span\u003ethe photon energy, and \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:n=\\frac{1}{2}\\)\u003c/span\u003e\u003c/span\u003efor allowed indirect transitions typical of V₂O₅ [\u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e, \u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e30\u003c/span\u003e]. The plot of \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:(\\alpha\\:h\\nu\\:{)}^{1/2}\\)\u003c/span\u003e\u003c/span\u003eversus \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:h\\nu\\:\\)\u003c/span\u003e\u003c/span\u003e(inset of Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e) yielded a linear region whose extrapolation to \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:\\left(\\alpha\\:h\\nu\\:\\right)=0\\)\u003c/span\u003e\u003c/span\u003egave \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:{E}_{g}\\approx\\:2.65\\)\u003c/span\u003e\u003c/span\u003eeV. This value falls within the reported range for nanocrystalline orthorhombic V₂O₅ (2.4\u0026ndash;2.7 eV) and is slightly lower than bulk V₂O₅ (\u0026asymp;\u0026thinsp;2.8 eV) due to quantum-size confinement and surface defect states [\u003cspan additionalcitationids=\"CR29\" citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e30\u003c/span\u003e]. The observed optical features are consistent with a semiconductor capable of visible-light absorption, suggesting potential for photocatalytic and optoelectronic applications in addition to biomedical uses [\u003cspan additionalcitationids=\"CR29\" citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e30\u003c/span\u003e]. The retention of a clear band edge and the absence of scattering tailing confirmed that the particles were well dispersed and optically homogeneous, a result attributed to biomolecular stabilization from \u003cem\u003eP. cereifera\u003c/em\u003e phytochemicals. The evolution of the UV\u0026ndash;Vis profile during synthesis (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e inset, time-resolved scans) also reflected the reduction kinetics. The gradual red-shift of the absorption edge with reaction time implies increasing particle size and the conversion from amorphous intermediates to crystalline V₂O₅ domains. Similar temporal behaviour has been reported in plant-mediated syntheses of vanadium and tungsten oxides [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e, \u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e], further validating the proposed reduction mechanism (Section \u003cspan refid=\"Sec31\" class=\"InternalRef\"\u003e3.7\u003c/span\u003e).\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec21\" class=\"Section2\"\u003e \u003ch2\u003e3.3. Fourier-Transform Infrared (FTIR) Spectroscopic Analysis\u003c/h2\u003e \u003cdiv id=\"Sec22\" class=\"Section3\"\u003e \u003ch2\u003e3.3.1. Comparison of Extract and Nanoparticle Spectra\u003c/h2\u003e \u003cp\u003eThe FTIR spectrum of the crude leaf extract exhibited characteristic absorption bands at 3415 cm⁻\u0026sup1; (O\u0026ndash;H stretching of phenolic and alcoholic groups), 2925 cm⁻\u0026sup1; (C\u0026ndash;H asymmetric stretching), 1635 cm⁻\u0026sup1; (C\u0026thinsp;=\u0026thinsp;O stretching of conjugated carbonyl groups in flavonoids), 1380 cm⁻\u0026sup1; (C\u0026ndash;N stretching of amines), and 1060 cm⁻\u0026sup1; (C\u0026ndash;O stretching of polyols) [\u003cspan additionalcitationids=\"CR10\" citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e]. These bands confirm the presence of polyphenols, flavonoids, and terpenoids capable of donating electrons during the reduction process. After reaction with NH₄VO₃, the FTIR spectrum of the P. cereifera\u0026ndash;V₂O₅ nanoparticles revealed clear spectral changes. A pronounced shift of the O\u0026ndash;H stretching band from 3415 \u0026rarr; 3392 cm⁻\u0026sup1;, along with attenuation of the C\u0026thinsp;=\u0026thinsp;O peak at 1635 cm⁻\u0026sup1;, indicated the involvement of hydroxyl and carbonyl groups in metal coordination with vanadium species [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e]. Simultaneously, two new peaks at 990 cm⁻\u0026sup1; and 820 cm⁻\u0026sup1; appeared, corresponding respectively to V\u0026thinsp;=\u0026thinsp;O and V\u0026ndash;O\u0026ndash;V stretching vibrations, confirming the formation of the orthorhombic V₂O₅ phase [\u003cspan additionalcitationids=\"CR5\" citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e, \u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e].The FTIR spectra of pure extract, uncalcined, and calcined V₂O₅ nanoparticles are shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e, clearly demonstrating phytochemical involvement in both reduction and stabilization of the nanoparticles.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec23\" class=\"Section3\"\u003e \u003ch2\u003e3.3.2. Evidence of biomolecular capping\u003c/h2\u003e \u003cp\u003eResidual organic features persisted even after calcination, though with reduced intensity, including weak bands near 3410 cm⁻\u0026sup1; (hydroxyl), 1620 cm⁻\u0026sup1; (amide I / C\u0026thinsp;=\u0026thinsp;O), and 1385 cm⁻\u0026sup1; (C\u0026ndash;O). Their presence indicates that a thin layer of carbonaceous or polymeric phytochemical residues remained adsorbed on the nanoparticle surface, acting as stabilizing capping agents [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]. Such surface-bound biomolecules enhance dispersion stability and provide reactive sites for potential biomedical conjugation. Comparable signatures of biomolecular coatings have been reported in plant-derived TiO₂ and Fe₂O₃ nanostructures [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e, \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e].\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec24\" class=\"Section3\"\u003e \u003ch2\u003e3.3.3. Mechanistic interpretation\u003c/h2\u003e \u003cp\u003eThe shift and intensity changes of the O\u0026ndash;H and C\u0026thinsp;=\u0026thinsp;O peaks support the proposed redox mechanism, wherein electron-donating hydroxyl groups of phenolic acids reduce vanadate ions (VO₃⁻ \u0026rarr; V₂O₅) while being oxidized to quinone-like species [\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e, \u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e]. The concurrent appearance of strong V\u0026ndash;O\u0026ndash;V stretching bands confirms the completion of reduction and subsequent condensation of VO₅ units into the V₂O₅ framework. Thus, FTIR data substantiate that \u003cem\u003eP. cereifera\u003c/em\u003e biomolecules perform dual functions\u0026mdash;chemical reduction and surface passivation\u0026mdash;without the need for external surfactants or stabilizers.\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv id=\"Sec25\" class=\"Section2\"\u003e \u003ch2\u003e3.4. X-ray Diffraction (XRD) Analysis\u003c/h2\u003e \u003cp\u003eX-ray diffraction (XRD) was performed to determine the crystallographic phase, structural purity, and average crystallite size of the \u003cem\u003eP. cereifera\u003c/em\u003e\u0026ndash;mediated V₂O₅ nanoparticles. The diffraction pattern (Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003e) of the calcined powder exhibited a distinct set of sharp and intense peaks, demonstrating that the particles were highly crystalline in nature. Prominent diffraction reflections were observed at 2θ values of 15.4\u0026deg;, 20.3\u0026deg;, 21.6\u0026deg;, 26.2\u0026deg;, 31.0\u0026deg;, 34.1\u0026deg;, 41.3\u0026deg;, and 49.2\u0026deg;, which correspond to the crystallographic planes (200), (001), (101), (110), (310), (301), (411), and (002), respectively. These reflections match perfectly with the orthorhombic phase of vanadium pentoxide (V₂O₅) as indexed by the standard JCPDS file No. 41-1426 [\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e, \u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e]. No additional impurity peaks were detected, confirming the phase purity of the biosynthesized product. The relatively narrow full width at half maximum (FWHM) of the reflections indicates fine crystallinity and uniform grain growth. The average crystallite size (D) was calculated using the Debye\u0026ndash;Scherrer equation, \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:D=K\\lambda\\:/(\\beta\\:\\text{c}\\text{o}\\text{s}\\theta\\:)\\)\u003c/span\u003e\u003c/span\u003e\u003cb\u003e[10]\u003c/b\u003e. The calculated average crystallite size was \u0026asymp;\u0026thinsp;45\u0026thinsp;\u0026plusmn;\u0026thinsp;5 nm, consistent with nanoscale dimensions observed in TEM micrographs (Section \u003cspan refid=\"Sec26\" class=\"InternalRef\"\u003e3.5\u003c/span\u003e). Similar crystallite size ranges (40\u0026ndash;50 nm) have been reported for green-synthesized V₂O₅ using \u003cem\u003eAloe vera\u003c/em\u003e and \u003cem\u003eMoringa oleifera\u003c/em\u003e extracts [\u003cspan additionalcitationids=\"CR54\" citationid=\"CR53\" class=\"CitationRef\"\u003e53\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR55\" class=\"CitationRef\"\u003e55\u003c/span\u003e]. The high-intensity (001) and (101) peaks signify preferred orientation along the c-axis, typical of layered orthorhombic V₂O₅, where VO₅ square pyramids stack through vanadyl oxygen bridges [\u003cspan additionalcitationids=\"CR28 CR29\" citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e30\u003c/span\u003e]. This orientation enhances ion intercalation capacity and redox reversibility\u0026mdash;properties valuable for catalytic and energy-storage applications [\u003cspan additionalcitationids=\"CR29\" citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e30\u003c/span\u003e]. Minor broadening at higher angles suggests microstrain and crystallite size distribution induced by the organic-mediated nucleation mechanism [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e]. During green synthesis, the presence of phytochemicals regulates crystal growth by selectively adsorbing on high-energy facets, resulting in smaller crystallites and surface-rich nanostructures. The absence of any detectable secondary phases such as V₂O₃, VO₂, or V₆O₁₃ confirms that the reaction and calcination parameters (450\u0026deg;C, 2 h) were optimized for complete conversion to V₂O₅ [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]. The well-defined XRD pattern therefore validates that the biosynthesized nanoparticles are single-phase orthorhombic V₂O₅ with high crystallinity and stability.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec26\" class=\"Section2\"\u003e \u003ch2\u003e3.5. Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM) Analysis\u003c/h2\u003e \u003cdiv id=\"Sec27\" class=\"Section3\"\u003e \u003ch2\u003e3.5.1. Surface morphology (SEM)\u003c/h2\u003e \u003cp\u003eThe surface morphology of the biosynthesized \u003cem\u003eP. cereifera\u003c/em\u003e\u0026ndash;V₂O₅ nanoparticles was examined using scanning electron microscopy (SEM), and representative micrographs are shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003e(a\u0026ndash;c). The SEM images revealed that the nanoparticles were uniformly distributed and predominantly exhibited quasi-spherical to slightly elongated morphologies. The average particle size determined from direct SEM measurements ranged between 20 and 60 nm, with a mean value of approximately 38\u0026thinsp;\u0026plusmn;\u0026thinsp;5 nm, which closely corresponds to the crystallite size estimated from XRD analysis (\u0026asymp;\u0026thinsp;45 nm). The nanosized dimension confirms that the phytochemical-mediated route enables efficient size control under mild synthesis conditions. Most particles appeared as loosely aggregated nanoscale clusters, attributable to the presence of surface-adsorbed phytochemical residues that act as natural capping and binding agents between individual crystallites [\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e, \u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e]. At higher magnification (Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003ec), the nanoparticle surfaces appeared rough and textured, a characteristic feature of biogenically synthesized metal oxides where residual biomolecules influence nucleation and limit excessive grain coalescence [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e, \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e]. The overall morphology is consistent with previous reports of green-synthesized V₂O₅ nanoparticles obtained from \u003cem\u003eAloe vera\u003c/em\u003e and \u003cem\u003eAzadirachta indica\u003c/em\u003e extracts [\u003cspan additionalcitationids=\"CR54\" citationid=\"CR53\" class=\"CitationRef\"\u003e53\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR55\" class=\"CitationRef\"\u003e55\u003c/span\u003e], confirming that the phytochemical matrix of \u003cem\u003eP. cereifera\u003c/em\u003e effectively governs nucleation and growth kinetics, yielding smaller, homogeneous nanostructures. The energy-dispersive X-ray (EDX) spectrum (Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003ed) confirmed the elemental composition, showing intense peaks corresponding exclusively to vanadium (V) and oxygen (O), verifying the formation of phase-pure V₂O₅. Trace peaks of carbon were attributed to surface-bound organic residues from phytochemical capping. The absence of extraneous signals for nitrogen, chlorine, or other contaminants indicates complete removal of unreacted precursors. The observed V:O atomic ratio (~\u0026thinsp;1:2.4) agrees well with the stoichiometric composition of V₂O₅ [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e], affirming the high chemical purity and homogeneity of the biosynthesized nanoparticles.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec28\" class=\"Section3\"\u003e \u003ch2\u003e3.5.2. Internal structure and particle size (TEM)\u003c/h2\u003e \u003cp\u003eTransmission electron microscopy (TEM) provided detailed insight into particle size, shape, and crystallinity. Representative TEM micrographs are shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig6\" class=\"InternalRef\"\u003e6\u003c/span\u003e(a\u0026ndash;d). The nanoparticles exhibited a predominantly spherical morphology with an average particle size range of 20\u0026ndash;60 nm (mean\u0026thinsp;\u0026asymp;\u0026thinsp;38 nm), in close agreement with the XRD-derived crystallite size (\u0026asymp;\u0026thinsp;45 nm). The narrow particle-size distribution demonstrated that the reaction kinetics under mild temperature (70\u0026deg;C) and near-neutral pH favored controlled nucleation and uniform growth [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e]. The high-resolution TEM (HRTEM) image (Fig.\u0026nbsp;\u003cspan refid=\"Fig6\" class=\"InternalRef\"\u003e6\u003c/span\u003ec) displayed well-defined lattice fringes with an interplanar spacing (d) of 0.34 nm, corresponding to the (001) plane of orthorhombic V₂O₅ [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e]. The presence of clear lattice fringes confirmed the high degree of crystallinity obtained even at relatively low calcination temperature (450\u0026deg;C). The selected-area electron diffraction (SAED) pattern (Fig.\u0026nbsp;\u003cspan refid=\"Fig6\" class=\"InternalRef\"\u003e6\u003c/span\u003ed) showed a set of concentric bright rings indexed to the (001), (101), (110), (310), and (301) planes, further substantiating the polycrystalline nature of the nanoparticles [\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e, \u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e]. The well-defined SAED rings and the absence of amorphous halos indicated that the nanoparticles were crystalline and free from significant structural defects.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec29\" class=\"Section3\"\u003e \u003ch2\u003e3.5.3. Morphological mechanism and comparison\u003c/h2\u003e \u003cp\u003eThe formation of uniform spherical particles can be attributed to the coordinating action of phenolic and flavonoid compounds present in \u003cem\u003eP. cereifera\u003c/em\u003e extract. During nucleation, these biomolecules adsorb onto the nascent nuclei through \u0026ndash;OH and \u0026ndash;C\u0026thinsp;=\u0026thinsp;O interactions, creating an organic matrix that regulates growth direction and prevents uncontrolled aggregation [\u003cspan additionalcitationids=\"CR18\" citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e]. This biotemplating mechanism is a distinguishing feature of green synthesis methods and is responsible for the high surface smoothness and stable morphology observed here. In comparison to hydrothermally synthesized V₂O₅ (which typically exhibits rod- or plate-like morphology with particle sizes\u0026thinsp;\u0026gt;\u0026thinsp;100 nm) [\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e, \u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e], the \u003cem\u003eP. cereifera\u003c/em\u003e\u0026ndash;derived V₂O₅ nanoparticles are smaller and more uniformly distributed, demonstrating the superior morphology-control ability of plant-derived reducing systems. Overall, SEM and TEM analyses confirmed that the biogenic nanoparticles possessed uniform nanoscale morphology, high crystallinity, and phase purity, which are prerequisites for consistent biological and catalytic performance.\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv id=\"Sec30\" class=\"Section2\"\u003e \u003ch2\u003e3.6. Zeta Potential and Colloidal Stability Analysis\u003c/h2\u003e \u003cp\u003eThe zeta potential of the \u003cem\u003eP. cereifera\u003c/em\u003e\u0026ndash;V₂O₅ nanoparticle suspension was measured to assess colloidal stability and surface charge characteristics. The recorded value of \u0026minus;\u0026thinsp;28.4 mV (Fig.\u0026nbsp;\u003cspan refid=\"Fig7\" class=\"InternalRef\"\u003e7\u003c/span\u003e) indicates that the nanoparticles possess a moderate-to-high degree of electrostatic stability, which effectively prevents aggregation through inter-particle repulsion [\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e, \u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e]. According to classical stability criteria (DLVO paradigm), dispersions exhibiting absolute zeta-potential values greater than \u0026plusmn;\u0026thinsp;25 mV are considered electrostatically stable because the repulsive potential energy outweighs van der Waals attractions [\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e, \u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e]. Therefore, the \u003cem\u003eP. cereifera\u003c/em\u003e\u0026ndash;derived nanoparticles are sufficiently stable for long-term dispersion in aqueous media without requiring synthetic surfactants or polymeric stabilizers. The observed negative surface charge originates primarily from the deprotonation of phenolic (\u0026ndash;OH) and carboxyl (\u0026ndash;COOH) groups of the phytochemicals adsorbed on the nanoparticle surface. These functional moieties form coordination bonds with surface vanadium atoms while exposing anionic oxygen groups to the surrounding medium, thereby imparting a persistent negative potential [\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e, \u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e]. FTIR analysis (Section \u003cspan refid=\"Sec21\" class=\"InternalRef\"\u003e3.3\u003c/span\u003e) had already confirmed the presence of these groups, validating their dual role in reduction and capping. The relatively high magnitude of zeta potential (\u0026minus;\u0026thinsp;28.4 mV) correlates strongly with the excellent colloidal stability observed visually and through optical measurements\u0026mdash;no sedimentation or turbidity increase was detected even after 30 days of storage at 25\u0026deg;C (Fig.\u0026nbsp;\u003cspan refid=\"Fig7\" class=\"InternalRef\"\u003e7\u003c/span\u003e inset). Comparable stability values have been reported for green-synthesized V₂O₅ nanoparticles derived from \u003cem\u003eMoringa oleifera\u003c/em\u003e (\u0026minus;\u0026thinsp;26 mV) and \u003cem\u003eAloe vera\u003c/em\u003e (\u0026minus;\u0026thinsp;29 mV) [\u003cspan citationid=\"CR53\" class=\"CitationRef\"\u003e53\u003c/span\u003e, \u003cspan citationid=\"CR55\" class=\"CitationRef\"\u003e55\u003c/span\u003e], confirming that naturally occurring capping agents can generate surface charges equivalent to those achieved using chemical surfactants. The high surface charge also plays a vital role in the biological performance of the nanoparticles. Negatively charged surfaces favor dispersion in physiological media and reduce nonspecific protein adsorption, thereby improving cytocompatibility during cellular exposure [\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e, \u003cspan citationid=\"CR40\" class=\"CitationRef\"\u003e40\u003c/span\u003e]. Furthermore, electrostatic attraction between negatively charged nanoparticle surfaces and positively charged microbial membranes enhances antimicrobial interactions, contributing to the activity discussed later in Section \u003cspan refid=\"Sec32\" class=\"InternalRef\"\u003e3.8\u003c/span\u003e [\u003cspan additionalcitationids=\"CR32 CR33\" citationid=\"CR31\" class=\"CitationRef\"\u003e31\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR34\" class=\"CitationRef\"\u003e34\u003c/span\u003e]. Overall, the zeta-potential data validate that the \u003cem\u003eP. cereifera\u003c/em\u003e\u0026ndash;mediated synthesis yields electrostatically stable, biocompatible V₂O₅ nanoparticles with surface properties suitable for biomedical and catalytic applications.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec31\" class=\"Section2\"\u003e \u003ch2\u003e3.7. Antidiabetic (α-Amylase Inhibition) and Anticancer (MTT) Activities\u003c/h2\u003e \u003cp\u003eThe α-amylase inhibition assay showed a clear, concentration-dependent suppression of enzymatic activity by \u003cem\u003eP. cereifera\u003c/em\u003e\u0026ndash;V₂O₅ nanoparticles, yielding an IC₅₀ of \u003cb\u003e\u0026asymp;\u0026thinsp;38.4 \u0026micro;g mL⁻\u0026sup1;\u003c/b\u003e, consistent with green-synthesized metal-oxide nanomaterials evaluated by the DNS method and non-linear regression analysis [\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e, \u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e]. The efficiency is attributable to (i) the high surface area of nanosized V₂O₅ which enables effective enzyme\u0026ndash;nanoparticle interactions and (ii) surface-bound phytochemicals that may sterically/electrostatically perturb the active site environment [\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e, \u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e, \u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e]. Cytotoxicity profiling by MTT revealed \u003cb\u003edose-dependent antiproliferative effects\u003c/b\u003e against A549 cells with significantly lower impact on HEK-293 at working concentrations, indicating a \u003cb\u003etherapeutic window\u003c/b\u003e for cancer targeting [\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e]. The observed anticancer action aligns with established mechanisms for vanadium-based nanostructures: \u003cb\u003eROS overproduction\u003c/b\u003e, \u003cb\u003emitochondrial membrane depolarization\u003c/b\u003e, and \u003cb\u003eapoptosis induction\u003c/b\u003e in malignant cells [\u003cspan additionalcitationids=\"CR2\" citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e, \u003cspan citationid=\"CR38\" class=\"CitationRef\"\u003e38\u003c/span\u003e]. Literature on vanadium nanomaterials further supports selective bioactivity and biomedical promise when particle size, surface chemistry, and capping ligands are optimized [\u003cspan citationid=\"CR37\" class=\"CitationRef\"\u003e37\u003c/span\u003e]. Together, these results corroborate the dual \u003cb\u003eantidiabetic\u003c/b\u003e and \u003cb\u003eanticancer\u003c/b\u003e potential of the biogenic V₂O₅ system while remaining compatible with colloidal stability and dispersion behavior reported earlier [\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e, \u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e].\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec32\" class=\"Section2\"\u003e \u003ch2\u003e3.8. Antimicrobial and Antifungal Activity\u003c/h2\u003e \u003cp\u003eAgar diffusion assays demonstrated \u003cb\u003ebroad-spectrum antimicrobial efficacy\u003c/b\u003e of \u003cem\u003eP. cereifera\u003c/em\u003e\u0026ndash;V₂O₅ nanoparticles (Figs.\u0026nbsp;\u003cspan refid=\"Fig8\" class=\"InternalRef\"\u003e8\u003c/span\u003e\u0026ndash;\u003cspan refid=\"Fig11\" class=\"InternalRef\"\u003e11\u003c/span\u003e). Against bacteria, mean inhibition-zone diameters were \u003cb\u003e~\u0026thinsp;18 mm\u003c/b\u003e for \u003cem\u003eS. aureus\u003c/em\u003e and \u003cem\u003eE. coli\u003c/em\u003e, and \u003cb\u003e~\u0026thinsp;17\u0026ndash;18 mm\u003c/b\u003e for \u003cem\u003eB. subtilis\u003c/em\u003e and \u003cem\u003eP. aeruginosa\u003c/em\u003e, exceeding the plant extract (~\u0026thinsp;10\u0026ndash;11 mm) and approaching the standard antibiotic control (\u003cb\u003e~\u0026thinsp;20 mm\u003c/b\u003e) [\u003cspan additionalcitationids=\"CR32 CR33\" citationid=\"CR31\" class=\"CitationRef\"\u003e31\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR34\" class=\"CitationRef\"\u003e34\u003c/span\u003e]. Antifungal assays likewise showed\u0026thinsp;\u003cb\u003e~\u0026thinsp;14\u0026ndash;16 mm\u003c/b\u003e zones against \u003cem\u003eCandida albicans\u003c/em\u003e, \u003cem\u003eAspergillus niger\u003c/em\u003e, \u003cem\u003eFusarium oxysporum\u003c/em\u003e, and \u003cem\u003ePenicillium\u003c/em\u003e sp., outperforming the extract and aligning with recent reports on vanadium-oxide nanomaterials [\u003cspan additionalcitationids=\"CR32 CR33\" citationid=\"CR31\" class=\"CitationRef\"\u003e31\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR34\" class=\"CitationRef\"\u003e34\u003c/span\u003e, \u003cspan citationid=\"CR38\" class=\"CitationRef\"\u003e38\u003c/span\u003e, \u003cspan citationid=\"CR41\" class=\"CitationRef\"\u003e41\u003c/span\u003e, \u003cspan citationid=\"CR42\" class=\"CitationRef\"\u003e42\u003c/span\u003e].Mechanistically, activity is explained by \u003cb\u003emultimodal interactions\u003c/b\u003e: (i) \u003cb\u003eROS generation\u003c/b\u003e at the nanoparticle interface causing lipid peroxidation, protein oxidation, and DNA damage [\u003cspan additionalcitationids=\"CR2\" citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e, \u003cspan citationid=\"CR36\" class=\"CitationRef\"\u003e36\u003c/span\u003e, \u003cspan citationid=\"CR40\" class=\"CitationRef\"\u003e40\u003c/span\u003e, \u003cspan additionalcitationids=\"CR44\" citationid=\"CR43\" class=\"CitationRef\"\u003e43\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR45\" class=\"CitationRef\"\u003e45\u003c/span\u003e]; (ii) \u003cb\u003emembrane association\u003c/b\u003e and local disruption, aided by negative surface charge and nanoscale curvature that promote adhesion to microbe envelopes [\u003cspan additionalcitationids=\"CR32 CR33\" citationid=\"CR31\" class=\"CitationRef\"\u003e31\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR34\" class=\"CitationRef\"\u003e34\u003c/span\u003e]; and (iii) a \u003cb\u003ephytochemical corona\u003c/b\u003e that can synergize with V₂O₅ to enhance redox stress and/or chelation at cell surfaces [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e, \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e, \u003cspan citationid=\"CR39\" class=\"CitationRef\"\u003e39\u003c/span\u003e]. The magnitude of zeta potential (\u0026minus;\u0026thinsp;28.4 mV) reported in Section \u003cspan refid=\"Sec30\" class=\"InternalRef\"\u003e3.6\u003c/span\u003e supports \u003cb\u003estable dispersion and effective cell-surface contact\u003c/b\u003e, which correlates with stronger inhibition outcomes [\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e, \u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e, \u003cspan additionalcitationids=\"CR32 CR33\" citationid=\"CR31\" class=\"CitationRef\"\u003e31\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR34\" class=\"CitationRef\"\u003e34\u003c/span\u003e]. Overall, the antimicrobial/antifungal results validate the \u003cb\u003ebiogenic V₂O₅\u003c/b\u003e as a potent, plant-assisted oxide nanomaterial consistent with current literature benchmarks [\u003cspan additionalcitationids=\"CR32 CR33\" citationid=\"CR31\" class=\"CitationRef\"\u003e31\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR34\" class=\"CitationRef\"\u003e34\u003c/span\u003e, \u003cspan additionalcitationids=\"CR39 CR40 CR41 CR42 CR43 CR44\" citationid=\"CR38\" class=\"CitationRef\"\u003e38\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR45\" class=\"CitationRef\"\u003e45\u003c/span\u003e] and reinforce its suitability for biomedical disinfection or coating applications.\u003c/p\u003e \u003c/div\u003e"},{"header":"4. Discussion","content":"\u003cp\u003eThe green synthesis route used in this study demonstrates several advantages over conventional chemical approaches reported for V₂O₅ nanoparticles, including reduced energy consumption, lower toxicity, and higher sustainability when compared to sol\u0026ndash;gel and hydrothermal synthesis methods [\u003cspan citationid=\"CR41\" class=\"CitationRef\"\u003e41\u003c/span\u003e, \u003cspan citationid=\"CR42\" class=\"CitationRef\"\u003e42\u003c/span\u003e]. The presence of phenolics and flavonoids in \u003cem\u003eParmentiera cereifera\u003c/em\u003e extract enabled effective reduction and stabilization of vanadium species, which aligns with previous green synthesis reports using \u003cem\u003eAloe vera\u003c/em\u003e and \u003cem\u003eMoringa oleifera\u003c/em\u003e extracts [\u003cspan additionalcitationids=\"CR54\" citationid=\"CR53\" class=\"CitationRef\"\u003e53\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR55\" class=\"CitationRef\"\u003e55\u003c/span\u003e].The zeta potential value of \u0026minus;\u0026thinsp;28.4 mV confirms the electrostatic stability of the nanoparticles, supporting the findings of Alam et al. [\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e, \u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e], who demonstrated that phytochemical-mediated synthesis generates sufficient surface charge to prevent aggregation. Additionally, the crystalline morphology observed in XRD and TEM corresponds well with previous studies on orthorhombic V₂O₅ formation [\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e, \u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e, \u003cspan additionalcitationids=\"CR28 CR29\" citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e30\u003c/span\u003e]. The biological activity observed in this work may be attributed to a dual mechanism:\u003c/p\u003e \u003cp\u003e \u003col\u003e \u003cspan\u003e \u003cli\u003e \u003cp\u003eROS-mediated stress generation and\u003c/p\u003e \u003c/li\u003e \u003c/span\u003e \u003cspan\u003e \u003cli\u003e \u003cp\u003esynergistic interaction between vanadium ions and surface-bound phytochemicals.\u003c/p\u003e \u003c/li\u003e \u003c/span\u003e \u003c/ol\u003e \u003c/p\u003e \u003cp\u003eThis mechanism is consistent with reports indicating that vanadium-based nanomaterials induce oxidative damage in microbial and cancer cells [\u003cspan additionalcitationids=\"CR2\" citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e, \u003cspan citationid=\"CR36\" class=\"CitationRef\"\u003e36\u003c/span\u003e, \u003cspan additionalcitationids=\"CR39\" citationid=\"CR38\" class=\"CitationRef\"\u003e38\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR40\" class=\"CitationRef\"\u003e40\u003c/span\u003e]. Similar biological responses were documented by Liu et al. [2024] and Hussain et al. [2024], who proposed apoptosis induction via mitochondrial membrane depolarization and ROS overproduction [\u003cspan citationid=\"CR38\" class=\"CitationRef\"\u003e38\u003c/span\u003e, \u003cspan citationid=\"CR45\" class=\"CitationRef\"\u003e45\u003c/span\u003e]. Although this study demonstrates promising results, certain limitations exist, including the absence of molecular pathway analysis such as ROS quantification, apoptosis-marker expression, Western blot, or qPCR analysis. Future studies should include in vivo biocompatibility, gene expression analysis, and the development of nanocomposites for biomedical applications, as recommended by Thomas et al. [2025] and Basha et al. [2025].\u003c/p\u003e"},{"header":"5. Conclusion and Future Perspectives","content":"\u003cp\u003eIn this study, a sustainable, low-cost, and eco-friendly route was successfully developed for the green synthesis of vanadium pentoxide (V₂O₅) nanoparticles using the aqueous leaf extract of \u003cem\u003eParmentiera cereifera\u003c/em\u003e for the first time. The phytochemical constituents\u0026mdash;primarily phenolic acids, flavonoids, tannins, and terpenoids\u0026mdash;played a dual role as reducing and stabilizing agents, enabling the efficient conversion of vanadate ions (VO₃⁻) into crystalline V₂O₅ under mild, near-neutral conditions. The distinctive color transition from pale yellow to reddish-brown visually confirmed nanoparticle formation, while spectroscopic and microscopic characterizations substantiated their structural integrity and stability.The biogenic V₂O₅ nanoparticles exhibited an orthorhombic crystalline phase (JCPDS 41-1426) with an average crystallite size of ~\u0026thinsp;45 nm, as verified by XRD and TEM analyses. FTIR confirmed the involvement of hydroxyl and carbonyl groups in the reduction and capping mechanism, while zeta potential measurements (\u0026minus;\u0026thinsp;28.4 mV) validated their colloidal stability. The nanoparticles demonstrated notable biological functionality, including \u0026alpha;-amylase inhibition (IC₅₀ \u0026asymp; 38.4 \u0026micro;g mL⁻\u0026sup1;), selective cytotoxicity against A549 cancer cells, and broad-spectrum antimicrobial activity against \u003cem\u003eStaphylococcus aureus\u003c/em\u003e, \u003cem\u003eEscherichia coli\u003c/em\u003e, and \u003cem\u003eCandida albicans\u003c/em\u003e. The observed activities were attributed to the synergistic effects of the V₂O₅ core and the phytochemical corona, which together enhanced redox reactivity, cellular uptake, and surface interactions.The present work not only identifies \u003cem\u003eP. cereifera\u003c/em\u003e as an unexplored and effective biogenic resource for vanadium-based nanomaterials but also establishes a reproducible green synthesis platform compatible with biomedical and environmental applications. Quantitative green metrics confirmed high atom economy and a reduced environmental footprint compared to conventional chemical or hydrothermal synthesis. These findings align with the global transition toward sustainable nanotechnology and circular bioeconomy principles.\u003c/p\u003e\n\u003cp\u003eFuture Perspectives\u003c/p\u003e\n\u003cp\u003eWhile this study demonstrates the feasibility and multifunctionality of \u003cem\u003eP. cereifera\u003c/em\u003e\u0026ndash;mediated V₂O₅ nanoparticles, several avenues remain open for future exploration:\u003c/p\u003e\n\u003cp\u003e1. Biomedical mechanistic studies:\u003c/p\u003e\n\u003cdiv class=\"BlockQuote\"\u003e\n\u003cp\u003eDetailed molecular-level investigations, such as ROS quantification, mitochondrial membrane potential assays, and apoptotic pathway analysis, could further elucidate the anticancer mechanism of these nanoparticles.\u003c/p\u003e\n\u003cp\u003e2. In vivo biocompatibility and toxicity profiling:\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv class=\"BlockQuote\"\u003e\n\u003cp\u003eAnimal-model studies are essential to assess pharmacokinetics, biodistribution, and long-term biocompatibility, thereby validating biomedical applicability.\u003c/p\u003e\n\u003cp\u003e3. Catalytic and photocatalytic applications:\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv class=\"BlockQuote\"\u003e\n\u003cp\u003eThe visible-light band gap (~\u0026thinsp;2.65 eV) suggests potential use in environmental photocatalysis, such as organic pollutant degradation and solar energy conversion.\u003c/p\u003e\n\u003cp\u003e4. Nanocomposite development:\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv class=\"BlockQuote\"\u003e\n\u003cp\u003eIncorporating \u003cem\u003eP. cereifera\u003c/em\u003e\u0026ndash;derived V₂O₅ NPs into polymeric or biopolymer matrices could yield hybrid materials for wound healing, drug delivery, or biosensing.\u003c/p\u003e\n\u003cp\u003e5. Phytochemical mechanistic mapping:\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv class=\"BlockQuote\"\u003e\n\u003cp\u003eAdvanced spectroscopic and chromatographic analyses (LC\u0026ndash;MS/MS, NMR) could identify specific biomolecules responsible for vanadate reduction, improving reproducibility and scalability.\u003c/p\u003e\n\u003c/div\u003e\n\u003cp\u003eIn conclusion, the present research not only contributes a novel biogenic route for vanadium oxide nanoparticle synthesis but also advances the broader agenda of sustainable nanomaterial development. Future interdisciplinary studies integrating green chemistry, nanobiotechnology, and materials engineering could establish \u003cem\u003eP. cereifera\u003c/em\u003e\u0026ndash;based nanostructures as versatile agents for biomedical, catalytic, and environmental applications.\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003cdiv class=\"DefinitionList\"\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eNPs\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eNanoparticles\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eUV\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eVis\u0026ndash;Ultraviolet\u0026ndash;Visible Spectroscopy\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eFTIR\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eFourier Transform Infrared Spectroscopy\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eXRD\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eX\u0026ndash;ray Diffraction\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eSEM\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eScanning Electron Microscopy\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eTEM\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eTransmission Electron Microscopy\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eEDX\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eEnergy\u0026ndash;Dispersive X\u0026ndash;ray Spectroscopy\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eROS\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eReactive Oxygen Species\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eTPC\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eTotal Phenolic Content\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eTFC\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eTotal Flavonoid Content\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eGAE\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eGallic Acid Equivalent\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eQE\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eQuercetin Equivalent\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eDNS\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eDinitrosalicylic Acid\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eANOVA\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eAnalysis of Variance\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eSD\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eStandard Deviation\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eS/N Ratio\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eSignal\u0026ndash;to\u0026ndash;Noise Ratio\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eJCPDS\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eJoint Committee on Powder Diffraction Standards\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eMTT\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003e3\u0026ndash;(4,5\u0026ndash;dimethyl\u0026ndash;thiazol\u0026ndash;2\u0026ndash;yl)\u0026ndash;2,5\u0026ndash;diphenyltetrazolium bromide\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eRPM\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eRevolutions Per Minute\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003ePBS\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003ePhosphate Buffered Saline\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eIC50\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eHalf\u0026ndash;Maximal Inhibitory Concentration\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eWHO\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eWorld Health Organization\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eFDA\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eFood and Drug Administration\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eDLS\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eDynamic Light Scattering\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eMeOH\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eMethanol\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eDMSO\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eDimethyl Sulfoxide\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eCV\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eCell Viability\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eNIST\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eNational Institute of Standards and Technology\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eOD\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eOptical Density\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003c/div\u003e"},{"header":"Declarations","content":"\u003ch2\u003e\u003cstrong\u003eEthics approval and consent to participate:\u003c/strong\u003e\u003c/h2\u003e\n\u003cp\u003eNot applicable.\u003c/p\u003e\n\u003ch2\u003eFunding Statement\u003c/h2\u003e\n\u003cp\u003eThis research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.\u003c/p\u003e\n\u003ch2\u003eFunding:\u003c/h2\u003e\n\u003cp\u003eNo funding was received for this research work.\u003c/p\u003e\n\u003cp\u003eEthical statement: This research involved only plant extracts and in vitro biological assays. No human or animal subjects were involved.\u003c/p\u003e\n\u003ch2\u003eAuthor Contribution\u003c/h2\u003e\n\u003cp\u003e**P. Naveen:** Conceptualization, Methodology, Experimental Work, Data Analysis, Original Draft Preparation. **Dr.Gopi.Mamidi:** Supervision, Resources, Validation, and Critical Revision of the Manuscript. **Dr.A.Indira Priyadarsini:** Characterization Support, Visualization, Data Curation, and Review EditingAll authors have read and approved the final version of the manuscript and agree to its submission.\u003c/p\u003e\n\u003ch2\u003eAcknowledgement\u003c/h2\u003e\n\u003cp\u003eAcknowledgmentsThe authors gratefully acknowledge the support and research facilities provided by the Department of Chemistry and the Department of Botany, Government Degree College (Autonomous), Nagari, Andhra Pradesh, India. The authors express sincere thanks to Dr. Indira Priyadarshini, Botanist, GDC(A), Nagari, for authenticating the Parmentiera cereifera plant species. Technical assistance provided by the Central Instrumentation Facility (CIF), S.V. University, Tirupathi., for analytical characterization (UV\u0026ndash;Vis, FTIR, XRD, SEM, TEM, and zeta potential) is deeply appreciated. The authors also thank the Lalbagh Botanical Garden authorities, Bengaluru, for granting permission for sample collection.\u003c/p\u003e\n\u003ch2\u003eData Availability\u003c/h2\u003e\n\u003cp\u003eAll data generated or analyzed during this study are included in this published article and its supplementary information file. Additional data supporting the findings of this study are available from the corresponding author upon reasonable request.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eLiu, Y., Wang, C., Zhao, H., et al. Enhanced antibacterial properties of vanadium-based nanostructures via ROS-mediated membrane disruption. \u003cem\u003eJ. Hazard. 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Toxicol. Pharmacol.\u003c/em\u003e 110 (2024) 104097.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003ePatel, A., et al. Reactive oxygen species and metal oxide nanotoxicology. \u003cem\u003eJ. Nanobiotechnol.\u003c/em\u003e 22 (2024) 77.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBalakrishnan, R., et al. Mechanistic pathways of oxidative stress induced by transition metal oxides. \u003cem\u003eFree Radic. Biol. Med.\u003c/em\u003e 211 (2025) 73\u0026ndash;89.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eShankar, R., et al. Molecular mechanisms of nanoparticle-induced ROS generation. \u003cem\u003eBiochem. Biophys. Rep.\u003c/em\u003e 38 (2024) 101485.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eL\u0026oacute;pez, J., Contreras, F., Herrera, M. Phytochemical composition and antioxidant activity of \u003cem\u003eParmentiera cereifera\u003c/em\u003e leaf and fruit extracts. \u003cem\u003eJ. Ethnopharmacol.\u003c/em\u003e 318 (2023) 116952.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMendoza, L., P\u0026eacute;rez, E., Rivera, L. Bioactive compounds and radical scavenging capacity of Bignoniaceae species. \u003cem\u003ePhytochem. Lett.\u003c/em\u003e 62 (2024) 98\u0026ndash;106.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eCastillo, D., Morales, J., Rojas, L. Antimicrobial and antioxidant properties of phenolic-rich extracts of \u003cem\u003eParmentiera\u003c/em\u003e species. \u003cem\u003eS. Afr. J. Bot.\u003c/em\u003e 159 (2023) 62\u0026ndash;70.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMart\u0026iacute;nez, J.R., G\u0026oacute;mez, P.A. Identification of flavonoids and tannins from \u003cem\u003eParmentiera cereifera\u003c/em\u003e. \u003cem\u003eNat. Prod. Res.\u003c/em\u003e 38 (2024) 3014\u0026ndash;3025.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eVel\u0026aacute;zquez, A., Jim\u0026eacute;nez, F., Ortega, C. Biological evaluation of \u003cem\u003eParmentiera\u003c/em\u003e extracts: Antioxidant and antimicrobial potential. \u003cem\u003eInd. Crops Prod.\u003c/em\u003e 213 (2024) 117291.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eRivera, G., Rojas, A., Vargas, D. Bioresource potential of underexplored tropical flora for green nanotechnology. \u003cem\u003eEnviron. Nanotechnol. Monit. Manag.\u003c/em\u003e 26 (2025) 101099.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eCarvalho, R., da Silva, P.M. Phytochemical screening and green reduction capacity of Bignoniaceae plants. \u003cem\u003ePlant Biosyst.\u003c/em\u003e 159 (2025) 388\u0026ndash;401.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSingh, R., Meena, V.K., Sharma, P. Comparative evaluation of green-synthesized metal oxide nanoparticles using \u003cem\u003eAzadirachta indica\u003c/em\u003e, \u003cem\u003eAloe vera\u003c/em\u003e, and \u003cem\u003eMoringa oleifera\u003c/em\u003e. \u003cem\u003eMater. Today Proc.\u003c/em\u003e 74 (2024) 211\u0026ndash;219.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKumar, S., Pandey, R., Bhattacharjee, A. Mechanistic and sustainability assessment of plant-based nanomaterial synthesis. \u003cem\u003eJ. Cleaner Prod.\u003c/em\u003e 443 (2025) 140872.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGhosh, T., Natarajan, R. Integrating green chemistry principles into nanoparticle synthesis for sustainable biomedical applications. \u003cem\u003eGreen Chem. Lett. Rev.\u003c/em\u003e 17 (2024) 301\u0026ndash;317.\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"beni-suef-university-journal-of-basic-and-applied-sciences","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"jbas","sideBox":"Learn more about [Beni-Suef University Journal of Basic and Applied Sciences](https://bjbas.springeropen.com)","snPcode":"43088","submissionUrl":"https://submission.springernature.com/new-submission/43088/3","title":"Beni-Suef University Journal of Basic and Applied Sciences","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"","lastPublishedDoi":"10.21203/rs.3.rs-8174388/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-8174388/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eBackground:\u003c/h2\u003e \u003cp\u003eGreen nanotechnology offers a sustainable alternative to conventional synthesis of metal and metal-oxide nanomaterials by eliminating toxic reagents and reducing environmental burdens [\u003cspan additionalcitationids=\"CR2\" citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e]. Vanadium pentoxide (V₂O₅) holds exceptional catalytic and biomedical potential, yet its green synthesis remains largely unexplored. \u003cem\u003eParmentiera cereifera\u003c/em\u003e\u0026mdash;a phenolic and flavonoid-rich plant\u0026mdash;has never been utilized for nanoparticle fabrication. This study reports the first biogenic synthesis of V₂O₅ nanoparticles using P. cereifera leaf extract, establishing an unexplored metal\u0026ndash;plant system with biomedical relevance. To the best of our knowledge, no literature reports exist on vanadium nanoparticle synthesis using any Bignoniaceae species, highlighting the novelty of this work.\u003c/p\u003e\u003ch2\u003eMethods:\u003c/h2\u003e \u003cp\u003eThe aqueous extract of \u003cem\u003eP. cereifera\u003c/em\u003e was employed as a natural reducing and stabilizing agent for converting NH₄VO₃ into V₂O₅ nanoparticles at 70\u0026deg;C under near-neutral conditions. Characterization included UV\u0026ndash;Vis, FTIR, XRD, SEM, TEM, EDX, and zeta potential analyses. Biological activities\u0026mdash;α-amylase inhibition, MTT cytotoxicity, and antimicrobial assays\u0026mdash;were evaluated using standard protocols [\u003cspan additionalcitationids=\"CR13 CR14\" citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e]. Green metrics such as atom economy, energy consumption, and E-factor were assessed against sol\u0026ndash;gel and hydrothermal methods [\u003cspan additionalcitationids=\"CR17 CR18 CR19 CR20\" citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e].\u003c/p\u003e\u003ch2\u003eResults:\u003c/h2\u003e \u003cp\u003eA distinct absorption band at ~\u0026thinsp;320 nm and V\u0026ndash;O/V\u0026thinsp;=\u0026thinsp;O FTIR peaks confirmed nanoparticle formation. XRD indicated the orthorhombic V₂O₅ phase (JCPDS 41-1426) with crystallite size of ~\u0026thinsp;45\u0026thinsp;\u0026plusmn;\u0026thinsp;5 nm. SEM/TEM showed quasi-spherical nanoparticles (20\u0026ndash;60 nm), supported by a zeta potential of \u0026minus;\u0026thinsp;28.4 mV, indicating excellent colloidal stability. The nanoparticles demonstrated strong α-amylase inhibition (IC₅₀ \u0026asymp; 38.4 \u0026micro;g mL⁻\u0026sup1;), selective cytotoxicity toward A549 cancer cells, and broad-spectrum antimicrobial activity against \u003cem\u003eStaphylococcus aureus\u003c/em\u003e, \u003cem\u003eE. coli\u003c/em\u003e, and \u003cem\u003eCandida albicans\u003c/em\u003e [\u003cspan additionalcitationids=\"CR32 CR33\" citationid=\"CR31\" class=\"CitationRef\"\u003e31\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR34\" class=\"CitationRef\"\u003e34\u003c/span\u003e]. The dual bioactivity profile identified in this work has not been previously reported for any green-synthesized V₂O₅ system, indicating biomedical novelty. A\u0026thinsp;\u0026gt;\u0026thinsp;60% reduction in chemical usage, reaction temperature, and energy demand confirmed high sustainability over conventional synthesis.\u003c/p\u003e\u003ch2\u003eConclusions:\u003c/h2\u003e \u003cp\u003eThis work identifies \u003cem\u003eP. cereifera\u003c/em\u003e as a new biogenic resource for scalable V₂O₅ nanomaterial synthesis and introduces a reproducible pathway aligned with circular bioeconomy principles. The phytochemical-mediated mechanism produced structurally stable, functionally active nanoparticles with strong biomedical potential. Future work should involve molecular-level mechanistic studies, nanocomposite fabrication, and \u003cem\u003ein vivo\u003c/em\u003e validation.\u003c/p\u003e","manuscriptTitle":"Green Synthesis and Characterization of Vanadium Oxide (V₂O₅) Nanoparticles Using Parmentiera cereifera Leaf Extract: A Sustainable Biogenic Route with Biomedical Implications","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-05-04 09:18:51","doi":"10.21203/rs.3.rs-8174388/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2026-05-10T12:09:41+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-05-10T12:00:15+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-04-27T06:43:05+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-04-26T12:06:47+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"211894467578021928123305196912075117148","date":"2026-04-26T11:30:46+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"122077986874405387677250891531209414019","date":"2026-04-24T14:13:22+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"181784168490707897183022215101431060700","date":"2026-04-23T12:24:34+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"24701586059338320904709824532693459321","date":"2026-04-23T11:48:48+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2026-04-23T11:13:32+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2025-11-27T22:55:34+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2025-11-27T22:54:32+00:00","index":"","fulltext":""},{"type":"submitted","content":"Beni-Suef University Journal of Basic and Applied Sciences","date":"2025-11-21T14:05:29+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"beni-suef-university-journal-of-basic-and-applied-sciences","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"jbas","sideBox":"Learn more about [Beni-Suef University Journal of Basic and Applied Sciences](https://bjbas.springeropen.com)","snPcode":"43088","submissionUrl":"https://submission.springernature.com/new-submission/43088/3","title":"Beni-Suef University Journal of Basic and Applied Sciences","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false}}],"origin":"","ownerIdentity":"70d8a79a-6eea-4609-98bd-f61ebe43e2cc","owner":[],"postedDate":"May 4th, 2026","published":true,"recentEditorialEvents":[{"type":"decision","content":"Revision requested","date":"2026-05-10T12:09:41+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-05-10T12:00:15+00:00","index":26,"fulltext":""}],"rejectedJournal":[],"revision":"","amendment":"","status":"under-review","subjectAreas":[],"tags":[],"updatedAt":"2026-05-11T14:23:16+00:00","versionOfRecord":[],"versionCreatedAt":"2026-05-04 09:18:51","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-8174388","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-8174388","identity":"rs-8174388","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}