Membrane-Mediated Sars-cov-2 Host Cell Entry: Potential Inhibitory Roles of Terpenoids in Silico

Membrane-Mediated Sars-cov-2 Host Cell Entry: Potential Inhibitory Roles of Terpenoids in Silico | 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 Membrane-Mediated Sars-cov-2 Host Cell Entry: Potential Inhibitory Roles of Terpenoids in Silico Gideon Ampoma Gyebi, Oludare Ogunyemi, Ibrahim M. Ibrahim, Olalekan B. Ogunro, and 2 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-259624/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Targeting viral cell entry proteins is an emerging therapeutic strategy for inhibiting the first stage of SARS-CoV-2 infection. In this study, 106 bioactive terpenoids from African medicinal plants were screened through molecular docking analysis against human angiotensin-converting enzyme 2 ( h ACE2), human transmembrane protease serine 2 (TMPRSS2) and the S proteins of SARS-CoV-2, SARS-CoV and MERS-CoV. In silico ADMET and drug-likeness prediction, molecular dynamics simulation (MDS), binding free energy calculations and clustering analysis of MDS trajectories were performed on the top docked compounds to respective targets. The results revealed eight terpenoids with high binding tendencies to the catalytic residues of different targets. Pentacyclic terpenoids: 24-methylene cycloartenol and isoiguesterin interacted with the h ACE2 binding hotspots for the SARS-CoV-2 Spike protein. 11-hydroxy-2 - (3,4-dihydroxybenzoyloxy) abieta -5,7,9 (11),13-tetraene-12-one, 11-hydroxy-2 -(4-hydroxybenzoyloxy)-abieta- 5,7,9(11),13-tetraene-12-one and other abietane diterpenes interacted strongly with the S1-specificy pocket of TMPRSS2. 3-benzoylhosloppone and cucurbitacin interacted with the RBD and S2 subunit of SARS-CoV-2 spike protein respectively. The predicted druggable and ADMET favourable terpenoids formed structurally stable complexes in the simulated dynamics environment. These terpenoids provides core structure that can be exploited for further lead optimization to design drugs against SARS-CoV-2 cell mediated entry, subject to further in vitro and in vivo studies. General Biochemistry Biotechnology and Bioengineering SARS-CoV-2 ACE2 TMPRSS2 spike protein terpenoids molecular docking Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 Figure 10 Figure 11 Figure 12 Figure 13 Figure 14 Figure 15 Introduction The coronavirus disease-19 (COVID-19) caused by the new severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has been declared a public health emergency by the World Health Organization (WHO) [ 1-4 ]. The death toll from this virus has by far surpassed that of 2003 severe acute respiratory syndrome-coronavirus (SARS-CoV) and the 2012 Middle East respiratory syndrome coronavirus (MERS-CoV) outbreaks combined [ 5 , 6 ]. The SARS-CoV-2 earlier known as 2019 novel corona virus (2019-nCoV) is evolutionarily related (80% identity) to SARS-CoV [ 7 ]. It causes multiple organ failure, which may present as fever, cough, shortness of breath, dyspnea, pneumonia, severe acute respiratory syndrome, kidney failure, and even death [ 8 , 9 ]. Cell entry of coronaviruses depends on a fine interplay between the viral membrane spike (S) proteins and the host cell membrane proteins more importantly are the angiotensin-converting enzyme 2 (ACE2) and serine protease transmembrane protease serine 2 (TMPRSS2). [ 10 ]. The S-protein comprises two subunits, S1 as the receptor-binding domain (RBD) and S2 subunit for the fusion of viral membrane and the host cellular membrane. The SARS-CoV-2 relies on the host ACE2, for entry and the TMPRSS2 for S-protein priming. Upon binding of the S-protein to host receptor through the receptor-binding domain (RBD) in the S1 subunit, the S2 subunit mediates fusion of the viral envelope with the host membranes[ 11 ]. Although, the overall sequence similarities between S-protein of SARS-COV-2 and SARS-CoV are approximately ~76%, affinity between S-RBD of SARS-COV-2 and ACE2 is found to be approximately ten times higher when compared with SARS-CoV RBD [ 11-13 ]. This molecular interaction is responsible for regulating both the cross-species and higher human-to-human transmissions of SARS-CoV-2 [ 14 , 15 ]. Therefore, these protein effectors of viral attachment, membrane fusion and cell entry are known as emerging targets for development of entry inhibitors, antibodies, and vaccines [ 14 ]. The use of phytomedicines as cheap alternatives to combat viral diseases and other infections, forms an integral component of African cultural practices, and hence a prominent feature in Africa [ 16-20 ]. Terpenoids are a well known class of phytochemicals of tremendous pharmaceutical value over time because of their relevant broad-spectrum utility in medicine [ 21 , 22 ]. Screening a database of phytochemicals from indigenous African medicinal plants may help identify terpenoids with therapeutic potentials against the novel COVID-19 pandemic. Therefore, this study explores computational based screening of terpenoids from indigenous African medicinal plants as potential inhibitors of the emerging protein targets responsible for coronavirus cell entry and subsequent infection. Methods 2.1 Protein preparation The crystal structures of proteins for the docking studies were retrieved from the Protein Databank (http://www.rcsb.org) with their various PDB identification codes [1r42: Angiotensin-Converting Enzyme 2 (ACE2) [ 23 ]; 2OQ5: type II transmembrane serine proteinases ( TMPRSS2) [ 24 ]; 6vw1: 2019-nCoV chimeric receptor-binding domain complexed with its receptor human ACE2 (ACE2-RBD) [ 25 ] and coronoviruses spike protein (6VSB: SARS-CoV-2) [ 3 ]; (5X5B: SARS-CoV) [ 26 ] and (5x5c : MERS-CoV) [ 26 ]. All the crystal structures were prepared by removing existing ligands and water molecules while missing hydrogen atoms were added using Autodock version 4.2 program (Scripps Research Institute, La Jolla, CA). Subsequently, non-polar hydrogens were merged while polar hydrogen was added to each protein. The well-ordered scheme was repeated for each protein and thereafter saved into dockable pdbqt format for molecular docking. 2.2 Ligand preparation One hundred and six (106) bioactive terpenoids from African medicinal plants were complied base on literature search. Structure Data Format (SDF) of the reference inhibitors (S1: MLN-4760; S2: Camostat and S3: Nelfinavir mesylates) and 106 bioactive terpenoids derived from African plants were retrieved from the PubChem database (www.pubchem.ncbi.nlm.nih.gov) and converted to mol2 chemical format using Open babel [ 27 ]. Other compounds that were not available on the database were drawn with Chemdraw version 19 and converted to mol2 chemical format. Polar hydrogen charges of the gasteiger-type were assigned and the nonpolar hydrogen molecules were merged with the carbons and the internal degrees of freedom and torsions were set to zero. The protein and ligand molecules were further converted to the dockable pdbqt format using Autodock tools. 2.3 Molecular docking Molecular docking was performed to evaluate the binding energy and to provide initial coordinates and topology parameters for the MD simulations. Virtual screening of human enzymes and active regions of the coronaviruses spike protein and determination of binding affinities were carried out using AutoDock Vina [ 28 ] and the binding scores from vina analysis were further validated by BINDSURF [ 29 ]. Docking of bioactive terpenoids and reference compounds against human ACE2, human TMPRSS2 and : SARS-CoV-2 spike protein was performed by AutoDock Vina to locate alternate binding sites enclosing the whole macromolecules with a very extended grid (60 Å × 60 Å × 60Å) to reveal all the possible interaction sites applying exhaustiveness values of 8. Pdbqt form of each protein and terpenoid were uploaded into their respective columns of Autodock Vina and BINDSURF (the online tool) to run the interaction. The compounds were then ranked by their binding affinity scores. The molecular interactions between proteins and selected compounds with higher binding affinity to the proteins were viewed with Discovery Studio Visualizer version 16. 2.4 Molecular Dynamics Simulation Molecular Dynamics simulations were carried out on selected compounds, to evaluate their binding interactions with. The protein–ligand for the top docked terpenoids to SARS-CoV-2 spike (S) protein, human angiotensin-converting enzyme 2 (ACE2) and transmembrane protease serine 2 (TMPRSS2) from AutoDock Vina docking step were used in Molecular Dynamics Simulation (MDS) using NAMD software [ 30 ]. Necessary files for MDS were generated using CHARMM-GUI webserver [ 31 , 32 ]. For each complex, the system was minimized for 10000 steps then a production run for 100 ns was performed. Temperature was set to be 310 K and salt concentration was set to be the physiological concentration 0 .154 M NaCl. Afterwards, calculations of Backbone-Root Mean Square Deviation (RMSD), Per residue Root Mean Square Fluctuations (RMSF), Radius of Gyration (RoG), Surface Accessible Surface Area (SASA) were performed using VMD TK console scripts [ 33 ]. 2.5 Binding Free Energy calculation and Clustering analysis Molecular Mechanics/Generalized Born Surface Area (MM/GBSA) [ 34 ] calculation was performed using AmberTools 20 [ 35 ] on the results from MDS. TTClust version 4.7.2 were used to cluster the trajectory automatically according to the elbow method and produce a representative structure for each cluster [ 36 ]. These representative conformations were analyzed using Protein Ligand Interaction Profiler (PLIP) to know the interacting amino acids and the types of interactions [ 37 ]. 2.6 Drug-likeness and ADMET studies The top terpenoids that demonstrated highest binding affinity for ACE2, TMPRSS2 and active regions of SARS-CoV-2 spike protein were subjected to several drug-likeness predictive descriptors which an orally bio-active drug should comply to criteria for drug likeness [ 38 , 39 ]. The predicted Absorption, Distribution, Metabolism, Excretion and Toxicity (ADMET) study was analysed using the admetSAR webserver [ 40 ]. The SDF file and SMILES of the compounds were downloaded from PubChem database to calculate ADMET properties using default parameters. Results 3.1. Molecular docking Figure 1 provides a flow chart showing the stepwise screening of African derived terpenoids for potential inhibitors of membrane-mediated SARS-CoV-2 cell entry proteins. The result from the docking analysis of the reference inhibitors and bioactive terpenoids with the human ACE2, TMPRSS2 and SARS-CoV-2 spike protein is shown in table S3 (supplementary material). The top 20 terpenoids with the highest binding affinity for the ACE2 were further analyzed for binding interactions with SARS-CoV-2 chimeric Receptor-Binding Domain complexed with its human receptor ACE2 (ACE2-RBD) and the S protein of SARS-CoV and MERS-CoV as shown in table 2. The docking analysis revealed that the reference inhibitor (MLN-4760) to the human ACE2 protein had binding energy of -7.7 Kcal/mol respectively, while Camostat an inhibitor of TMPRSS2 had a binding energy of - 7.6 Kcal/mol as represented in figure 3. It was further observed that the topmost docked terpenoids to the ACE2 had higher binding affinity for the S protein of SARS-CoV and MERS-CoV than SARS-CoV-2. More than 10 terpenoids had higher binding affinity than the 3 inhibitors used in this study table S1 (supplementary material). The top 20 docked compounds to SARS-CoV-2 S-proteins had higher binding affinity than nelfinavir mesylates S2 (supplementary material). From the binding scores generated by the interacting terpenoids with the ACE2 and TMPRSS2 proteins, the 2 best docked terpenoids with the highest binding affinity are: 24-methylene cycloarteno and isoiguesterin with the corresponding binding energy of -9.7, and -9.5 Kcal/mol respectively. The 2 best docked terpenoids to SARS-CoV-2 S protein are 3-benzoylhosloppone and cucurbitacin with binding energies of -9.4 and -9.3 Kcal/mol respectively. 3-benzoylhosloppone had the highest binding affinity for SARS-CoV-2 S protein and the second top binding affinity to MERS-CoV S protein (Figure 3). 3.1.1 Amino acid interaction of selected terpenoids with target proteins. The amino acid interactions of the human target proteins (ACE2 and TMPRSS2) with reference inhibitors and plant derived terpenoids that demonstrated the highest binding tendencies are represented in table 1. In the same way, the amino acid residues of the coronaviruses S protein that interacted with reference inhibitors and terpenoids with the highest binding affinity are shown in table 2. The interacting residues of ACE2 and TMPRSS2 with respective ligand groups were majorly through hydrophobic interactions and H-bond. Few H-bonding below 3.40 Å were observed with coronaviruses S protein (table 4). The binding of MLN-4760 to ACE2 showed that it was docked into the N terminus and zinc-containing subdomain I of ACE2 (figure 4a). MLN-4760 exhibited several types of hydrophobic interactions (Pi-Sigma, Pi-Pi T-Shaped, Pi-Alkyl and Alkyl) with TYR 510 PHE 504 MET 360 , LYS 363 and CYS 344 , a Salt and attractive charges to ARG 514 , ARG 518 and ARG 278 and hydrogen bond to TYR 515 , THR 371 , PRO 346 and ARG 273 (figure 4a). 24-methylene cycloartenol the best docked terpenoid was docked into the C terminus-containing subdomain II of ACE2 but interacted with different residue as with the case of N-acetyl-D-glucosamine (figures 4b). 24-methylene cycloartenol interacted via H-bond to TRP 163 , SER 170 and TYR 497 .A Pi-Alkyl interaction was also observed with TYR 613 , PRO 492 and VAL 491 . Isoiguesterin interacted via H-bond to ASP 350 , TYR 385 and ASN 394 . A Pi-Alkyl and Alkyl interactions was observed with the ALA 99 , PHE 40 , PHE 390 and LEU 73 , TRP 69 residues respectively in a similar binding pattern with MLN-4760 (figure 4c). Camostat was docked into the S1-specificity pocket of TMPRSS2 (figure 5a). It interacted via conventional H-bond to five amino residues (ARG 41 , SER 195 , TRP 215 , ALA 190 and ASP 189 ) and via carbon hydrogen bond to GLN 192 of TMPRSS2. The conventional H-bond was formed in the direction of the guanidine group in this order: first ester bond, second ester bond, while the last three residues interacted with amidino nitrogen of guanidine group respectively. The phenyl ring was responsible for the carbon-hydrogen bond with GLN 192 (figure 5a). T3 and T4 were docked into S1-specificity pocket of TMPRSS2 in a similar binding pattern as in the case of camostat (figure 5b & 5c). The only difference observed between the binding pattern of T3 and T4 was an additional H-bond between T3 with ARG 41 (figure 5b). Nelfinavir mesylates an inhibitor of SARS-CoV and MERS-CoV S protein interacted in its best docked conformation to the S protein of SARS-CoV-2 in a different manner. Nelfinavir mesylates was docked into the S2 Subunit of SARS-CoV S protein (figure 7a). The same inhibitor was docked into to the N-terminal domain (NTD) region of the S1 subunit of SARS-CoV-2 and MERS-CoV S protein (figure 6a & 8a). 3-benzoylhosloppone with the highest binding affinity for SARS-CoV-2 S protein interacted via H-bond to THR 547 ; Alkyl interaction to PHE 541 and Pi-Alkyl interaction to PRO 589 and LEU 546 . The region of interaction was between the CTD and SD1 region of S1 subunit of SARS-CoV-2 S protein. Cucurbitacin B was docked to the S2 subunit of SARS-CoV-2 S protein but interacted with different amino acid residue. The interaction of cucurbitacin B to the protein was via H-bond to ARG 1091 , ASN 914 , THR 912 and GLN 1113 ; Pi-Sigma bond to PHE 1121 and Alkyl interaction to ILE 1114 and GLY 1124 (figure 6c). The same pattern of interaction was observed in both 7-Deacetoxy-7-oxogedunin and 3-friedelanone to the S2 subunit of SARS-CoV S protein. Both terpenoids interacted via a H-bond to ARG 982 and GLY 726 of the S2 subunit. While 7-deacetoxy-7-oxogedunin interacted with the upstream helix and central helix, 3-friedelanone interacted with the connecting region of the S2 subunit. A hydrophobic interaction via Pi-Alkyl and alkyl bonds was observed with the remaining amino acid residue (table 2; figure 7b & 7c) 7-Deacetoxy-7-oxogedunin interacted via H-bond to the SER 51 residue of N-terminal domain of the S1 subunit of MERS-CoV S protein. A Pi-Pi T-shaped interaction was formed between 7-deacetoxy-7-oxogedunin and PHE 354 ; HIS 670 of MERS-CoV S protein. Other hydrophobic interactions via Pi-Alkyl and Pi-Sigma bonds were observed to with the remaining amino acid residues (table 4; figure 8a & 8b). 3-benzoylhosloppone interacted via: Pi-Sigma interaction to (PHE 341 ) of NTD; Pi-Pi Stacking to (MET 698 ) of SD2; Pi-Alkyl interaction to (LYS 689 ) of SD2; and an Alkyl interaction to (LEU 344 and ILE 337 ) of NTD with the S1 subunit (figure 8c). In summary, the binding of ligands to various proteins revealed eight terpenoid with remarkable binding affinities. Those with very good interactions with ACE2 and TMPRSS2 are 24-methylene cycloartenol; isoiguesterin; 11-Hydroxy-2 - (3,4-dihydroxybenzoyloxy) abieta-5,7,9(11),13-tetraene-12-one; and 11-Hydroxy-2 -(4-hydroxybenzoyloxy)-abieta-5,7,9(11),13-tetraene-12-one. Similarly, 3-benzoylhosloppone, and cucurbitacin B interacted well with SARS-CoV-2 spike protein, while 7-deacetoxy-7-oxogedunin, and 3-friedelanone interacted well with SARS-CoV and MERS-CoV spike protein. 3.1.2 Energy profile of best docked terpenoids to respective proteins The overall energy profiles of terpenoid-protein complexes in the selected clusters with the best docked poses are shown in figures 9-11. Figure 9a-11a shows the breakdown of the binding energy of the selected cluster into different contributions. Gauss 1 (blue) and 2 (leaf green) bars: represent the non-bonding interactions, red bar: repulsion, light blue bar: Hydrophobic, Purple bar: Hydrogen bonds, light green bar: rotational forces, while the black bar represents total binding affinity which is a representative contribution of all bonding and non-bonding interactions between the terpenoids and the protein residues. The contributions of the various type of interaction as presented in graph (figure 9a-11a) shows that of the total binding energy of -9.7 Kcal/mol exhibited by the binding of 24-methylene cycloartenol to the ACE2, -2.1 and 1.8 Kcal/mol of hydrophobic and H-bond energies respectively was contributed, while the rest was contributed by non-bonding interaction mainly van der Waals, repulsive and rotational forces. A H-bond, Hydrophobic interaction and repulsive energy of -2.8 -0.8 and +2.3 Kcal/mol respectively was contributed to the total binding energy of - 10.0 Kcal/mol between T3 and TMPRSS2. A hydrophobic interaction energies of -2.1, -0.6 and -1.5, a H-bond energies of 0.3, -0.6, -0.3 Kcal/mol was contributed to the total binding energy of the spike protein of SARS-CoV-2, SARS-CoV and MERS-CoV with respective terpenoids. The rest of the energy was contributed by non-binding interactions. Figures 9b-11b shows the overall energy profile of the ligand-receptor complex of the selected cluster, showing the individual energetic contributions for each atom in the ligand. The colour indication is similar to (a) above. 3.2 Molecular Dynamics Simulation Four compounds which are, camostat, 11-hydroxy-2 - (3,4-dihydroxybenzoyloxy) abieta-5,7,9(11),13-tetraene-12-one, 24-methylene cycloartenol, and 3-benzoylhosloppone, were analysed for their interactions with SARS-CoV-2 Spike glycoprotein (S protein), Angiotensin-converting enzyme 2 (ACE2), and Transmembrane protease serine 2 ( TMPRSS2) proteins. Molecular dynamics simulation was done on each of the protein-ligand complexes and the trajectories were analyzed. The Radius of Gyraion (RoG), Root Mean Square Deviation (RMSD), Root Mean Square Fluctuation (RMSF), and Surface Accessible Surface Area (SASA) results were calculated for each trajectory and are shown in figure 11. There was no observed difference between the RoG of TMPRSS2_camostat and TMPRSS2_(11-hydroxy-2 - (3,4-dihydroxybenzoyloxy) abieta-5,7,9(11),13-tetraene-12-one) complexes, while that of ACE2 is larger and S protein has the largest values because it is a monomer of the SARS-CoV-2 spike trimer. All of them are fluctuating about certain values. The RMSD values of TMPRSS2_(T3), ACE2-24_methylene cycloartenol), TMPRSS2_camostat, and S protein_(3-benzoylhosloppone) complexes are around 2.13 Å, 3.6 Å, 2.14 Å, and 16.78 Å, respectively. While the RMSF values for TMPRSS2_(11-hydroxy-2 - (3,4-dihydroxybenzoyloxy) abieta-5,7,9(11),13-tetraene-12-one), ACE2_24-methylenecycloartenol), TMPRSS2_camostat, and S protein_(3- benzoylhosloppone) complex are fluctuating around 0.68 Å, 1.29 Å, 0.73 Å, and 7.36 Å, respectively. TMPRSS2_(11-hydroxy-2 - (3,4-dihydroxybenzoyloxy) abieta-5,7,9(11),13-tetraene-12-one), ACE2_(24-methylene cycloartenol), and TMPRSS2_camostat complexes have a spike in the end of their RMSF results indicating the motion of the terminals. The spikes in the middle and the start of the RMSF of ACE2_(24-methylene cycloartenol) complex between amino acid 265 and amino acid 443 and spikes in S protein_(3-benzoylhosloppone) complex corresponds to the loops in the two protein respectively (Figure 12). The values of SASA can be found to be nearly stable for each complex but differ from each other. Molecular Mechanics/Generalized Born Surface Area (MMGBSA) algorithm in AmberTools 20 was utilized to calculate the ligand binding free energy. All frames (~1000 frame) were used in this calculation for each protein-drug complex. Figure 14 shows the binding affinity in Kcal/mol from MMGBSA analysis with Standard Deviation as error bars for each protein-drug complex. The best binding affinity (more negative) is for TMPRSS2_camostat (-53.5059 Kcal/mol) which indicates the strong binding between them. Table 4 shows the number of clusters, representative frame produced for each trajectory, and the interaction types using PLIP webserver. Hydrophobic, H-bond, salt-bridges, pi-cation and pi-stacking are the types of interactions found by PLIP webserver. Most of complexes have H-bond and hydrophobic interactions, with TMPRSS2_camostat having the largest number of bonds in each cluster compared to other complexes. Figure 15 shows the protein-drug cluster representatives for the protein-ligand complexes and the mode of interaction in the enlarged part of the image. Images were generated using PyMol software V 2.2.2. 3.3 Drug likeness and Pharmacokinetic properties of selected terpenoids. The result generated from the Lipinski and ADMET filtering analyses are represented in table 4 and figure S1 (supplementary file). Four terpenoids T1, T3, T5 and T6 fulfilled the requirement for Lipinski analysis of the rule of-five with corresponding favourble predicted ADMET parameters. The in silico predictive pharmacokinetic and ADMET properties from the filtering analyses suggested T1, T3, T5 and T6 with a high probability of absorption, subcellular distribution, low toxicity. Though pharmacokinetic analysis indicated T1 (Table 4) to be less soluble while the ADME/tox analysis indicated high aqueous solubility, ability to pass the high human intestinal absorption, low acute oral toxicity with a good bioavailability score as exhibited by T3, T5 and T6 (Table 4). Discussion Interference with several proteins that mediate viral attachment, membrane fusion, and cell entry of coronaviruses is an emerging therapeutic strategy for preventing COVID-19 infection [ 10 , 41 ]. This principle was earlier demonstrated with HIV [ 42 , 43 ] and SARS-CoV [ 44 ]. Earlier screening and prospecting of therapeutic phytocompound have been reported for both SARS-CoV and MERS-CoV [ 45-48 ]. Cell-based assays have shown the antiviral potentials of specific plant terpenoids against Severe Acute Respiratory Syndrome Coronavirus (SARS- CoV) [ 45 , 49 ]. This study was therefore undertaken to identify potential inhibitors of membrane-mediated SARS-CoV-2 entry proteins form the class of the plant derived terpenoids. Specifically, two triterpenes namely 24-methylene cycloartenol and isoiguesterin were reported to target ACE2 as well as the host-virus interface (S-protein-ACE2 Receptor Complex). These compounds interacted with adjacent residues in the conserved domain, apparently portraying its ability to bind and block interactions of hotspot 31 residues. The residues near lysine 31, and tyrosine 41, 82–84, and 353–357 in human ACE2 are important for the binding of S-protein of coronavirus [ 50 ]. The hotspots: 31 and 353, makes salt bridge between Lys31 and Glu35, and the hotspot 353, comprising a salt bridge between Lys353 and Asp38, and are both buried in hydrophobic environment, therefore interaction within this region is suggested to affect the binding of its substrate [ 51 ]. Abietane diterpenes, namely 11-hydroxy-2 - (3,4-dihydroxybenzoyloxy) abieta-5,7,9(11),13-tetraene-12-one (T3), and 11-hydroxy-2-(4-hydroxybenzoyloxy)-abieta- 5,7,9(11),13-tetraene-12-one (T4) showed the strongest interaction with with TMPRSS2. In a similar binding pattern to camostat, these compounds were fitted into the S1-specificity pocket. They interacted with residue ALA 190 , ASP 189 and GLN 192 ­­­ that are known to be part of the amino acid found at the basement of the pocket. ASP 189 at the bottom of the pocket is known to determine the specificity of the S1 pocket for basic residues Arg and Lys at position P1 of the substrate [ 24 ]. The result showed that the hydroxybenzoyloxyl moiety of the terpenoids (T3 and T4) was responsible for atleast 75% of the H-Bond with the protein. It was further observed that just as in the case of benzamidine (the native ligand) and camostat, the hydroxybenzoyloxyl moiety of the two terpenoids points with its hydroxyl group towards the carboxylate group of ASP 189 forming strong H-bonds with ASP 189 and other residue in the pocket. For camostat, the phenylquanidine moiety pointed into the hydrophobic pocket with the negatively charged ASP 189 at its bottom. Unlike the H-bond formed between the amidino nitrogen of the phenylquanidine and benzamidine, in T3 and T4 the H-Bonds were formed mainly with the hydroxyl, and carboxylate group. A striking similarity observed was that the ester bond that linked both the phenylquanidine moiety of camostat and the hydroxybenzoyloxyl moiety of T3 and T4 to the remaining structural unit of the compounds formed strong H-Bonds to the same residue SER 195 . The phenyl group of the hydroxybenzoyloxy moiety of T3 and T4 further interacted with hydrophobic interactions to CYS 119 and CYS 219 just as the peptide planes of the bonds between Trp215–Gly216 and Cys191–Gln192 sandwich the phenyl ring of benzamidine [ 24 , 52 ] The additional hydrophobic interaction by T3 and T4 may have been responsible for the exhibited higher binding affinities than camostat and benzamidine. Furthermore, while the hydroxybenzoyloxy moiety was directed toward the hydrophobic cleft created by ASP 189 , the abietane agylcon interacted with the imidazol ring of HIS 57 of the S2 pocket that is found next to the S1 pocket and ARG 41 (in the case of T4) which are outside the hydrophobic cleft. A similar interaction as the later was observed with camostat. The strong similarity in the binding pattern and even a far strong binding affinity than the camostat and benzamidine indicates that T3, T4 and other abietane diterpenes especially those with hydroxybenzoyloxyl moiety attached to the abietane aglycon are potential inhibitors of TMPRSS2 thus preventing some coronaviruses from entering host [ 24 ]. It is known that, like SARS-CoV, SARS-CoV-2 S protein recognizes and binds to host-cell receptor angiotensin-converting enzyme 2 (ACE2) using a transmembrane protease serine 2 (TMPRSS2) which activates the S protein to facilitate viral fusion and entry into cells [ 9 ]. It is important to note that serine protease inhibitors like camostat mesylate, which blocks the activity of TMPRSS2 [ 53 ], has been approved in Japan for human use. Related compounds with antiviral activity potentiates as an anti-SARS-CoV-2 agent [ 54 ]. Also some abietane terpenoids have been identified to exhibit in vitro anti-SARS-CoV activity [ 45 ]. This is corroborates the result of our study that shows that abietane diterpenes exhibits a wide spectrum and multiplicity of protein binding; and may thereby specifically execute a complete blockage of viral entry. With regards to coronavirus S-proteins two compounds, 3- Benzoylhosloppone and Cucurbitacin B, were of utmost interest. While 3-benzoylhosloppone interacted with amino acid residue of the RBD and SD1 region of the S1 subunit, Cucurbitacin B was docked into the S2 subunit of SARS-CoV-2 S protein. The former subunit is responsible for receptor recognition while the later mediates the fusion of viral membrane and the host cellular membrane [ 55 ]. These terpenoids may prevent interaction of spike protein with its host cell receptor, thereby preventing entry of the virus into the host cell. 3-benzoylhosloppone has been reported for its antimalarial property while Cucurbitacin B is an anticancer agent [ 56 , 57 ]. The MDS analysis of the top docked with their complexed proteins were stable and could be therefore subjected to experimental processes in further studies. From the Lipinski, pharmacokinetic and ADMET filtering analyses, we identified four druggable and non-toxic, natural terpenoids that exhibited strong binding tendency to the various protein targets that mediates coronavirus-host cell entry. The result from the predicted filtering analyses of the four compounds showed parameters that suggest a favourable in silico ADMET and pharmacokinetic properties The terpenoids expressed high probability of human intestinal absorption. They were also non-substrate to the permeability-glycoprotein (P-gp) [ 58 ], expressed capability to cross the blood brain barrier (BBB). SARS-CoV-2 has been reported to infect the brain, thus indicating its ability to cross the blood brain barrier (BBB) [ 59 ], compounds that can cross the BBB will be beneficail in the overal all viral clearance, The four terpenoids did not show indication of mutagenicity in silico , thereby they may not cause genetic mutations. The compounds did not display inhibitory potential for the various cytochrome P450, thus may not adversely affect phase I drug metabolism in the liver. These terpenoids are therefore considered as potential drug candidates. Conclusion A virtual screening approach was successfully applied to identify plant derived terpenoids as potential inhibitor of coronavirus cells entry proteins. The pentacyclic terpenoids, 4-methylene cycloartenol and isoiguesterin interacted strongly with binding sites residues that are known to interfere with the activity of ACE2. Compounds: 11-Hydroxy-2 - (3,4-dihydroxybenzoyloxy) abieta -5,7,9 (11),13-tetraene-12-one (T3), and 11-Hydroxy-2 -(4-hydroxybenzoyloxy)-abieta- 5,7,9(11),13-tetraene-12-one (T4) and other abietane diterpenes exhibited a similar binding pattern to the S1-specificity pocket of TMPRSS2 as camostat (reference inhibitor). They also showed wide spectrum and multiplicity of entry protein binding. The terpenoids binding conformations in the complexes were stable in a simulated dynamic environment. Since the identified lead compounds showed drug-likeness and low toxicity as indicated by the in silico pharmacokinetically relevant molecular descriptors, they are postulated as potential inhibitors that can be considered for further in vitro and in vivo studies towards developing entry inhibitors against the ongoing coronavirus pandemic. Declarations Acknowledgments The authors appreciate the members of the BioNet-AP : Bioinformatics Network on African Phytomedicine for COVID-19 research. - Ethical Approval: Not applicable - Consent to Participate: Not applicable - Consent to Publish: Not applicable - Authors Contributions A. Gyebi Conceived and designed the analysis M. Ogunyemi Performed molecular docking analysis M. Ibrahim Performed molecular simulations B. Ogunro Wrote manuscript P. Adegunloye Interprets results and wrote manuscript O. Afolabi Editing and review of manuscript -Funding: The research did not receive any funding or grants -Conflicts of interest: The authors declare no conflicting interest -Availability of data and materials The authors confirm that the data supporting the findings of this study are available within the article [and/or] its supplementary materials. References Taniguchi, Y., Nishikawa, H., Maeda, N., & Terada, Y. (2020). 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Tables Table 1: Interacting amino acid residue of human ACE2 and TMPRSS2 with the top binding terpenoids from African phytochemicals Bioactive compound Human Protein targets Interacted residues Protein atom involved in H-Bonding (BOND DISTANCE) S1 (MLN-4760) ACE2 ARG 514 ARG 518 ARG 278 TYR 510 PHE 504 MET 360 LYS 363 CYS 344 TYR 515 (3.44) THR 371 (3.03) PRO 346 (3.08) ARG 273 (2.93) 24-Methylene cycloartenol (T1) TRP 163 SER 170 TYR 497 TYR 613 PRO 492 VAL 491 SER 167 TRP 163 (3.22) SER 170 (2.81) TYR 497 (3.27) Isoiguesterin ( T2) ASP 350 TYR 385 ASN 394 ALA 99 PHE 40 PHE 390 LEU 73 TRP 69 ASP 350 (3.27) TYR 385 (3.27) ASN 394 (3.27) S2 (Camostat) TMPRSS2 ARG 41 SER 195 ALA 190 ASP 189 TRP 215 GLN 192 ARG 41 SER 195 ALA 190 ASP 189 TRP 215 11-Hydroxy-2 - (3,4-dihydroxybenzoyloxy)abieta -5,7,9(11),13-tetraene-12-one (T3) ARG 41 GLN 192 SER 195 ALA 190 ASP 189 CYS 191 HIS 57 CYS 191 ARG 41 (2.41)GLN 192 (2.89)SER 195 (2.89)ALA 190 (2.65)ASP 189 (2.39) 11-Hydroxy-2 -(4-hydroxybenzoyloxy)-abieta- 5,7,9(11),13-tetraene-12-one (T4) GLN 192 ASP 189 ALA 190 SER 195 HIS 57 SER 214 TRP 192 CYS 219 GLN 192 (2.32) ASP 189 (2.62) ALA 190 (2.27) SER 195 (2.32) Table 2: Interacting amino acid residue of Spike protein of coronaviruses with the top binding terpenoids from selected African phytochemicals Bioactive compound Coronavirus spike proteins Interacted residues Protein atom involved in H-Bonding(BOND DISTANCE) (S3) Nelfinavir mesylates SARS-Cov-2 THR 886 ASP 867 PRO 869 PRO 862 VAL 860 SER 730 HIS 1058 THR 886 (3.48) ASP 867 (2.13) SER 730 (2.57) HIS 1058 (2.03) 3- Benzoylhosloppone ( T5) THR 547 PHE 541 LEU 546 PRO 589 THR 547 (3.03) Cucurbitacin B ( T6) ARG 1091 ASN 914 THR 912 GLN 1113 PHE 1121 ILE 1114 GLY 1124 ARG 1091 ­­ (2.93) ASN 914­­ (3.32) THR 912 ­­ (2.95) GLN 1113 ­­ (2.89) (S3) Nelfinavir mesylates SARS-CoV SER 556 THR 535 THR 559 PHE 558 PRO 575 PHE 527 SER 556 (2.14) THR 535 (2.38, 2.59) THR 559 (3.30) 7-Deacetoxy-7-oxogedunin ( T7 ) ARG 982 GLY 726 VAL 958 PHE 837 ARG 982 (2.73, 2.16) GLY 726 (2.52) 3-Friedelanone ( T8 ) ARG 982 GLY 726 VAL 958 PHE 837 VAL 945 LYS 836 LEU 948 ASN 838 ARG 982 (3.23) GLY 726 (3.03) ASN 838 (3.12) (S3) Nelfinavir mesylates MERS-CoV SER 51 ARG 335 HIS 348 HIS 670 LEU 344 ILE 337 PHE 354 LYS 668 SER 51 (2.90) ARG 335 (2.89) 7-Deacetoxy-7-oxogedunin ( T7 ) SER 51 HIS 348 HIS 670 ILE 337 PHE 354 LEU 344 ARG 335 SER 51 (2.74) 3- Benzoylhosloppone LYS 689 PHE 341 MET 698 VAL 958 LEU 344 ILE 337 Table 3: Shows the number of clusters produced from TTClust, its representative frame for each of the protein-ligand complexes, and the interactions between the ligand and the protein from PLIP webserver for that frame. TMPRSS2_(11-Hydroxy-2 - (3,4-dihydroxybenzoyloxy)abieta-5,7,9(11),13-tetraene-12-one) complex CLUSTER NUMBER (REPRESENTATIVE FRAME) Hydrophobic H-bond Salt-bridges Pi-cation Cluster 1 (frame 140) W215 A190 (2) None None Cluster 2 (frame 853) R41 - T62 S39 – H40 - R41 R41 R41 Cluster 3 (frame 977) T61 None None R41 ACE2 _(24-Methylene cycloartenol) complex CLUSTER NUMBER (REPRESENTATIVE FRAME) Hydrophobic CLUSTER 1 (FRAME 172) Y255 (2)- P612 CLUSTER 2 (FRAME 721) L142 (2) – I151 – L162 (2) TMPRSS2_ camostat complex cluster number (representative frame) Hydrophobic H-bond Salt-bridges Pi-stacking Cluster 1 (frame 92) None A190 (2) – Q192 – D217 – E218 – A220 D189 H57 Cluster 2 (frame 618) Q192 - V213 R41 – A190 – S195 – D217 – E218 H57 - D189 None Cluster 3 (frame 284) Q192 A190 (2) – S195 – D217 (2) D189 None Cluster 4 (frame 728) None A190 (2) – D217 (2) D189 None Cluster 5 (frame 915) Q192 A190 (2) – D217 (2) – A220 D189 None S protein_(3- Benzoylhosloppone) complex CLUSTER NUMBER (REPRESENTATIVE FRAME) Hydrophobic H-bond Pi-stacking CLUSTER 1 (FRAME 184) L546 – V576 – I587 (2) - P589 None None CLUSTER 2 (FRAME 631) F541 – F543 – L546 – T549 - P589 T573 F543 CLUSTER 3 (FRAME 935) F541 – F543 – L546 – F565 – 573 - V576 None None Amino acid residues were represented by single letter code. Bold amino acids are common in each protein-drug complex Table 4: Physicochemical properties of the top binding terpenoids from African plants to ACE2, TMPRSS2 and S protein of SARS-Cov-2 a) Lipinski filter analysis Lipinski filters T1 T3 T5 T6 Molecular weight (g/mol) 454.77 450.52 402.48 558.70 Num. heavy atoms 33 33 30 40 Num. rotatable bonds 5 4 4 6 Num. H-bond acceptors 1 6 4 8 Hydrogen bond donor 1 3 0 3 MLogP 7.30 2.96 3.79 1.76 Molar Refractivity 144.50 126.11 116.15 150.94 Lipinski violation 1 0 0 1 (b) admet SAR Absorption (Probability) Blood-Brain Barrier BBB+ (0.96) BBB+ (0.60) BBB+ (0.61) BBB+ (0.81) Human Intestinal Absorption HIA+ (0.99) HIA+ (0.92) HIA+ (0.92) HIA+ (0.97) Bioavailability Score 0.55 0.55 0.55 0.55 Caco-2 Permeability Caco2+ (0.79) Caco2+ (0.59) Caco2+ (0.59) Caco2+ (0.61) P-glycoprotein Substrate Substrate (0.73) Substrate (0.78) Non-inhibitor (0.58) Substrate (0.79) P-glycoprotein Inhibitor Non-inhibitor (0.65) Non-inhibitor (0.74) Non-inhibitor (0.74) Non-inhibitor (0.61) Renal Organic Cation Transporter Inhibitor (0.75) Inhibitor (0.90) Non-inhibitor (0.90) Non-inhibitor (0.87) Distribution (Probability) Subcellular localization Lysosome (0.55) Mitochondria (0.86) Mitochondria (0.86) Mitochondria (0.77) Metabolism CYP450 Substrate Substrate (0.77) Non-inhibitor (0.78) Substrate Non-inhibitor (0.83) Non-substrate (0.65) inhibitor (0.80) Inhibitor (0.79) Non-substrate (0.83) Toxicity AMES Toxicity Non AMES toxic (0.71) AMES toxic (0.87) Non AMES toxic (0.87) Non AMES toxic (0.84) Carcinogens Non-carcinogens (0.92) Non-carcinogens (0.90) Non-carcinogens (0.90) Non-carcinogens (0.92) Acute Oral Toxicity III (0.77) III (0.59) III (0.57) I (0.78) Rat Acute Toxicity LD 50 , mol/kg 3.2804 2.5370 2.5370 3.8742 Aqueous solubility (LogS) -4.76258 -4.5550 -4.7201 -4.5035 Pharmacokinetics Lower GI absorption Low High High low Log K p (skin permeation) cm/s -1.48 -5.58 -5.33 -7.83 4-Methylene cycloartenol (T1); 11-Hydroxy-2 - (3,4-dihydroxybenzoyloxy)abieta -5,7,9(11),13-tetraene-12-one (T3); 3- Benzoylhosloppone ( T5) and Cucurbitacin B ( T6) Supplementary Files SupplementaryData.docx Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. 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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-259624","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":13293175,"identity":"a3f7e2b0-259e-4d5c-b04f-d0a2384bec31","order_by":0,"name":"Gideon Ampoma Gyebi","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA/UlEQVRIiWNgGAWjYDACZgYDKIuH4cAHIMXGToqWgzNAWpgJ24PQwswDMQQ/kHdn3vjg4w47uw3Hew8etvm1TZ6PmYHxw8cc3FoMD7MVG848k5y84cy5hMO5fbcN25gZmCVnbsOjpZnHTJq3jTnZ4EaOweHcntuMQC1szLz4tZj/5m2rTza4/8bgsGXPbXuCWuSZecyYedsO2xnc4DE4zPDjdiJBLQbMbMWSM9uOJ0ieyUs42NtwO7mNmbEZr1/k+w9v/PCxrdqe7/jZwx9+/LltO7+9+eCHj/hsOQChExeAGIxtIDZjA271IFug0vYQxh+8ikfBKBgFo2CEAgCWiVTzvjzn4QAAAABJRU5ErkJggg==","orcid":"https://orcid.org/0000-0002-1945-1739","institution":"Bingham University","correspondingAuthor":true,"submittingAuthor":false,"prefix":"","firstName":"Gideon","middleName":"Ampoma","lastName":"Gyebi","suffix":""},{"id":13293176,"identity":"d1b27d1e-a2e2-41ca-9a24-b02605a88d9a","order_by":1,"name":"Oludare Ogunyemi","email":"","orcid":"","institution":"Salem University","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Oludare","middleName":"","lastName":"Ogunyemi","suffix":""},{"id":13293177,"identity":"ccb8b374-5083-45b3-9601-9e21077e885c","order_by":2,"name":"Ibrahim M. Ibrahim","email":"","orcid":"","institution":"Cairo University","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Ibrahim","middleName":"M.","lastName":"Ibrahim","suffix":""},{"id":13293178,"identity":"d961798d-879e-4b1f-8512-a49610d0e8f1","order_by":3,"name":"Olalekan B. Ogunro","email":"","orcid":"","institution":"KolaDaisi University","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Olalekan","middleName":"B.","lastName":"Ogunro","suffix":""},{"id":13293179,"identity":"acfa90f4-cc87-4ff1-a275-b0cf3aa0f4b2","order_by":4,"name":"Adegbenro P. Adegunloye","email":"","orcid":"","institution":"University of Ilorin","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Adegbenro","middleName":"P.","lastName":"Adegunloye","suffix":""},{"id":13293180,"identity":"d5f50ddb-1c76-4054-bc96-e35a00bdcd5f","order_by":5,"name":"Saheed Afolabi","email":"","orcid":"","institution":"University of Ilorin","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Saheed","middleName":"","lastName":"Afolabi","suffix":""}],"badges":[],"createdAt":"2021-02-20 17:21:21","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-259624/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-259624/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":6614177,"identity":"66fe7332-a538-434e-a61b-0777757206b4","added_by":"auto","created_at":"2021-03-04 17:45:24","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":144451,"visible":true,"origin":"","legend":"Flow chart showing the stepwise screening of African derived terpenoids for potential inhibitors of membrane-mediated SARS-CoV-2 cell entry","description":"","filename":"Fig01.png","url":"https://assets-eu.researchsquare.com/files/rs-259624/v1/9fc82115ab3f059c0222b86a.png"},{"id":6615303,"identity":"cbae67ce-f598-4160-bbd2-9e6e43826f5e","added_by":"auto","created_at":"2021-03-04 17:49:53","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":35483,"visible":true,"origin":"","legend":"Chemical structure of terpenoid with remarkable binding energyto human ACE2, TMPRSS2 and SARS-coronoviruses S protein (T1) 24-Methylene cycloartenol; (T2) Isoiguesterin;(T3)11-Hydroxy-2 - (3,4-dihydroxybenzoyloxy)abieta-5,7,9(11),13-tetraene-12-one; (T4)11-Hydroxy-2 -(4-hydroxybenzoyloxy)-abieta-5,7,9(11),13-tetraene-12-one; (T5) 3-Benzoylhosloppone; (T6) Cucurbitacin B; (T7) 7-Deacetoxy-7-oxogedunin and (T8) 3-Friedelanone.","description":"","filename":"Fig02.png","url":"https://assets-eu.researchsquare.com/files/rs-259624/v1/48c783e3facd8c14eb6587ad.png"},{"id":6614166,"identity":"9d3ab4bc-045a-4fc1-940e-03f30f9a2ee0","added_by":"auto","created_at":"2021-03-04 17:45:23","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":24932,"visible":true,"origin":"","legend":"AutoDock scores (binding energies) of standard drugs and top bioactive terpenoids with human Angiotensin-Converting Enzyme 2 (ACE2), Transmembrane Protease Serine 2 (TMPRSS2), and ACE2-Spike Receptor Binding Domain complex (ACE2-RBD) and (*S P) spike protein of coronaviruses. S1: MLN-4760; S2: Camostat S3: Nelfinavir mesylates T1: 24-Methylene cycloartenol; T2: Isoiguesterin; T3:11-Hydroxy-2 - (3,4-dihydroxybenzoyloxy)abieta-5,7,9(11),13-tetraene-12-one; T4: 11-Hydroxy-2 -(4-hydroxybenzoyloxy)-abieta-5,7,9(11),13-tetraene-12-one; T5: 3-Benzoylhosloppone; T6: Cucurbitacin B; T7: 7-Deacetoxy-7-oxogedunin and T8: 3-Friedelanone.","description":"","filename":"Fig03.png","url":"https://assets-eu.researchsquare.com/files/rs-259624/v1/ea75fd28a8dc13552360aead.png"},{"id":6614175,"identity":"a8333764-f189-44b3-a98c-f6706a0d2cbd","added_by":"auto","created_at":"2021-03-04 17:45:24","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":216781,"visible":true,"origin":"","legend":"Visualization of interacting amino acid residues of human ACE2 with ligands in 3D (i) and 2D (ii) representation: Ligands in stick representation are presented in different colours: (a) Green: S1 (MLN-4760) (b) Read: 24-methylene cycloartenol (c)Blue: Isoiguesterin. Types of interactions are represented by Green- dotted lines: H-bond interactions, light purple-dotted line: hydrophobic interactions (Pi-Alkyl, Alkyl \u0026 pi-stacking) purple-dotted line: Pi-Pi T Shaped, yellow-dotted lines: Pi-sulphur interactions, pi-stacking interactions. Three-letter amino acids are in red colour","description":"","filename":"Fig04.png","url":"https://assets-eu.researchsquare.com/files/rs-259624/v1/bea6458a28d3b96c8a002076.png"},{"id":6615306,"identity":"a495224d-512f-4528-a08c-eb4035650ca7","added_by":"auto","created_at":"2021-03-04 17:49:53","extension":"png","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":190831,"visible":true,"origin":"","legend":"The interactive view of ligands in binding cavity of human TMPRSS2 in cartoon representation. Ligands in sticks representation are represented by colours (a) Green:Camostat (b) Red:11-Hydroxy-2 - (3,4-dihydroxybenzoyloxy)abieta -5,7,9(11),13-tetraene-12-one (c) Yellow: 11-Hydroxy-2 -(4-hydroxybenzoyloxy)-abieta-5,7,9(11),13-tetraene-12-one. Types of interactions are represented by Green- dotted lines: H-bond interactions, light purple-dotted line: hydrophobic interactions (Pi-Alkyl, Alkyl \u0026 pi-stacking) purple-dotted line: Pi-Pi T Shaped, yellow-dotted lines: Pi-sulphur interactions, pi-stacking interactions. Three-letter amino acids are in red colour","description":"","filename":"Fig05.png","url":"https://assets-eu.researchsquare.com/files/rs-259624/v1/5b600ea5116096bf44e762cd.png"},{"id":6615357,"identity":"d57ce356-6c73-4fef-8e47-4922d14e9498","added_by":"auto","created_at":"2021-03-04 17:49:58","extension":"png","order_by":6,"title":"Figure 6","display":"","copyAsset":false,"role":"figure","size":201196,"visible":true,"origin":"","legend":"Visualization of interacting amino acid residues of SARS-Cov-2 Spiike proten with ligands in 3D (i) and 2D (ii) representation: Ligands in stick representation are presented in different colours: (a) Green: Nelfinavir mesylates (S3) (b) Red: 3- benzoylhosloppone (c) Blue: Cucurbitacin B. Types of interactions are represented by Green- dotted lines: H-bond interactions, light purple-dotted line: hydrophobic interactions (Pi-Alkyl, Alkyl \u0026 pi-stacking) purple-dotted line: Pi-Pi T Shaped, yellow-dotted lines: Pi-sulphur interactions, pi-stacking interactions. Three-letter amino acids are in red colour","description":"","filename":"Fig06.png","url":"https://assets-eu.researchsquare.com/files/rs-259624/v1/45c28330403cd5ce2efdee32.png"},{"id":6614173,"identity":"c650ee28-3394-4390-bf68-f318fe72fc05","added_by":"auto","created_at":"2021-03-04 17:45:23","extension":"png","order_by":7,"title":"Figure 7","display":"","copyAsset":false,"role":"figure","size":216851,"visible":true,"origin":"","legend":"Visualization of interacting amino acid residues of SARS-Cov-2 Spiike proten with ligands in 3D (i) and 2D (ii) representation: Ligands in stick representation are presented in different colours: (a) Green: Nelfinavir mesylates (S3) (b) Red: 7-deacetoxy-7-oxogedunin (c) Blue: 3-friedelanone.. Types of interactions are represented by Green- dotted lines: H-bond interactions, light purple-dotted line: hydrophobic interactions (Pi-Alkyl, Alkyl \u0026 pi-stacking) purple-dotted line: Pi-Pi T Shaped, yellow-dotted lines: Pi-sulphur interactions, pi-stacking interactions. Three-letter amino acids are in red colour","description":"","filename":"Fig07.png","url":"https://assets-eu.researchsquare.com/files/rs-259624/v1/f878902e9d751ffd94d8a459.png"},{"id":6614181,"identity":"70fdf33a-e5b8-4cc0-b3c8-1731b80c4e37","added_by":"auto","created_at":"2021-03-04 17:45:24","extension":"png","order_by":8,"title":"Figure 8","display":"","copyAsset":false,"role":"figure","size":200445,"visible":true,"origin":"","legend":"Visualization of interacting amino acid residues of SARS-Cov-2 Spiike proten with ligands in 3D (i) and 2D (ii) representation: Ligands in stick representation are presented in different colours: (a) Green: Nelfinavir mesylates (S3) (b) Red: 7-deacetoxy-7-oxogedunin (c) Blue: 3- benzoylhosloppone. Types of interactions are represented by Green- dotted lines: H-bond interactions, light purple-dotted line: hydrophobic interactions (Pi-Alkyl, Alkyl \u0026 pi-stacking) purple-dotted line: Pi-Pi T Shaped, yellow-dotted lines: Pi-sulphur interactions, pi-stacking interactions. Three-letter amino acids are in red colour ","description":"","filename":"Fig08.png","url":"https://assets-eu.researchsquare.com/files/rs-259624/v1/5e40b6ace4fd7c54e5bbd120.png"},{"id":6614170,"identity":"93d6b3cc-fcd8-419f-bcd9-aeca38838831","added_by":"auto","created_at":"2021-03-04 17:45:23","extension":"png","order_by":9,"title":"Figure 9","display":"","copyAsset":false,"role":"figure","size":82668,"visible":true,"origin":"","legend":"Energy profile of 24-Methylene cycloartenol binding groups in human ACE2: (a) Energetic contribution to the Binding energy (d) Energetic contributions for each atom in the ligand. Number of poses in selected cluster: 68, best pose: 116 and binding site coordinate: 39.14, 35.33, and 12.71","description":"","filename":"Fig09.png","url":"https://assets-eu.researchsquare.com/files/rs-259624/v1/3435339f149ede9fc9972f30.png"},{"id":6615336,"identity":"ded53a5c-bb44-47d6-93b4-ff4c6c0c2571","added_by":"auto","created_at":"2021-03-04 17:49:57","extension":"png","order_by":10,"title":"Figure 10","display":"","copyAsset":false,"role":"figure","size":85808,"visible":true,"origin":"","legend":"Energy profile of T3 binding groups in human TMPRSS2: (a) Energetic contribution to the Binding energy (d) Energetic contributions for each atom in the ligand. Number of poses in selected cluster: 87, best pose: 40 and binding site coordinate: -2.96, 26.97, and 23.55","description":"","filename":"Fig10.png","url":"https://assets-eu.researchsquare.com/files/rs-259624/v1/6ed904593411fdd40126c3b7.png"},{"id":6614172,"identity":"053a42b1-5dcb-4fee-b6e9-bd0e53fc65e4","added_by":"auto","created_at":"2021-03-04 17:45:23","extension":"png","order_by":11,"title":"Figure 11","display":"","copyAsset":false,"role":"figure","size":104085,"visible":true,"origin":"","legend":"Energy profile of 3- benzoylhosloppone binding groups in SARS-Cov-2 S protein (a) Energetic contribution to the Binding (b) Energetic contributions for each atom in the ligand. Number of poses in selected cluster: 49, best pose: 571 and binding site coordinate: 214.85, 246.53, and 212.68","description":"","filename":"Fig11.png","url":"https://assets-eu.researchsquare.com/files/rs-259624/v1/7fc1f210625ad96c205512a1.png"},{"id":6615333,"identity":"9d77a323-c158-4cfc-8451-a7ab59a3b818","added_by":"auto","created_at":"2021-03-04 17:49:57","extension":"png","order_by":12,"title":"Figure 12","display":"","copyAsset":false,"role":"figure","size":84399,"visible":true,"origin":"","legend":"The Radius of Gyration, Root Mean Square Deviation (RMSD), and Surface Accessible Surface Area (SASA) for each of protein-ligand complexes","description":"","filename":"Fig12.png","url":"https://assets-eu.researchsquare.com/files/rs-259624/v1/6b6974fa754bc74ade10f293.png"},{"id":6615339,"identity":"3ce9f873-efc0-483f-a617-15ea59e0fd0d","added_by":"auto","created_at":"2021-03-04 17:49:57","extension":"png","order_by":13,"title":"Figure 13","display":"","copyAsset":false,"role":"figure","size":43559,"visible":true,"origin":"","legend":"The Root Mean Square Fluctuation for (A) TMPRSS2_(11-Hydroxy-2 - (3,4-dihydroxybenzoyloxy)abieta-5,7,9(11),13-tetraene-12-one), (B) TMPRSS2_camostat, (C) S protein_(3- Benzoylhosloppone), and (D) ACE2_(24-Methylenecycloartenol), respectively. ","description":"","filename":"Fig13.png","url":"https://assets-eu.researchsquare.com/files/rs-259624/v1/2291a397820e7b10b7729c45.png"},{"id":6615341,"identity":"4852ccb9-cd65-4efa-aaca-7f832c65ba19","added_by":"auto","created_at":"2021-03-04 17:49:57","extension":"png","order_by":14,"title":"Figure 14","display":"","copyAsset":false,"role":"figure","size":14836,"visible":true,"origin":"","legend":"The binding free energy from MMGBSA analysis for each protein-drug complex. Error bars represent standard deviation. T3 = 11-Hydroxy-2 - (3,4-dihydroxybenzoyloxy) abieta-5,7,9(11),13-tetraene-12-on.","description":"","filename":"Fig14.png","url":"https://assets-eu.researchsquare.com/files/rs-259624/v1/0c7eec668c894219e091679f.png"},{"id":6614179,"identity":"d8d445e7-f80f-4f3f-a9d6-db36c6a661a8","added_by":"auto","created_at":"2021-03-04 17:45:24","extension":"png","order_by":15,"title":"Figure 15","display":"","copyAsset":false,"role":"figure","size":958208,"visible":true,"origin":"","legend":"The representative structure for each cluster in cartoon representation, ligands in sticks representation and the types of interactions. Gray-dotted line: hydrophobic interactions, blue lines: H-bond interactions, yellow-dotted lines: salt-bridges interactions, and green-dotted lines: pi-stacking interactions. Single-letter amino acids are in red color. ","description":"","filename":"Fig15.png","url":"https://assets-eu.researchsquare.com/files/rs-259624/v1/e7ca6ef2117c4a2c7954cbcf.png"},{"id":13675424,"identity":"154237c2-a708-4f5c-9374-90ce8eb369f6","added_by":"auto","created_at":"2021-09-17 11:26:37","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":2760499,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-259624/v1/bcdd40be-e86c-4dc5-a3a6-252b3da9d84e.pdf"},{"id":6615345,"identity":"8688c6bc-efc0-412c-ad65-d058d7e37ed0","added_by":"auto","created_at":"2021-03-04 17:49:58","extension":"docx","order_by":4,"title":"","display":"","copyAsset":false,"role":"supplement","size":100665,"visible":true,"origin":"","legend":"","description":"","filename":"SupplementaryData.docx","url":"https://assets-eu.researchsquare.com/files/rs-259624/v1/cbdfeb2d1c8060ba8ab62980.docx"}],"financialInterests":"","formattedTitle":"\u003cp\u003eMembrane-Mediated Sars-cov-2 Host Cell Entry: Potential Inhibitory Roles of Terpenoids in Silico\u003c/p\u003e","fulltext":[{"header":"Introduction","content":"\u003cp\u003eThe coronavirus disease-19 (COVID-19) caused by the new severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has been declared a public health emergency by the World Health Organization (WHO) [\u003ca href=\"#_ENREF_1\"\u003e1-4\u003c/a\u003e]. \u0026nbsp;The death toll from this virus has by far surpassed that of 2003 severe acute respiratory syndrome-coronavirus (SARS-CoV) and the 2012 Middle East respiratory syndrome coronavirus (MERS-CoV) outbreaks combined [\u003ca href=\"#_ENREF_5\"\u003e5\u003c/a\u003e, \u003ca href=\"#_ENREF_6\"\u003e6\u003c/a\u003e]. The SARS-CoV-2 earlier known as 2019 novel corona virus (2019-nCoV) is evolutionarily related (80% identity) to SARS-CoV [\u003ca href=\"#_ENREF_7\"\u003e7\u003c/a\u003e]. It causes multiple organ failure, which may present as fever, cough, shortness of breath, dyspnea, pneumonia, severe acute respiratory syndrome, kidney failure, and even death [\u003ca href=\"#_ENREF_8\"\u003e8\u003c/a\u003e, \u003ca href=\"#_ENREF_9\"\u003e9\u003c/a\u003e].\u003c/p\u003e\n\u003cp\u003eCell entry of coronaviruses depends on a fine interplay between the viral membrane spike (S) proteins and the host cell membrane proteins more importantly are the angiotensin-converting enzyme 2 (ACE2) and serine protease transmembrane protease serine 2 (TMPRSS2). [\u003ca href=\"#_ENREF_10\"\u003e10\u003c/a\u003e]. \u0026nbsp;The S-protein comprises two subunits, S1 as the receptor-binding domain (RBD) and S2 subunit for the fusion of viral membrane and the host cellular membrane. The SARS-CoV-2 relies on the host ACE2, for entry and the TMPRSS2 for S-protein priming. Upon binding of the S-protein to host receptor through the receptor-binding domain (RBD) in the S1 subunit, the S2 subunit mediates fusion of the viral envelope with the host membranes[\u003ca href=\"#_ENREF_11\"\u003e11\u003c/a\u003e]. \u0026nbsp;Although, the overall sequence similarities between S-protein of SARS-COV-2 and SARS-CoV are approximately ~76%, affinity between S-RBD of SARS-COV-2 and ACE2 is found to be approximately ten times higher when compared with SARS-CoV RBD [\u003ca href=\"#_ENREF_11\"\u003e11-13\u003c/a\u003e]. This molecular interaction is responsible for regulating both the cross-species and higher human-to-human transmissions of SARS-CoV-2 [\u003ca href=\"#_ENREF_14\"\u003e14\u003c/a\u003e, \u003ca href=\"#_ENREF_15\"\u003e15\u003c/a\u003e]. Therefore, these protein effectors of viral attachment, membrane fusion and cell entry are known as emerging targets for development of entry inhibitors, antibodies, and vaccines [\u003ca href=\"#_ENREF_14\"\u003e14\u003c/a\u003e].\u003c/p\u003e\n\u003cp\u003eThe use of phytomedicines as cheap alternatives to combat viral diseases and other infections, forms an integral component of African cultural practices, and hence a prominent feature in Africa [\u003ca href=\"#_ENREF_16\"\u003e16-20\u003c/a\u003e]. Terpenoids are a well known class of phytochemicals of tremendous pharmaceutical value over time because of their relevant broad-spectrum utility in medicine [\u003ca href=\"#_ENREF_21\"\u003e21\u003c/a\u003e, \u003ca href=\"#_ENREF_22\"\u003e22\u003c/a\u003e]. Screening a database of phytochemicals from indigenous African medicinal plants may help identify terpenoids with therapeutic potentials against the novel COVID-19 pandemic. Therefore, this study explores computational based screening of terpenoids from indigenous African medicinal plants as potential inhibitors of the emerging protein targets responsible for coronavirus cell entry and subsequent infection.\u003c/p\u003e"},{"header":"Methods","content":"\u003cp\u003e\u003cstrong\u003e2.1 Protein preparation\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe crystal structures of proteins for the docking studies were retrieved from the Protein Databank (http://www.rcsb.org) with their various PDB identification codes [1r42: Angiotensin-Converting Enzyme 2 (ACE2) [\u003ca href=\"#_ENREF_23\"\u003e23\u003c/a\u003e]; 2OQ5: type II transmembrane serine proteinases \u003cstrong\u003e(\u003c/strong\u003eTMPRSS2) [\u003ca href=\"#_ENREF_24\"\u003e24\u003c/a\u003e]; 6vw1: 2019-nCoV chimeric receptor-binding domain complexed with its receptor human ACE2 (ACE2-RBD) [\u003ca href=\"#_ENREF_25\"\u003e25\u003c/a\u003e] and coronoviruses spike protein (6VSB: SARS-CoV-2) [\u003ca href=\"#_ENREF_3\"\u003e3\u003c/a\u003e]; (5X5B: SARS-CoV) [\u003ca href=\"#_ENREF_26\"\u003e26\u003c/a\u003e] and (5x5c : MERS-CoV) [\u003ca href=\"#_ENREF_26\"\u003e26\u003c/a\u003e]. All the crystal structures were prepared by removing existing ligands and water molecules while missing hydrogen atoms were added using Autodock version 4.2 program (Scripps Research Institute, La Jolla, CA). Subsequently, non-polar hydrogens were merged while polar hydrogen was added to each protein. The well-ordered scheme was repeated for each protein and thereafter saved into dockable pdbqt format for molecular docking.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e2.2 Ligand preparation\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eOne hundred and six (106) bioactive terpenoids from African medicinal plants were complied base on literature search. Structure Data Format (SDF) of the reference inhibitors (S1: MLN-4760; S2: Camostat and S3: Nelfinavir mesylates) and 106 bioactive terpenoids derived from African plants were retrieved from the PubChem database (www.pubchem.ncbi.nlm.nih.gov) and converted to mol2 chemical format using Open babel [\u003ca href=\"#_ENREF_27\"\u003e27\u003c/a\u003e]. Other compounds that were not available on the database were drawn with Chemdraw version 19 and converted to mol2 chemical format. Polar hydrogen charges of the gasteiger-type were assigned and the nonpolar hydrogen molecules were merged with the carbons and the internal degrees of freedom and torsions were set to zero. The protein and ligand molecules were further converted to the dockable pdbqt format using Autodock tools.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e2.3 Molecular docking\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eMolecular docking was performed to evaluate the binding energy and to provide initial\u003cbr /\u003e coordinates and topology parameters for the MD simulations. Virtual screening of human enzymes and active regions of the coronaviruses spike protein and determination of binding affinities were carried out using AutoDock Vina [\u003ca href=\"#_ENREF_28\"\u003e28\u003c/a\u003e] and the binding scores from vina analysis were further validated by BINDSURF [\u003ca href=\"#_ENREF_29\"\u003e29\u003c/a\u003e]. Docking of bioactive terpenoids and reference compounds against human ACE2, human TMPRSS2 and : SARS-CoV-2 spike protein was performed by AutoDock Vina to locate alternate binding sites enclosing the whole macromolecules with a very extended grid (60 \u0026Aring; \u0026times; 60 \u0026Aring; \u0026times; 60\u0026Aring;) to reveal all the possible interaction sites applying exhaustiveness values of 8. Pdbqt form of each protein and terpenoid were uploaded into their respective columns of Autodock Vina and BINDSURF (the online tool) to run the interaction. The compounds were then ranked by their binding affinity scores. The molecular interactions between proteins and selected compounds with higher binding affinity to the proteins were viewed with Discovery Studio Visualizer version 16.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e2.4 Molecular Dynamics Simulation\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eMolecular Dynamics simulations were carried out on selected compounds, to evaluate their binding interactions with. The protein\u0026ndash;ligand for the top docked terpenoids to SARS-CoV-2 spike (S) protein, human angiotensin-converting enzyme 2 (ACE2) and transmembrane protease serine 2 (TMPRSS2) from AutoDock Vina docking step were used in Molecular Dynamics Simulation (MDS) using NAMD software [\u003ca href=\"#_ENREF_30\"\u003e30\u003c/a\u003e]. Necessary files for MDS were generated using CHARMM-GUI webserver [\u003ca href=\"#_ENREF_31\"\u003e31\u003c/a\u003e, \u003ca href=\"#_ENREF_32\"\u003e32\u003c/a\u003e]. For each complex, the system was minimized for 10000 steps then a production run for 100 ns was performed. Temperature was set to be 310 K and salt concentration was set to be the physiological concentration 0 .154 M NaCl. Afterwards, calculations of Backbone-Root Mean Square Deviation (RMSD), Per residue Root Mean Square Fluctuations (RMSF), Radius of Gyration (RoG), Surface Accessible Surface Area (SASA) were performed using VMD TK console scripts [\u003ca href=\"#_ENREF_33\"\u003e33\u003c/a\u003e].\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e2.5 Binding Free Energy calculation and Clustering analysis \u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eMolecular Mechanics/Generalized Born\u0026nbsp;Surface Area (MM/GBSA) [\u003ca href=\"#_ENREF_34\"\u003e34\u003c/a\u003e] calculation was performed using AmberTools 20 [\u003ca href=\"#_ENREF_35\"\u003e35\u003c/a\u003e] on the results from MDS. TTClust version 4.7.2 were used to cluster the trajectory automatically according to the elbow method and produce a representative structure for each cluster [\u003ca href=\"#_ENREF_36\"\u003e36\u003c/a\u003e]. These representative conformations were analyzed using Protein Ligand Interaction Profiler (PLIP) to know the interacting amino acids and the types of interactions [\u003ca href=\"#_ENREF_37\"\u003e37\u003c/a\u003e].\u003c/p\u003e\n\u003ch3\u003e2.6 Drug-likeness and ADMET studies\u003c/h3\u003e\n\u003cp\u003eThe top terpenoids that demonstrated highest binding affinity for ACE2, TMPRSS2 and active regions of SARS-CoV-2 spike protein were subjected to several drug-likeness predictive descriptors which an orally bio-active drug should comply to criteria for drug likeness [\u003ca href=\"#_ENREF_38\"\u003e38\u003c/a\u003e, \u003ca href=\"#_ENREF_39\"\u003e39\u003c/a\u003e]. The predicted Absorption, Distribution, Metabolism, Excretion and Toxicity (ADMET) study was analysed using the admetSAR webserver [\u003ca href=\"#_ENREF_40\"\u003e40\u003c/a\u003e]. The SDF file and SMILES of the compounds were downloaded from PubChem database to calculate ADMET properties using default parameters.\u003c/p\u003e"},{"header":"Results","content":"\u003cp\u003e\u003cstrong\u003e3.1. Molecular docking \u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eFigure 1 provides a flow chart showing the stepwise screening of African derived terpenoids for potential inhibitors of membrane-mediated SARS-CoV-2 cell entry proteins.\u003c/p\u003e\n\u003cp\u003eThe result from the docking analysis of the reference inhibitors and bioactive terpenoids with the human ACE2, TMPRSS2 and SARS-CoV-2 spike protein is shown in table S3 (supplementary material). The top 20 terpenoids with the highest binding affinity for the ACE2 were further analyzed for binding interactions with SARS-CoV-2 chimeric Receptor-Binding Domain complexed with its human receptor ACE2 (ACE2-RBD) and the S protein of SARS-CoV and MERS-CoV as shown in table 2.\u003c/p\u003e\n\u003cp\u003eThe docking analysis revealed that the reference inhibitor (MLN-4760) to the human ACE2 protein had binding energy of \u003cstrong\u003e-7.7 \u003c/strong\u003eKcal/mol respectively, while Camostat an inhibitor of TMPRSS2 had a binding energy of \u003cstrong\u003e-\u003c/strong\u003e7.6 Kcal/mol as represented in figure 3. It was further observed that the topmost docked terpenoids to the ACE2 had higher binding affinity for the S protein of SARS-CoV and MERS-CoV than SARS-CoV-2. More than 10 terpenoids had higher binding affinity than the 3 inhibitors used in this study table S1 (supplementary material). The top 20 docked compounds to SARS-CoV-2 S-proteins had higher binding affinity than nelfinavir mesylates S2 (supplementary material).\u003c/p\u003e\n\u003cp\u003eFrom the binding scores generated by the interacting terpenoids with the ACE2 and TMPRSS2 proteins, the 2 best docked terpenoids with the highest binding affinity are: 24-methylene cycloarteno and isoiguesterin with the corresponding binding energy of -9.7, and -9.5 Kcal/mol respectively. The 2 best docked terpenoids to SARS-CoV-2 S protein are 3-benzoylhosloppone and cucurbitacin with binding energies of -9.4 and -9.3 Kcal/mol respectively. 3-benzoylhosloppone had the highest binding affinity for SARS-CoV-2 S protein and the second top binding affinity to MERS-CoV S protein (Figure 3).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e3.1.1 Amino acid interaction of selected terpenoids with target proteins.\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe amino acid interactions of the human target proteins (ACE2 and TMPRSS2) with reference inhibitors and plant derived terpenoids that demonstrated the highest binding tendencies are represented in table 1. In the same way, the amino acid residues of the coronaviruses S protein that interacted with reference inhibitors and terpenoids with the highest binding affinity are shown in table 2. The interacting residues of ACE2 and TMPRSS2 with respective ligand groups were majorly through hydrophobic interactions and H-bond. Few H-bonding below 3.40 \u0026Aring; were observed with coronaviruses S protein (table 4).\u003c/p\u003e\n\u003cp\u003eThe binding of MLN-4760 to ACE2 showed that it was docked into the N terminus and zinc-containing subdomain I of ACE2 (figure 4a). MLN-4760 exhibited several types of hydrophobic interactions (Pi-Sigma, Pi-Pi T-Shaped, Pi-Alkyl and Alkyl) with TYR\u003csup\u003e510 \u003c/sup\u003ePHE\u003csup\u003e504\u003c/sup\u003e MET\u003csup\u003e360\u003c/sup\u003e, LYS\u003csup\u003e363 \u003c/sup\u003eand CYS\u003csup\u003e344\u003c/sup\u003e, a Salt and attractive charges to ARG\u003csup\u003e514\u003c/sup\u003e, ARG\u003csup\u003e518 \u003c/sup\u003eand ARG\u003csup\u003e278\u003c/sup\u003e and hydrogen bond to TYR\u003csup\u003e515\u003c/sup\u003e, THR\u003csup\u003e371\u003c/sup\u003e, PRO\u003csup\u003e346\u003c/sup\u003e and ARG\u003csup\u003e273\u003c/sup\u003e (figure 4a).\u003c/p\u003e\n\u003cp\u003e24-methylene cycloartenol the best docked terpenoid was docked into the C terminus-containing subdomain II of ACE2 but interacted with different residue as with the case of N-acetyl-D-glucosamine (figures 4b). 24-methylene cycloartenol interacted via H-bond to TRP\u003csup\u003e163\u003c/sup\u003e, SER\u003csup\u003e170\u003c/sup\u003e and TYR\u003csup\u003e497\u003c/sup\u003e.A Pi-Alkyl interaction was also observed with TYR\u003csup\u003e613\u003c/sup\u003e, PRO\u003csup\u003e492 \u003c/sup\u003eand VAL\u003csup\u003e491\u003c/sup\u003e. Isoiguesterin interacted via H-bond to ASP\u003csup\u003e350\u003c/sup\u003e, TYR\u003csup\u003e385\u003c/sup\u003e and ASN\u003csup\u003e394\u003c/sup\u003e. A Pi-Alkyl and Alkyl interactions was observed with the ALA\u003csup\u003e99\u003c/sup\u003e, PHE\u003csup\u003e40\u003c/sup\u003e, PHE\u003csup\u003e390 \u003c/sup\u003eand LEU\u003csup\u003e73\u003c/sup\u003e, TRP\u003csup\u003e69\u003c/sup\u003e residues respectively in a similar binding pattern with MLN-4760 (figure 4c).\u003c/p\u003e\n\u003cp\u003eCamostat was docked into the S1-specificity pocket of TMPRSS2 (figure 5a). It interacted via conventional H-bond to five amino residues (ARG\u003csup\u003e41\u003c/sup\u003e, SER\u003csup\u003e195\u003c/sup\u003e, TRP\u003csup\u003e215\u003c/sup\u003e, ALA\u003csup\u003e190 \u003c/sup\u003eand ASP\u003csup\u003e189\u003c/sup\u003e) and via carbon hydrogen bond to GLN\u003csup\u003e192\u003c/sup\u003e of TMPRSS2. The conventional H-bond was formed in the direction of the guanidine group in this order: first ester bond, second ester bond, while the last three residues interacted with amidino nitrogen of guanidine group respectively. The phenyl ring was responsible for the carbon-hydrogen bond with GLN\u003csup\u003e192\u003c/sup\u003e (figure 5a). T3 and T4 were docked into S1-specificity pocket of TMPRSS2 in a similar binding pattern as in the case of camostat (figure 5b \u0026amp; 5c). The only difference observed between the binding pattern of T3 and T4 was an additional H-bond between T3 with ARG\u003csup\u003e41 \u003c/sup\u003e(figure 5b).\u003c/p\u003e\n\u003cp\u003eNelfinavir mesylates an inhibitor of SARS-CoV and MERS-CoV S protein interacted in its best docked conformation to the S protein of SARS-CoV-2 in a different manner. Nelfinavir mesylates was docked into the S2 Subunit of SARS-CoV S protein (figure 7a). The same inhibitor was docked into to the N-terminal domain (NTD) region of the S1 subunit of SARS-CoV-2 and MERS-CoV S protein (figure 6a \u0026amp; 8a).\u003c/p\u003e\n\u003cp\u003e3-benzoylhosloppone with the highest binding affinity for SARS-CoV-2 S protein interacted via H-bond to THR\u003csup\u003e547\u003c/sup\u003e; Alkyl interaction to PHE\u003csup\u003e541\u003c/sup\u003e and Pi-Alkyl interaction to PRO\u003csup\u003e589\u003c/sup\u003e and LEU\u003csup\u003e546\u003c/sup\u003e. The region of interaction was between the CTD and SD1 region of S1 subunit of SARS-CoV-2 S protein. Cucurbitacin B was docked to the S2 subunit of SARS-CoV-2 S protein but interacted with different amino acid residue. The interaction of cucurbitacin B to the protein was via H-bond to ARG\u003csup\u003e1091\u003c/sup\u003e\u003cstrong\u003e, \u003c/strong\u003eASN\u003csup\u003e914\u003c/sup\u003e\u003cstrong\u003e, \u003c/strong\u003eTHR\u003csup\u003e912 \u003c/sup\u003eand GLN\u003csup\u003e1113\u003c/sup\u003e; Pi-Sigma bond to PHE\u003csup\u003e1121\u003c/sup\u003e and Alkyl interaction to ILE\u003csup\u003e1114 \u003c/sup\u003eand GLY\u003csup\u003e1124 \u003c/sup\u003e(figure 6c).\u003c/p\u003e\n\u003cp\u003eThe same pattern of interaction was observed in both 7-Deacetoxy-7-oxogedunin and 3-friedelanone to the S2 subunit of SARS-CoV S protein. Both terpenoids interacted via a H-bond to ARG\u003csup\u003e982 \u003c/sup\u003eand GLY\u003csup\u003e726 \u003c/sup\u003eof the S2 subunit. While 7-deacetoxy-7-oxogedunin interacted with the upstream helix and central helix, 3-friedelanone interacted with the connecting region of the S2 subunit. A hydrophobic interaction via Pi-Alkyl and alkyl bonds was observed with the remaining amino acid residue (table 2; figure 7b \u0026amp; 7c)\u003c/p\u003e\n\u003cp\u003e7-Deacetoxy-7-oxogedunin interacted via H-bond to the SER\u003csup\u003e51 \u003c/sup\u003eresidue of N-terminal domain of the S1 subunit of MERS-CoV S protein. A Pi-Pi T-shaped interaction was formed between 7-deacetoxy-7-oxogedunin and PHE\u003csup\u003e354\u003c/sup\u003e; HIS\u003csup\u003e670 \u003c/sup\u003eof MERS-CoV S protein. Other hydrophobic interactions via Pi-Alkyl and Pi-Sigma bonds were observed to with the remaining amino acid residues (table 4; figure 8a \u0026amp; 8b). 3-benzoylhosloppone interacted via: Pi-Sigma interaction to (PHE\u003csup\u003e341\u003c/sup\u003e) of NTD; Pi-Pi Stacking to (MET\u003csup\u003e698\u003c/sup\u003e) of SD2; Pi-Alkyl interaction to (LYS\u003csup\u003e689\u003c/sup\u003e) of SD2; and an Alkyl interaction to (LEU\u003csup\u003e344 \u003c/sup\u003eand ILE\u003csup\u003e337\u003c/sup\u003e) of NTD with the S1 subunit (figure 8c).\u003c/p\u003e\n\u003cp\u003eIn summary, the binding of ligands to various proteins revealed eight terpenoid with remarkable binding affinities. Those with very good interactions with ACE2 and TMPRSS2 are 24-methylene cycloartenol; isoiguesterin; 11-Hydroxy-2 - (3,4-dihydroxybenzoyloxy) abieta-5,7,9(11),13-tetraene-12-one; and 11-Hydroxy-2 -(4-hydroxybenzoyloxy)-abieta-5,7,9(11),13-tetraene-12-one. Similarly, 3-benzoylhosloppone, and cucurbitacin B interacted well with SARS-CoV-2 spike protein, while 7-deacetoxy-7-oxogedunin, and 3-friedelanone interacted well with SARS-CoV and MERS-CoV spike protein.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e3.1.2 Energy profile of best docked terpenoids to respective proteins \u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe overall energy profiles of terpenoid-protein complexes in the selected clusters with the best docked poses are shown in figures 9-11. Figure 9a-11a shows the breakdown of the binding energy of the selected cluster into different contributions. Gauss 1 (blue) and 2 (leaf green) bars: represent the non-bonding interactions, red bar: repulsion, light blue bar: Hydrophobic, Purple bar: Hydrogen bonds, light green bar: rotational forces, while the black bar represents total binding affinity which is a representative contribution of all bonding and non-bonding interactions between the terpenoids and the protein residues. The contributions of the various type of interaction as presented in graph (figure 9a-11a) shows that of the total binding energy of \u003cstrong\u003e-9.7 \u003c/strong\u003eKcal/mol exhibited by the binding of 24-methylene cycloartenol to the ACE2, -2.1 and 1.8 Kcal/mol of hydrophobic and H-bond energies respectively was contributed, while the rest was contributed by non-bonding interaction mainly van der Waals, repulsive and rotational forces. A H-bond, Hydrophobic interaction and repulsive energy of -2.8 -0.8 and +2.3 Kcal/mol respectively was contributed to the total binding energy of -\u003cstrong\u003e10.0 \u003c/strong\u003eKcal/mol between T3 and TMPRSS2. A hydrophobic interaction energies of -2.1, -0.6 and -1.5, a H-bond energies of 0.3, -0.6, -0.3 Kcal/mol was contributed to the total binding energy of the spike protein of SARS-CoV-2, SARS-CoV and MERS-CoV with respective terpenoids. The rest of the energy was contributed by non-binding interactions.\u003c/p\u003e\n\u003cp\u003eFigures 9b-11b shows the overall energy profile of the ligand-receptor complex of the selected cluster, showing the individual energetic contributions for each atom in the ligand. The colour indication is similar to (a) above.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e3.2 Molecular Dynamics Simulation\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eFour compounds which are, camostat, 11-hydroxy-2 - (3,4-dihydroxybenzoyloxy) abieta-5,7,9(11),13-tetraene-12-one, 24-methylene cycloartenol, and 3-benzoylhosloppone, were analysed for their interactions with SARS-CoV-2 Spike glycoprotein (S protein), Angiotensin-converting enzyme 2 (ACE2), and Transmembrane protease serine 2\u003cstrong\u003e (\u003c/strong\u003eTMPRSS2) proteins. Molecular dynamics simulation was done on each of the protein-ligand complexes and the trajectories were analyzed. The Radius of Gyraion (RoG), Root Mean Square Deviation (RMSD), Root Mean Square Fluctuation (RMSF), and Surface Accessible Surface Area (SASA) results were calculated for each trajectory and are shown in figure 11. There was no observed difference between the RoG of TMPRSS2_camostat and TMPRSS2_(11-hydroxy-2 - (3,4-dihydroxybenzoyloxy) abieta-5,7,9(11),13-tetraene-12-one) complexes, while that of ACE2 is larger and S protein has the largest values because it is a monomer of the SARS-CoV-2 spike trimer. All of them are fluctuating about certain values. The RMSD values of TMPRSS2_(T3), ACE2-24_methylene cycloartenol), TMPRSS2_camostat, and S protein_(3-benzoylhosloppone) complexes are around 2.13 \u0026Aring;, 3.6 \u0026Aring;, 2.14 \u0026Aring;, and 16.78 \u0026Aring;, respectively. While the RMSF values for TMPRSS2_(11-hydroxy-2 - (3,4-dihydroxybenzoyloxy) abieta-5,7,9(11),13-tetraene-12-one), ACE2_24-methylenecycloartenol), TMPRSS2_camostat, and S protein_(3- benzoylhosloppone) complex are fluctuating around 0.68 \u0026Aring;, 1.29 \u0026Aring;, 0.73 \u0026Aring;, and 7.36 \u0026Aring;, respectively.\u003c/p\u003e\n\u003cp\u003eTMPRSS2_(11-hydroxy-2 - (3,4-dihydroxybenzoyloxy) abieta-5,7,9(11),13-tetraene-12-one), ACE2_(24-methylene cycloartenol), and TMPRSS2_camostat complexes have a spike in the end of their RMSF results indicating the motion of the terminals. The spikes in the middle and the start of the RMSF of ACE2_(24-methylene cycloartenol) complex between amino acid 265 and amino acid 443 and spikes in S protein_(3-benzoylhosloppone) complex corresponds to the loops in the two protein respectively (Figure 12). The values of SASA can be found to be nearly stable for each complex but differ from each other.\u003c/p\u003e\n\u003cp\u003eMolecular Mechanics/Generalized Born\u0026nbsp;Surface Area (MMGBSA) algorithm in AmberTools 20 was utilized to calculate the ligand binding free energy. All frames (~1000 frame) were used in this calculation for each protein-drug complex. Figure 14 shows the binding affinity in Kcal/mol from MMGBSA analysis with Standard Deviation as error bars for each protein-drug complex. The best binding affinity (more negative) is for TMPRSS2_camostat (-53.5059 Kcal/mol) which indicates the strong binding between them.\u003c/p\u003e\n\u003cp\u003eTable 4 shows the number of clusters, representative frame produced for each trajectory, and the interaction types using PLIP webserver. Hydrophobic, H-bond, salt-bridges, pi-cation and pi-stacking are the types of interactions found by PLIP webserver. Most of complexes have H-bond and hydrophobic interactions, with TMPRSS2_camostat having the largest number of bonds in each cluster compared to other complexes. Figure 15 shows the protein-drug cluster representatives for the protein-ligand complexes and the mode of interaction in the enlarged part of the image. Images were generated using PyMol software V 2.2.2.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e3.3 Drug likeness and Pharmacokinetic properties of selected terpenoids.\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe result generated from the Lipinski and ADMET filtering analyses are represented in table 4 and figure S1 (supplementary file).\u003c/p\u003e\n\u003cp\u003eFour terpenoids T1, T3, T5 and T6 fulfilled the requirement for Lipinski analysis of the rule of-five with corresponding favourble predicted ADMET parameters.\u003c/p\u003e\n\u003cp\u003eThe \u003cem\u003ein silico \u003c/em\u003epredictive pharmacokinetic and ADMET properties from the filtering analyses suggested T1, T3, T5 and T6 with a high probability of absorption, subcellular distribution, low toxicity. Though pharmacokinetic analysis indicated T1 (Table 4) to be less soluble while the ADME/tox analysis indicated high aqueous solubility, ability to pass the high human intestinal absorption, low acute oral toxicity with a good bioavailability score as exhibited by T3, T5 and T6 (Table 4).\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eInterference with several proteins that mediate viral attachment, membrane fusion, and cell entry of coronaviruses is an emerging therapeutic strategy for preventing COVID-19 infection [\u003ca href=\"#_ENREF_10\"\u003e10\u003c/a\u003e, \u003ca href=\"#_ENREF_41\"\u003e41\u003c/a\u003e]. This principle was earlier demonstrated with HIV [\u003ca href=\"#_ENREF_42\"\u003e42\u003c/a\u003e, \u003ca href=\"#_ENREF_43\"\u003e43\u003c/a\u003e] and SARS-CoV [\u003ca href=\"#_ENREF_44\"\u003e44\u003c/a\u003e]. Earlier screening and prospecting of therapeutic phytocompound have been reported for both SARS-CoV and MERS-CoV [\u003ca href=\"#_ENREF_45\"\u003e45-48\u003c/a\u003e]. Cell-based assays have shown the antiviral potentials of specific plant terpenoids against Severe Acute Respiratory Syndrome Coronavirus (SARS- CoV) [\u003ca href=\"#_ENREF_45\"\u003e45\u003c/a\u003e, \u003ca href=\"#_ENREF_49\"\u003e49\u003c/a\u003e]. This study was therefore undertaken to identify potential inhibitors of membrane-mediated SARS-CoV-2 entry proteins form the class of the plant derived terpenoids. Specifically, two triterpenes namely 24-methylene cycloartenol and isoiguesterin were reported to target ACE2 as well as the host-virus interface (S-protein-ACE2 Receptor Complex). These compounds interacted with adjacent residues in the conserved domain, apparently portraying its ability to bind and block interactions of hotspot 31 residues. The residues near lysine 31, and tyrosine 41, 82\u0026ndash;84, and 353\u0026ndash;357 in human ACE2 are important for the binding of S-protein of coronavirus [\u003ca href=\"#_ENREF_50\"\u003e50\u003c/a\u003e]. The hotspots: 31 and 353, makes salt bridge between Lys31 and Glu35, and the hotspot 353, comprising a salt bridge between Lys353 and Asp38, and are both buried in hydrophobic environment, therefore interaction within this region is suggested to affect the binding of its substrate [\u003ca href=\"#_ENREF_51\"\u003e51\u003c/a\u003e]. Abietane diterpenes, namely 11-hydroxy-2 - (3,4-dihydroxybenzoyloxy) abieta-5,7,9(11),13-tetraene-12-one (T3), and 11-hydroxy-2-(4-hydroxybenzoyloxy)-abieta- 5,7,9(11),13-tetraene-12-one (T4) showed the strongest interaction with with TMPRSS2. In a similar binding pattern to camostat, these compounds were fitted into the S1-specificity pocket. They interacted with residue ALA\u003csup\u003e190\u003c/sup\u003e, ASP\u003csup\u003e189 \u003c/sup\u003eand GLN\u003csup\u003e192 \u0026shy;\u0026shy;\u0026shy;\u003c/sup\u003ethat are known to be part of the amino acid found at the basement of the pocket. ASP\u003csup\u003e189 \u003c/sup\u003eat the bottom of the pocket is known to determine the specificity of the S1 pocket for basic residues Arg and Lys at position P1 of the substrate [\u003ca href=\"#_ENREF_24\"\u003e24\u003c/a\u003e]. The result showed that the hydroxybenzoyloxyl moiety of the terpenoids (T3 and T4) was responsible for atleast 75% of the H-Bond with the protein. It was further observed that just as in the case of benzamidine (the native ligand) and camostat, the hydroxybenzoyloxyl moiety of the two terpenoids points with its hydroxyl group towards the carboxylate group of ASP\u003csup\u003e189\u003c/sup\u003e forming strong H-bonds with ASP\u003csup\u003e189 \u003c/sup\u003eand other residue in the pocket. For camostat, the phenylquanidine moiety pointed into the hydrophobic pocket with the negatively charged ASP\u003csup\u003e189\u003c/sup\u003e at its bottom. Unlike the H-bond formed between the amidino nitrogen of the phenylquanidine and benzamidine, in T3 and T4 the H-Bonds were formed mainly with the hydroxyl, and carboxylate group. A striking similarity observed was that the ester bond that linked both the phenylquanidine moiety of camostat and the hydroxybenzoyloxyl moiety of T3 and T4 to the remaining structural unit of the compounds formed strong H-Bonds to the same residue SER\u003csup\u003e195\u003c/sup\u003e\u003csub\u003e. \u003c/sub\u003eThe phenyl group of the hydroxybenzoyloxy moiety of T3 and T4 further interacted with hydrophobic interactions to CYS\u003csup\u003e119\u003c/sup\u003e and CYS\u003csup\u003e219\u003c/sup\u003e just as the peptide planes of the bonds between Trp215\u0026ndash;Gly216 and Cys191\u0026ndash;Gln192 sandwich the phenyl ring of benzamidine [\u003ca href=\"#_ENREF_24\"\u003e24\u003c/a\u003e, \u003ca href=\"#_ENREF_52\"\u003e52\u003c/a\u003e] The additional hydrophobic interaction by T3 and T4 may have been responsible for the exhibited higher binding affinities than camostat and benzamidine. Furthermore, while the hydroxybenzoyloxy moiety was directed toward the hydrophobic cleft created by ASP\u003csup\u003e189\u003c/sup\u003e, the abietane agylcon interacted with the imidazol ring of HIS\u003csup\u003e57\u003c/sup\u003e of the S2 pocket that is found next to the S1 pocket and ARG\u003csup\u003e41 \u003c/sup\u003e(in the case of T4) which are outside the hydrophobic cleft. A similar interaction as the later was observed with camostat. The strong similarity in the binding pattern and even a far strong binding affinity than the camostat and benzamidine indicates that T3, T4 and other abietane diterpenes especially those with hydroxybenzoyloxyl moiety attached to the abietane aglycon are potential inhibitors of TMPRSS2 thus preventing some coronaviruses from entering host [\u003ca href=\"#_ENREF_24\"\u003e24\u003c/a\u003e]. It is known that, like SARS-CoV, SARS-CoV-2 S protein recognizes and binds to host-cell receptor angiotensin-converting enzyme 2 (ACE2) using a transmembrane protease serine 2 (TMPRSS2) which activates the S protein to facilitate viral fusion and entry into cells [\u003ca href=\"#_ENREF_9\"\u003e9\u003c/a\u003e]. It is important to note that serine protease inhibitors like camostat mesylate, which blocks the activity of TMPRSS2 [\u003ca href=\"#_ENREF_53\"\u003e53\u003c/a\u003e], has been approved in Japan for human use. Related compounds with antiviral activity potentiates as an anti-SARS-CoV-2 agent [\u003ca href=\"#_ENREF_54\"\u003e54\u003c/a\u003e]. Also some abietane terpenoids have been identified to exhibit \u003cem\u003ein vitro\u003c/em\u003e anti-SARS-CoV activity [\u003ca href=\"#_ENREF_45\"\u003e45\u003c/a\u003e]. This is corroborates the result of our study that shows that abietane diterpenes exhibits a wide spectrum and multiplicity of protein binding; and may thereby specifically execute a complete blockage of viral entry.\u003c/p\u003e\n\u003cp\u003eWith regards to coronavirus S-proteins two compounds, 3- Benzoylhosloppone and Cucurbitacin B, were of utmost interest. While 3-benzoylhosloppone interacted with amino acid residue of the RBD and SD1 region of the S1 subunit, Cucurbitacin B was docked into the S2 subunit of SARS-CoV-2 S protein. The former subunit is responsible for receptor recognition while the later mediates the fusion of viral membrane and the host cellular membrane [\u003ca href=\"#_ENREF_55\"\u003e55\u003c/a\u003e]. These terpenoids may prevent interaction of spike protein with its host cell receptor, thereby preventing entry of the virus into the host cell. 3-benzoylhosloppone has been reported for its antimalarial property while Cucurbitacin B is an anticancer agent [\u003ca href=\"#_ENREF_56\"\u003e56\u003c/a\u003e, \u003ca href=\"#_ENREF_57\"\u003e57\u003c/a\u003e]. The MDS analysis of the top docked with their complexed proteins were stable and could be therefore subjected to experimental processes in further studies. From the Lipinski, pharmacokinetic and ADMET filtering analyses, we identified four druggable and non-toxic, natural terpenoids that exhibited strong binding tendency to the various protein targets that mediates coronavirus-host cell entry. The result from the predicted filtering analyses of the four compounds showed parameters that suggest a favourable \u003cem\u003ein silico\u003c/em\u003e ADMET and pharmacokinetic properties The terpenoids expressed high probability of human intestinal absorption. They were also non-substrate to the permeability-glycoprotein (P-gp) [\u003ca href=\"#_ENREF_58\"\u003e58\u003c/a\u003e], expressed capability to cross the blood brain barrier (BBB). SARS-CoV-2 has been reported to infect the brain, thus indicating its ability to cross the blood brain barrier (BBB) [\u003ca href=\"#_ENREF_59\"\u003e59\u003c/a\u003e], compounds that can cross the BBB will be beneficail in the overal all viral clearance, The four terpenoids did not show indication of mutagenicity \u003cem\u003ein silico\u003c/em\u003e, thereby they may not cause genetic mutations. The compounds did not display inhibitory potential for the various cytochrome P450, thus may not adversely affect phase I drug metabolism in the liver. These terpenoids are therefore considered as potential drug candidates.\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eA virtual screening approach was successfully applied to identify plant derived terpenoids as potential inhibitor of coronavirus cells entry proteins. The pentacyclic terpenoids, 4-methylene cycloartenol and isoiguesterin interacted strongly with binding sites residues that are known to interfere with the activity of ACE2. Compounds: 11-Hydroxy-2 - (3,4-dihydroxybenzoyloxy) abieta -5,7,9 (11),13-tetraene-12-one (T3), and 11-Hydroxy-2 -(4-hydroxybenzoyloxy)-abieta- 5,7,9(11),13-tetraene-12-one (T4) and other abietane diterpenes exhibited a similar binding pattern to the S1-specificity pocket of TMPRSS2 as camostat (reference inhibitor). They also showed wide spectrum and multiplicity of entry protein binding. The terpenoids binding conformations in the complexes were stable in a simulated dynamic environment. Since the identified lead compounds showed drug-likeness and low toxicity as indicated by the \u003cem\u003ein silico\u003c/em\u003e pharmacokinetically relevant molecular descriptors, they are postulated as potential inhibitors that can be considered for further \u003cem\u003ein vitro\u003c/em\u003e and \u003cem\u003ein vivo\u003c/em\u003e studies towards developing entry inhibitors against the ongoing coronavirus pandemic.\u003c/p\u003e"},{"header":"Declarations","content":"\u003ch4\u003e\u003cb\u003eAcknowledgments\u003c/b\u003e\u003c/h4\u003e\n\u003cp\u003eThe authors appreciate the members of the \u003cstrong\u003e\u003cem\u003eBioNet-AP\u003c/em\u003e\u003c/strong\u003e: Bioinformatics Network on African Phytomedicine for COVID-19 research.\u003c/p\u003e\n\u003cp\u003e-\u003cstrong\u003eEthical\u003c/strong\u003e Approval: Not applicable \u003cbr /\u003e -\u003cstrong\u003eConsent\u003c/strong\u003e \u003cstrong\u003eto Participate:\u003c/strong\u003e Not applicable\u003c/p\u003e\n\u003cp\u003e-\u003cstrong\u003eConsent to Publish:\u003c/strong\u003e Not applicable\u003cbr /\u003e -\u003cstrong\u003eAuthors Contributions\u003c/strong\u003e\u003c/p\u003e\n\u003col\u003e\n\u003cli\u003eA. Gyebi Conceived and designed the analysis\u003c/li\u003e\n\u003cli\u003eM. Ogunyemi Performed molecular docking analysis\u003c/li\u003e\n\u003cli\u003eM. Ibrahim Performed molecular simulations\u003c/li\u003e\n\u003cli\u003eB. Ogunro Wrote manuscript\u003c/li\u003e\n\u003cli\u003eP. Adegunloye Interprets results and wrote manuscript\u003c/li\u003e\n\u003cli\u003eO. Afolabi Editing and review of manuscript\u003c/li\u003e\n\u003c/ol\u003e\n\u003cp\u003e\u003cstrong\u003e-Funding: The research did not receive any funding or grants \u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e-Conflicts of interest: \u003c/strong\u003eThe authors declare no conflicting interest\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e-Availability of data and materials\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors confirm that the data supporting the findings of this study are available within the article [and/or] its supplementary materials.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eTaniguchi, Y., Nishikawa, H., Maeda, N., \u0026amp; Terada, Y. (2020). 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K., Chang, S. T., Kuo, C. J., Lee, S. S., Hou, C. C., Hsiao, P. W., Chien, S. C., Shyur, L. F., \u0026amp; Yang, N. S. (2007). Specific plant terpenoids and lignoids possess potent antiviral activities against severe acute respiratory syndrome coronavirus. \u003cem\u003eJournal of medicinal chemistry, 50\u003c/em\u003e, 4087\u0026ndash;4095.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eRyu, Y. B., Park, S. J., Kim, Y. M., Lee, J. Y., Seo, W. D., Chang, J. S., Park, K. H., Rho, M. C., \u0026amp; Lee, W. S. (2010). SARS-CoV 3CLpro inhibitory effects of quinone-methide triterpenes from Tripterygium regelii. \u003cem\u003eBioorg Med Chem Lett, 20\u003c/em\u003e, 1873\u0026ndash;1876.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003ePark, J. Y., Kim, J. H., Kim, Y. M., Jeong, H. J., Kim, D. W., Park, K. H., Kwon, H. J., Park, S. J., Lee, W. S., \u0026amp; Ryu, Y. B. (2012). 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P., Renisi, G., Signorini, L., Migliorati, K., \u0026amp; Fontanella, M. M. SARS-CoV-2 can induce brain and spine demyelinating lesions, Acta Neurochirurgica, (2020) 1\u0026ndash;4.\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"},{"header":"Tables","content":"\u003cp\u003e\u003cstrong\u003eTable 1:\u003c/strong\u003e Interacting amino acid residue of human ACE2 and TMPRSS2 with the top binding terpenoids from African phytochemicals\u003c/p\u003e\n\u003ctable border=\"1\" width=\"0\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd width=\"205\"\u003e\u003cbr /\u003e\n\u003cp\u003eBioactive compound\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"83\"\u003e\n\u003cp\u003eHuman Protein targets\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"187\"\u003e\n\u003cp\u003eInteracted residues\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"168\"\u003e\n\u003cp\u003eProtein atom involved in H-Bonding (BOND\u003c/p\u003e\n\u003cp\u003eDISTANCE)\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"205\"\u003e\n\u003cp\u003e\u0026nbsp; S1 (MLN-4760)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd rowspan=\"3\" width=\"83\"\u003e\n\u003cp\u003eACE2\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"187\"\u003e\n\u003cp\u003eARG\u003csup\u003e514 \u003c/sup\u003eARG\u003csup\u003e518 \u003c/sup\u003eARG\u003csup\u003e278\u003c/sup\u003e TYR\u003csup\u003e510 \u003c/sup\u003ePHE\u003csup\u003e504\u003c/sup\u003e MET\u003csup\u003e360\u003c/sup\u003e LYS\u003csup\u003e363 \u003c/sup\u003eCYS\u003csup\u003e344 \u003c/sup\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"168\"\u003e\n\u003cp\u003eTYR\u003csup\u003e515\u003c/sup\u003e(3.44) THR\u003csup\u003e371 \u003c/sup\u003e(3.03)\u0026nbsp;\u0026nbsp; PRO\u003csup\u003e346\u003c/sup\u003e (3.08) ARG\u003csup\u003e273\u003c/sup\u003e (2.93)\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"205\"\u003e\n\u003cp\u003e24-Methylene cycloartenol \u003cstrong\u003e(T1)\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"187\"\u003e\n\u003cp\u003eTRP\u003csup\u003e163 \u003c/sup\u003e\u0026nbsp;SER\u003csup\u003e170\u003c/sup\u003e TYR\u003csup\u003e497\u003c/sup\u003e TYR\u003csup\u003e613 \u003c/sup\u003ePRO\u003csup\u003e492 \u003c/sup\u003eVAL\u003csup\u003e491\u0026nbsp; \u003c/sup\u003eSER\u003csup\u003e167\u003c/sup\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"168\"\u003e\n\u003cp\u003eTRP\u003csup\u003e163 \u003c/sup\u003e(3.22)\u0026nbsp; SER\u003csup\u003e170\u003c/sup\u003e\u0026nbsp; (2.81) TYR\u003csup\u003e497\u003c/sup\u003e\u0026nbsp; (3.27)\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"205\"\u003e\n\u003cp\u003eIsoiguesterin (\u003cstrong\u003eT2)\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"187\"\u003e\n\u003cp\u003eASP\u003csup\u003e350 \u003c/sup\u003eTYR\u003csup\u003e385\u003c/sup\u003eASN\u003csup\u003e394\u003c/sup\u003e ALA\u003csup\u003e99 \u003c/sup\u003ePHE\u003csup\u003e40 \u003c/sup\u003ePHE\u003csup\u003e390 \u003c/sup\u003eLEU\u003csup\u003e73\u003c/sup\u003e TRP\u003csup\u003e69\u003c/sup\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"168\"\u003e\n\u003cp\u003eASP\u003csup\u003e350 \u003c/sup\u003e(3.27) TYR\u003csup\u003e385\u003c/sup\u003e\u0026nbsp; (3.27) ASN\u003csup\u003e394 \u003c/sup\u003e(3.27)\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"205\"\u003e\n\u003cp\u003eS2 (Camostat)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd rowspan=\"3\" width=\"83\"\u003e\n\u003cp\u003eTMPRSS2\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"187\"\u003e\n\u003cp\u003eARG\u003csup\u003e41 \u003c/sup\u003eSER\u003csup\u003e195 \u003c/sup\u003eALA\u003csup\u003e190 \u003c/sup\u003eASP\u003csup\u003e189 \u003c/sup\u003eTRP\u003csup\u003e215 \u003c/sup\u003e\u0026nbsp;GLN\u003csup\u003e192\u003c/sup\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"168\"\u003e\n\u003cp\u003eARG\u003csup\u003e41 \u003c/sup\u003eSER\u003csup\u003e195 \u003c/sup\u003eALA\u003csup\u003e190 \u003c/sup\u003eASP\u003csup\u003e189 \u003c/sup\u003eTRP\u003csup\u003e215 \u003c/sup\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"205\"\u003e\n\u003cp\u003e11-Hydroxy-2 - (3,4-dihydroxybenzoyloxy)abieta\u003cbr /\u003e -5,7,9(11),13-tetraene-12-one\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e(T3)\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"187\"\u003e\n\u003cp\u003eARG\u003csup\u003e41 \u003c/sup\u003eGLN\u003csup\u003e192 \u003c/sup\u003eSER\u003csup\u003e195 \u003c/sup\u003eALA\u003csup\u003e190 \u003c/sup\u003eASP\u003csup\u003e189 \u003c/sup\u003eCYS\u003csup\u003e191 \u003c/sup\u003eHIS\u003csup\u003e57 \u003c/sup\u003eCYS\u003csup\u003e191\u003c/sup\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"168\"\u003e\n\u003cp\u003eARG\u003csup\u003e41 \u003c/sup\u003e(2.41)GLN\u003csup\u003e192 \u003c/sup\u003e(2.89)SER\u003csup\u003e195 \u003c/sup\u003e(2.89)ALA\u003csup\u003e190 \u003c/sup\u003e(2.65)ASP\u003csup\u003e189\u003c/sup\u003e(2.39)\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"205\"\u003e\n\u003cp\u003e11-Hydroxy-2 -(4-hydroxybenzoyloxy)-abieta-\u003cbr /\u003e 5,7,9(11),13-tetraene-12-one \u003cstrong\u003e(T4)\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"187\"\u003e\n\u003cp\u003eGLN\u003csup\u003e192 \u003c/sup\u003eASP\u003csup\u003e189 \u003c/sup\u003eALA\u003csup\u003e190\u003c/sup\u003e\u003c/p\u003e\n\u003cp\u003eSER\u003csup\u003e195 \u003c/sup\u003eHIS\u003csup\u003e57 \u003c/sup\u003eSER\u003csup\u003e214 \u003c/sup\u003eTRP\u003csup\u003e192 \u003c/sup\u003eCYS\u003csup\u003e219\u003c/sup\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"168\"\u003e\n\u003cp\u003eGLN\u003csup\u003e192 \u003c/sup\u003e(2.32) ASP\u003csup\u003e189 \u003c/sup\u003e(2.62) ALA\u003csup\u003e190 \u003c/sup\u003e(2.27)\u003c/p\u003e\n\u003cp\u003eSER\u003csup\u003e195\u0026nbsp; \u003c/sup\u003e(2.32)\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cbr /\u003eTable 2:\u003c/strong\u003e Interacting amino acid residue of Spike protein of coronaviruses with the top binding terpenoids from selected African phytochemicals\u003c/p\u003e\n\u003ctable border=\"1\" width=\"0\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd width=\"206\"\u003e\u003cbr /\u003e\n\u003cp\u003eBioactive compound\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"107\"\u003e\n\u003cp\u003eCoronavirus spike proteins\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"181\"\u003e\n\u003cp\u003eInteracted residues\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"149\"\u003e\n\u003cp\u003eProtein atom involved in H-Bonding(BOND\u003c/p\u003e\n\u003cp\u003eDISTANCE)\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"206\"\u003e\n\u003cp\u003e(S3) Nelfinavir mesylates\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd rowspan=\"3\" width=\"107\"\u003e\n\u003cp\u003eSARS-Cov-2\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"181\"\u003e\n\u003cp\u003eTHR\u003csup\u003e886 \u003c/sup\u003eASP\u003csup\u003e867 \u003c/sup\u003ePRO\u003csup\u003e869 \u003c/sup\u003ePRO\u003csup\u003e862\u0026nbsp; \u003c/sup\u003eVAL\u003csup\u003e860 \u003c/sup\u003eSER\u003csup\u003e730 \u003c/sup\u003eHIS\u003csup\u003e1058\u003c/sup\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"149\"\u003e\n\u003cp\u003eTHR\u003csup\u003e886 \u003c/sup\u003e\u003cstrong\u003e(3.48) \u003c/strong\u003eASP\u003csup\u003e867 \u003c/sup\u003e\u003cstrong\u003e(2.13) \u003c/strong\u003eSER\u003csup\u003e730 \u003c/sup\u003e\u003cstrong\u003e(2.57)\u003c/strong\u003e HIS\u003csup\u003e1058 \u003c/sup\u003e\u003cstrong\u003e(2.03)\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"206\"\u003e\n\u003cp\u003e3- Benzoylhosloppone (\u003cstrong\u003eT5)\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"181\"\u003e\n\u003cp\u003eTHR\u003csup\u003e547 \u003c/sup\u003ePHE\u003csup\u003e541 \u003c/sup\u003eLEU\u003csup\u003e546\u003c/sup\u003e\u003c/p\u003e\n\u003cp\u003ePRO\u003csup\u003e589\u003c/sup\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"149\"\u003e\n\u003cp\u003eTHR\u003csup\u003e547\u003c/sup\u003e\u003cstrong\u003e(3.03)\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"206\"\u003e\n\u003cp\u003e\u0026nbsp;Cucurbitacin B (\u003cstrong\u003eT6)\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"181\"\u003e\n\u003cp\u003eARG\u003csup\u003e1091 \u003c/sup\u003e\u0026nbsp;\u0026nbsp;ASN\u003csup\u003e914\u003c/sup\u003e THR\u003csup\u003e912 \u003c/sup\u003eGLN\u003csup\u003e1113 \u003c/sup\u003e\u0026nbsp;\u0026nbsp;PHE\u003csup\u003e1121\u003c/sup\u003e ILE\u003csup\u003e1114 \u003c/sup\u003eGLY\u003csup\u003e1124\u003c/sup\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"149\"\u003e\n\u003cp\u003eARG\u003csup\u003e1091 \u0026shy;\u0026shy;\u003c/sup\u003e\u003cstrong\u003e(2.93)\u003c/strong\u003e\u0026nbsp; ASN\u003csup\u003e914\u0026shy;\u0026shy;\u003c/sup\u003e\u003cstrong\u003e(3.32)\u003c/strong\u003e THR\u003csup\u003e912 \u0026shy;\u0026shy;\u003c/sup\u003e\u003cstrong\u003e(2.95) \u003c/strong\u003eGLN\u003csup\u003e1113 \u0026shy;\u0026shy;\u003c/sup\u003e\u003cstrong\u003e(2.89)\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"206\"\u003e\n\u003cp\u003e(S3) Nelfinavir mesylates\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd rowspan=\"3\" width=\"107\"\u003e\n\u003cp\u003eSARS-CoV\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"181\"\u003e\n\u003cp\u003e\u0026nbsp;SER\u003csup\u003e556 \u003c/sup\u003eTHR\u003csup\u003e535\u0026nbsp; \u003c/sup\u003eTHR\u003csup\u003e559 \u003c/sup\u003ePHE\u003csup\u003e558 \u003c/sup\u003ePRO\u003csup\u003e575 \u003c/sup\u003ePHE\u003csup\u003e527 \u003c/sup\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"149\"\u003e\n\u003cp\u003eSER\u003csup\u003e556 \u003c/sup\u003e\u003cstrong\u003e(2.14) \u003c/strong\u003eTHR\u003csup\u003e535\u0026nbsp; \u003c/sup\u003e\u003cstrong\u003e(2.38, 2.59) \u003c/strong\u003eTHR\u003csup\u003e559 \u003c/sup\u003e\u003cstrong\u003e(3.30)\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"206\"\u003e\n\u003cp\u003e7-Deacetoxy-7-oxogedunin (\u003cstrong\u003eT7\u003c/strong\u003e)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"181\"\u003e\n\u003cp\u003eARG\u003csup\u003e982 \u003c/sup\u003e\u0026nbsp;\u0026nbsp;GLY\u003csup\u003e726\u003c/sup\u003e VAL\u003csup\u003e958\u0026nbsp; \u003c/sup\u003e\u0026nbsp;\u0026nbsp;PHE\u003csup\u003e837\u003c/sup\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"149\"\u003e\n\u003cp\u003eARG\u003csup\u003e982\u0026nbsp; \u003c/sup\u003e\u003cstrong\u003e(2.73, 2.16)\u003c/strong\u003e\u0026nbsp; GLY\u003csup\u003e726 \u003c/sup\u003e\u003cstrong\u003e(2.52)\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"206\"\u003e\n\u003cp\u003e\u0026nbsp; 3-Friedelanone (\u003cstrong\u003eT8\u003c/strong\u003e)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"181\"\u003e\n\u003cp\u003eARG\u003csup\u003e982 \u003c/sup\u003e\u0026nbsp;GLY\u003csup\u003e726 \u003c/sup\u003eVAL\u003csup\u003e958\u003c/sup\u003e PHE\u003csup\u003e837\u003c/sup\u003e VAL\u003csup\u003e945 \u003c/sup\u003eLYS\u003csup\u003e836 \u003c/sup\u003eLEU\u003csup\u003e948 \u003c/sup\u003e\u0026nbsp;ASN\u003csup\u003e838\u003c/sup\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"149\"\u003e\n\u003cp\u003eARG\u003csup\u003e982 \u003c/sup\u003e(3.23) GLY\u003csup\u003e726\u003c/sup\u003e (3.03) ASN\u003csup\u003e838 \u003c/sup\u003e(3.12)\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"206\"\u003e\n\u003cp\u003e(S3) Nelfinavir mesylates\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd rowspan=\"3\" width=\"107\"\u003e\n\u003cp\u003eMERS-CoV\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"181\"\u003e\n\u003cp\u003eSER\u003csup\u003e51 \u003c/sup\u003e\u0026nbsp;ARG\u003csup\u003e335\u003c/sup\u003e\u0026nbsp;\u0026nbsp; HIS\u003csup\u003e348 \u003c/sup\u003eHIS\u003csup\u003e670 \u003c/sup\u003eLEU\u003csup\u003e344 \u003c/sup\u003eILE\u003csup\u003e337 \u003c/sup\u003ePHE\u003csup\u003e354\u003c/sup\u003e LYS\u003csup\u003e668\u003c/sup\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"149\"\u003e\n\u003cp\u003eSER\u003csup\u003e51 \u003c/sup\u003e\u0026nbsp;(2.90) ARG\u003csup\u003e335\u003c/sup\u003e (2.89)\u0026nbsp;\u0026nbsp;\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"206\"\u003e\n\u003cp\u003e7-Deacetoxy-7-oxogedunin (\u003cstrong\u003eT7\u003c/strong\u003e)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"181\"\u003e\n\u003cp\u003eSER\u003csup\u003e51 \u003c/sup\u003e\u0026nbsp;HIS\u003csup\u003e348\u0026nbsp; \u003c/sup\u003eHIS\u003csup\u003e670 \u003c/sup\u003eILE\u003csup\u003e337 \u003c/sup\u003ePHE\u003csup\u003e354\u003c/sup\u003e LEU\u003csup\u003e344 \u003c/sup\u003eARG\u003csup\u003e335\u003c/sup\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"149\"\u003e\n\u003cp\u003eSER\u003csup\u003e51 \u003c/sup\u003e(2.74)\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"206\"\u003e\n\u003cp\u003e3- Benzoylhosloppone\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"181\"\u003e\n\u003cp\u003eLYS\u003csup\u003e689 \u003c/sup\u003e\u0026nbsp;PHE\u003csup\u003e341\u003c/sup\u003e MET\u003csup\u003e698 \u003c/sup\u003eVAL\u003csup\u003e958 \u003c/sup\u003eLEU\u003csup\u003e344 \u003c/sup\u003e\u0026nbsp;ILE\u003csup\u003e337\u003c/sup\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"149\"\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u003cbr /\u003e\u003cstrong\u003eTable 3:\u003c/strong\u003e Shows the number of clusters produced from TTClust, its representative frame for each of the protein-ligand complexes, and the interactions between the ligand and the protein from PLIP webserver for that frame.\u003c/p\u003e\n\u003ctable border=\"1\" width=\"0\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd colspan=\"5\" width=\"586\"\u003e\n\u003cp\u003e\u003cstrong\u003eTMPRSS2_(11-Hydroxy-2 - (3,4-dihydroxybenzoyloxy)abieta-5,7,9(11),13-tetraene-12-one) complex\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"199\"\u003e\n\u003cp\u003e\u003cstrong\u003eCLUSTER NUMBER (REPRESENTATIVE FRAME)\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"114\"\u003e\n\u003cp\u003e\u003cstrong\u003eHydrophobic\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"108\"\u003e\n\u003cp\u003e\u003cstrong\u003eH-bond\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"67\"\u003e\n\u003cp\u003e\u003cstrong\u003eSalt-bridges\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"98\"\u003e\n\u003cp\u003e\u003cstrong\u003ePi-cation\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"199\"\u003e\n\u003cp\u003e\u003cstrong\u003eCluster 1 (frame 140)\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"114\"\u003e\n\u003cp\u003eW215\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"108\"\u003e\n\u003cp\u003eA190 (2)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"67\"\u003e\n\u003cp\u003eNone\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"98\"\u003e\n\u003cp\u003eNone\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"199\"\u003e\n\u003cp\u003e\u003cstrong\u003eCluster 2 (frame 853)\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"114\"\u003e\n\u003cp\u003e\u003cstrong\u003eR41\u003c/strong\u003e - T62\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"108\"\u003e\n\u003cp\u003eS39 \u0026ndash; H40 - \u003cstrong\u003eR41\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"67\"\u003e\n\u003cp\u003e\u003cstrong\u003eR41\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"98\"\u003e\n\u003cp\u003e\u003cstrong\u003eR41\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"199\"\u003e\n\u003cp\u003e\u003cstrong\u003eCluster 3 (frame 977)\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"114\"\u003e\n\u003cp\u003eT61\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"108\"\u003e\n\u003cp\u003eNone\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"67\"\u003e\n\u003cp\u003eNone\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"98\"\u003e\n\u003cp\u003e\u003cstrong\u003eR41\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd colspan=\"5\" width=\"586\"\u003e\n\u003cp\u003e\u003cstrong\u003eACE2 _(24-Methylene cycloartenol) complex\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"199\"\u003e\n\u003cp\u003e\u003cstrong\u003eCLUSTER NUMBER (REPRESENTATIVE FRAME)\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"114\"\u003e\n\u003cp\u003e\u003cstrong\u003eHydrophobic\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"108\"\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"67\"\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"98\"\u003e\n\u003cp\u003e\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"199\"\u003e\n\u003cp\u003e\u003cstrong\u003eCLUSTER 1 (FRAME 172)\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"114\"\u003e\n\u003cp\u003eY255 (2)- P612\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"108\"\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"67\"\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"98\"\u003e\n\u003cp\u003e\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"199\"\u003e\n\u003cp\u003e\u003cstrong\u003eCLUSTER 2 (FRAME 721)\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"114\"\u003e\n\u003cp\u003eL142 (2) \u0026ndash; I151 \u0026ndash;\u0026nbsp;\u0026nbsp; L162 (2)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"108\"\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"67\"\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"98\"\u003e\n\u003cp\u003e\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd colspan=\"5\" width=\"586\"\u003e\n\u003cp\u003e\u003cstrong\u003eTMPRSS2_ camostat complex\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"199\"\u003e\n\u003cp\u003e\u003cstrong\u003ecluster number (representative frame)\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"114\"\u003e\n\u003cp\u003e\u003cstrong\u003eHydrophobic\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"108\"\u003e\n\u003cp\u003e\u003cstrong\u003eH-bond\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"67\"\u003e\n\u003cp\u003e\u003cstrong\u003eSalt-bridges\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"98\"\u003e\n\u003cp\u003e\u003cstrong\u003ePi-stacking\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"199\"\u003e\n\u003cp\u003e\u003cstrong\u003eCluster 1 (frame 92)\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"114\"\u003e\n\u003cp\u003eNone\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"108\"\u003e\n\u003cp\u003e\u003cstrong\u003eA190\u003c/strong\u003e (2) \u0026ndash; Q192 \u0026ndash; \u003cstrong\u003eD217\u003c/strong\u003e \u0026ndash; E218 \u0026ndash; A220\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"67\"\u003e\n\u003cp\u003e\u003cstrong\u003eD189\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"98\"\u003e\n\u003cp\u003eH57\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"199\"\u003e\n\u003cp\u003e\u003cstrong\u003eCluster 2 (frame 618)\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"114\"\u003e\n\u003cp\u003eQ192 - V213\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"108\"\u003e\n\u003cp\u003eR41 \u0026ndash; \u003cstrong\u003eA190\u003c/strong\u003e \u0026ndash; S195 \u0026ndash; \u003cstrong\u003eD217\u003c/strong\u003e \u0026ndash; E218\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"67\"\u003e\n\u003cp\u003eH57 - \u003cstrong\u003eD189\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"98\"\u003e\n\u003cp\u003eNone\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"199\"\u003e\n\u003cp\u003e\u003cstrong\u003eCluster 3 (frame 284)\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"114\"\u003e\n\u003cp\u003eQ192\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"108\"\u003e\n\u003cp\u003e\u003cstrong\u003eA190\u003c/strong\u003e (2) \u0026ndash; S195 \u0026ndash; \u003cstrong\u003eD217\u003c/strong\u003e (2)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"67\"\u003e\n\u003cp\u003e\u003cstrong\u003eD189\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"98\"\u003e\n\u003cp\u003eNone\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"199\"\u003e\n\u003cp\u003e\u003cstrong\u003eCluster 4 (frame 728)\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"114\"\u003e\n\u003cp\u003eNone\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"108\"\u003e\n\u003cp\u003e\u003cstrong\u003eA190\u003c/strong\u003e (2) \u0026ndash; \u003cstrong\u003eD217\u003c/strong\u003e (2)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"67\"\u003e\n\u003cp\u003e\u003cstrong\u003eD189\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"98\"\u003e\n\u003cp\u003eNone\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"199\"\u003e\n\u003cp\u003e\u003cstrong\u003eCluster 5 (frame 915)\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"114\"\u003e\n\u003cp\u003eQ192\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"108\"\u003e\n\u003cp\u003e\u003cstrong\u003eA190\u003c/strong\u003e\u0026nbsp; (2) \u0026ndash; \u003cstrong\u003eD217\u003c/strong\u003e (2) \u0026ndash; A220\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"67\"\u003e\n\u003cp\u003e\u003cstrong\u003eD189\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"98\"\u003e\n\u003cp\u003eNone\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd colspan=\"5\" width=\"586\"\u003e\n\u003cp\u003e\u003cstrong\u003eS protein_(3- Benzoylhosloppone) complex\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"199\"\u003e\n\u003cp\u003e\u003cstrong\u003eCLUSTER NUMBER (REPRESENTATIVE FRAME)\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"114\"\u003e\n\u003cp\u003e\u003cstrong\u003eHydrophobic\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"108\"\u003e\n\u003cp\u003e\u003cstrong\u003eH-bond\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"67\"\u003e\n\u003cp\u003e\u003cstrong\u003ePi-stacking\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"98\"\u003e\n\u003cp\u003e\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"199\"\u003e\n\u003cp\u003e\u003cstrong\u003eCLUSTER 1 (FRAME 184)\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"114\"\u003e\n\u003cp\u003eL546 \u0026ndash; \u003cstrong\u003eV576\u003c/strong\u003e \u0026ndash; I587 (2) - P589\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"108\"\u003e\n\u003cp\u003eNone\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"67\"\u003e\n\u003cp\u003eNone\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"98\"\u003e\n\u003cp\u003e\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"199\"\u003e\n\u003cp\u003e\u003cstrong\u003eCLUSTER 2 (FRAME 631)\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"114\"\u003e\n\u003cp\u003eF541 \u0026ndash; \u003cstrong\u003eF543\u003c/strong\u003e \u0026ndash; L546 \u0026ndash; T549 - P589\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"108\"\u003e\n\u003cp\u003eT573\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"67\"\u003e\n\u003cp\u003e\u003cstrong\u003eF543\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"98\"\u003e\n\u003cp\u003e\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"199\"\u003e\n\u003cp\u003e\u003cstrong\u003eCLUSTER 3 (FRAME 935)\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"114\"\u003e\n\u003cp\u003eF541 \u0026ndash; \u003cstrong\u003eF543\u003c/strong\u003e \u0026ndash; L546 \u0026ndash; F565 \u0026ndash; 573 - \u003cstrong\u003eV576\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"108\"\u003e\n\u003cp\u003eNone\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"67\"\u003e\n\u003cp\u003eNone\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"98\"\u003e\n\u003cp\u003e\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003eAmino acid residues were represented by single letter code. Bold amino acids are common in each protein-drug complex\u003c/p\u003e\n\u003ch3\u003eTable 4: Physicochemical properties of the top binding terpenoids from African plants to ACE2, TMPRSS2 and S protein of\u0026nbsp; SARS-Cov-2\u003c/h3\u003e\n\u003ctable border=\"1\" width=\"0\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd colspan=\"5\" width=\"649\"\u003e\n\u003cp\u003e\u003cstrong\u003ea) Lipinski filter analysis\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"127\"\u003e\n\u003cp\u003eLipinski filters\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"132\"\u003e\n\u003cp\u003e\u003cstrong\u003eT1\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"120\"\u003e\n\u003cp\u003e\u003cstrong\u003eT3\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"138\"\u003e\n\u003cp\u003e\u003cstrong\u003eT5\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"132\"\u003e\n\u003cp\u003e\u003cstrong\u003eT6\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"127\"\u003e\n\u003cp\u003eMolecular weight (g/mol)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"132\"\u003e\n\u003cp\u003e454.77\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"120\"\u003e\n\u003cp\u003e450.52\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"138\"\u003e\n\u003cp\u003e402.48\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"132\"\u003e\n\u003cp\u003e558.70\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"127\"\u003e\n\u003cp\u003eNum. heavy atoms\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"132\"\u003e\n\u003cp\u003e33\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"120\"\u003e\n\u003cp\u003e33\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"138\"\u003e\n\u003cp\u003e30\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"132\"\u003e\n\u003cp\u003e40\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"127\"\u003e\n\u003cp\u003eNum. rotatable bonds\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"132\"\u003e\n\u003cp\u003e5\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"120\"\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e4\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"138\"\u003e\n\u003cp\u003e4\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"132\"\u003e\n\u003cp\u003e6\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"127\"\u003e\n\u003cp\u003eNum. H-bond acceptors\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"132\"\u003e\n\u003cp\u003e1\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"120\"\u003e\n\u003cp\u003e6\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"138\"\u003e\n\u003cp\u003e4\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"132\"\u003e\n\u003cp\u003e8\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"127\"\u003e\n\u003cp\u003eHydrogen bond donor\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"132\"\u003e\n\u003cp\u003e1\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"120\"\u003e\n\u003cp\u003e3\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"138\"\u003e\n\u003cp\u003e0\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"132\"\u003e\n\u003cp\u003e3\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"127\"\u003e\n\u003cp\u003eMLogP\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"132\"\u003e\n\u003cp\u003e7.30\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"120\"\u003e\n\u003cp\u003e2.96\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"138\"\u003e\n\u003cp\u003e3.79\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"132\"\u003e\n\u003cp\u003e1.76\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"127\"\u003e\n\u003cp\u003eMolar Refractivity\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"132\"\u003e\n\u003cp\u003e144.50\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"120\"\u003e\n\u003cp\u003e126.11\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"138\"\u003e\n\u003cp\u003e116.15\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"132\"\u003e\n\u003cp\u003e150.94\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"127\"\u003e\n\u003cp\u003eLipinski violation\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"132\"\u003e\n\u003cp\u003e1\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"120\"\u003e\n\u003cp\u003e0\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"138\"\u003e\n\u003cp\u003e0\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"132\"\u003e\n\u003cp\u003e1\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd colspan=\"5\" width=\"649\"\u003e\n\u003cp\u003e\u003cstrong\u003e(b) admet SAR\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd colspan=\"5\" width=\"649\"\u003e\n\u003cp\u003e\u003cstrong\u003eAbsorption (Probability)\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"127\"\u003e\n\u003cp\u003eBlood-Brain Barrier\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"132\"\u003e\n\u003cp\u003eBBB+ (0.96)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"120\"\u003e\n\u003cp\u003eBBB+ (0.60)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"138\"\u003e\n\u003cp\u003eBBB+ (0.61)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"132\"\u003e\n\u003cp\u003eBBB+ (0.81)\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"127\"\u003e\n\u003cp\u003eHuman Intestinal Absorption\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"132\"\u003e\n\u003cp\u003eHIA+\u0026nbsp; (0.99)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"120\"\u003e\n\u003cp\u003eHIA+\u0026nbsp; (0.92)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"138\"\u003e\n\u003cp\u003eHIA+ (0.92)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"132\"\u003e\n\u003cp\u003eHIA+ (0.97)\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"127\"\u003e\n\u003cp\u003eBioavailability Score\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"132\"\u003e\n\u003cp\u003e0.55\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"120\"\u003e\n\u003cp\u003e0.55\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"138\"\u003e\n\u003cp\u003e0.55\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"132\"\u003e\n\u003cp\u003e0.55\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"127\"\u003e\n\u003cp\u003eCaco-2 Permeability\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"132\"\u003e\n\u003cp\u003eCaco2+ (0.79)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"120\"\u003e\n\u003cp\u003eCaco2+ (0.59)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"138\"\u003e\n\u003cp\u003eCaco2+ (0.59)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"132\"\u003e\n\u003cp\u003eCaco2+ (0.61)\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"127\"\u003e\n\u003cp\u003eP-glycoprotein Substrate\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"132\"\u003e\n\u003cp\u003eSubstrate (0.73)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"120\"\u003e\n\u003cp\u003eSubstrate (0.78)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"138\"\u003e\n\u003cp\u003eNon-inhibitor (0.58)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"132\"\u003e\n\u003cp\u003eSubstrate (0.79)\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"127\"\u003e\n\u003cp\u003eP-glycoprotein Inhibitor\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"132\"\u003e\n\u003cp\u003eNon-inhibitor (0.65)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"120\"\u003e\n\u003cp\u003eNon-inhibitor (0.74)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"138\"\u003e\n\u003cp\u003eNon-inhibitor (0.74)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"132\"\u003e\n\u003cp\u003eNon-inhibitor (0.61)\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"127\"\u003e\n\u003cp\u003eRenal Organic Cation Transporter\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"132\"\u003e\n\u003cp\u003eInhibitor (0.75)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"120\"\u003e\n\u003cp\u003eInhibitor (0.90)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"138\"\u003e\n\u003cp\u003eNon-inhibitor (0.90)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"132\"\u003e\n\u003cp\u003eNon-inhibitor (0.87)\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd colspan=\"5\" width=\"649\"\u003e\n\u003cp\u003e\u003cstrong\u003eDistribution\u0026nbsp; \u003c/strong\u003e\u003cstrong\u003e(Probability)\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"127\"\u003e\n\u003cp\u003eSubcellular localization\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"132\"\u003e\n\u003cp\u003eLysosome (0.55)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"120\"\u003e\n\u003cp\u003eMitochondria (0.86)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"138\"\u003e\n\u003cp\u003eMitochondria (0.86)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"132\"\u003e\n\u003cp\u003eMitochondria (0.77)\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd colspan=\"5\" width=\"649\"\u003e\n\u003cp\u003e\u003cstrong\u003eMetabolism\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"127\"\u003e\n\u003cp\u003eCYP450\u0026nbsp; Substrate\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"132\"\u003e\n\u003cp\u003eSubstrate\u0026nbsp; (0.77)\u003c/p\u003e\n\u003cp\u003eNon-inhibitor (0.78)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"120\"\u003e\n\u003cp\u003eSubstrate\u003c/p\u003e\n\u003cp\u003eNon-inhibitor (0.83)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"138\"\u003e\n\u003cp\u003eNon-substrate\u0026nbsp; (0.65)\u003c/p\u003e\n\u003cp\u003einhibitor (0.80)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"132\"\u003e\n\u003cp\u003eInhibitor (0.79)\u003c/p\u003e\n\u003cp\u003eNon-substrate (0.83)\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd colspan=\"5\" width=\"649\"\u003e\n\u003cp\u003e\u003cstrong\u003eToxicity\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"127\"\u003e\n\u003cp\u003eAMES Toxicity\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"132\"\u003e\n\u003cp\u003eNon AMES toxic (0.71)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"120\"\u003e\n\u003cp\u003eAMES toxic (0.87)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"138\"\u003e\n\u003cp\u003eNon AMES toxic\u0026nbsp;\u0026nbsp; (0.87)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"132\"\u003e\n\u003cp\u003eNon AMES toxic (0.84)\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"127\"\u003e\n\u003cp\u003eCarcinogens\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"132\"\u003e\n\u003cp\u003eNon-carcinogens (0.92)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"120\"\u003e\n\u003cp\u003eNon-carcinogens (0.90)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"138\"\u003e\n\u003cp\u003eNon-carcinogens (0.90)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"132\"\u003e\n\u003cp\u003eNon-carcinogens (0.92)\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"127\"\u003e\n\u003cp\u003eAcute Oral Toxicity\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"132\"\u003e\n\u003cp\u003eIII (0.77)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"120\"\u003e\n\u003cp\u003eIII (0.59)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"138\"\u003e\n\u003cp\u003eIII\u0026nbsp;\u0026nbsp; (0.57)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"132\"\u003e\n\u003cp\u003eI (0.78)\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"127\"\u003e\n\u003cp\u003eRat Acute Toxicity LD\u003csub\u003e50\u003c/sub\u003e, mol/kg\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"132\"\u003e\n\u003cp\u003e3.2804\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"120\"\u003e\n\u003ctable\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd width=\"49\"\u003e\u0026nbsp;\u003c/td\u003e\n\u003ctd width=\"5\"\u003e\u0026nbsp;\u003c/td\u003e\n\u003c/tr\u003e\n\u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e2.5370\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"138\"\u003e\n\u003cp\u003e2.5370\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"132\"\u003e\n\u003cp\u003e3.8742\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"127\"\u003e\n\u003cp\u003eAqueous solubility (LogS)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"132\"\u003e\n\u003cp\u003e-4.76258\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"120\"\u003e\n\u003cp\u003e-4.5550\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"138\"\u003e\n\u003cp\u003e-4.7201\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"132\"\u003e\n\u003cp\u003e-4.5035\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd colspan=\"5\" width=\"649\"\u003e\n\u003cp\u003e\u003cstrong\u003ePharmacokinetics\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"127\"\u003e\n\u003cp\u003eLower GI absorption\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"132\"\u003e\n\u003cp\u003eLow\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"120\"\u003e\n\u003cp\u003eHigh\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"138\"\u003e\n\u003cp\u003eHigh\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"132\"\u003e\n\u003cp\u003elow\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"127\"\u003e\n\u003cp\u003eLog \u003cem\u003eK\u003c/em\u003e\u003csub\u003ep\u003c/sub\u003e (skin permeation) cm/s\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"132\"\u003e\n\u003cp\u003e-1.48\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"120\"\u003e\n\u003cp\u003e-5.58\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"138\"\u003e\n\u003cp\u003e-5.33\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"132\"\u003e\n\u003cp\u003e-7.83\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e4-Methylene cycloartenol \u003cstrong\u003e(T1); \u003c/strong\u003e11-Hydroxy-2 - (3,4-dihydroxybenzoyloxy)abieta -5,7,9(11),13-tetraene-12-one\u003cstrong\u003e(T3); \u003c/strong\u003e3- Benzoylhosloppone (\u003cstrong\u003eT5) and\u0026nbsp; \u003c/strong\u003eCucurbitacin B (\u003cstrong\u003eT6)\u003c/strong\u003e\u003c/p\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"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":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"SARS-CoV-2, ACE2, TMPRSS2, spike protein, terpenoids, molecular docking","lastPublishedDoi":"10.21203/rs.3.rs-259624/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-259624/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eTargeting viral cell entry proteins is an emerging therapeutic strategy for inhibiting the first stage of SARS-CoV-2 infection. In this study, 106 bioactive terpenoids from African medicinal plants were screened through molecular docking analysis against \u003cem\u003ehuman\u003c/em\u003e angiotensin-converting enzyme 2 (\u003cem\u003eh\u003c/em\u003eACE2), \u003cem\u003ehuman\u003c/em\u003e transmembrane protease serine 2 (TMPRSS2) and the S proteins of SARS-CoV-2, SARS-CoV and MERS-CoV. \u003cem\u003eIn silico \u003c/em\u003eADMET and drug-likeness prediction, molecular dynamics simulation (MDS), binding free energy calculations and clustering analysis of MDS trajectories were performed on the top docked compounds to respective targets. The results revealed eight terpenoids with high binding tendencies to the catalytic residues of different targets. Pentacyclic terpenoids: 24-methylene cycloartenol and isoiguesterin interacted with the \u003cem\u003eh\u003c/em\u003eACE2 binding hotspots for the SARS-CoV-2 Spike protein. 11-hydroxy-2 - (3,4-dihydroxybenzoyloxy) abieta -5,7,9 (11),13-tetraene-12-one, 11-hydroxy-2 -(4-hydroxybenzoyloxy)-abieta- 5,7,9(11),13-tetraene-12-one and other abietane diterpenes interacted strongly with the S1-specificy pocket of TMPRSS2. 3-benzoylhosloppone and cucurbitacin interacted with the RBD and S2 subunit of SARS-CoV-2 spike protein respectively. The predicted druggable and ADMET favourable terpenoids formed structurally stable complexes in the simulated dynamics environment. These terpenoids provides core structure that can be exploited for further lead optimization to design drugs against SARS-CoV-2 cell mediated entry, subject to further \u003cem\u003ein vitro\u003c/em\u003e and \u003cem\u003ein vivo\u003c/em\u003e studies.\u0026nbsp;\u003c/p\u003e","manuscriptTitle":"Membrane-Mediated Sars-cov-2 Host Cell Entry: Potential Inhibitory Roles of Terpenoids in Silico","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2021-03-04 17:45:20","doi":"10.21203/rs.3.rs-259624/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"1d6e41d9-9ee1-4969-b1c8-d989b5949b01","owner":[],"postedDate":"March 4th, 2021","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[{"id":2772185,"name":"General Biochemistry"},{"id":2772186,"name":"Biotechnology and Bioengineering"}],"tags":[],"updatedAt":"2021-06-02T01:32:35+00:00","versionOfRecord":[],"versionCreatedAt":"2021-03-04 17:45:20","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-259624","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-259624","identity":"rs-259624","version":["v1"]},"buildId":"-HB7Z8yhvgn0wM9Nzuekk","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}