Id |
Subject |
Object |
Predicate |
Lexical cue |
T123 |
0-2 |
Sentence |
denotes |
2. |
T124 |
4-25 |
Sentence |
denotes |
Materials and methods |
T125 |
27-31 |
Sentence |
denotes |
2.1. |
T126 |
33-69 |
Sentence |
denotes |
Selection and preparation of ligands |
T127 |
70-263 |
Sentence |
denotes |
The present study was carried out at Molecular Chemoinformatics Section, Cell and Tissue Culture Lab, Dept. of Biochemistry, Era’s Lucknow Medical College and Hospital, Era University, Lucknow. |
T128 |
264-445 |
Sentence |
denotes |
The ligands (WS phytoconstituents) selected for the study were first evaluated for their ability to obey Lipinski’s rule of five (Lipinski et al., 1997) using Molinspiration server. |
T129 |
446-592 |
Sentence |
denotes |
Lipinski's rules are used to determine the drug like characteristics of a compound with properties that would make it a potential drug for humans. |
T130 |
593-695 |
Sentence |
denotes |
PubChem database was used to access the 3D structures of the WS phytoconstituents and reference drugs. |
T131 |
696-872 |
Sentence |
denotes |
Prior to docking, energy minimization of ligands was carried out using Merck Molecular Force Field (MMFF94) in order to achieve a better relaxation in the arrangement of atoms. |
T132 |
873-1382 |
Sentence |
denotes |
The PubChem IDs of the reference drugs and selected ligands were as follows: arbidol (CID-131411), losartan (CID-3961), procainamide (CID-4913), cinacalcet (CID-156419), oberadilol (CID-3047798), poziotinib (CID-25127713), hydroxychloroquine (CID-3652), anaferine (CID-443143), withanolide A (CID-11294368), withanolide B (CID-14236711), withanolide D (CID-161671), withanolide E (CID-301751), withaferin A (CID-265237), withasomnine (CID-442877), withanone (CID-21679027) and viscosalactone B (CID-57403080). |
T133 |
1383-1584 |
Sentence |
denotes |
Prior to docking, the protonation states of the ligands were determined at pH 7.4 using Protoss, a fully automated hydrogen prediction online tool for protein–ligand complexes (https://proteins.plus/). |
T134 |
1586-1590 |
Sentence |
denotes |
2.2. |
T135 |
1592-1653 |
Sentence |
denotes |
Prediction of activity spectra for substances (PASS) analysis |
T136 |
1654-1744 |
Sentence |
denotes |
PASS is an online web tool hosted at http://195.178.207.233/PASS/index.html (Ahmad, 2019). |
T137 |
1745-1894 |
Sentence |
denotes |
Based on the structure–activity relationship with a known chemical entity, PASS analysis server predicts biological activities of chemical compounds. |
T138 |
1895-2053 |
Sentence |
denotes |
The tool predicts the pharmacological behavior, mechanism of action and side effects such as mutagenicity, carcinogenicity, embryotoxicity and teratogenicity. |
T139 |
2054-2208 |
Sentence |
denotes |
In the present study, PASS analysis was performed using OSIRIS Property Explorer version 4.5.1. (http://www.openmolecules.org/propertyexplorer/index.html) |
T140 |
2210-2216 |
Sentence |
denotes |
2.2.1. |
T141 |
2218-2241 |
Sentence |
denotes |
Lipinski’s rule of five |
T142 |
2242-2394 |
Sentence |
denotes |
The druglikeness of WS phytoconstituents was also assessed using Lipinski’s rule of five (Ertl et al., 2000; Lipinski et al., 1997; Veber et al., 2002). |
T143 |
2395-2638 |
Sentence |
denotes |
The parameters of druglikeness such as MW ≤500, logP ≤5, number of hydrogen bond donors (NOHNH) ≤5 and hydrogen bond acceptor sites (NON)≤10, topological polar surface area (TPSA) (≤140 Å2), and number of rotatable bonds (≤10) were determined. |
T144 |
2639-2845 |
Sentence |
denotes |
In the present study, the druglikeness of selected WS phytoconstituents was analyzed using Molinspiration (http://www.molinspiration.com/cgi-bin/properties) and compared to that of standard reference drugs. |
T145 |
2847-2853 |
Sentence |
denotes |
2.2.2. |
T146 |
2855-2865 |
Sentence |
denotes |
Veber rule |
T147 |
2866-2937 |
Sentence |
denotes |
For oral bioavailability, membrane permeability is an important factor. |
T148 |
2938-3074 |
Sentence |
denotes |
Polar surface area and number of rotatable bonds are two critical considerations for a compound to behave as a potential drug candidate. |
T149 |
3075-3243 |
Sentence |
denotes |
With a reduction in polar surface area, permeation increases and with the increase in number of rotatable bonds permeation decreases significantly (Veber et al., 2002). |
T150 |
3244-3364 |
Sentence |
denotes |
The following two criteria should be met by a potential drug candidate in order to obey Veber rules:≤10 rotatable bonds; |
T151 |
3365-3436 |
Sentence |
denotes |
Polar surface area ≤140Å2 (or 12 or fewer H-bond donors and acceptors). |
T152 |
3438-3444 |
Sentence |
denotes |
2.2.3. |
T153 |
3446-3458 |
Sentence |
denotes |
Ghose filter |
T154 |
3459-3604 |
Sentence |
denotes |
Receptor binding, cellular uptake and bioavailability of drug molecules is strongly influenced by molecular lipophilicity and molar refractivity. |
T155 |
3605-3855 |
Sentence |
denotes |
Both of them signify hydrophobic and dispersive (van der Waals) interactions (Ghose & Crippen, 1987) of a drug molecule and are employed in 3D-QSAR studies to evaluate the drug-like character of molecules under study (Viswanadhan et al., 1990, 1991). |
T156 |
3856-4014 |
Sentence |
denotes |
The following are the qualifying parameters for a putative drug candidate as per Ghose filter:clogP range between -0.4 and 5.6, with an average value of 2.52; |
T157 |
4015-4074 |
Sentence |
denotes |
MW range between 160 and 480, with an average value of 357; |
T158 |
4075-4148 |
Sentence |
denotes |
Molar refractivity range between 40 and 130, with an average value of 97; |
T159 |
4149-4218 |
Sentence |
denotes |
Total number of atoms between 20 and 70, with an average value of 48. |
T160 |
4219-4391 |
Sentence |
denotes |
The above parameters should be kept in mind for testing hypothetically proposed compounds before any in vitro and in vivo experimentation (Ghose, 1987; Ghose et al., 1999). |
T161 |
4393-4399 |
Sentence |
denotes |
2.2.4. |
T162 |
4401-4413 |
Sentence |
denotes |
Leadlikeness |
T163 |
4414-4572 |
Sentence |
denotes |
According to Teague et al. (1999) compounds with MW in the range 250–350, a XLOGP3 value of <3.5 and <7 rotatable bonds satisfy the criteria for leadlikeness. |
T164 |
4574-4580 |
Sentence |
denotes |
2.2.5. |
T165 |
4582-4591 |
Sentence |
denotes |
Egan rule |
T166 |
4592-4717 |
Sentence |
denotes |
It is defined as compounds having TPSA > 131.6 Å or log p > 5.88 have drug-like character and properties (Egan et al., 2000). |
T167 |
4719-4725 |
Sentence |
denotes |
2.2.6. |
T168 |
4727-4738 |
Sentence |
denotes |
Muegge rule |
T169 |
4739-5063 |
Sentence |
denotes |
It states that compounds having MW between 200 and 600, XLogP between −2 and 5, TPSA < 150, no. of rings < 7, no. of carbon atoms >4, no. of heteroatoms > 1, no. of rotatable bonds < 15, no. of H-bond acceptors < 10, no. of H-bond donors < 5 are found to obey Muegge rule and behave as potential drugs (Muegge et al., 2001). |
T170 |
5065-5069 |
Sentence |
denotes |
2.3. |
T171 |
5071-5113 |
Sentence |
denotes |
Pharmacokinetic (PK) parameters prediction |
T172 |
5114-5211 |
Sentence |
denotes |
Drug discovery process requires early prediction of ADMET properties of candidate drug molecules. |
T173 |
5212-5367 |
Sentence |
denotes |
The fate of a therapeutic drug in an organism can be predicted conveniently by employing a user-friendly interface of SwissADME (http://www.swissadme.ch.). |
T174 |
5368-5533 |
Sentence |
denotes |
The server predicts important properties like lipophilicity (LIPO), flexibility (FLEX), TPSA, size, unsaturation (INSATU), insolubility (INSOLU) and bioavailability. |
T175 |
5534-5809 |
Sentence |
denotes |
Another online program admetSAR v1.0 (http://lmmd.ecust.edu.cn/admetsar2/) calculates and predicts physicochemical properties like lipophilicity (LIPO) of a query compound (XLOGP3) by using a known logP value of a reference compound as a starting point (Teague et al., 1999). |
T176 |
5810-5967 |
Sentence |
denotes |
The percentage of sp-hybridized carbons in the overall carbon count (Fraction Csp3) in the saturation percentage should be at least 0.25 (Tian et al., 2015). |
T177 |
5968-6386 |
Sentence |
denotes |
For solubility, log S (calculated with the ESOL model) should not exceed 6 (Delaney, 2004). admetSAR is also used to predict physiological and biochemical properties of a prospective drug candidate like human intestinal absorption (HIA), blood–brain barrier (BBB) permeability, Caco-2 penetration, P-glycoprotein inhibitor, Ames test-based mutagenesis, subcellular localization, biodegradation and acute oral toxicity. |
T178 |
6388-6392 |
Sentence |
denotes |
2.4. |
T179 |
6394-6438 |
Sentence |
denotes |
Selection and preparation of protein targets |
T180 |
6439-6621 |
Sentence |
denotes |
The available X-ray crystal structures of human ACE2 receptor, SARS-CoV and SARS-CoV-2 protein targets were downloaded from Protein Data Bank in PDB format (http://www.rcsb.org/pdb). |
T181 |
6622-6723 |
Sentence |
denotes |
Before docking analyses, the protein structures were subjected to refinement and energy minimization. |
T182 |
6724-6884 |
Sentence |
denotes |
The refinement involved the addition of missing atoms, polar hydrogen atoms and Kollman charges to the residues and removal of crystallographic water-molecules. |
T183 |
6885-6991 |
Sentence |
denotes |
These structures were visualized in Accelrys Biovia Discovery Studio 2017 R2 (Biovia, San Diego, CA, USA). |
T184 |
6992-7043 |
Sentence |
denotes |
The PDB IDs of the target proteins were as follows: |
T185 |
7044-7082 |
Sentence |
denotes |
Angiotensin converting enzyme (PDB ID: |
T186 |
7083-7126 |
Sentence |
denotes |
1O8A), SARS-CoV spike glycoprotein (PDB ID: |
T187 |
7127-7172 |
Sentence |
denotes |
5WRG), SARS-CoV-2 spike glycoprotein (PDB ID: |
T188 |
7173-7213 |
Sentence |
denotes |
6VXX), SARS-CoV-2 main protease (PDB ID: |
T189 |
7214-7323 |
Sentence |
denotes |
6LU7), SARS-CoV main protease (3CL-pro) structure (PDB ID: IP9U), papain like protease of SARS-CoV-2 (PDB ID: |
T190 |
7324-7377 |
Sentence |
denotes |
6W9C), Nsp-10/Nsp-16 complex from SARS-CoV-2 (PDB ID: |
T191 |
7378-7434 |
Sentence |
denotes |
6W75), SARS-CoV-2 spike receptor-binding domain (PDB ID: |
T192 |
7435-7516 |
Sentence |
denotes |
6M0J) and SARS-CoV-2 spike receptor-binding domain (RBD) bound with ACE2 (PDB ID: |
T193 |
7517-7523 |
Sentence |
denotes |
6M0J). |
T194 |
7524-7711 |
Sentence |
denotes |
The identification of protein ligand-binding sites was carried out using online server Metapocket 2.0 (http://metapocket.eml.org) which combines prediction of sites from four methods viz. |
T195 |
7712-7782 |
Sentence |
denotes |
LIGSITE csc, PASS, Q-SiteFinder and SURFNET to improve the prediction. |
T196 |
7783-7995 |
Sentence |
denotes |
The active site residues of enzymes 3CL-pro, PL-pro of SARS-CoV, SARS-CoV-2 and human ACE2 were found from review of literature (Báez-Santos et al., 2015; Chen et al., 2020; Guy et al., 2005; Zhang et al., 2020). |
T197 |
7997-8001 |
Sentence |
denotes |
2.5. |
T198 |
8003-8028 |
Sentence |
denotes |
Molecular docking studies |
T199 |
8030-8036 |
Sentence |
denotes |
2.5.1. |
T200 |
8038-8046 |
Sentence |
denotes |
AutoDock |
T201 |
8047-8308 |
Sentence |
denotes |
Molecular docking of selected phytoconstituents of WS against human ACE2 receptor, SARS-CoV and SARS-CoV-2 target proteins was performed using AutoDock 4.0/ADT version 4.2.6 program (Morris et al., 1998) and further validated using two additional softwares viz. |
T202 |
8309-8431 |
Sentence |
denotes |
AutoDock vina and iGEMDOCK version 2.1 in order to investigate binding kinetics and binding modes to the refined proteins. |
T203 |
8432-8532 |
Sentence |
denotes |
Grid spacing was set at 0.375 Å and the grid points in the X, Y and Z axes were set to 60 × 60 × 60. |
T204 |
8533-8711 |
Sentence |
denotes |
The quest was based on the Lamarckian genetic algorithm (Miyamoto & Kollman, 1992; Oprea et al., 2001) and the binding energies of the results were subjected to further analysis. |
T205 |
8712-8947 |
Sentence |
denotes |
Molecular docking computation and visualization of binding interactions of withanolide analogs to human ACE2 receptor and selected SARS-CoV and SARS-CoV-2 protein targets was done using Accelrys Biovia Discovery Studio version 2017 R2. |
T206 |
8948-9125 |
Sentence |
denotes |
The best possible orientation of the ligand(s) in the protein binding pocket was selected for analysis on the basis of lowest binding energy (BE) and dissociation constant (Kd). |
T207 |
9127-9133 |
Sentence |
denotes |
2.5.2. |
T208 |
9135-9148 |
Sentence |
denotes |
AutoDock Vina |
T209 |
9149-9304 |
Sentence |
denotes |
AutoDock Vina is a free platform designed to be significantly faster than AutoDock 4, yet at the same time more accurate in predictions of binding pockets. |
T210 |
9305-9490 |
Sentence |
denotes |
It calculates grid maps and clusters automatically, in contrast to AutoDock 4 and as a result of multithreading on multicore machines, faster results are obtained (Trott & Olson, 2010). |
T211 |
9492-9508 |
Sentence |
denotes |
2.5.3. iGEMDOCK |
T212 |
9509-9734 |
Sentence |
denotes |
Institute of Bioinformatics in Taiwan's National Chiao Tung University developed iGEMDOCK version 2.1, a graphical, user-friendly and automated software for integrated docking, screening and post-analysis (Yang & Chen, 2004). |
T213 |
9735-9979 |
Sentence |
denotes |
Binding sites for a particular ligand were established with the help of the software. iGEMDOCK employs a generic evolutionary method (GA) in order to calculate ligand conformation and orientation with respect to the target protein binding site. |
T214 |
9980-10131 |
Sentence |
denotes |
The parameters selected for GA were as follows: population size = 200, generations = 70, solution number = 2 and docking feature as 'standard docking'. |
T215 |
10132-10293 |
Sentence |
denotes |
Once a set of poses is generated, the software recalculates the energy of each pose and the interaction data represents the individual as well as overall energy. |
T216 |
10294-10495 |
Sentence |
denotes |
Best fit is selected, representing the total energy viz. vdW (van der Waals energy), H-bond (hydrogen bonding energy) and Elect (electrostatic energy) of the predicted pose at the protein binding site. |
T217 |
10497-10501 |
Sentence |
denotes |
2.6. |
T218 |
10503-10537 |
Sentence |
denotes |
Bioactivity score (BAS) prediction |
T219 |
10538-10615 |
Sentence |
denotes |
Bioactivity score values also predict the overall druglikeness of a compound. |
T220 |
10616-10764 |
Sentence |
denotes |
Molinspiration version 2016.10 was used to predict the drug score of WS phytoconstituents with respect to several human receptors (Proudfoot, 2002). |
T221 |
10765-10902 |
Sentence |
denotes |
As a general rule, the higher the bioactivity score, the greater is the probability of the compound under investigation for being active. |
T222 |
10904-10908 |
Sentence |
denotes |
2.7. |
T223 |
10910-10934 |
Sentence |
denotes |
Toxicity risk prediction |
T224 |
10935-11175 |
Sentence |
denotes |
Toxicity prediction was done using OSIRIS Property Explorer version 4.5.1. (Information Management Drug Discovery, Actelion Ltd, Allschwil, Switzerland) in order to identify possible side effects of WS phytoconstituents (Khan et al., 2018). |
T225 |
11177-11181 |
Sentence |
denotes |
2.8. |
T226 |
11183-11206 |
Sentence |
denotes |
Swiss Target Prediction |
T227 |
11207-11359 |
Sentence |
denotes |
Computational approaches are key players in narrowing down the dataset of potential drug targets and suggesting alternative targets for known molecules. |
T228 |
11360-11538 |
Sentence |
denotes |
Molecular insight of the bioactive molecules and their mode of actions are important for understanding the observed phenotypes, prediction and optimization of existing compounds. |
T229 |
11539-11776 |
Sentence |
denotes |
Swiss Target Prediction (http://www.swisstargetprediction.ch.) is an online web-based interface which helps in finding bioactive molecules having similar configuration with related or similar biochemical targets (Campillos et al., 2008). |
T230 |
11777-11886 |
Sentence |
denotes |
The primary goal of the tool is to identify biochemical targets of molecules which are known to be bioactive. |
T231 |
11887-12300 |
Sentence |
denotes |
In the present study, Swiss Target Prediction online server was used for predicting the percentage proportion activity of each selected WS phytoconstituent with known intracellular targets like kinases, nuclear receptors, transcription factors, phosphodiesterases, oxidoreductases, cytochrome P450, voltage gated-ion channels, hydrolases, phosphatases, G-protein coupled receptors and primary active transporters. |
T232 |
12302-12306 |
Sentence |
denotes |
2.9. |
T233 |
12308-12372 |
Sentence |
denotes |
Prediction of cytochrome P450 mediated sites of metabolism (SOM) |
T234 |
12373-12521 |
Sentence |
denotes |
Most of the FDA-approved drugs are known to be metabolized by a ubiquitous protein family of heme-thiolate enzymes known as cytochrome P450s (CYPs). |
T235 |
12522-12770 |
Sentence |
denotes |
Regioselectivity-WebPredictor (http://reccr.chem.rpi.edu/Software/RS-WebPredicto/) is an algorithm for accurate prediction of isozyme-specific cytochrome P450 (CYP)-mediated sites of metabolism (SOM) on drug like molecules (Nebert & Russell, 2002). |
T236 |
12771-13034 |
Sentence |
denotes |
This is the very first repository that makes metabolic predictions for nine isozymes (1A2, 2A6, 2B6, 2C8, 2C9, 2C19, 2D6, 2E1 and 3A4) available to the public and uses models trained on the largest set of CYP substrate and metabolite data (Zaretzki et al., 2013). |
T237 |
13036-13041 |
Sentence |
denotes |
2.10. |
T238 |
13043-13077 |
Sentence |
denotes |
Principal component analysis (PCA) |
T239 |
13078-13303 |
Sentence |
denotes |
The process of drug discovery has come to involve a critical concept known as ‘Chemical space’ which is defined as a multidimensional space projection of the number of property descriptors calculated for each chemical entity. |
T240 |
13304-13443 |
Sentence |
denotes |
PCA is a method to visualize chemical space in lower dimensions in order to identify and underline dominant patterns of drug like entities. |
T241 |
13444-13571 |
Sentence |
denotes |
The term PCA was first coined by Karl Pearson in 1901 and is an application of linear algebra (Ahmad, 2019, Khan et al., 2018). |
T242 |
13572-13915 |
Sentence |
denotes |
Osiris Property Explorer 4.5.1 was used for defining and visualizing multivariate datasets of prospective drug candidates from WS and standard reference drugs through comparison of properties like TPSA, percent absorption, MW, hydrogen bond donor, hydrogen bond acceptor, number of rotatable bonds, Lipinski’s violations, leadlikeness and BAS. |
T243 |
13916-14003 |
Sentence |
denotes |
PCA helps in reducing the dimensionality of the dataset and increases interpretability. |
T244 |
14004-14095 |
Sentence |
denotes |
It does so by creating new uncorrelated variables which maximize the variance successively. |
T245 |
14096-14297 |
Sentence |
denotes |
Another added advantage of PCA is a 3D visualization in chemical space of how ‘drug-like’ are the molecules under study to known standard drugs in terms of their proximity to them in 3D chemical space. |
T246 |
14299-14304 |
Sentence |
denotes |
2.11. |
T247 |
14306-14340 |
Sentence |
denotes |
Molecular dynamics (MD) simulation |
T248 |
14342-14349 |
Sentence |
denotes |
2.11.1. |
T249 |
14351-14375 |
Sentence |
denotes |
Playmolecule open server |
T250 |
14376-14606 |
Sentence |
denotes |
Two of the WS phytoconstituents viz. withanolides A and B showing significant binding to selected viral target proteins were subjected to molecular dynamics simulation studies with SARS CoV-2 spike receptor binding domain (PDB ID: |
T251 |
14607-14657 |
Sentence |
denotes |
6M0J) and SARS CoV-2 papain like protease (PDB ID: |
T252 |
14658-14678 |
Sentence |
denotes |
6W9C), respectively. |
T253 |
14679-14990 |
Sentence |
denotes |
The playmolecule web platform (https://www.playmolecule.com/SimpleRun/) is publicly available at www.playmolecule.org and uses high-throughput molecular dynamics (HTMD), a python-based framework in order to perform simple molecular-simulation-based drug discovery (Raimondas et al., 2019; Rossell et al., 2017). |
T254 |
14991-15148 |
Sentence |
denotes |
The MD simulation was run for 3 ns for both SARS-Cov-2 glycoprotein–withanolide A complex and SARS CoV-2 papain like protease-withanolide B complex at 300 K. |
T255 |
15150-15157 |
Sentence |
denotes |
2.11.2. |
T256 |
15159-15219 |
Sentence |
denotes |
Ligand and receptor molecular dynamics (LARMD) online server |
T257 |
15220-15286 |
Sentence |
denotes |
The MD simulation analyses of SARS-CoV spike glycoprotein (PDB ID: |
T258 |
15287-15349 |
Sentence |
denotes |
5WRG) with withanolide B and SARS-CoV-2 main protease (PDB ID: |
T259 |
15350-15538 |
Sentence |
denotes |
6LU7) with withanolide A were performed using Ligand and Receptor Molecular Dynamics (LARMD, http://chemyang.ccnu.edu.cn/ccb/server/LARMD/;http://agroda.gzu.edu.cn:9999/ccb/server/LARMD/). |
T260 |
15539-15635 |
Sentence |
denotes |
It is an online bioinformatics tool to investigate and visualize ligand-driven protein dynamics. |
T261 |
15636-15797 |
Sentence |
denotes |
LARMD comprises of three computational modules out of which Int_mod, which aids in the investigation of protein fluctuation, was implemented (Yang et al., 2019). |