Drug-likeness Criteria Research Articles

Identification of Promising Sulfonamide Chalcones as Inhibitors of SARS-CoV-2 3CLpro through Structure-Based Virtual Screening and Experimental Approaches.

3CLpro is a viable target for developing antiviral therapies against the coronavirus. With the urgent need to find new possible inhibitors, a structure-based virtual screening approach was developed. This study recognized 75 pharmacologically bioactive compounds from our in-house library of 1052 natural product-based compounds that satisfied drug-likeness criteria and exhibited good bioavailability and membrane permeability. Among these compounds, three promising sulfonamide chalcones were identified by combined theoretical and experimental approaches, with SWC423 being the most suitable representative compound due to its competitive inhibition and low cytotoxicity in Vero E6 cells (EC50 = 0.89 ± 0.32 μM; CC50 = 25.54 ± 1.38 μM; SI = 28.70). The binding and stability of SWC423 in the 3CLpro active site were investigated through all-atom molecular dynamics simulation and fragment molecular orbital calculation, indicating its potential as a 3CLpro inhibitor for further SARS-CoV-2 therapeutic research. These findings suggested that inhibiting 3CLpro with a sulfonamide chalcone such as SWC423 may pave the effective way for developing COVID-19 treatments.

Comparative Computational Screening of Natural-based Partial Agonists for PPARγ Receptor.

The nuclear transcription factor PPARγ, which can modulate cell growth via proliferation and apoptosis-related mechanisms, is a promising target in cancer therapy. This study aims to focus on PPARγ as the target and use virtual screening to find hits. A set of 5,677 flavonoid compounds were filtered by subjecting them to descriptor-based drug-likeness and ADMET strategies to discover drug-like compounds. The candidates' modes of binding to PPARγ were then evaluated using docking and MD simulation. PharmMapper was used to identify the potential targets of selected hits. The pharmacological network was constructed based on the GO and KEGG pathway analysis. In primary screening, 3,057 compounds met various drug-likeness criteria and docked well as partial agonists in the PPARγ-LBD. Five compounds (euchrenone b1, kaempferol-7-Orhamnoside, vincetoxicoside B, morusin, and karanjin) were selected with the use of ADMET profiles for further MD simulation investigation. Based on the PharmMapper findings, 52 proteins were then submitted to GO and KEGG enrichment analysis. As expected by GO and KEGG pathway enrichment studies, core targets were enriched in the PI3K-Akt signaling pathway (p < 0.01), indicating that certain chemicals may be involved in cancer processes. Our results suggested that the selected compounds might have sufficient drug-likeness, pharmacokinetics, and in silico bioactivity by acting as PPARγ partial agonists. Although much work remains to illuminate extensive cancer therapeutic/ chemopreventive efficacy of flavonoids in vivo, in silico methodology of our cheminformatics research may be able to provide additional data regarding the efficacy and safety of potential candidates for therapeutic targets.

Design, synthesis, and antitumor efficacy of novel 5-deazaflavin derivatives backed by kinase screening, docking, and ADME studies

Novel 5-deazaflavins were designed as potential anticancer candidates. Compounds 4j, 4k, 5b, 5i, and 9f demonstrated high cytotoxicity against MCF-7 cell line with IC50 of 0.5–190nM. Compounds 8c and 9g showed preferential activity against Hela cells (IC50: 1.69 and 1.52 μM respectively). However, compound 5d showed notable potency against MCF-7 and Hela cell lines of 0.1 nM and 1.26 μM respectively. Kinase profiling for 4e showed the highest inhibition against a 20 kinase panel. Additionally, ADME prediction studies exhibited that compounds 4j, 5d, 5f, and 9f have drug-likeness criteria to be considered promising antitumor agents deserving of further investigation. SAR study showed that substitutions with 2-benzylidene hydra zino have a better fitting into PTK with enhanced antiproliferative potency. Noteworthy, the incorporation of hydrazino or ethanolamine moieties at position 2 along with small alkyl or phenyl at N-10, respectively revealed an extraordinary potency against MCF-7 cells with IC50 values in the nanomolar range.

Novel drug-like fluorenyl derivatives as selective butyrylcholinesterase and β-amyloid inhibitors for the treatment of Alzheimer’s disease

Butyrylcholinesterase (BuChE) and amyloid β (Aβ) aggregation remain important biological target and mechanism in the search for effective treatment of Alzheimer’s disease. Simultaneous inhibition thereof by the application of multifunctional agents may lead to improvement in terms of symptoms and causes of the disease. Here, we present the rational design, synthesis, biological evaluation and molecular modelling studies of novel series of fluorene-based BuChE and Aβ inhibitors with drug-like characteristics and advantageous Central Nervous System Multiparameter Optimization scores. Among 17 synthesized and tested compounds, we identified 22 as the most potent eqBuChE inhibitor with IC50 of 38 nM and 37.4% of Aβ aggregation inhibition at 10 μM. Based on molecular modelling studies, including molecular dynamics, we determined the binding mode of the compounds within BuChE and explained the differences in the activity of the two enantiomers of compound 22. A novel series of fluorenyl compounds meeting the drug-likeness criteria seems to be a promising starting point for further development as anti-Alzheimer agents.

Fourteen immunomodulatory alkaloids and two prenylated phenylpropanoids with dual therapeutic approach for COVID-19: molecular docking and dynamics studies

The pandemic outbreak of COVID-19 caused by the new severe acute respiratory syndrome coronavirus (SARS-CoV-2) is a global health burden. To date, there is no highly effective antiviral therapy to eradicate the virus; as a result, researchers are racing to introduce new potential therapeutic agents. Alternatively, traditional immunity boosters and symptomatic treatment based on natural bioactive compounds are also an option. The 3-chymotrypsin-like protease (3CLpro) crystal structure, the main proteolytic enzyme of SARS-CoV-2, has been unraveled, allowing the development of effective protease inhibitors via in silico and biological studies. In COVID-19 infected patients, the loss of lung function, and mortality are reported to be linked to several inflammatory mediators and cytokines. In this context, the approach of introducing immunomodulatory agents may be considered a dual lifesaving strategy in combination with antiviral drugs. This study aims to provide immunomodulatory natural products exhibiting potential protease inhibitory activities. Selected groups of alkaloids of different classes and two prenylated phenylpropanoids from the Brazilian green propolis were in silico screened for their ability to inhibit COVID-19 3CLpro protease. Results showed that compounds exhibited binding energy scores with values ranging from −6.96 to −3.70 compared to the reference synthetic protease inhibitor O6K with a binding energy score of −7.57. O6K binding energy was found comparable with lead phytochemicals in our study, while their toxicity and drug-likeness criteria are better than that of O6K. The activities of these molecules are mainly ascribed to their ability to form hydrogen bonding with 3CLpro crucial amino acid residues of the catalytic site. In addition, the molecular dynamics simulations further showed that some of these compounds formed stable complexes as evidenced by the occupancy fraction measurements. The study suggested that the major immunomodulators 3β, 20α-diacetamido-5α-pregnane, (20S)-(benzamido)-3β-(N,N-dimethyamino)-pregnane, and baccharin are 3CLpro inhibitors. Biological screenings of these phytochemicals will be valuable to experimentally validate and consolidate the results of this study before a rigid conclusion is reached, which may pave the way for the development of efficient modulatory bioactive compounds with dual bioactions in COVID-19 intervention. Communicated by Ramaswamy H. Sarma

In silico assessment of risks associated with pesticides exposure during pregnancy

Novel Quantitative Structure-Activity Relationship (QSAR) models of compounds' placenta (PL) permeability expressed as their log FM (fetus-to-mother blood concentration) values or binary PL1/0 (crossing/non-crossing) score were generated using a number of statistical tools: Multiple Linear Regression, Boosted Trees, Principal Component Analysis and Artificial Neural Networks, on the basis of molecular descriptors calculated by Mordred software and selected using Partial Least Squares (PLS) analysis. It was established that the most important predictor of both log FM and the binary PL1/0 score is Lipinski – a binary variable reflecting the compounds' ability to satisfy the criteria of drug-likeness according to the Lipinski's “Rule of 5”. The quantitative (log FM) and qualitative (PL1/0) models of PL permeability were applied to 345 pesticides from different chemical families (triazines, carbamates, pyrethroids, organochlorine, organophosphorus and miscellaneous compounds). The ability of studied pesticides to cross the placenta was assessed; the basic physico-chemical parameters responsible for good or poor placenta transport of pesticides were identified and the relationships between the pesticides' PL permeability, blood-brain barrier (BBB) transfer and gastro-intestinal (GI) absorption were investigated. It was found (on the basis of logistic regression analysis) that the probability of a compound crossing the placenta (PL1) is inversely correlated with its lipophilicity and molar refractivity and positively correlated with the total count of oxygen and nitrogen atoms.

Computational investigation of Arbutus serratifolia Salisb molecules as new potential SARS-CoV-2 inhibitors

Abstract The outbreak of the current pandemic and the evolution of virus resistance against standard drugs led to the emergency of new and potent antiviral agents. Owing to its crucial role in viral replication, the protease enzyme is taken into survey to be a promising target for antiviral drug therapy using computational methods. In order to bring this important class of natural products in the limelight of research for prospective application as chemotherapeutic agents, the anti-SARS-CoV-2 activity of some bioactive molecules obtained from Arbutus serratifolia Salisb which is an Algerian medicinal plant, was investigated using in-silico methods. The molecular docking was performed by AutoDock Vina and UCSF Chimera, as well as ADMET and drug-likeness properties of these molecules were calculated using preADMET web-based application and the Swiss ADME server respectively. The phytochemicals (from Pr(1) to Pr(12)) were tested for their pharmacokinetic properties and docked into the main protease binding site on (PDB ID: 6Y84) in order to find a promising antiviral ligand. All tested molecules induced binding affinities into the binding pocket of (PDB ID: 6Y84) with energy scores ranging from moderate to better (from −6.4 to −8.00 kcal/mol). It is worthy to note that both Pr(2): (1S,5R,6S,8S,9S)-6,8-Dihydroxy-8-methyl-1,5,6,7,8,9-hexahydrocyclopenta [c] pyran-1-yl-β-D-glucopyranoside and Pr(7): ((1S,5S,6S,9S)-1-(β-D-Glucopyranosyloxy)-14-oxo-1,5,6,9-tetrahydro-1H-2,15-dioxacyclopenta [cd] inden-8-yl) methyl acetate, were found to be the best inhibitors with binding affinities (−7.7 kcal/mol and −8.0 kcal/mol), respectively, by virtue of the fact that all these tested molecules exhibited good binding affinities compared with those of Ritonavir and Nirmatrelvir (−1.73 and −1.93 kcal/mol), respectively, which are used as standard antiviral drugs to prevent viral growth. The amino acids: His-163; Glu-166; Arg-188; Thr-190 and Gln-192 represent the key residues of the interaction of SARS-CoV-2 main protease with Pr(7). Furthermore, the results of pharmacodynamic and pharmacokinetic investigations revealed that Pr(6), Pr(8) and Pr(9) uphold the drug-likeness criteria and more particularly, these substances can be absorbed by the human intestine. In addition, all these molecules were shown to be neither hepatotoxic nor significantly noxious to human organism. These natural products are therefore promising inhibitor candidates of viral main protease. However, further in-vitro, in-vivo and even clinical assays are required to probe their functional mechanisms and then to assess their antiviral potency against COVID-19.

Exploring the mechanism of action of Hedyotis diffusa Willd on acne using network analysis.

In this study, we used a network pharmacological method to explore the active ingredients of Hedyotis diffusa Willd (HDW) in the treatment of acne and elucidated the physiological mechanisms in the human body in which they are involved. We identified the active compounds of HDW that are expected to act effectively in the human body using the Traditional Chinese Medicine Systems Pharmacology database and analysis platform and extracted potential interacting proteins for each active compound using the Swiss Target Prediction platform. Next, we analyzed the potential mechanisms of action of the protein targets shared by HDW and each standard drug on acne and assessed the possibility of spontaneous occurrence of the binding between proteins and active compounds through the molecular docking process. Seven active compounds were selected according to the oral bioavailability and drug-likeness criteria of the Traditional Chinese Medicine Systems Pharmacology database and analysis platform. Subsequently, 300 protein targets were collected from the Swiss Target Prediction. Using the Search Tool for the Retrieval of Interacting Genes/Proteins database, a protein-protein interaction network was constructed by analyzing the relationship between HDW, acne, and each standard drug. By analyzing the gene ontology terms and Kyoto Encyclopedia of Genes and Genomes pathway, the "positive regulation of lipid metabolic process" was found to be the most involved pathway shared by HDW, acne, and isotretinoin. An analysis of the protein targets shared by the antibiotic agents with HDW and acne found that "cholesterol storage" in tetracycline, "icosacoid transport" in azithromycin, "steroid hydroxylase activity" in erythromycin, "positive regulation of leukocyte tethering or rolling" in clindamycin, "response to UV-A" in minocycline, "steroid 11-beta-monooxygenase activity" in doxycycline, and "neutrophil-mediated immunity" in trimethoprim were the most involved. Virtual molecular docking analysis showed that all proteins spontaneously bound to their corresponding active compounds. Our analysis suggests that HDW can, directly and indirectly, suppress sebum secretion and exert antiinflammatory effects on acne. Further, HDW may regulate free radicals and suppress apoptosis. Therefore, HDW can be used as an alternative or supplement to standard drugs for acne treatment in patients who cannot use standard treatments due to side effects.

Leaf Extract of Perilla frutescens (L.) Britt Promotes Adipocyte Browning via the p38 MAPK Pathway and PI3K-AKT Pathway

The leaf of Perilla frutescens (L.) Britt (PF) has been reported to negatively affect adipocyte formation, inhibit body-fat formation, and lower body weight. However, its effect on adipocyte browning remains unknown. Thus, the mechanism of PF in promoting adipocyte browning was investigated. The ingredients of PF were acquired from the online database and filtered with oral bioavailability and drug-likeness criteria. The browning-related target genes were obtained from the Gene Card database. A Venn diagram was employed to obtain the overlapped genes that may play a part in PF promoting adipocyte browning, and an enrichment was analysis conducted based on these overlapped genes. A total of 17 active ingredients of PF were filtered, which may regulate intracellular receptor-signaling pathways, the activation of protein kinase activity, and other pathways through 56 targets. In vitro validation showed that PF promotes mitochondrial biogenesis and upregulates brite adipocyte-related gene expression. The browning effect of PF can be mediated by the p38 MAPK pathway as well as PI3K-AKT pathway. The study revealed that PF could promote adipocyte browning through multitargets and multipathways. An in vitro study validated that the browning effect of PF can be mediated by both the P38 MAPK pathway and the PI3K-AKT pathway.

Identification of Four New Chemical Series of Small Drug-Like Natural Products as Potential Neuropilin-1 Inhibitors by Structure-Based Virtual Screening: Pharmacophore-Based Molecular Docking and Dynamics Simulation.

Neuropilin-1 (NRP-1), a surface transmembrane glycoprotein, is one of the most important co-receptors of VEGF-A165 (vascular endothelial growth factor) responsible for pathological angiogenesis. In general, NRP-1 overexpression in cancer correlates with poor prognosis and more tumor aggressiveness. NRP-1 role in cancer has been mainly explained by mediating VEGF-A165-induced effects on tumor angiogenesis. NRP-1 was recently identified as a co-receptor and an independent gateway for SARS-CoV-2 through binding subunit S2 of Spike protein in the same way as VEGF-A165. Thus, NRP-1 is of particular value as a target for cancer therapy and other angiogenesis-dependent diseases as well as for SARS-CoV-2 antiviral intervention. Herein, The Super Natural II, the largest available database of natural products (∼0.33 M), pre-filtered with drug-likeness criteria (absorption, distribution, metabolism and excretion/toxicity), was screened against NRP-1. NRP-1/VEGF-A165 interaction is one of protein-protein interfaces (PPIs) known to be challenging when approached in-silico. Thus, a PPI-suited multi-step virtual screening protocol, incorporating a derived pharmacophore with molecular docking and followed by MD (molecular dynamics) simulation, was designed. Two stages of pharmacophorically constrained molecular docking (standard and extra precisions), a mixed Torsional/Low-mode conformational search and MM-GBSA ΔG binding affinities calculation, resulted in the selection of 100 hits. These 100 hits were subjected to 20 ns MD simulation, that was extended to 100 ns for top hits (20) and followed by post-dynamics analysis (atomic ligand-protein contacts, RMSD, RMSF, MM-GBSA ΔG, Rg, SASA and H-bonds). Post-MD analysis showed that 19 small drug-like nonpeptide natural molecules, grouped in four chemical scaffolds (purine, thiazole, tetrahydropyrimidine and dihydroxyphenyl), well verified the derived pharmacophore and formed stable and compact complexes with NRP-1. The discovered molecules are promising and can serve as a base for further development of new NRP-1 inhibitors.

Coumarin-Based Sulfonamide Derivatives as Potential DPP-IV Inhibitors: Pre-ADME Analysis, Toxicity Profile, Computational Analysis, and In Vitro Enzyme Assay.

Recent research on dipeptidyl peptidase-IV (DPP-IV) inhibitors has made it feasible to treat type 2 diabetes mellitus (T2DM) with minimal side effects. Therefore, in the present investigation, we aimed to discover and develop some coumarin-based sulphonamides as potential DPP-IV inhibitors in light of the fact that molecular hybridization of many bioactive pharmacophores frequently results in synergistic activity. Each of the proposed derivatives was subjected to an in silico virtual screening, and those that met all of the criteria and had a higher binding affinity with the DPP-IV enzyme were then subjected to wet lab synthesis, followed by an in vitro biological evaluation. The results of the pre-ADME and pre-tox predictions indicated that compounds 6e, 6f, 6h, and 6m to 6q were inferior and violated the most drug-like criteria. It was observed that 6a, 6b, 6c, 6d, 6i, 6j, 6r, 6s, and 6t displayed less binding free energy (PDB ID: 5Y7H) than the reference inhibitor and demonstrated drug-likeness properties, hence being selected for wet lab synthesis and the structures being confirmed by spectral analysis. In the in vitro enzyme assay, the standard drug Sitagliptin had an IC50 of 0.018 µM in the experiment which is the most potent. All the tested compounds also displayed significant inhibition of the DPP-IV enzyme, but 6i and 6j demonstrated 10.98 and 10.14 µM IC50 values, respectively, i.e., the most potent among the synthesized compounds. Based on our findings, we concluded that coumarin-based sulphonamide derivatives have significant DPP-IV binding ability and exhibit optimal enzyme inhibition in an in vitro enzyme assay.

In silico ADME, Bioactivity and Toxicity Prediction of some Selected Antiviral Drugs.

Viruses have been the cause of some of the world's worst and most dreadful diseases. COVID-19 is one of them, and it is the name given to the novel corona virus discovered in 2019. Due to the unavailability of any proven treatment, there is an urgent need for therapeutics for COVID-19. In this computational investigation, ADME profiles and bioactivity results of 2-deoxy D-glucose (1), Hydroxy chloroquine (2), and Favipiravir (3) compounds were calculated. Drug likeness criteria based on Lipinski and Veber’s rules indicate that the compounds have classic physicochemical and pharmacokinetic properties that make them a good candidate for oral drug administration.

Rational design and synthesis of novel biphenyl thiazolidinedione conjugates as inhibitors of protein tyrosine phosphatase 1B for the management of type 2 diabetes

To achieve the unmet discovery of protein tyrosine phosphatase 1B (PTP1B) inhibitors, we have rationally designed novel biphenyl thiazolidinedione conjugates (8a-n). The designed molecules were found fit on in silico absorption, distribution, metabolism, excretion, and toxicity (ADMET) screening criteria of drug-likeness. Ligand-target binding study revealed that N-methyl benzoic acid derivative (8j) was best target fit and displayed extended plausible binding interactions with phospho-tyrosine (pTyr) loop of PTP1B, a unique bidentate binding mode for PTP1B selectivity over other PTPs. The designed analogues (8a-n) were synthesized (Scheme 1) and accessed for their in vitro PTP1B inhibitory potency, in vivo anti-hyperglycemic efficacy as well as the effect of treatment on weight and pancreatic safety. Molecules 8a-n showed moderate to good PTP1B inhibitory activity (IC50 = 5.897–48.150 µM) compared to Suramin (IC50 = 11.104 µM) and exhibited time-dependent in vivo efficacy, ranging from inferior to better, as compared to Pioglitazone. Moreover, 8j was found best pre-clinical candidate exhibiting good in vitro potency (IC50 = 5.897 µM), better in vivo efficacy with the advantage of control in weight and pancreatic safety, compared to glitazone therapy.

Analyzing the potential of selected plant extracts and their structurally diverse secondary metabolites for α-glucosidase inhibitory activity: in vitro and in silico approach

Inhibiting α-glucosidase activity is a therapeutic method to regulate post-prandial hyperglycemia in humans. Here, in-vitro and in-silico studies were used to find α-glucosidase inhibitory plant secondary metabolites (PSM). Among 408 solvent extracts from 70 plants tested for α-glucosidase inhibition, 174 had IC50 ≤ 3 mg/ml. α-glucosidase inhibitory PSM is found in several plant species and solvent extracts, indicating their diversity. Further, ensemble molecular docking and structural activity relationship analysis supported this hypothesis where the top 100 PSM with the least binding energy (BE) among the 539 PSM belonged to sesquiterpenoids (34%), catechols (11%), flavonoids (9%) and steroidal lactones (8%). Shortlisted 11 PSM were subjected to molecular dynamic simulation. Withanolide J recorded the least BE of −66.424 ± 22.333 kJ/mol, followed by Withacoagulin I (-64.665 ± 24.030 kJ/mol). When different simulation frames were analyzed, PSM of withanolide groups was stabilized in the narrow entrance of the active pocket forming H-bond with LYS156, TYR158, PHE159, PHE303 PRO312, LEU313, ARG315 and PHE134. Similarly, Hydroxytuberosone and 1, 8-Dihydroxy-3-carboxy-9, 10-anthraquinone (DHCA) formed H-bond with ASP307 located on the loop at the entrance of the active pocket. In the case of Neoliquiritin and Kaempferol-3-o-alpha-L-rhamnoside (KALR), glucose moiety interacted with the GLU277 and ASP215 (catalytic amino acid residues) through H-bonds. In addition, these 11 PSM were found to fulfil the criteria of drug-likeness as per Lipinski’s rule of five and pharmacokinetic profile. The present study strengthens the library of α-glucosidase inhibitory plants and PSM, providing valuable information for Type-II Diabetes mellitus management. Communicated by Ramaswamy H. Sarma

Antioxidant activity of novel diosgenin derivatives: Synthesis, biological evaluation, and in silico ADME prediction

A series of novel diosgenin (DSG) derivatives has been synthesized and tested in vitro for their antioxidant activity. Initially, four analogues have been evaluated for their cytotoxicity using normal human skin fibroblast (NHDF) as model cells. As a result, 84% of NHDF cells were still alive at 5 µM, so these compounds can be considered as innoxious to fibroblasts at this concentration. Then, hemolytic activity against human erythrocytes was studied in order to evaluate the potential impact of tested compounds against normal host cells. The result < 5% of hemolysis rates suggest no lytic activity for most compounds. After that, the main test — evaluation the antioxidant effect of DSG and its new derivatives against lipid peroxidation in the o/w emulsion model — was performed. The most promising compound (8) exhibited the significant antioxidant activity and the biocompatibility towards normal human dermal fibroblasts and red bloods cells. This p–aminobenzoic derivative revealed 61.6% blocking of induced lipid oxidation. Furthermore, eleven predicted ADME properties were predicted for all tested compounds and revealed that they are in compliance with drug–likeness criteria.

Identification of novel mycocompounds as inhibitors of PI3K/AKT/mTOR pathway against RCC

PI3K/AKT/mTOR pathway is one of the frequently disrupted signaling pathways in renal cell carcinoma (RCC) that plays a significant role in tumor formation, disease progression and therapeutic resistance. Therefore, novel natural molecules targeting the critical proteins of this pathway will provide the best alternative to existing drugs, which are toxic and develops resistance. Recent studies have recognized the anti-cancer therapeutic potential of mycocompounds. The current study is focused on screening various mycocompounds from Astraeus hygrometricus against key cancer signaling proteins phosphoinositide 3‐kinase (PI3K), protein kinase B, PKB (AKT1) and mammalian target of rapamycin (mTOR). We also studied in-silico cancer cells cytotoxicity and ADMET (absorption, distribution, metabolism, excretion and toxicity) profiles to elucidate the molecular mechanism against RCC and also to uncover the pharmacokinetic profile of these compounds. Astrakurkurone and Ergosta-4,6, 8-(14) 22-tetraene-3-one were the two most efficacious compounds with highest interaction scores and bonding. These compounds were both active against RCC4 and VMRC-RCZ cell lines of RCC. The ADME profiles of both were satisfactory based on druglikeness and bioavailability score criteria. Thus, this proposed study identified astrakurkurone and ergosta-4,6, 8-(14) 22-tetraene-3-one as potential anticancer drug candidates, and provides comparative structural insight into their binding to the 3 protein kinases.

Potential Coronaviral Inhibitors of the Nucleocapsid Protein Identified In Silico and In Vitro from a Large Natural Product Library.

The nucleocapsid protein (NP) is one of the main proteins out of four structural proteins of coronaviruses including the severe acute respiratory syndrome coronavirus 2, SARS-CoV-2, discovered in 2019. NP packages the viral RNA during virus assembly and is, therefore, indispensable for virus reproduction. NP consists of two domains, i.e., the N- and C-terminal domains. RNA-binding is mainly performed by a binding pocket within the N-terminal domain (NTD). NP represents an important target for drug discovery to treat COVID-19. In this project, we used the Vina LC virtual drug screening software and a ZINC-based database with 210,541 natural and naturally derived compounds that specifically target the binding pocket of NTD of NP. Our aim was to identify coronaviral inhibitors that target NP not only of SARS-CoV-2 but also of other diverse human pathogenic coronaviruses. Virtual drug screening and molecular docking procedures resulted in 73 candidate compounds with a binding affinity below −9 kcal/mol with NP NTD of SARS-CoV-1, SARS-CoV-2, MERS-CoV, HCoV-OC43, HCoV-NL63, HoC-229E, and HCoV-HKU1. The top five compounds that met the applied drug-likeness criteria were then tested for their binding in vitro to the NTD of the full-length recombinant NP proteins using microscale thermophoresis. Compounds (1), (2), and (4), which belong to the same scaffold family of 4-oxo-substituted-6-[2-(4a-hydroxy-decahydroisoquinolin-2-yl)2H-chromen-2-ones and which are derivates of coumarin, were bound with good affinity to NP. Compounds (1) and (4) were bound to the full-length NP of SARS-CoV-2 (aa 1–419) with Kd values of 0.798 (±0.02) µM and 8.07 (±0.36) µM, respectively. Then, these coumarin derivatives were tested with the SARS-CoV-2 NP NTD (aa 48–174). Compounds (1) and (4) revealed Kd-values of 0.95 (±0.32) µM and 7.77 (±6.39) µM, respectively. Compounds (1) and (4) caused low toxicity in human A549 and MRC-5 cell lines. These compounds may represent possible drug candidates, which need further optimization to be used against COVID-19 and other coronaviral infections.

Pathogenomic in silico approach identifies NSP-A and Fe-IIISBP as possible drug targets in Neisseria Meningitidis MC58 and development of pharmacophores as novel therapeutic candidates.

Meningitis creates a life-threatening clinical crisis. Moreover, the administered antibiotics result into multi-drug resistance, thereby necessitating development of alternative therapeutic strategies. This study aimed at identifying novel-drug targets in Neisseria meningitidis and therapeutic molecules which can be exploited for the treatment of meningitis. Novel targets were identified by applying a pathogenomic approach involving protein data-set mining, subtractive channel analysis and subsequent qualitative analysis comprising of in silico pharmacokinetics, molecular docking and pharmacophore generation. Pathogenomic studies revealed Neisserial Surface Protein A (NSP-A) and Iron-III-Substrate Binding Protein (Fe-IIISBP) as potential targets. Two pharmacophore models comprising of 2-(biaryl) carbapenems, efavirenz, praziquantel and pyrimethamine for NSP-A and 2-(biaryl) carbapenems, trimipramine and pyrimethamine for Fe-IIISBP, showed successful docking, followed drug-likeness criteria and generated pharmacophore model with a score of 8.08 and 8.818, respectively, which had further been docked to the target stably. Thus, our study identifies NSP-A and Fe-IIISBP as novel targets in Neisseria meningitidis for which 2-(biaryl) carbapenems, efavirenz, praziquantel, trimipramine and pyrimethamine may be employed for effective treatment of meningitis.

Quantitative structure–activity relationship modeling and docking of some synthesized bioactive oxopyrolidines against Staphylococcus aureus

Quantitative correlations of chemical compounds' biological activity (response variables) with their molecular structures are known as QSARs (independent variables). The molecular descriptors account for a molecule's conformational, constitutional, thermodynamic, steric effects, and electronic characteristics. Molecular docking is one of the most commonly used strategies in structure-based drug design because of its ability to predict the binding-conformation of small-molecule ligands to the proper target binding site. The study of binding behaviour aids in the rational design of therapeutics at the molecular level. A series of novel bioactive oxopyrrolidine derivatives were reported to be synthesized from benzimidazole, pyrrolidinone, pyrrole, 1,2,4-triazole, thiazole, and oxadiazole with 1-(3-(1,3-thiazol-2-yl)phenyl)-5-oxopyrrolidines substituents. Consequently, oxopyrrolidines used possess thiazole ring obtained from reaction of either benzenecarbothioamide, tioureido acid or thiocarbamide with 1-(4-(bromoacetyl)phenyl)-5-oxopyrrolidine-3-carboxylic acid heterocyclic fragments. It was further compared with control Oxytetracycline in which quinoxaline containing fragment showed the more marked effect than of the used control antibiotic. Therefore, this study aimed to build a robust QSAR model to predict the anti-bacterial activity of some oxopyrolidines compounds against Staphylococcus aureus and carry out molecular docking studies between the compounds of the tyrosyltRNAsynthethase receptor. Based on the obtained values of the validation parameters, such as R2 (0.9049), R2adj (0.8789), and Q2cv(0.8365), necessary to evaluate the strength and robustness of the QSAR model, the developed QSAR model was deemed to be statistically significant. Some compounds were chosen and docked with the Staphylococcustyrosyl tRNA synthethase receptor, and the results suggest that C3, C7, C12, C17, C18, and C19 with free binding energies (FBE) −10.0 kcal/mol, −9.6 kcal/mol, −10.2 kcal/mol, −10.1 kcal/mol, −10.6 kcal/mol and −9.7 kcal/mol respectively were better than the standard tyrosyltRNAsynthethase inhibitor (Linezolid, FBE = −8.3 kcal mol−1). Furthermore, these compounds met the drug-likeness criteria and were orally bioavailable. The six compounds' modeling, docking, and drug similarity features broaden the scope of novel derivative design, manufacturing, and testing against Staphylococcus aureus.

In-silico validation of novel therapeutic activities of withaferin a using molecular docking and dynamics studies

Withaferin A is a bioactive molecule of W. somnifera. We access its efficacy against various target proteins associated with Cancer, Type-II Diabetes and hypercholesterolemia using molecular docking. Although it’s efficacy against some of these targets have been reported earlier, we validate each mechanism in order to report the most appropriate mechanism of action. We explain the anti-cancer activity of Withaferin A by inhibition of Mortalin (mtHsp70) and Nrf2 protein with binding energies −8.85 kcal/mol and −12.59 kcal/mol respectively. Similarly, the anti-diabetic activity could be explained by inhibition of alpha and betα-glucosidase with binding energies −6.44 and −4.43 kcal/mol respectively and the cholesterol reduction could be explained by its ability to inhibition of NPC1 and SRB1 with binding energies −5.73 and −7.16 kcal/mol respectively. The molecular dynamics of the apoprotein and the protein-ligand complex simulated for the best targets of each activity namely Nrf2 protein for anti-cancer, α-glucosidase for anti-diabetic and SR-B1 for anti-hypercholesterolemia activity indicated the formation of stable complexes due to low RMSD deviations, low RMSF fluctuations and low RG values after the docking simulation. Finally, an ADME + T (Adsorption, distribution, metabolism, excretion and toxicity) prediction on Withaferin A showed that it obeyed all the Lipinsky’s rules and qualified the drug-like criteria. All these results validate that Withaferin A possess potential anti-cancer, anti-diabetic and cholesterol reducing properties. This is the first report that indicates the possibility of Withaferin A binding and inhibiting SR-B1 as a mechanism of its anti-hypercholesterolemia activity.