Computational and In Vitro Experimental Investigations Reveal Anti-Viral Activity of Licorice and Glycyrrhizin against Severe Acute Respiratory Syndrome Coronavirus 2

Without effective antivirals, the COVID-19 pandemic will likely continue to substantially affect public health. Medicinal plants and phytochemicals are attractive therapeutic options, particularly those targeting viral proteins essential for replication cycle. Herein, a total 179 phytochemicals of licorice (Glycyrrhiza glabra) were screened and scrutinized against the SARS-CoV-2 main protease (Mpro) with considerable binding affinities in the range of −9.831 to −2.710 kcal/mol. The top 10 compounds with the best docking scores, licuraside, glucoliquiritin apioside, 7,3′-Dihydroxy-5′-methoxyisoflavone, licuroside, kanzonol R, neoisoliquiritin, licochalcone-A, formononetin, isomucronulatol, and licoricone, were redocked using AutoDock Vina, yielding −8.7 to −7.3 kcal/mol binding energy against Glycyrrhizin (−8.0 kcal/mol) as a reference ligand. Four compounds, licuraside, glucoliquiritin apioside, 7,3′-Dihydroxy-5′-methoxyisoflavone, and licuroside, with glycyrrhizin (reference ligand) were considered for the 100 ns MD simulation and post-simulation analysis which support the stability of docked bioactive compounds with viral protein. In vitro studies demonstrated robust anti-SARS-CoV-2 activity of licorice and glycyrrhizin under different treatment protocols (simulations treatment with viral infection, post-infection treatment, and pre-treatment), suggesting multiple mechanisms for action. Although both compounds inhibited SARS-CoV-2 replication, the half-maximal inhibitory concentration (IC50) of glycyrrhizin was substantially lower than licorice. This study supports proceeding with in vivo experimentation and clinical trials and highlights licorice and glycyrrhizin as potential therapeutics for COVID-19.

New Natural Compound Inhibitors of Checkpoint Kinase-1(CHK1) Based on Computational Study

As a malignant tumor of the ovary, the general treatment principle of ovarian cancer is surgical treatment, supplemented by chemotherapy, and some patients can use targeted drugs. Its treatment effect is relatively poor, so the prognosis is poor, the mortality rate is high. To contribute to drug design and refinement, ideal lead compounds with potential inhibitory effects on ATP-competitive CHK1 (Checkpoint kinase-1) inhibitors were downloaded from the drug library (ZINC15 database) and screened afterwards. The ATP-competitive CHK1 inhibitors were identified by using computer-aided virtual screening technology. We first calculated the LibDock score through the docking of proteins and molecules, and then analyzed the pharmacological and toxicological properties. Then, we performed precise docking of the small molecules selected in the above steps with CHK1 protein to analyze their docking mechanism and affinity. Next, we used molecular dynamics simulation to make a assessment if the ligand-CHK1 complex were stable in natural environment. As the result shown, ZINC000008214547 and ZINC000072103632 were proved to bind with CHK1 with a higher binding affinity and stability. Additionally, their toxicological analysis shows that they are less toxic and will not inhibit the activity of cytochrome P-450 2D6. In the simulation of molecular dynamics, we also found that ZINC000008214547-CHK1 and ZINC000072103632-CHK1 complexes’ potential energy were more favorable compared with reference ligand, Prexasertib. Not only that, the two complexes also showed better stability in the natural environment. So, all results elucidated that ZINC000008214547 and ZINC000072103632 were favorable lead inhibitors of CHK1 protein. ZINC000008214547 and ZINC000072103632 were safe and had the potential to inhibit CHK1 protein. They may contribute a solid foundation for the development of CHK1 target drug.

High Throughput Virtual Screening and Molecular Dynamics Simulation for Identifying a Putative Inhibitor of Bacterial CTX-M-15

Background: Multidrug resistant bacteria are a major therapeutic challenge. CTX-M-type enzymes are an important group of class A extended-spectrum β-lactamases (ESBLs). ESBLs are the enzymes that arm bacterial pathogens with drug resistance to an array of antibiotics, notably the advanced-generation cephalosporins. The current need for an effective CTX-M-inhibitor is high. Objective: The aim of the current study was to identify a promising anti-CTX-M-15 ligand whose chemical skeleton could be used as a ‘seed-molecule’ for future drug design against resistant bacteria. Methods: Virtual screening of 5,000,000 test molecules was performed by ‘MCULE Drug Discovery Platform’. ‘ADME analyses’ was performed by ‘SWISS ADME’. TOXICITY CHECKER of MCULE was employed to predict the safety profile of the test molecules. The complex of the ‘Top inhibitor’ with the ‘bacterial CTX-M-15 enzyme’ was subjected to 102.25 ns molecular dynamics simulation. This simulation was run for 3 days on a HP ZR30w workstation. Trajectory analyses were performed by employing the macro ‘md_analyze.mcr’ of YASARA STRUCTURE version 20.12.24.W.64 using AMBER14 force field. YANACONDA macro language was used for complex tasks. Figures, including RMSD and RMSF plots, were generated. Snapshots were acquired after every 250 ps. Finally, two short videos of ‘41 s’ and ‘1 min and 22 s’ duration were recorded. Results: 5-Amino-1-(2H-[1,2,4]triazino[5,6-b]indol-3-yl)-1H-pyrazole-4-carbonitrile, denoted by the MCULE-1352214421-0-56, displayed the most efficient binding with bacterial CTX-M-15 enzyme. This screened molecule significantly interacted with CTX-M-15 via 13 amino acid residues. Notably, nine amino acid residues were found common to avibactam binding (the reference ligand). Trajectory analysis yielded 410 snapshots. The RMSD plot revealed that around 26 ns, equilibrium was achieved and, thereafter, the complex remained reasonably stable. After a duration of 26 ns and onwards until 102.25 ns, the backbone RMSD fluctuations were found to be confined within a range of 0.8–1.4 Å. Conclusion: 5-Amino-1-(2H-[1,2,4]triazino[5,6-b]indol-3-yl)-1H-pyrazole-4-carbonitrile could emerge as a promising seed molecule for CTX-M-15-inhibitor design. It satisfied ADMET features and displayed encouraging ‘simulation results’. Advanced plots obtained by trajectory analyses predicted the stability of the proposed protein-ligand complex. ‘Hands on’ wet laboratory validation is warranted.

New sulphonamide pyrolidine carboxamide derivatives: Synthesis, molecular docking, antiplasmodial and antioxidant activities

Carboxamides bearing sulphonamide functionality have been shown to exhibit significant lethal effect on Plasmodium falciparum, the causative agent of human malaria. Here we report the synthesis of thirty-two new drug-like sulphonamide pyrolidine carboxamide derivatives and their antiplasmodial and antioxidant capabilities. In addition, molecular docking was used to check their binding affinities for homology modelled P. falciparum N-myristoyltransferase, a confirmed drug target in the pathogen. Results revealed that sixteen new derivatives killed the parasite at single-digit micromolar concentration (IC50 = 2.40–8.30 μM) and compounds 10b, 10c, 10d, 10j and 10o scavenged DPPH radicals at IC50s (6.48, 8.49, 3.02, 6.44 and 4.32 μg/mL respectively) comparable with 1.06 μg/mL for ascorbic acid. Compound 10o emerged as the most active of the derivatives to bind to the PfNMT with theoretical inhibition constant (Ki = 0.09 μM) comparable to the reference ligand pyrazole-sulphonamide (Ki = 0.01 μM). This study identifies compound 10o, and this series in general, as potential antimalarial candidate with antioxidant activity which requires further attention to optimise activity.

Peganum harmala and its Alkaloids as Dopamine Receptor Antagonists: in Silico Study

Peganum harmala is known to have active metabolites such as alkaloids, which can affect the central nervous system. One of the various alkaloids is thought to be related to their activity as dopamine receptor antagonists, which can be developed in the therapy of various neurological diseases. This study aims to determine the alkaloid from P. harmala, which has the highest potential as the dopamine receptor antagonist. The method used was molecular docking against dopamine receptors with risperidone as the reference ligand. The results showed that among the known alkaloids from P. harmala, dipegine, harmalanine, and harmalacinine showed the highest potency in terms of both free energy of binding and similarity of ligand-receptor interactions. The results of this investigation anticipate that some alkaloids from P. harmala have the potential as the dopamine receptor antagonist.

In silico approach: Anthocyanin derivatives as potential inhibitors of the COVID-19 main protease

In silico approach has been carried out for the determination of drug candidates from anthocyanin derivative as inhibitors of the COVID-19 main protease. Geometry optimization has performed using the DFT/B3LYP/6-31G(d,p) method as an initial step to prepare candidate ligand. The results of molecular docking showed that candidates C5 and C6 had promising results with a grid score smaller than the ligand reference (X77) with a flexible conformation type. Studies on absorption, distribution, metabolism, excretion, and toxicity of C5 and C6 candidates were conducted to study the physicochemical properties of drug candidates and to show good predictive results as drugs. Molecular dynamic simulation uses the ffSB14 force field for 200 ns to study the interaction between ligand and receptor, the system stability, solvent accessibility, energy interactions, and hydrogen bonds. The results show good interaction stability on the C5 complex compared to the reference ligand which is characterized by the binding free energy value of C5 was -42.77 ± 0.37 kcal/mol and X77 was -42.37 ± 0.41 kcal/mol.

Fragment tailoring strategy to design novel chemical entities as potential binders of novel corona virus main protease

<p></p><p>The recent pandemic of novel corona virus (nCoV) infections (COVID19) has put the world on serious alert. The main protease of nCov (nCov-MP) cleaves the long polyprotein chains to release functional proteins required for replication of the virus and thus is a potential drug target to design new chemical entities in order to inhibit the viral replication in human cells. The current study employs state of art computational methods to design novel molecules by linking molecular fragments which specifically bind to different constituent sub-pockets of the nCov-MP binding site. A huge library of 191678 fragments was screened against the binding cavity of nCov-MP and high affinity fragments binding to adjacent sub-pockets were tailored to generate new molecules. These newly formed molecules were further subjected to molecular docking, ADMET property filters and MM-GBSA binding free energy calculations to select 17 best molecules (named as MP-In1 to Mp-In17), which showed comparable binding affinities and interactions with the key binding site residues as the reference ligand. The complexes of these 17 molecules and the reference molecule with nCov-MP, were subjected to molecular dynamics simulations, which assessed the stabilities of their binding with nCov-MP. Fifteen molecules were found to form stable complexes with nCov-MP. These novel chemical entities designed specifically according to the pharmacophoric requirements of nCov-MP binding pockets showed good synthetic feasibility and returned no exact match when searched against chemical databases. Considering their interactions, binding efficiencies and novel chemotypes, they can be further evaluated as potential starting points for nCov drug discovery. </p><br><p></p>

Fragment tailoring strategy to design novel chemical entities as potential binders of novel corona virus main protease

<p></p><p>The recent pandemic of novel corona virus (nCoV) infections (COVID19) has put the world on serious alert. The main protease of nCov (nCov-MP) cleaves the long polyprotein chains to release functional proteins required for replication of the virus and thus is a potential drug target to design new chemical entities in order to inhibit the viral replication in human cells. The current study employs state of art computational methods to design novel molecules by linking molecular fragments which specifically bind to different constituent sub-pockets of the nCov-MP binding site. A huge library of 191678 fragments was screened against the binding cavity of nCov-MP and high affinity fragments binding to adjacent sub-pockets were tailored to generate new molecules. These newly formed molecules were further subjected to molecular docking, ADMET property filters and MM-GBSA binding free energy calculations to select 17 best molecules (named as MP-In1 to Mp-In17), which showed comparable binding affinities and interactions with the key binding site residues as the reference ligand. The complexes of these 17 molecules and the reference molecule with nCov-MP, were subjected to molecular dynamics simulations, which assessed the stabilities of their binding with nCov-MP. Fifteen molecules were found to form stable complexes with nCov-MP. These novel chemical entities designed specifically according to the pharmacophoric requirements of nCov-MP binding pockets showed good synthetic feasibility and returned no exact match when searched against chemical databases. Considering their interactions, binding efficiencies and novel chemotypes, they can be further evaluated as potential starting points for nCov drug discovery. </p><br><p></p>

Design, Synthesis, and Acute Anti-inflammatory Assessment of New 2-methyl Benzoimidazole Derivatives Having 4-Thiazolidinone Nucleus

New two derivatives of 2- methyl benzoimidazole were designed, synthesized and evaluated as a potential cyclooxygenase-2 [COX-2] inhibitors. The synthesized compounds have been recognized according to their spectral FT-IR, 1H-NMR data and physical pro- perties. The newly synthesized compounds were investigated in vivo for their anti-inflammatory activities using egg-white stimulated paw edema method with respect to the effect of propylene glycol 50%v/v [control group] and the ibuprofen [10mg/kg i.p.] was selected as a reference ligand. New compounds showed a significantly higher in vivo anti-inflammatory activity compared with ibuprofen as a reference drug. COX-2 selectivity evaluation through molecular docking via GOLD suite [v. 5.6.2.]. The new compounds via molecular docking showed significant higher activities when compared with ibuprofen as referenced drugs because of having hydrogen bonding interaction toward the key amino acids within COX-2 structure and all these results were compatible with the study of in vivo acute anti-inflammatory activities for tested compounds. ADME studies were performed to predict absorption, bioavailability, topological polar surface area, and drug-likeness. The results of ADME studies showed that all synthesized compounds absorbed from the gastrointestinal tract.