Novel ciprofloxacin and norfloxacin-tetrazole hybrids as potential antibacterial and antiviral agents: Targeting S. aureus topoisomerase and SARS-CoV-2-MPro.

This study was designed to synthesize hybridizing molecules from ciprofloxacin and norfloxacin by enhancing their biological activity with tetrazoles. The synthesized compounds were investigated in the interaction with the target enzyme of fluoroquinolones (DNA gyrase) and COVID-19 main protease using molecular similarity, molecular docking, and QSAR studies. A QSAR study was carried out to explore the antibacterial activity of our compounds over Staphylococcus aureus a QSAR study, using descriptors obtained from the docking with DNA gyrase, in combination with steric type descriptors, was done obtaining suitable statistical parameters ( R 2 = 87.00 , Q L M O 2 = 71.67 , and Q E X T 2 = 73.49 ) to support our results. The binding interaction of our compounds with CoV-2-Mpro was done by molecular docking and were compared with different covalent and non-covalent inhibitors of this enzyme. For the docking studies we used several crystallographic structures of the CoV-2-Mpro. The interaction energy values and binding mode with several key residues, by our compounds, support the capability of them to be CoV-2-Mpro inhibitors. The characterization of the compounds was completed using FT-IR, 1H-NMR, 13C-NMR, 19F-NMR and HRMS spectroscopic methods. The results showed that compounds 1, 4, 5, 10 and 12 had the potential to be further studied as new antibacterial and antiviral compounds.

Insight into designing of 2-pyridone derivatives for COVID-19 drug discovery - A computational study.

Presently, the prime global focus is on SARS-CoV-2, as no fully established, licensed medicine has been found thus far, in spite of the existence of various reports and administration of partially proven certain class of natural products. However, in case of natural products, the extraction and purification limit their application. This situation drives researchers to explore synthetically viable drugs. In the present investigation, twenty-three 2-pyridone synthetic derivatives (P1-P23) have been theoretically tested for their suitability as potential inhibitors for COVID-19 main protease through DFT, molecular docking, and molecular dynamics simulations. DFT calculations offer insights into structure-property relationships, while ADMET studies indicate the pharmacological characteristics of these molecules. Molecular docking studies ascertain the nature and mode of interactions of these entities with COVID-19 main protease. Furthermore, covalent docking has been carried out to verify the feasibility of the formation of a covalent bond with the active site. The top protein-inhibitor complexes, such as P18, P11, and P12, were identified based on their glide score. These molecules, along with the covalent docked complexes, namely P18 and P16, were selected and subjected to molecular dynamics simulations. The 100 ns simulation process exhibited that the covalent docked ones, due to their stable form could serve as lead compounds against SARS-CoV-2. Hence, this study affirms the potential candidature of 2-pyridone-based inhibitors.

Isolation and In Silico SARS-CoV-2 Main Protease Inhibition Potential of Jusan Coumarin, a New Dicoumarin from Artemisia glauca.

A new dicoumarin, jusan coumarin, (1), has been isolated from Artemisia glauca aerial parts. The chemical structure of jusan coumarin was estimated, by 1D, 2D NMR as well as HR-Ms spectroscopic methods, to be 7-hydroxy-6-methoxy-3-[(2-oxo-2H-chromen-6-yl)oxy]-2H-chromen-2-one. As the first time to be introduced in nature, its potential against SARS-CoV-2 has been estimated using various in silico methods. Molecular similarity and fingerprints experiments have been utilized for 1 against nine co-crystallized ligands of COVID-19 vital proteins. The results declared a great similarity between Jusan Coumarin and X77, the ligand of COVID-19 main protease (PDB ID: 6W63), Mpro. To authenticate the obtained outputs, a DFT experiment was achieved to confirm the similarity of X77 and 1. Consequently, 1 was docked against Mpro. The results clarified that 1 bonded in a correct way inside Mpro active site, with a binding energy of -18.45 kcal/mol. Furthermore, the ADMET and toxicity profiles of 1 were evaluated and showed the safety of 1 and its likeness to be a drug. Finally, to confirm the binding and understand the thermodynamic characters between 1 and Mpro, several molecular dynamics (MD) simulations studies have been administered. Additionally, the known coumarin derivative, 7-isopentenyloxycoumarin (2), has been isolated as well as ß-sitosterol (3).

Jusanin, a New Flavonoid from Artemisia commutata with an In Silico Inhibitory Potential against the SARS-CoV-2 Main Protease.

A new flavonoid, Jusanin, (1) has been isolated from the aerial parts of Artemisia commutata. The chemical structure of Jusanin has been elucidated using 1D, 2D NMR, and HR-Ms spectroscopic methods to be 5,2',4'-trihydroxy-6,7,5'-trimethoxyflavone. Being new in nature, the inhibition potential of 1 has been estimated against SARS-CoV-2 using different in silico techniques. Firstly, molecular similarity and fingerprint studies have been conducted for Jusanin against co-crystallized ligands of eight different SARS-CoV-2 essential proteins. The studies indicated the similarity between 1 and X77, the co-crystallized ligand SARS-CoV-2 main protease (PDB ID: 6W63). To confirm the obtained results, a DFT study was carried out and indicated the similarity of (total energy, HOMO, LUMO, gap energy, and dipole moment) between 1 and X77. Accordingly, molecular docking studies of 1 against the target enzyme have been achieved and showed that 1 bonded correctly in the protein's active site with a binding energy of -19.54 Kcal/mol. Additionally, in silico ADMET in addition to the toxicity evaluation of Jusanin against seven models have been preceded and indicated the general safety and the likeness of Jusanin to be a drug. Finally, molecular dynamics simulation studies were applied to investigate the dynamic behavior of the Mpro-Jusanin complex and confirmed the correct binding at 100 ns. In addition to 1, three other metabolites have been isolated and identified to be сapillartemisin A (2), methyl-3-[S-hydroxyprenyl]-cumarate (3), and ß-sitosterol (4).

Evaluating anti-coronavirus activity of some phosphoramides and their influencing inhibitory factors using molecular docking, DFT, QSAR, and NCI-RDG studies.

The recent prevalence of coronavirus disease in 2019 (COVID-19) has triggered widespread global health concerns.Antiviral drugs based on phosphoramides have significant inhibitory activity against the main protease (Mpro) of the virus and prevent transcription and viral replication. Hence, in order to design and introduce a group of inhibitors affecting the coronavirus, 35 phosphoramide compounds based on phospho-guanine and phospho-pyrazine derivatives were selected for molecular docking study. The results showed that most phosphoguanides containing the amino benzimidazole have a high interaction tendency with COVID-19. Among them, compound 19 was identified as the strongest inhibitor with the -9.570 kcal/mol binding energy whereas, the binding energy of Remdesivir is -6.75 kcal/mol. The quantitative structure-activity relationship (QSAR) results demonstrated that the number of aromatic rings, amide's nitrogens and their ability in π-staking, and hydrogen interactions with Mpro active sites are major factors contributing to the inhibitory activity of these compounds.Also, the NCI-RDG and DFT results were in good accordance with those of QSAR and molecular docking. The findings of this investigation can be underlying the synthesis of effective and efficient drugs against COVID-19.

In silico analysis of phytochemicals as potential inhibitors of proteases involved in SARS-CoV-2 infection.

In silico analysis of six phytochemicals, flabelliferin, marmelosin, piperine, ocimin, curcumin and leucoanthocyanin, along with three drug compounds, nelfinavir, remdesivir and hydroxychloroquine, as positive control against drug targets of one SARS-CoV-2 viral protease, COVID-19 main protease (SARS CoV-2 3CLpro/Mpro), two coronavirus proteases, SARS-CoV main peptidase (SARS CoV Mpro), SARS-CoV main proteinase (SARS CoV 3CLpro), and one human cellular transmembrane serine proteinase (TMPRSS2), was carried out. Except leucoanthocyanin all other phytochemicals proved better than all three positive control drugs against SARS-CoV main peptidase, whereas, flabelliferin was found to be the potential inhibitor for SARS-CoV main proteinase out performing all the positive control drugs and phytochemicals. Amongst the compounds studied, the best inhibitor for COVID-19 main protease was nelfinavir followed by flabelliferin and ocimin. Flabelliferin was found to the best promising inhibitor of human cellular transmembrane serine proteinase, followed by nelfinavir, curcumin, piperine and marmelosin. The result on the inhibition of human cellular transmembrane serine proteinase against COVID-19 has a stable therapeutic advantage as mutation may quickly occur on viral drug targets. Hence, all the phytochemicals tested in the present study are the potential inhibitors of the all the four drug targets and can form a part of therapeutics against COVID-19 with further clinical studies.Communicated by Ramaswamy H. Sarma.

Screening of plant-based natural compounds as a potential COVID-19 main protease inhibitor: an in silico docking and molecular dynamics simulation approach.

A new strain of coronavirus (CoV) has been identified as SARS-CoV-2, which is responsible for the recent COVID-19 pandemic. Currently, there is no approved vaccine or drug available to combat the pandemic. COVID-19 main protease (Mpro) is a key CoV enzyme, which plays an important role in triggering viral replication and transcription, turns it into an attractive target. Therefore, we aim to screen natural products library to find out potential COVID-19 Mpro inhibitors. Plant-based natural compounds from Sigma-Aldrich plant profiler chemical library have been screened through virtual molecular docking and molecular dynamics simulation to identify potential inhibitors of COVID Mpro. Our virtual molecular docking results have shown that there are twenty-eight natural compounds with a greater binding affinity toward the COVID-19 Mpro inhibition site as compared to the co-crystal native ligand Inhibitor N3 (-7.9 kcal/mol). Also, molecular dynamics simulation results have confirmed that Peonidin 3-O-glucoside, Kaempferol 3-O-ß-rutinoside, 4-(3,4-Dihydroxyphenyl)-7-methoxy-5-[(6-O-ß-D-xylopyranosyl-ß-D-glucopyranosyl)oxy]-2H-1-benzopyran-2-one, Quercetin-3-D-xyloside, and Quercetin 3-O-α-L-arabinopyranoside (selected based on the docking score) possess a significant amount of dynamic properties such as stability, flexibility and binding energy. Our In silco results suggests that all the above mention natural compounds have the potential to be developed as a COVID-19 Mpro inhibitor. But before that, it must go through under the proper preclinical and clinical trials for further scientific validation.Communicated by Ramaswamy H. Sarma.

Medicinal plants with anti-SARS-CoV activity repurposing for treatment of COVID-19 infection: A systematic review and meta-analysis.

The novel SARS-CoV-2 (severe acute respiratory syndrome coronavirus) has emerged as a significant threat to public health with startling drawbacks in all sectors globally. This study investigates the practicality of some medicinal plants for SARS-CoV-2 therapy using a systematic review and meta-analysis of their reported SARS-CoV-1 inhibitory potencies. Relevant data were systematically gathered from three databases, viz., Web of Science, PubMed and Scopus. The information obtained included botanical information, extraction method and extracts concentrations, as well as the proposed mechanisms. Fourteen articles describing 30 different plants met our eligibility criteria. Random effects model and subgroup analysis were applied to investigate heterogeneity. According to subgroup analysis, the substantial heterogeneity of the estimated mean based on the IC 50 values reporting the most potent anti-SARS-CoV 3C--like protease (3CLpro) inhibitors (10.07 %, p < 0.0001), was significantly higher compared to the most active anti-SARS-CoV papain-like protease (PLpro) inhibitors (6.12 %, p < 0.0001). More importantly, the literature analysis revealed that fruit extracts of Rheum palmatum L. and the compound cryptotanshinone isolated from the root of Salvia miltiorrhiza (IC 50 = 0.8 ± 0.2 µmol L-1) were excellent candidates for anti--SARS-CoV targeting PLpro. Meanwhile, iguesterin (IC 50 = 2.6 ± 0.6 µmol L-1) isolated from the bark of Tripterygium regelii emerged as the most excellent candidate for anti-SARS--CoV targeting 3CLpro. The present systematic review and meta-analysis provide valuable and comprehensive information about potential medicinal plants for SARS-CoV-2 inhibition. The chemotypes identified herein can be adopted as a starting point for developing new drugs to contain the novel virus.

Design of new bis-triazolyl structure for identification of inhibitory activity on COVID-19 main protease by molecular docking approach.

In the rapidly growing COVID-19 pandemic, designing of new drugs and evaluating their inhibitory action against main targets of corona virus could be an effective strategy to accelerate the drug discovery process and their efficacy towards corona virus disease. Herein, we design new bis-triazolyl probe for an investigation of inhibitory activity towards COVID-19 main protease by Molecular docking approach. The formulated compound has been thoroughly characterized by elemental analysis, NMR (1H and 13C) and complete structure elucidation was achieved via X-ray crystallography. Docking study reveals that newly synthesized compound confers good inhibitory response to COVID-19 main protease as supported by calculated docking score and binding energy. Strong hydrogen bonding and hydrophobic interactions of the newly synthesized compound with several important amino acids of the main protease also helps to explain the potency of the compound to inhibit the main protease. We hope that the present study would help the researcher in the field of Medicinal chemistry and to develop potential drug against the novel corona virus.

Medicinal plant compounds as promising inhibitors of coronavirus (COVID-19) main protease: an in silico study.

The novel Coronavirus (COVID-19) has spread rapidly across the globe and has involved more than 215 countries and territories. Due to a lack of effective therapy or vaccine, urgent and concerted efforts are needed to identify therapeutic targets and medications. COVID-19 main protease represents a major target for drug treatment to inhibit viral function. The present study sought to evaluate medicinal plant compounds as potential inhibitors of the COVID-19 main protease using molecular docking and molecular dynamic analysis. The PDB files of COVID-19 main protease and some medicinal plant compounds were retrieved from the Protein Data Bank (http://www.rcsb.org) and Pubchem server, respectively. The Gromacs software was used for simulation studies, and molecular docking analysis was done using Autodock 4.2. The COVID-19 main protease simulation, compared with some phytochemicals docked to the COVID-19 main protease, were analyzed. Glabridin, catechin, and fisetin had the greatest tendency to interact with the COVID-19 main protease by hydrogen and hydrophobic interactions. Docking of these phytochemicals to COVID-19 main protease led to an increase in the radius of gyration (Rg), decrease in the Root mean square fluctuation (RMSF), and induced variation in COVID-19 main protease secondary structure. The high tendency interaction of glabridin, catechin, and fisetin to COVID-19 main protease induced conformational changes on this enzyme. These interactions can lead to enzyme inhibition. This simulated study indicates that these phytochemicals may be considered as potent inhibitors of the viral protease; however, more investigations are required to explore their potential medicinal use.Communicated by Ramaswamy H. Sarma.

Synthesis, crystal structure, computational study and anti-virus effect of mixed ligand copper (II) complex with ONS donor Schiff base and 1, 10-phenanthroline.

This work deals with the synthesis, crystal structure, computational study and antiviral potential of mixed ligand copper(II) complex [Cu(L)(phen)](1), (where, H2L = (Z)-N'-((E)-2-hydroxy-3,5-diiodobenzylidene)-N,N-dimethylcarbamohydrazonothioic acid, phen = 1,10-phenanthroline). The Schiff base ligand (H2L) is coordinated with Cu(II) ion in O, N, S-tridentate mode. The copper complex (1) crystallized in the monoclinic system of the space group P21/c with eight molecules in the unit cell and reveals a square pyramidal geometry. Furthermore, we also perform quantum chemical calculations to get insights into the structure-property relationship and functional properties of ligand (H2L) and its copper (II) complex [Cu(L)(phen)](1). Complex [Cu(L)(phen)](1) was also virtually designed in-silico evaluation by Swiss-ADME. Additionally, inspiring by recent developments to find a potential inhibitor for the COVID-19 virus, we have also performed molecular docking study of ligand and its copper complex (1) to see if our compounds shows an affinity for the main protease (Mpro) of COVID-19 spike protein (PDB ID: 7C8U). Interestingly, the results are found quite encouraging where the binding affinity and inhibition constant were found to be -7.14 kcal/mol and 5.82 µM for ligand (H2L) and -6.18 kcal/mol and 0.76 µM for complex [Cu(L)(phen)](1) with Mpro protein. This binding affinity is reasonably well as compared to recently known antiviral drugs. For instance, the binding affinity of ligand and complex was found to be better than docking results of chloroquine (-6.293 kcal/mol), hydroxychloroquine (-5.573 kcal/mol) and remdesivir (-6.352 kcal/mol) with Mpro protein. The present study may offer the technological solutions and potential inhibition to the COVID-19 virus in the ongoing and future challenges of the global community. In the framework of synthesis and characterization of mixed ligand copper (II) complex; the major conclusions can be drawn as follow.

Crystal structure and mol-ecular docking study of (E)-2-{[(E)-2-hy-droxy-5-methyl-benzyl-idene]hydrazinyl-idene}-1,2-di-phenyl-ethan-1-one.

The title compound, C22H18N2O2, is a Schiff base that exists in the phenol-imine tautomeric form and adopts an E configuration with respect to the C=N bond. The mol-ecular structure is stabilized by an O-H⋯N hydrogen bond, forming an S(6) ring motif. In the crystal, pairs of C-H⋯O hydrogen bonds link the mol-ecules to form inversion dimers. Weak π-π stacking inter-actions along the a-axis direction provide additional stabilization of the crystal structure. The mol-ecule is non-planar, the aromatic ring of the benzaldehyde residue being nearly perpendicular to the phenyl and 4-methyl-phenol rings with dihedral angles of 88.78 (13) and 82.26 (14)°, respectively. A mol-ecular docking study between the title mol-ecule and the COVID-19 main protease (PDB ID: 6LU7) was performed, showing that it is a potential agent because of its affinity and ability to adhere to the active sites of the protein.

In silico detection of inhibitor potential of Passiflora compounds against SARS-Cov-2(Covid-19) main protease by using molecular docking and dynamic analyses.

SARS-Cov-2(Covid-19) is a new strain of coronavirus and was firstly emerged in December 2019 in Wuhan, China. Now, there is no known specific treatment of Covid-19 available. COVID-19 main protease is a potential drug target and is firstly crystallised by Liu et al (2020). In the study, we investigated the drug potential of molecules that the components of an important medicinal plant Passiflora by using molecular docking, molecular dynamic and drug possibility properties of these molecules. Docking performances were done by Autodock. Chloroquine, hydroxychloroquine were used as standarts for comparison of tested ligands. The molecular docking results showed that the Luteolin, Lucenin, Olealonic acid, Isoorientin, Isochaphoside, Saponarin, Schaftoside etc. ligands was bound with COVID-19 main protease above -8,0 kcal/mol binding energy. Besides, ADME, drug-likeness features of compounds of Passiflora were investigated using the rules of Lipinski, Veber, and Ghose. According to the results obtained, it has been shown that compounds of Passiflora have the potential to be an effective drug in the COVID-19 pandemic. Further studies are needed to reveal the drug potential of these ligands. Our results will be a source for these studies.

Role of phytoconstituents in the management of COVID-19.

BACKGROUND: COVID-19, a severe global pandemic caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has emerged as one of the most threatening transmissible disease. As a great threat to global public health, the development of treatment options has become vital, and a rush to find a cure has mobilized researchers globally from all areas. SCOPE AND APPROACH: This review focuses on deciphering the potential of different secondary metabolites from medicinal plants as therapeutic options either as inhibitors of therapeutic targets of SARS-CoV-2 or as blockers of viral particles entry through host cell receptors. The use of medicinal plants containing specific phytomoieties could be seen in providing a safer and long-term solution for the population with lesser side effects. Key Findings and Conclusions: Considering the high cost and time-consuming drug discovery process, therapeutic repositioning of existing drugs was explored as treatment option in COVID-19, however several molecules have been retracted as therapeutics either due to no positive outcomes or the severe side effects. These effects call for exploring the alternate treatment options which are therapeutically effective as well as safe. Keeping this in mind, phytopharmaceuticals derived from medicinal plants could be explored as important resources in the development of COVID-19 treatment, as their role in the past for treatment of viral diseases like HIV, MERS-CoV, and influenza has been well reported. Considering this fact, different phytoconstituents such as flavonoids, alkaloids, tannins and glycosides etc. Possessing antiviral properties against coronaviruses and possessing potential against SARS-CoV-2 have been reviewed in the present work.

Application of green synthesised copper iodide particles on cotton fabric-protective face mask material against COVID-19 pandemic.

Microorganisms cause variety of diseases that constitutes a severe threat to mankind. Due to the upsurge of many infectious diseases, there is a high requirement and demand for the development of safety products finished with antimicrobial properties. The study involves the antimicrobial activity of natural cotton coated with copper iodide capped with Hibiscus rosa-sinensis L. flower extract (CuI-FE) which is rich in anthocyanin, cyanidin-3-sophoroside by ultrasonication method. The coated and uncoated cotton fabric was characterised through XRD, SEM, AFM, tensile strength and UV-Visible spectroscopic techniques. XRD confirmed the formation of CuI particles, SEM showed that CuI-FE was prismatic in shape. The average size of CuI-FE particles was found to be 552.45 nm. Anti-bacterial studies showed copper iodide particles to be a potent antimicrobial agent. AFM images confirmed the rupture of bacterial cell walls in the presence of prismatic CuI-FE. In-vitro cytotoxicity investigation of CuI-FE was performed against cancer and spleen cell lines to evaluate the cell viability. Cytotoxicity analysis revealed the IC50 value of 233.93 µg/mL in the presence of CuI-FE. Molecular docking study was also carried out to understand the interaction of CuI-FE with COVID-19 main protease. This paper has given an insight on the usage of CuI-FE coated on the cotton fabric that has proved to have strong inhibition against the nano ranged bacterial, cancerous cell line and a strong interaction with the COVID-19 protease. Such eco-friendly material will provide a safe environment even after the disposable of medical waste from the infectious diseases like influenza and current pandemic like COVID-19.

Discovery of Some Antiviral Natural Products to Fight Against Novel Coronavirus (SARS-CoV-2) Using an In silico Approach.

BACKGROUND: Novel coronavirus is a type of enveloped viruses with a single-stranded RNA enclosing helical nucleocapsid. The envelope consists of spikes on the surface which are made up of proteins through which virus enters into human cells. Until now, there is no specific drug or vaccine available to treat COVID-19 infection. In this scenario, reposting of drug or active molecules may provide rapid solution to fight against this deadly disease. OBJECTIVE: We selected 30 phytoconstituents from the different plants which are reported for antiviral activities against coronavirus (CoVs) and performed in silico screening to find out phytoconstituents which have potency to inhibit specific target of the novel coronavirus. METHODS: We performed molecular docking studies on three different proteins of novel coronavirus, namely COVID-19 main protease (3CL pro), papain-like protease (PL pro) and spike protein (S) attached to ACE2 binding domain. The screening of the phytoconstituents on the basis of binding affinity compared to standard drugs. The validations of screened compounds were done using ADMET and bioactivity prediction. RESULTS: We screened five compounds biscoclaurine, norreticuline, amentoflavone, licoricidin and myricetin, using in silico approach. All compounds were found safe in In silico toxicity studies. Bioactivity prediction reveals that these compounds may act through protease or enzyme inhibition. Results of compound biscoclaurine norreticuline were more interesting as this biscoclaurine had higher binding affinity for the target 3CLpro and PLpro targets and norreticuline had a higher binding affinity for the target PLpro and Spike protein. CONCLUSION: Our study concludes that these compounds could be further explored rapidly as it may have potential to fight against COVID-19.

Structural dynamics of COVID-19 main protease.

Based on the importance of protease enzymes in functioning some viruses particularly coronaviridae, we have carried out an in silico investigation on the biologically important, yet unmapped phenomenon of activity and internal dynamics of COVID-19 main protease (Mpro) via applying finite-temperature all-atom molecular dynamics simulations. Temperature quench echoes generated by applying two successive cooling signals have therefore been analyzed in terms of the temperature-temperature correlation function of the protease within the harmonic approximation. An exponentially decaying brand of behavior has been found for the calculated echo depth values with increasing time, which has accordingly led to a much small dephasing time of about 150 fs, revealing a significant anharmonicity and therefore an overall structural stiffness for the COVID-19 main protease.

An in-silico evaluation of COVID-19 main protease with clinically approved drugs.

A novel strain of coronavirus, namely, SARS-CoV-2 identified in Wuhan city of China in December 2019, continues to spread at a rapid rate worldwide. There are no specific therapies available and investigations regarding the treatment of this disease are still lacking. In order to identify a novel potent inhibitor, we performed blind docking studies on the main virus protease Mpro with eight approved drugs belonging to four pharmacological classes such as: anti-malarial, anti-bacterial, anti-infective and anti-histamine. Among the eight studied compounds, Lymecycline and Mizolastine appear as potential inhibitors of this protease. When docked against Mpro crystal structure, these two compounds revealed a minimum binding energy of -8.87 and -8.71 kcal/mol with 168 and 256 binding modes detected in the binding substrate pocket, respectively. Further, to study the interaction mechanism and conformational dynamics of protein-ligand complexes, Molecular dynamic simulation and MM/PBSA binding free calculations were performed. Our results showed that both Lymecycline and Mizolastine bind in the active site. And exhibited good binding affinities towards target protein. Moreover, the ADMET analysis also indicated drug-likeness properties. Thus it is suggested that the identified compounds can inhibit Chymotrypsin-like protease (3CLpro) of SARS-CoV-2.

Ciprofloxacin and moxifloxacin could interact with SARS-CoV-2 protease: preliminary in silico analysis.

BACKGROUND: A large body of research has focused on fluoroquinolones. It was shown that this class of synthetic antibiotics could possess antiviral activity as a broad range of anti-infective activities. Based on these findings, we have undertaken in silico molecular docking study to demonstrate, for the first time, the principle for the potential evidence pointing ciprofloxacin and moxifloxacin ability to interact with COVID-19 Main Protease. METHODS: In silico molecular docking and molecular dynamics techniques were applied to assess the potential for ciprofloxacin and moxifloxacin interaction with COVID-19 Main Protease (Mpro). Chloroquine and nelfinavir were used as positive controls. RESULTS: We revealed that the tested antibiotics exert strong capacity for binding to COVID-19 Main Protease (Mpro). According to the results obtained from the GOLD docking program, ciprofloxacin and moxifloxacin bind to the protein active site more strongly than the native ligand. When comparing with positive controls, a detailed analysis of the ligand-protein interactions shows that the tested fluoroquinolones exert a greater number of protein interactions than chloroquine and nelfinavir. Moreover, lower binding energy values obtained from KDEEP program were stated when compared to nelfinavir. CONCLUSIONS: Here, we have demonstrated for the first time that ciprofloxacin and moxifloxacin may interact with COVID-19 Main Protease (Mpro).

Recognition of Natural Products as Potential Inhibitors of COVID-19 Main Protease (Mpro): In-Silico Evidences.

SARS-CoV-2 (2019-nCoV) emerged in 2019 and proliferated rapidly across the globe. Scientists are attempting to investigate antivirals specific to COVID-19 treatment. The 2019-nCoV and SARS-CoV utilize the same receptor of the host which is COVID-19 of the main protease (Mpro).COVID-19 caused by SARS-CoV-2 is burdensome to overcome by presently acquired antiviral candidates. So the objective and purpose of this work was to investigate the plants with reported potential antiviral activity. With the aid of in silico techniques such as molecular docking and druggability studies, we have proposed several natural active compounds including glycyrrhizin, bicylogermecrene, tryptanthrine, ß-sitosterol, indirubin, indican, indigo, hesperetin, crysophanic acid, rhein, berberine and ß-caryophyllene which can be encountered as potential herbal candidate exhibiting anti-viral activity against SARS-CoV-2. Promising docking outcomes have been executed which evidenced the worthy of these selected herbal remedies for future drug development to combat coronavirus disease.