Computational screening of natural compounds from Salvia plebeia R. Br. for inhibition of SARS-CoV-2 main protease.

The novel Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV-2) has emerged to be the reason behind the COVID-19 pandemic. It was discovered in Wuhan, China and then began spreading around the world, impacting the health of millions. Efforts for treatment have been hampered as there are no antiviral drugs that are effective against this virus. In the present study, we have explored the phytochemical constituents of Salvia plebeia R. Br., in terms of its binding affinity by targeting COVID-19 main protease (Mpro) using computational analysis. Molecular docking analysis was performed using PyRx software. The ADMET and drug-likeness properties of the top 10 compounds showing binding affinity greater than or equal to - 8.0 kcal/mol were analysed using pkCSM and DruLiTo, respectively. Based on the docking studies, it was confirmed that Rutin and Plebeiosides B were the most potent inhibitors of the main protease of SARS-CoV-2 with the best binding affinities of - 9.1 kcal/mol and - 8.9 kcal/mol, respectively. Further, the two compounds were analysed by studying their biological activity using the PASS webserver. Molecular dynamics simulation analysis was performed for the selected protein-ligand complexes to confirm their stability at 300 ns. MM-PBSA provided the basis for analyzing the affinity of the phytochemicals towards Mpro by calculating the binding energy, and secondary structure analysis indicated the stability of protease structure when it is bound to Rutin and Plebeiosides B. Altogether, the study identifies Rutin and Plebeiosides B to be potent Mpro inhibitors of SARS-CoV-2. Supplementary Information: The online version contains supplementary material available at 10.1007/s42535-021-00304-z.

In silico screening of antiviral compounds from Moringa oleifera for inhibition of SARS-CoV-2 main protease

COVID-19 as per early April 2021, has globally exceeded 129 million cases and is the cause of about 2.8 million deaths. Since the illness is known to have a wide array of symptoms, in addition to its ability to spread rapidly through contact and the complexity involved in developing drugs, there is an immediate need to look into alternative treatment regimes. This study was intended to identify potential antiviral compounds from Moringa oleifera against the selected target main protease (Mpro), which is vital for the survival of the virus. In silico molecular docking and dynamics was performed to determine a potential inhibitor against Mpro. Phytochemicals of Moringa olifera reported in literature were retrieved from public databases and employed for molecular docking studies against Mpro. PyRx software was used to perform docking analysis. Visualization of amino acid interactions between the ligand and target was performed using Maestro and Discovery studio visualizer to analyze the type of interactions. Compounds displaying high binding affinities were subjected for analysis of pharmacokinetic studies, later molecular dynamics (MD) and MM-PBSA studies was conducted over selected compounds using GROMACS. Rutin and Isorhamnetin-3-O-rutinoside, both flavonoids thoroughly studied for their medicinal properties showcased strong interactions and the highest binding affinity of −8.9 kcal/mol with the Mpro. The binding energy calculated employing MM-PBSA for Rutin and Isorhamnetin-3-O-rutinoside were −86.832 kJ/mol and −72.984 kJ/mol, respectively. The overall studies revealed that Rutin and Isorhamnetin-3-O-rutinoside are portenial in inhibiting the SARS-CoV-2 Mpro and can be validated through in-vitro and in-vivo studies.

Screening of natural compounds from Cyperus rotundus Linn against SARS-CoV-2 main protease (Mpro): An integrated computational approach.

Coronavirus disease 2019 (COVID-19) is a viral respiratory disease that has been spreading across the globe. The World Health Organization (WHO) declared it as a public health emergency. The treatment of COVID-19 has been hampered due to the lack of effective therapeutic efforts. Main Protease (Mpro) is a key enzyme in the viral replication cycle and its non-specificity to human protease makes it a potential drug target. Cyperus rotundus Linn, which belongs to the Cyperaceae family, is a traditional herbal medicine that has been widely studied for its antiviral properties. In this study, a computational approach was used to screen natural compounds from C. rotundus Linn using BIOVIA Discovery Suite and novel potential molecules against Mpro of SARS-CoV-2 were predicted. Molecular docking was performed using LibDock protocol and selected ligands were further subjected to docking analysis by CDOCKER. The docking scores of the selected ligands were compared with standard antiretroviral drugs such as lopinavir and ritonavir to assess their binding potentials. Interaction pharmacophore analysis was then performed for the compounds exhibiting good binding scores to evaluate their protein-ligand interactions. The selected protein-ligand complexes were subjected to molecular dynamics simulation for 50 ns. Results of binding free energy analysis revealed that two compounds-ß-amyrin and stigmasta-5,22-dien-3-ol-exhibited the best binding interactions and stability. Finally, absorption, distribution, metabolism, excretion, and toxicity (ADMET) studies were performed to understand the pharmacokinetic properties and safety profile of the compounds. The overall results indicate that the phytochemicals from Cyperus rotundus Linn, namely ß-amyrin and stigmasta-5,22-dien-3-ol, can be screened as potential inhibitors of SARS-CoV-2 Mpro.