The SARS-CoV-2 3CL protease (3CLpro) shows a high similarity with 3CL proteases of other beta-coronaviruses, such as SARS and MERS. It is the main enzyme involved in generating various non-structural proteins that are important for viral replication and is one of the most important proteins responsible for SARS-CoV-2 virulence. In this study, we have conducted an ensemble docking of molecules from the DrugBank database using both the crystallographic structure of the SARS-CoV-2 3CLpro, as well as five conformations obtained after performing a cluster analysis of a 300 ns molecular dynamics (MD) simulation. This procedure elucidated the inappropriateness of the active site for non-covalent inhibitors, but it has also shown that there exists an additional, more favorable, allosteric binding site, which could be a better target for non-covalent inhibitors, as it could prevent dimerization and activation of SARS-CoV-2 3CLpro. Two such examples are radotinib and nilotinib, tyrosine kinase inhibitors already in use for treatment of leukemia and which binding to the newly found allosteric binding site was also confirmed using MD simulations. Communicated by Ramaswamy H. Sarma Graphical Abstract

The complementarity principle is a well-established concept in the field of chemistry and biology. This concept is widely studied as the lock-and-key relationship between two structures, such as en... Graphical abstract

Background: The SARS-CoV-2 3CLpro is one of the primary targets for designing new and repurposing known drugs. Methodology: A virtual screening of molecules from the Natural Product Atlas was perfo... Graphical abstract

Kyasanur forest disease (KFD) is a tick-borne, neglected tropical disease, caused by KFD virus (KFDV) which belongs to Flavivirus (Flaviviridae family). This emerging viral disease is a major threat to humans. Currently, vaccination is the only controlling method against the KFDV, and its effectiveness is very low. An effective control strategy is required to combat this emerging tropical disease using the existing resources. In this regard, in silico drug repurposing method offers an effective strategy to find suitable antiviral drugs against KFDV proteins. Drug repurposing is an effective strategy to identify new use for approved or investigational drugs that are outside the scope of their initial usage and the repurposed drugs have lower risk and higher safety compared to de novo developed drugs, because their toxicity and safety issues are profoundly investigated during the preclinical trials in human/other models. In the present work, we evaluated the effectiveness of the FDA approved and natural compounds against KFDV proteins using in silico molecular docking and molecular simulations. At present, no experimentally solved 3D structures for the KFD viral proteins are available in Protein Data Bank and hence their homology model was developed and used for the analysis. The present analysis successfully developed the reliable homology model of NS3 of KFDV, in terms of geometry and energy contour. Further, in silico molecular docking and molecular dynamics simulations successfully presented four FDA approved drugs and one natural compound against the NS3 homology model of KFDV. Communicated by Ramaswamy H. Sarma

Deciphering the ethnopharmacological importance is one of the prime steps towards understanding the indigenous traditional medicines practised over the centuries. With the advent of modern techniques, it is possible to unravel and explore the hidden ethnopharmacological benefits, comprising complex bioactive compounds of substantial health benefits and together it helps to treat the complex diseases without any side effects as seen in the case of modern synthetic drugs. In this concern, the present study aims to identify the ethnomycologically significant mycocompounds derived from the fruiting body of wild edible macrofungi, Lentinus squarrosulus that contain a vast array of compounds with notable edibility and a wide spectrum of medicinal applications. Proper authentication of mushroom taxonomy was exclusively done using macro and microscopic observations combining ITS DNA-based methods. Further, the isolate was subjected to fractionation in different solvent systems for mycochemical examination followed by GC–MS analysis. A total of 38 mycocompounds were identified through GC–MS and further subjected to in silico studies for drug-likeness, bioactivity and ADMET predictions to explore the druggability of mycocompounds. In silico analysis revealed 10 mycocompounds having good drug-likeness and ADMET properties. Altogether, the present study explored the ethnomycological potential of L. squarrosulus and identified potential mycocompounds.