Proposing a fungal metabolite-flaviolin as a potential inhibitor of 3CLpro of novel coronavirus SARS-CoV-2 identified using docking and molecular dynamics.

The novel SARS-CoV-2 is the etiological agent causing the Coronavirus disease 2019 (COVID-19), which continues to become an inevitable pandemic outbreak. Over a short span of time, the structures of therapeutic target proteins for SARS-CoV-2 were identified based on the homology modelled structure of similar virus, SARS-CoV that transmitted rapidly in 2003. Since the outset of the disease, the research community has been looking for a potential drug lead. Out of all the known resolved structures related to SARS-CoV-2; 3-chymotrypsin (3 C) like protease (3CLpro) is considered as an attractive anti-viral drug compound on the grounds of its role in viral replication and probable non-interactive competency to bind to any viral host protein. To the best of our knowledge, till date only one compound has been identified and tested in-vitro as a potent inhibitor of 3CLpro protein, addressed as N3 (PubChem Compound CID: 6323191) and is known to bind irreversibly to 3CLpro suppressing its activity. Using computational approach, we intend to identify a probable natural fungal metabolite to interact and inhibit 3CLpro. Here after performing docking and molecular dynamics of various small molecules derived as a secondary metabolite from fungi, we propose Flaviolin as potent inhibitor of 3CLpro of novel Coronavirus SARS-CoV-2.Communicated by Ramaswamy H. Sarma.