Virtual Screening and Molecular Docking of FDA Approved Antiviral Drugs for the Identification of Potential Inhibitors of SARS-CoV-2 RNA-MTase Protein

Background: SARS-CoV-2 is a novel coronavirus discovered in December 2019 and is responsible for pandemic disease COVID-19. In the absence of any available vaccines or drugs to combat the virus, it has caused enormous damage. Methods: An in-silico docking approach was applied to determine potential inhibitors of SARS-CoV-2 RNA-MTase by screening against a ligand library of FDA approved antiviral compounds. Results: Ten compounds including Daclatasvir, Pibrentasvir, Tenofovir, Velpatasvir, Grazoprevir, Ledipasvir, Elbasvir, Delavirdine, Nilutamide, and Ribavirin triphosphate showed a strong binding affinity with RNA-MTase of which Daclatasvir and Pibrentasvir exhibited the highest affinity.  Moreover, Daclatasvir, Grazoprevir, and Tenofovir, which have recently been reported to have a binding affinity with other SARS-CoV-2 proteins, showed good binding interactions with RNA-MTase, suggesting a role to act as dual inhibitors. Conclusion: The suggested antiviral compounds can tightly bind to RNA-MTase of SARS-Cov-2 and thus have the potential to be used against this deadly virus. Importantly, as FDA already approved, these drugs do not need to undergo toxicity evaluation.