Abstract
A novel coronavirus [severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), or 2019 novel coronavirus] has been identified as the pathogen of coronavirus disease 2019. The main protease (M(pro) , also called 3-chymotrypsin-like protease) of SARS-CoV-2 is a potential target for treatment of COVID-19. A M(pro) homodimer structure suitable for docking simulations was prepared using a crystal structure (PDB ID: 6Y2G; resolution 2.20 Å). Structural refinement was performed in the presence of peptidomimetic α-ketoamide inhibitors, which were previously disconnected from each Cys145 of the M(pro) homodimer, and energy calculations were performed. Structure-based virtual screenings were performed using the ChEMBL database. Through a total of 1 485 144 screenings, 64 potential drugs (11 approved, 14 clinical, and 39 preclinical drugs) were predicted to show high binding affinity with M(pro) . Additional docking simulations for predicted compounds with high binding affinity with M(pro) suggested that 28 bioactive compounds may have potential as effective anti-SARS-CoV-2 drug candidates. The procedure used in this study is a possible strategy for discovering anti-SARS-CoV-2 drugs from drug libraries that may significantly shorten the clinical development period with regard to drug repositioning.