IDX-184

The outbreak of the second severe acute respiratory syndrome coronavirus (SARS-CoV-2) known as COVID-19 has caused global concern. No effective vaccine or treatment to control the virus has been approved yet. Social distancing and precautionary protocols are still the only way to prevent person-to-person transmission. We hope to identify anti-COVID-19 activity of the existing drugs to overcome this pandemic as soon as possible. The present study used HEX and AutoDock Vina softwares to predict the affinity of about 100 medicinal structures toward the active site of 3-chymotrypsin-like protease (3Clpro) and RNA-dependent RNA polymerase (RdRp), separately. Afterwards, MOE software and the pharmacophore-derived query methodology were employed to determine the pharmacophore model of their inhibitors. Tegobuvir (19) and compound 45 showed the best binding affinity toward RdRp and 3Clpro of SARS-CoV-2 in silico, respectively. Tegobuvir -previously applied for hepatitis C virus- formed highly stable complex with uncommon binding pocket of RdRp (E total: -707.91 Kcal/mol) in silico. In addition to compound 45, tipranavir (28) and atazanavir (26) as FDA-approved HIV protease inhibitors were tightly interacted with the active site of SARS-CoV-2 main protease as well. Based on pharmacophore modelling, a good structural pattern for potent candidates against SARS-CoV-2 main enzymes is suggested. Re-tasking or taking inspiration from the structures of tegobuvir and tipranavir can be a proper approach toward coping with the COVID-19 in the shortest possible time and at the lowest cost.Communicated by Ramaswamy H. Sarma.

During the past few months, mucormycosis has been associated with SARS-CoV-2 infections. Molecular docking combined with molecular dynamics simulation is utilized to test nucleotide-based inhibitors against the RdRps of SARS-CoV-2 solved structure and Rhizopus oryzae RdRp model built in silico. The results reveal a comparable binding affinity of sofosbuvir, galidesivir, ribavirin and remdesivir compared with the physiological nucleotide triphosphates against R. oryzae RdRp as well as the SARS-CoV-2 RdRp as reported before. Additionally, other compounds such as setrobuvir, YAK, IDX-184 and modified GTP compounds 2, 3 and 4 show potential calculated average binding affinities against R. oryzae RdRp. The present in silico study suggests the dual inhibition potential of the recommended drugs and compounds against SARS-CoV-2 and R. oryzae RdRps.