A theoretical survey to find potential natural compound for inhibition of binding the RBD domain to ACE2 receptor based on plant antivirals.

The spike protein of coronavirus is crucial in binding and arrival of the virus to the human cell via binding to the human ACE2 receptor. In this study, at first 25 antiviral phytochemicals were docked into the RBD domain of spike protein, and then all complexes and free RBD domains were separately subjected to molecular dynamics simulation for 100 ns and MM/PBSA binding free energy calculation. In this phase, four ligands were chosen as hit compounds and a natural compound database (NPASS) was screened based on high similarity with these ligands, and 367 ligands were found. Then the same previous procedure was repeated for these ligands and ADME properties were investigated. Finally, virtual screening and 4400 ns MD simulation and MM/PBSA calculation revealed that new ligands including NPC67959, NPC157855, NPC248793, and NPC216361 can inhibit the RBD domain of spike protein and we propose them as potential drugs for experimental studies.Communicated by Ramaswamy H. Sarma.