LAUSR

Abstract SARS‐CoV‐2 wreaks havoc around the world, triggering the COVID‐19 pandemic. It has been confirmed that the endoribonuclease NSP15 is crucial to the viral replication, and thus identified as a potential drug target against COVID‐19. The NSP15 protein was used as the target to conduct high‐throughput virtual screening on 30,926 natural products from the NPASS database to identify potential NSP15 inhibitors. And 100 ns molecular dynamics simulations were performed on the NSP15 and NSP15‐NPC198199 system. In all, 10 natural products with high docking scores with NSP15 protein were obtained, among which compound NPC198199 scored the highest. The analysis of the binding mode between NPC198199 and NSP15 found that NPC198199 would form H‐bond interactions with multiple key residues at the catalytic site. Subsequently, a series of post‐dynamics simulation analyses (including RMSD, RMSF, PCA, DCCM, RIN, binding free energy, and H‐bond occupancy) were performed to further explore inhibitory mechanism of compound NPC198199 on NSP15 protein at the molecular level. The research strongly indicates that the 10 natural compounds screened can be used as potential inhibitors of NSP15, and provides valuable information for the subsequent drug discovery of anti‐SARS‐CoV‐2. Practical applications Natural products play an important role in the treatment of many difficult diseases. In this study, high‐throughput virtual screening technology was used to screen the natural product database to obtain potential inhibitors against endoribonuclease NSP15. The binding mechanism between natural products and NSP15 was investigated at the molecular level by molecular dynamics technology so that it is expected to become candidate drugs for the treatment of SARS‐CoV‐2. We hope that our research can provide new clue to combat COVID‐19 and overcome the epidemic situation as soon as possible.