Discovery and structure-activity relationship studies of novel alpha-ketoamide derivatives targeting the SARS-CoV-2 main protease.
Huang, C., Zeng, R., Qiao, J., Quan, B., Luo, R., Huang, Q., Guo, N., Li, Y., Long, X., Ma, R., Xia, A., Fang, Z., Wang, Y., Li, Y., Zheng, Y., Li, L., Lei, J., Yang, S.(2023) Eur J Med Chem 259: 115657-115657
- PubMed: 37517202 
- DOI: https://doi.org/10.1016/j.ejmech.2023.115657
- Primary Citation of Related Structures:  
8I30 - PubMed Abstract: 
The SARS-CoV-2 main protease (M pro , also named 3CL pro ) is a promising antiviral target against COVID-19 due to its functional importance in viral replication and transcription. Herein, we report the discovery of a series of α-ketoamide derivatives as a new class of SARS-CoV-2 M pro inhibitors. Structure-activity relationship (SAR) of these compounds was analyzed, which led to the identification of a potent M pro inhibitor (27h) with an IC 50 value of 10.9 nM. The crystal structure of M pro in complex with 27h revealed that α-ketoamide warhead covalently bound to Cys145s of the protease. In an in vitro antiviral assay, 27h showed excellent activity with an EC 50 value of 43.6 nM, comparable to the positive control, Nirmatrelvir. This compound displayed high target specificity for M pro against human proteases and low toxicity. It also possesses favorable pharmacokinetic properties. Overall, compound 27h could be a promising lead compound for drug discovery targeting SARS-CoV-2 M pro and deserves further in-depth studies.
Organizational Affiliation: 
Department of Biotherapy, Cancer Center and State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, Sichuan, 610041, China.