Structure-activity relationship studies of thiazole-based derivatives leading to the identification of novel and potent SARS-CoV-2 main protease inhibitors.
Yin, W., Kong, W.P., Leung, S.L., Hung, C.H., Wong, K.Y.(2025) Eur J Med Chem 297: 117952-117952
- PubMed: 40644922 
- DOI: https://doi.org/10.1016/j.ejmech.2025.117952
- Primary Citation of Related Structures:  
9M2V - PubMed Abstract: 
The COVID-19 pandemic has highlighted the need for effective antiviral agents targeting SARS-CoV-2. This study presents the development of thiazole-based inhibitors against SARS-CoV-2 Main Protease, a key enzyme for viral replication. Using Masitinib and MAC-5576 as leads, we designed 29 compounds featuring a pyridinyl ester for covalent binding to Cys145 and a thiazole core for S2 subsite interaction. Structure-activity relationship (SAR) analysis identified the pyridinyl ester as a critical pharmacophore, with the thiazole core providing superior inhibition compared to oxazole. Compound MC12 (IC 50 = 77.7 ± 14.1 nM) demonstrated inhibitory activities comparable to Nirmatrelvir (IC 50 = 58.4 ± 8.6 nM). Mass spectrometry and X-ray crystallography confirmed reversible covalent binding of MC compounds to SARS-CoV-2 Main Protease. These compounds also showed low cytotoxicity and dual inhibition of SARS-CoV and SARS-CoV-2 M pro . Thiazole-based compounds thus emerge as promising leads for developing potent and safe SARS-CoV-2 M pro inhibitors.
- State Key Laboratory of Chemical Biology and Drug Discovery, Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Kowloon, Hong Kong, China.
Organizational Affiliation: 
















