biostudies-literatureAshraf-Uz-Zaman MNational Institute of Allergy and Infectious DiseasesNIAID NIH HHSNational Cancer InstituteNCI NIH HHSCancer Prevention and Research Institute of TexasNIGMS NIH HHSNIH HHS715-731https://www.ebi.ac.uk/biostudies/studies/S-EPMC10922772biostudies-literatureUnknown10(2)Highly contagious SARS-CoV-2 coronavirus has infected billions of people worldwide with flu-like symptoms since its emergence in 2019. It has caused deaths of several million people. The viral main protease (Mpro) is essential for SARS-CoV-2 replication and therefore a drug target. Several series of covalent inhibitors of Mpro were designed and synthesized. Structure-activity relationship studies show that (1) several chloroacetamide- and epoxide-based compounds targeting Cys145 are potent inhibitors with IC₅₀ values as low as 0.49 μM and (2) Cys44 of Mpro is not nucleophilic for covalent inhibitor design. High-resolution X-ray studies revealed the protein-inhibitor interactions and mechanisms of inhibition. It is of interest that Cys145 preferably attacks the more hindered C_α atom of several epoxide inhibitors. Chloroacetamide inhibitor <b>13</b> and epoxide inhibitor <b>30</b> were found to inhibit cellular SARS-CoV-2 replication with an EC₆₈ (half-log reduction of virus titer) of 3 and 5 μM. These compounds represent new pharmacological leads for anti-SARS-CoV-2 drug development.ACS infectious diseasesDesign, Synthesis, X-ray Crystallography, and Biological Activities of Covalent, Non-Peptidic Inhibitors of SARS-CoV-2 Main Protease.PMC10922772R21AI159323R21 AI159323RP220232R01 CA266057P30 GM133893R01CA266057S10 OD030246Chua TKAvadhanula VLi XPiedra PAYao YMishra CBAshraf-Uz-Zaman MMoku BKSong YfalseDesign, Synthesis, X-ray Crystallography, and Biological Activities of Covalent, Non-Peptidic Inhibitors of SARS-CoV-2 Main Protease.Highly contagious SARS-CoV-2 coronavirus has infected billions of people worldwide with flu-like symptoms since its emergence in 2019. It has caused deaths of several million people. The viral main protease (Mpro) is essential for SARS-CoV-2 replication and therefore a drug target. Several series of covalent inhibitors of Mpro were designed and synthesized. Structure-activity relationship studies show that (1) several chloroacetamide- and epoxide-based compounds targeting Cys145 are potent inhibitors with IC₅₀ values as low as 0.49 μM and (2) Cys44 of Mpro is not nucleophilic for covalent inhibitor design. High-resolution X-ray studies revealed the protein-inhibitor interactions and mechanisms of inhibition. It is of interest that Cys145 preferably attacks the more hindered C_α atom of several epoxide inhibitors. Chloroacetamide inhibitor <b>13</b> and epoxide inhibitor <b>30</b> were found to inhibit cellular SARS-CoV-2 replication with an EC₆₈ (half-log reduction of virus titer) of 3 and 5 μM. These compounds represent new pharmacological leads for anti-SARS-CoV-2 drug development.2024-01-01T00:00:00Z2024 Feb2025-04-04T01:37:19.408Z2025-04-04T01:37:19.408ZS-EPMC109227723819210910.1021/acsinfecdis.3c00565