Identification of SARS-CoV-2 Mpro inhibitors containing P1’ 4-fluorobenzothiazole moiety highly active against SARS-CoV-2
Nobuyo Higashi‐Kuwata, Kohei Tsuji, Hironori Hayashi, Haydar Bulut, Maki Kiso, Masaki Imai, Hiromi Ogata-Aoki, Takahiro M. Ishii, Takuya Kobayakawa, Kenta Nakano, Nobutoki Takamune, Naoki Kishimoto, Shin-ichiro Hattori, Debananda Das, Yukari Uemura, Yosuke Shimizu, Manabu Aoki, Kazuya Hasegawa, Satoshi Suzuki, Akie Nishiyama · Nature Communications · 2023
Abstract COVID-19 caused by SARS-CoV-2 has continually been serious threat to public health worldwide. While a few anti-SARS-CoV-2 therapeutics are currently available, their antiviral potency is not sufficient. Here, we identify two orally available 4-fluoro-benzothiazole-containing small molecules, TKB245 and TKB248, which specifically inhibit the enzymatic activity of main protease (Mpro) of SARS-CoV-2 and significantly more potently block the infectivity and replication of various SARS-CoV-2 strains than nirmatrelvir, molnupiravir, and ensitrelvir in cell-based assays employing various target cells. Both compounds also block the replication of Delta and Omicron variants in human-ACE2-knocked-in mice. Native mass spectrometric analysis reveals that both compounds bind to dimer Mpro, apparently promoting Mpro dimerization. X-ray crystallographic analysis shows that both compounds bind to Mpro’s active-site cavity, forming a covalent bond with the catalytic amino acid Cys-145 with the 4-fluorine of the benzothiazole moiety pointed to solvent. The data suggest that TKB245 and TKB248 might serve as potential therapeutics for COVID-19 and shed light upon further optimization to develop more potent and safer anti-SARS-CoV-2 therapeutics.