Identification of SARS-CoV-2 Mpro inhibitors containing P1' 4-fluorobenzothiazole moiety highly active against SARS-CoV-2 PMID: 36841831

ADC Targets in Oncology

2026-04-10

Identification of SARS-CoV-2 Mpro inhibitors containing P1' 4-fluorobenzothiazole moiety highly active against SARS-CoV-2

Nat Commun. 2023 Feb 25;14(1):1076. doi: 10.1038/s41467-023-36729-0.

Nobuyo Higashi-Kuwata ¹ , Kohei Tsuji ² , Hironori Hayashi ³ , Haydar Bulut ⁴ , Maki Kiso ⁵ , Masaki Imai ⁵ ⁶ , Hiromi Ogata-Aoki ⁴ , Takahiro Ishii ² , Takuya Kobayakawa ² , Kenta Nakano ⁷ , Nobutoki Takamune ⁸ , Naoki Kishimoto ⁸ , Shin-Ichiro Hattori ¹ , Debananda Das ⁴ , Yukari Uemura ⁹ , Yosuke Shimizu ⁹ , Manabu Aoki ⁴ , Kazuya Hasegawa ¹⁰ , Satoshi Suzuki ¹¹ , Akie Nishiyama ¹¹ , Junji Saruwatari ¹² , Yukiko Shimizu ⁷ , Yoshikazu Sukenaga ¹ , Yuki Takamatsu ¹ , Kiyoto Tsuchiya ¹³ , Kenji Maeda ¹ , Kazuhisa Yoshimura ¹⁴ , Shun Iida ¹⁵ , Seiya Ozono ¹⁵ , Tadaki Suzuki ¹⁵ , Tadashi Okamura ⁷ , Shogo Misumi ⁸ , Yoshihiro Kawaoka ⁵ ⁶ ¹⁶ , Hirokazu Tamamura ² , Hiroaki Mitsuya ¹⁷ ¹⁸ ¹⁹

Affiliations

1. Department of Refractory Viral Diseases, National Center for Global Health and Medicine Research Institute, Tokyo, Japan.
2. Department of Medicinal Chemistry, Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University, Tokyo, Japan.
3. Department of Infectious Diseases, International Research Institute of Disaster Science, Tohoku University, Miyagi, Japan.
4. Experimental Retrovirology Section, HIV and AIDS Malignancy Branch, National Cancer Institute, NIH, Bethesda, MD, USA.
5. Division of Virology, Institute of Medical Science, University of Tokyo, Tokyo, Japan.
6. The Research Center for Global Viral Diseases, National Center for Global Health and Medicine Research Institute, Tokyo, Japan.
7. Department of Laboratory Animal Medicine, Research Institute, National Center for Global Health and Medicine, Tokyo, Japan.
8. Department of Environmental and Molecular Health Sciences, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan.
9. Center for Clinical Sciences, National Center for Global Health and Medicine, Tokyo, Japan.
10. Structural Biology Division, Japan Synchrotron Radiation Research Institute, Hyogo, Japan.
11. Department of Infectious Diseases, Tohoku University Graduate School of Medicine, Miyagi, Japan.
12. Division of Pharmacology and Therapeutics, Graduate School of Pharmaceutical Sciences, Kumamoto University, Kumamoto, Japan.
13. AIDS Clinical Center, National Center for Global Health and Medicine, Tokyo, Japan.
14. Tokyo Metropolitan Institute of Public Health, Tokyo, Japan.
15. Department of Pathology, National Institute of Infectious Diseases, Tokyo, Japan.
16. Influenza Research Institute, Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, WI, USA.
17. Department of Refractory Viral Diseases, National Center for Global Health and Medicine Research Institute, Tokyo, Japan. [email protected].
18. Experimental Retrovirology Section, HIV and AIDS Malignancy Branch, National Cancer Institute, NIH, Bethesda, MD, USA. [email protected].
19. Kumamoto University Hospital, Kumamoto, Japan. [email protected].

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 (M^pro) 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 M^pro, apparently promoting M^pro dimerization. X-ray crystallographic analysis shows that both compounds bind to M^pro'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.