X77 is a potent non-covalent inhibitor of the main protease of SARS-CoV-2 (SARS-CoV-2 Mpro). X77 binds to SARS-CoV-2 Mpro with a Kd value of 0.057 μM[2].IC50 & Target: Kd: 0.057 μM (SARS-CoV-2 Mpro)[2]In Vitro: X77 can bind to SARS-CoV-2 Mpro (PDB code: 6W63). SARS-CoV-2 Mpro (PDB code: 6W63) is the main protease of SARS-CoV-2 and is one of the most important drug targets among coronaviruses.