ML2006a4 is an orally active inhibitor for SARS-CoV-2 main protease ( M pro ) with IC 50 in picomolare value. ML2006a4 is cell permeable and antiviral active, that inhibits replication in SARS-CoV-2 in cells Huh7.5.1-ACE2-TMPRSS2 (Huh7.5.1++) in picomolare level