BPRSJ338 exhibits high potency of anti-SARS-CoV-2 activity and is in development for fighting COVID-19 as a first-in-class drug. BPRSJ338 also potently inhibits against broad-spectrum coronaviruses including SARS-CoV-2, SARS-CoV, HCoV-229E, HCoV-OC43, TGEV, FIPV and MHV. Related US and Taiwan patents have been granted. Therefore it is also applicable to fight against severe evolving coronaviruses in the future.