A series of isatin derivatives were synthesized and tested against SARS CoV 3C-like protease. Substitutions at the N-1 and C-5 positions were examined to elucidate the differences in substrate binding sites of the rhinovirus 3C protease and SARS CoV 3C-like protease. Compound 5f shows significant inhibition with an IC50 of 0.37 μM. Further study showed that, unlike the irreversible covalent binding of isatin derivatives to human ...
