Anti-influenza virus activity of catechin derivatives

Six novel analogs of epigallocatechin gallate (EGCG) were designed and demonstrated a dose-dependent inhibition of human influenza A virus in several in vitro assays. The analogs exhibited obvious antiviral activity in both MDCK cell culture assay and neuraminidase inhibition assay. To estimate the order of magnitude of the activity for the analogs, the concentration causing 50% inhibition of six analogs and EGCG for influenza A virus were determined by plotting percentage inhibition against the concentration of each analog. The analogs and EGCG showed a similar inhibition against influenza A Virus. The results show that the hydroxyl substituents on the A-ring and B-ring are not critical for anti-influenza virus activity.