B-ring modified aurones as promising allosteric inhibitors of hepatitis C virus RNA-dependent RNA polymerase.

Following our recent report showing the potential of naturally occurring aurones (2-benzylidenebenzofuran-3(2H)-ones) as anti-hepatitis C virus (HCV) agents, efforts were continued in order to refine the structural requirements for the inhibitory effect on HCV RNA-dependent RNA polymerase (RdRp). In this study, we targeted the B-ring moiety of aurones with the aim to improve structural features associated with higher inhibition of the targeted polymerase. In vitro evaluation of the RdRp inhibitory activity of the 37 newly synthesized compounds pointed out that the replacement of the B-ring with an N-substituted indole moiety induced the highest inhibitory effect.