Improved replicon cellular activity of non-nucleoside allosteric inhibitors of HCV NS5B polymerase: from benzimidazole to indole scaffolds.

Benzimidazole-based allosteric inhibitors of the hepatitis C virus (HCV) NS5B polymerase were diversified to a variety of topologically related scaffolds. Replacement of the polar benzimidazole core by lipophilic indoles led to inhibitors with improved potency in the cell-based subgenomic HCV replicon system. Transposing the indole scaffold into a previously described series of benzimidazole-tryptophan amides generated the most potent inhibitors of HCV RNA replication in cell culture reported to date in this series (EC(50) approximately 50 nM).