Depeptidization efforts on α-ketoamide inhibitors of HCV NS3-4A serine protease: Effect on HCV replicon activity

Depeptidization efforts of the P 3 –P 2 region of P 3 capped α-ketoamide inhibitor of HCV NS3 serine protease 1 are reported. We clearly established that N-methylation of the P 2 nitrogen and modification of the P 2 ′ carboxylic acid terminus were essential for activity in the replicon assay.