Novel macrocyclic HCV NS3 protease inhibitors derived from a-amino cyclic boronates

A novel series of P2-P4 macrocyclic HCV NS3/4A protease inhibitors with a-amino cyclic boronates as warheads at the P1 site was designed and synthesized. When compared to their linear analogs, these macrocyclic inhibitors exhibited a remarkable improvement in cell-based replicon activities, with compounds 9a and 9e reaching sub-micromolar potency in replicon assay. The SAR around a-amino cyclic boronates clearly established the influence of ring size, chirality and of the substitution pattern. Furthermore, X-ray structure of the co-crystal of inhibitor 9a and NS3 protease revealed that Ser-139 in the enzyme active site traps boron in the warhead region of 9a, thus establishing its mode of action

Synthesis and evaluation of novel a-amino cyclic boronates as inhibitors of HCV NS3 protease

We have designed and synthesized a novel series of alpha-amino cyclic boronates and incorporated them successfully in several acyclic templates at the P1 position. These compounds are inhibitors of the HCV NS3 serine protease, and structural studies show that they inhibit the NS3 protease by trapping the Ser-139 hydroxyl group in the active site. Synthetic methodologies and SARs of this series of compounds are described