Background:

Danoprevir (R7227) is a potent and selective inhibitor of Hepatitis C Virus (HCV) NS3/4A protease, a chymotrypsin-like serine protease playing an essential role in the viral replication process of HCV, that non-covalently binds to and hence inhibits HCV NS3 protease with 50% inhibition concentration IC₅₀values ranging from 0.2 to 3.5 nM. X-ray crystallographic analysis has revealed that the cyclopropyl acylsulfonamide of danoprevir occupies the SI/SI’ pocket of HCV NS3 protease with the acyl carbonyl oxygen forming hydrogen bonds to Gly137 and Ser138 in the oxyanion hole of the protease active site and the acyl sulfonamide nitrogen forming a hydrogen bond with His57.

Reference

[1].Jiang Y, Andrews SW, Condroski KR, Buckman B, Serebryany V, Wenglowsky S, Kennedy AL, Madduru MR, Wang B, Lyon M, Doherty GA, Woodard BT, Lemieux C, Do MG, Zhang H, Ballard J, Vigers G, Brandhuber BJ, Stengel P, Josey JA, Beigelman L, Blatt L, Seiwert SD. Discovery of Danoprevir (ITMN-191/R7227), a Highly Selective and Potent Inhibitor of Hepatitis C Virus (HCV) NS3/4A Protease. J Med Chem. 2013 May 28. [Epub ahead of print]