Abstract
A series of 2,3,5-trisubstituted-1,2,4-thiadiazol-2-ium salts is reported by Vertex Pharmaceuticals to possess inhibitory properties against NS3, a multifunctional (serine protease and NTPase/helicase) protein of hepatitis C virus (HCV), the causative agent of non-A, non-B hepatitis. These compounds were prepared by simple synthetic procedures and assayed in vitro for their inhibitory properties of different enzymatic activity of NS3, such as the unwinding assay, the spectrophotometric ATPase assay, as well as the HPLC ATPase activity assay. Some of them showed in vitro inhibitory activity in the low micromolar range, making them interesting leads for the development of more efficient HCV helicase inhibitors. No in vivo data are presented.