3-Heterocyclyl quinolone inhibitors of the HCV NS5B polymerase

Graphical abstract The discovery and optimization of a novel class of quinolone small-molecules that inhibit NS5B polymerase, a key enzyme of the HCV viral life-cycle, is described. Our research led to the replacement of a hydrolytically labile ester functionality with bio-isosteric heterocycles. An X-ray crystal structure of a key analog bound to NS5B facilitated the optimization of this series of compounds to afford an increase in activity against the target enzyme and improved potency in the replicon assay. The discovery and optimization of a novel class of quinolone small-molecules that inhibit NS5B polymerase, a key enzyme of the HCV viral life-cycle, is described. Our research led to the replacement of a hydrolytically labile ester functionality with bio-isosteric heterocycles. An X-ray crystal structure of a key analog bound to NS5B facilitated the optimization of this series of compounds to afford increased activity against the target enzyme and in the cell-based replicon assay system.