Discovery of a series of aminopiperidines as novel iNOS inhibitors.

Nitric oxide (NO), a mediator of various physiological and pathophysiological processes, is synthesized by three isozymes of nitric oxide synthase (NOS). Potential candidate clinical drugs should be devoid of inhibitory activity against endothelial NOS (eNOS), since eNOS plays an important role in maintaining normal blood pressure and flow. A new series of aminopiperidines as potent inhibitors of iNOS were identified from a HTS lead. From this study, we identified compound 33 as a potent iNOS inhibitor, with >25-fold selectivity over eNOS and 16-fold selectivity over nNOS.