Design, synthesis, and evaluation of new type of l-amino acids containing pyridine moiety as nitric oxide synthase inhibitor Original Research Article

New amino acids 7–12 were designed and synthesized as candidate inhibitors of human nitric oxide synthase (NOS). The 2-aminopyridine-containing l-amino acids 8 had potent inhibitory activity toward all of the human NOS isozymes. However, the regioisomers 9 and 10, and 2-methylpyridine-containing compound 11 had much lower inhibitory activity. Human NOS isozymes were also inhibited by 7, which lacks an amino group on the pyridine moiety. A computational docking study was carried out to investigate the mechanism of the inhibitory effect.