Oxidation of N-hydroxyguanidines by copper(II): model systems for elucidating the physiological chemistry of the nitric oxide biosynthetic intermediate N-hydroxyl-l-arginine

The redox chemistry of models of N-hydroxy-l-arginine, the biosynthetic intermediate in the synthesis of NO by the family of nitric oxide synthase enzymes, has been explored experimentally and theoretically. The oxidation of N-hydroxyguanidine model compounds by Cu(II) was studied as a means of establishing possible metabolic fates and intermediates of this important functional group. These studies indicate than an iminoxyl intermediate is formed and may be an important biological species generated from N-hydroxyguanidines including N-hydroxy-l-arginine.