N-Nitrosated N-hydroxyguanidines are nitric oxide-releasing diazeniumdiolates

N-Hydroxyguanidines can be nitrosatively converted to zwitterionic diazeniumdiolates of crystallographically-confirmed structure H2N+C[NHR][N(O)NO]–, whose hydrolytic dissociation at physiological pH leads to both NO and N2O; the results appear to account for the formation of the ‘potential intercellular nitric oxide carrier’ produced on exposing NG- hydroxy-L-arginine (a metabolic intermediate in mammalian NO biosynthesis) to aerobic NO.