Angeli's salt (Na2N2O3) is a precursor of HNO and NO: a voltammetric study of the reactive intermediates released by Angeli's salt decomposition.
Under physiological conditions, it is usually accepted that the aerobic decomposition of Angeli's salt produces nitrite (NO(2)(-)) and nitroxyl (HNO), which dimerizes and leads to N(2)O. No consensus has yet been established on the formation of nitric oxide (NO) and/or peroxynitrite (ONOO(-)) by Angeli's salt. Because this salt has recently been shown to have pharmacological properties for the treatment of cardiovascular diseases, identification of its follow-up reactive intermediates is of increasing importance. In this work, we investigated the decomposition mechanism of Angeli's salt by voltammetry performed at platinized carbon fiber microelectrodes. By following the decomposition process of Angeli's salt, we showed that the mechanism depends on the experimental conditions. Under aerobic neutral and slightly alkaline conditions, the formation of HNO, NO(2)(-), but also of nitric oxide NO was demonstrated. In strongly alkaline buffer (pH>10), we observed the formation of peroxynitrite ONOO(-) in the presence of oxygen. These electrochemical results are supported by comparison with UV spectrophotometry data.
Amatore
Christian
C
Ecole Normale Supérieure, Département de Chimie, UMR CNRS-ENS-UPMC 8640 Pasteur, 24 rue Lhomond, 75231 Paris Cedex 05, France. Christian.Amatore@ens.fr
Arbault
Stéphane
S
Ducrocq
Claire
C
Hu
Shenghua
S
Tapsoba
Issa
I
D004563:Electrochemistry; D005609:Free Radicals; D006863:Hydrogen-Ion Concentration; D009569:Nitric Oxide / Q000737:chemistry*; D020030:Nitric Oxide Donors / Q000737:chemistry; D009573:Nitrites / Q000737:chemistry* / Q000378:metabolism*; D009589:Nitrogen Oxides / Q000737:chemistry*; D010100:Oxygen / Q000737:chemistry / Q000502:physiology; D030421:Peroxynitrous Acid / Q000737:chemistry; D012492:Salts / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet
D005609:Free Radicals; D020030:Nitric Oxide Donors; D009573:Nitrites; D009589:Nitrogen Oxides; D012492:Salts; D030421:Peroxynitrous Acid; C021229:oxyhyponitrite; D009569:Nitric Oxide; C039900:nitroxyl; D010100:Oxygen