37] Reaction of peroxynitrite and hydrogen peroxide to produce singlet molecular oxygen (1Δg)

Abstract

This chapter discusses the reaction of peroxynitrite and hydrogen peroxide to produce singlet molecular oxygen ( 1 Δ g ). Peroxynitrite (ONOO – ) is a biologically active species produced by the reaction of the superoxide anion radical (O 2 – ) with nitric oxide (NO . ). The decomposition of ONOO– generates the hydroxyl radical, a strong oxidant. Nitric oxide, identified as the endothelium-derived relaxing factor (EDRF), is formed by conversion of L -arginine to L -citrulline by NO synthase. The production of singlet molecular oxygen [O 2 ( 1 Δ g )] in the reaction of ONOO – with H 2 O 2 , uses (1) chemiluminescence (CL) measurement of dimol or monomol light emission in the visible and infrared spectral regions, and (2) water-soluble chemical trap, the sodium salt of anthracene 9,10-diyldiethyl disulfate (EAS), to provide evidence for the formation of O 2 ( l Δ g ) in this system. Peroxynitrite is synthesized in a quenched-flow reactor. The singlet molecular oxygen generation in the peroxynitrite-H 2 O 2 reaction is monitored by chemical trapping with EAS.