Thermodynamic considerations on the formation of reactive species from hypochlorite, superoxide and nitrogen monoxide Could nitrosyl chloride be produced by neutrophils and macrophages?

Abstract

Hypohalous acids are poor one‐electron oxidizing agents, such that reactions with hydrogen peroxide to yield radical species are not feasible. However, the oxidation of superoxide by hypohalous acids can be a source of hydroxyl or haline radicals. The oxidation of nitrogen monoxide by hypochlorous acid is favourable, but in all likelihood cannot compete with the diffusion‐controlled reaction with superoxide to yield peroxynitrite. The reaction of the latter with hypochlorous acid may lead to nitrosyl chloride, a strongly oxidizing agent [E°′(NOCl/NO•, Cl) = 1.0 V] that is capable of nitrosylating organic compounds and thereby generating mutagens or promutagens.