Thermodynamic considerations on the formation of reactive species from hypochlorite, superoxide and nitrogen monoxide. Could nitrosyl chloride be produced by neutrophils and macrophages?
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 [Eo'(NOCl/NO., Cl) = 1.0 V] that is capable of nitrosylating organic compounds and thereby generating mutagens or promutagens.
Department of Chemistry, Louisiana State University, Baton Rouge 70803.
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Koppenol
D005609:Free Radicals; D006997:Hypochlorous Acid / Q000378:metabolism; D008264:Macrophages / Q000378:metabolism*; D008956:Models, Chemical; D009504:Neutrophils / Q000378:metabolism*; D009569:Nitric Oxide / Q000378:metabolism; D009589:Nitrogen Oxides / Q000378:metabolism*; D010084:Oxidation-Reduction; D013481:Superoxides / Q000378:metabolism; D013816:Thermodynamics
D005609:Free Radicals; D009589:Nitrogen Oxides; D013481:Superoxides; D009569:Nitric Oxide; D006997:Hypochlorous Acid; C087991:nitrosyl chloride