Archives of Biochemistry and Biophysics 1999-07-15

Reactive oxygen species in the aerobic decomposition of sodium hydroxymethanesulfinate.

S V Makarov, C Mundoma, S A Svarovsky, X Shi, P M Gannett, R H Simoyi

Index: Arch. Biochem. Biophys. 367(2) , 289-96, (1999)

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Abstract

Sodium hydroxymethanesulfinate, (HOCH2SO2Na, HMS) is relatively stable in aqueous alkaline environments, but rapidly decomposes in acidic medium to give a variety of products that include sulfur dioxide. A detailed kinetic and mechanistic study of the decomposition of HMS in slightly acidic medium has shown a process that produces dithionite, S2O2-4, which is preceded by an induction period which persists for as long as molecular oxygen is present in the reaction solution. The complete consumption of molecular oxygen is a prerequisite for the formation of S2O2-4. Among some of the intermediates detected in the decomposition of HMS is the sulfite radical, SO-3. Comparisons are made between the decomposition mechanisms of thiourea dioxide (aminoiminomethanesulfinic acid) and HMS.Copyright 1999 Academic Press.