Cooxidation of styrene by horseradish peroxidase and glutathione.

Styrene is oxidized to styrene oxide and benzaldehyde in the presence of glutathione, horseradish peroxidase, and hydrogen peroxide. Styrene oxide is not formed if any one of these reaction components is omitted or if oxygen is exluded from the reaction. The oxygen atom in the styrene oxide derives from molecular oxygen rather than from hydrogen peroxide. Oxidation of trans[1-3H]styrene yields the epoxide in which the deuterium stereochemistry is completely scrambled. The results indicate that the glutathione thiyl radical directly or indirectly activates molecular oxygen to a species that cooxidizes styrene. The one-electron oxidation of glutathione thus may promote the cooxidation of physiological substrates.