Mischfunktionelle Oxygenierungen IV

Abstract

The mechanism of aerobic hydroxylation in the presence of peroxidase and dihydroxyfumarate has been studied. Reduction of molecular oxygen proceeds by the dihydroxyfumarate semichinone and leads to the formation of the O₂H radical which is reduced to an “oxen atom” as hydroxylating particle. In the peroxidase/dihydroxyfumarate/oxygen system OH radicals are also involved. Since they cannot originate from H₂O₂ a reduction of oxen atoms to OH radicals has to be assumed. Manganese (II) ions react with oxygen radicals and thereby inhibit hydroxylations by oxen atoms and OH radicals. The reactions involved in the peroxidase/dihydroxyfumarate/oxygen system are summarized in a diagrammatic scheme.