Manganese catalysis of dopamine oxidation.

摘要: Manganese catalysis of the oxidation dopamine by air was studied as part an investigation possible manganese intoxication amongst a group Aborigines living on manganese-rich soil Groote Eylandt, in Northern Territory Australia. significantly increased rate dopamine, and complexes with some purines were especially efficient catalysts. An mechanism, involving manganese(II)/(III) redox couple semiquinone free radical intermediate, is proposed. Stoichiometric hydrogen peroxide produced oxidation, products highly toxic to marine diatom Nitzschia closterium. Hydrogen superoxide did not oxidize at physiological pH. Some electrophilic compounds, including ascorbic acid, dehydroascorbic acid thiamine, effectively inhibited oxidation. The Eylandt are likely be deficient (vitamin C) thiamine B1), these deficiencies, well their lifestyle, may predispose them intoxication.