Catecholamines oxidation by xanthine oxidase

Aluminum Facilitation of the Iron-Mediated Oxidation of DOPA to Melanin

“…[21][22][23] Melanization can occur as a consequence of cell oxidative stress such as inflammation or PD. 24,25 Recent studies suggest that neuromelanin may be a double-edged sword, having the potential to be either cytotoxic or neuroprotective depending upon the cellular environment, such as the concentration of iron and the interactions between dopamine, neuromelanin and iron. 22,23,26,27 DOPA, biosynthesized from tyrosine and as a dopamine precursor, is a major treatment for the symptoms of PD and can synthesize melanin through a complex series of enzymatic and chemical reactions.…”

“…38 The H2O2 level tends to rise particularly with aging and PD when the level of glutathione peroxidase as well as those of other detoxifying enzymes is considerably lower. 40 In the presence of H2O2, tyrosinase, 29 lipoxygenase, 31,39 cytochrome c, 40 and xanthine oxidase 24 are able to produce melanins from catecholamine oxidation. Since tyrosinase has not been found in the brain, the synthesis of neuromelanin by autooxidation of catecholamine and other enzymes is considered.…”

“…Since tyrosinase has not been found in the brain, the synthesis of neuromelanin by autooxidation of catecholamine and other enzymes is considered. 24,40,42 The analysis techniques of spectrophotometry and cyclic voltammetry are very useful and convenient for determining the inter-products and monitoring the reaction process. In the present study, we examined the effects of aluminum ions on iron-induced DOPA to produce melanin under mildly acidic conditions and the cooperation of aluminum and iron ions on the conversion of DC, which is a key step in biosynthesis of melanin.…”

A new approach to studying the autoxidation of adrenaline: possibility of the determination of superoxide dismutase activity and the antioxidant properties of various preparations by polarography

“…1). Специфические ферменты этого пути окисления адреналина не выявлены, но образующиеся продукты идентифицированы, и известны ферменты их утилизирующие [3][4][5][6][7]. Удаление продуктов хиноидного окисления адреналина и других аминохромов происходит с участием ферментов глутатион-S-трансферазы [3,4] и хинонредуктаз [5].…”

“…Удаление продуктов хиноидного окисления адреналина и других аминохромов происходит с участием ферментов глутатион-S-трансферазы [3,4] и хинонредуктаз [5]. Такой адреналиновый тест может использоваться для анализа активности эпоксид гидролаз, липаз, эстераз [6] и ксантиноксидазы [7]. Согласно химической структуре и, соответственно своим свойствам, адреналин является донором электронов [8] и эта его функция реализуется именно в процессе хиноидного окисления.…”