Akagawa M, Suyama K
Department of Applied Bioorganic Chemistry, Division of Life Science, Graduate School of Agricultural Science, Tohoku University, Sendai, Japan.
Eur J Biochem. 2001 Apr;268(7):1953-63. doi: 10.1046/j.1432-1327.2001.02068.x.
Polyphenols in several oxidation systems gained amine oxidase-like activity, probably due to the formation of the corresponding quinones. In the presence of Cu(II), o- and p-phenolic compounds exhibited amine oxidase-like activity, whereas only the o-phenolic compounds showed the activity in the presence of 1,1-diphenyl-2-picrylhydrazyl radical. The activity was determined by measuring the conversion of benzylamine to benzaldehyde by HPLC. Moreover, gallic acid, chlorogenic acid, and caffeic acid, which are plant polyphenols, converted the lysine residue of bovine serum albumin to alpha-amino-adipic semialdehyde residue, indicating lysyl oxidase-like activity. We also characterized the activity of pyrocatechol, hydroquinone, and pyrogallol in the presence of Cu(II). The oxidative deamination was accelerated at a higher pH, and required O2 and transition metal ions. Furthermore, EDTA markedly inhibited the reaction but not beta-aminopropionitrile, which is a specific inhibitor of lysyl oxidase. Catalase significantly inhibited the oxidation, implying the participation of hydroxyl radical in the reaction, but superoxide dismutase stimulated the oxidation, probably due to its radical formation activity. We discussed the mechanism of the oxidative deamination by polyphenols and the possible significance of the activity for biological systems.
在几种氧化体系中，多酚获得了胺氧化酶样活性，这可能是由于相应醌的形成。在铜（II）存在下，邻位和对位酚类化合物表现出胺氧化酶样活性，而在1,1-二苯基-2-苦基肼自由基存在下只有邻位酚类化合物显示出该活性。通过高效液相色谱法测量苄胺向苯甲醛的转化来测定该活性。此外，作为植物多酚的没食子酸、绿原酸和咖啡酸，将牛血清白蛋白的赖氨酸残基转化为α-氨基己二酸半醛残基，表明具有赖氨酰氧化酶样活性。我们还表征了在铜（II）存在下邻苯二酚、对苯二酚和连苯三酚的活性。氧化脱氨在较高pH下加速，并且需要氧气和过渡金属离子。此外，乙二胺四乙酸显著抑制该反应，但对作为赖氨酰氧化酶特异性抑制剂的β-氨基丙腈没有抑制作用。过氧化氢酶显著抑制氧化反应，表示羟基自由基参与了该反应，但超氧化物歧化酶刺激了氧化反应，这可能是由于其自由基形成活性。我们讨论了多酚氧化脱氨的机制以及该活性对生物系统可能具有的意义。
