Rossetto Monica, Vanzani Paola, Mattivi Fulvio, Lunelli Michele, Scarpa Marina, Rigo Adelio
Dipartimento di Chimica Biologica, Università di Padova, 35121 Padova, Italy.
Arch Biochem Biophys. 2002 Dec 15;408(2):239-45. doi: 10.1016/s0003-9861(02)00561-1.
The inhibitory effect of anthocyanins has been investigated in the peroxidation of linoleic acid in micelles in the presence and in the absence of (+)-catechin. The peroxidation was initiated by thermal decomposition of 2,2(')-azobis[2-(2-imidazolin-2-yl)propane], and the kinetics of peroxidation were followed by measuring the rate of oxygen consumption and the rate of disappearance of the antioxidant. The analysis of the antioxidant effect of various anthocyanins, alone or in the presence of catechin, demonstrates that catechin, which is relatively inefficient at inhibiting linoleic acid oxidation, regenerates the highly efficient antioxidant malvidin 3-glucoside and, at a lower extent, peonidin 3-glucoside. The malvidin 3-glucoside recycling by catechin strongly increases the antioxidant efficiency of these two antioxidants. This protective mechanism appears specific for malvidin and peonidin 3-glucosides. The high unpaired spin density of the phenolic O atoms in the radicals generated by these anthocyanins, calculated by the semiempirical quantum chemical AM1 method, may explain the observed behavior.
在有和没有（+）-儿茶素存在的情况下，研究了花色苷对亚油酸在胶束中过氧化的抑制作用。过氧化反应由2,2'-偶氮双[2-(2-咪唑啉-2-基)丙烷]的热分解引发，通过测量耗氧速率和抗氧化剂消失速率来跟踪过氧化动力学。对各种花色苷单独或在儿茶素存在下的抗氧化作用分析表明，儿茶素在抑制亚油酸氧化方面相对低效，但能再生高效抗氧化剂矢车菊素3-葡萄糖苷，并在较低程度上再生芍药素3-葡萄糖苷。儿茶素对矢车菊素3-葡萄糖苷的循环利用极大地提高了这两种抗氧化剂的抗氧化效率。这种保护机制似乎对矢车菊素和芍药素3-葡萄糖苷具有特异性。通过半经验量子化学AM1方法计算得出，这些花色苷产生的自由基中酚氧原子的高未成对自旋密度可能解释了观察到的行为。
