Antioxidant activities of Sicilian prickly pear (Opuntia ficus indica) fruit extracts and reducing properties of its betalains:: Betanin and indicaxanthin
Antioxidant activities of Sicilian prickly pear (Opuntia ficus indica) fruit extracts and reducing properties of its betalains:: Betanin and indicaxanthin
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DOI：
10.1021/jf025696p
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发表时间：
2002-11-06
影响因子：
6.1
通讯作者：
Livrea, MA
中科院分区：
文献类型：
--
作者：
Butera, D;Tesoriere, L;Livrea, MA
西西里岛栽培的仙人掌果实有黄色、红色和白色三种颜色，这与两种甜菜色素的组合有关，紫红色甜菜色素和黄橙色的indicaxanthin。研究了甜菜色素在3个品种中的分布及果肉甲醇提取物的抗氧化活性。此外，纯化甜菜苷的还原能力。并测定了Indixanthin。根据分光光度分析，黄色品种表现出最高量的甜菜色素，其次是红色和白色品种。在白色果实中，约99%的甜菜色素为Indicaxanthin，而甜菜色素与Indicaxanthin的比例从黄色果实中的1：8（w：w）变化到红色果实中的2：1（w：w）。多酚色素仅在红色果实中是可以忽略不计的成分。当以每克果肉的6-羟基-2，5，1，8-四甲基苯并二氢吡喃-2-羧酸（Trolox）当量测量时，甲醇果实提取物显示出显著的抗氧化活性。维生素C不占所测活性的40%以上。此外，提取物剂量依赖性地抑制有机过氧化氢刺激的红细胞膜脂质氧化，以及金属依赖性和非依赖性低密度脂蛋白氧化。从白色水果的提取物显示出最高的保护在所有模型的脂质氧化。纯化的甜菜苷和靛黄素在清除[2，2 '-连氮双（3-乙基苯并噻唑啉-6-磺酸）]二铵盐阳离子自由基方面比Trolox更有效。循环伏安法测量显示两个阳极波甜菜苷和indixanthin，和差分脉冲伏安法显示三个阳极波甜菜苷，计算的峰值电位为404，616，和998 mV，和两个阳极波indixanthin，峰值电位为611和895 mV。Betanin通过与Cu 2+螯合而形成络合物，而indixanthin未被修饰。这些发现表明，上述甜菜色素有助于仙人掌果实的抗氧化活性。
Sicilian cultivars of prickly pear (Opuntia ficus indica) produce yellow, red, and white fruits-clue to the combination of two betalain pigments, the purple-red betanin and the yellow-orange indicaxanthin. The betalain distribution in the three cultivars and the antioxidant activities of methanolic extracts from edible pulp were investigated. In addition, the reducing capacity of purified betanin. and indicaxanthin was measured. According to a spectrophotometric analysis, the yellow cultivar exhibited the highest amount of betalains, followed by the red and white ones. Indicaxanthin accounted for about 99% of betalains in the white fruit, while the ratio of betanin to indicaxanthin varied from 1:8 (w:w) in the yellow fruit to 2:1 (w:w) in the red one. Polyphenol pigments were negligible components only in the red fruit. When measured as 6-hydroxy-2,5,1,8-tetramethylchroman-2-carboxylic acid (Trolox) equivalents per gram of pulp, the methanolic fruit extracts showed a marked antioxidant activity. Vitamin C did not account for more than 40% of the measured activity. In addition, the extracts dose-dependently inhibited the organic hydroperoxide-stimulated red cell membrane lipid oxidation, as well as the metal-dependent and -independent low-density lipoprotein oxidation. The extract from the white fruit showed the highest protection in all models of lipid oxidation. Purified betanin and indicaxanthin were more effective than Trolox at scavenging the [2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid)] diammonium salt cation radical. Cyclic voltammetric measurements show two anodic waves for betanin and indicaxanthin, and differential pulse voltammetry shows three anodic waves for betanin, with calculated peak potentials of 404, 616, and 998 mV, and two anodic waves for indicaxanthin, with peak potentials of 611 and 895 mV. Betanin underwent complex formation through chelation with Cu2+, whereas indicaxanthin was not modified. These findings suggest that the above betalains contribute to the antioxidant activity of prickly pear fruits.