Contribution of Flavonoids to the Overall Radical Scavenging Activity of Olive (Olea europaea L.) Leaf Polar Extracts
Contribution of Flavonoids to the Overall Radical Scavenging Activity of Olive (Olea europaea L.) Leaf Polar Extracts
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DOI：
10.1021/jf903823x
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发表时间：
2010-03-24
影响因子：
6.1
通讯作者：
Gerothanassis, Ioannis P.
中科院分区：
文献类型：
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作者：
Goulas, Vlassios;Papoti, Vassiliki T.;Gerothanassis, Ioannis P.
研究了类黄酮对橄榄叶极性提取物总体自由基清除活性的贡献，橄榄叶极性提取物已知是橄榄苦苷相关化合物的良好来源。采用离线和在线 HPLC-DPPH* 测定，而类黄酮含量则通过比色法估计。首先通过 RP-HPLC 结合二极管阵列和荧光检测器评估各个黄酮类成分，并通过 LC-MS 检测系统进行验证。无论采样参数（橄榄品种、叶龄或采样日期）如何，橄榄叶都是黄酮类化合物的重要来源。总黄酮类化合物占使用在线方案评估的总自由基清除活性的 13-27%。木犀草素 7-O-葡萄糖苷是主要的清除剂之一 (8-25%)。考虑到出现频率，木犀草素 (3-13%) 的贡献也被认为很重要。我们的研究结果表明，除了橄榄苦苷和相关化合物之外，橄榄叶也是生物活性黄酮类化合物的稳定来源。
The contribution of flavonoids to the overall radical scavenging activity of olive leaf polar extracts, known to be good sources of oleuropein related compounds, was examined. Off line and on line HPLC-DPPH* assays were employed, whereas flavonoid content was estimated colorimetrically. Individual flavonoid composition was first assessed by RP-HPLC coupled with diode array and fluorescence detectors and verified by LC-MS detection system. Olive leaf was found a robust source of flavonoids regardless sampling parameters (olive cultivar, leaf age or sampling date). Total flavonoids accounted for the 13-27% of the total radical scavenging activity assessed using the on line protocol. Luteolin 7-O-aglucoside was one of the dominant scavengers (8-25%). Taking into consideration frequency of appearance the contribution of luteolin (3-13%) was considered important, too. Our findings support that olive leaf, except for oleuropein and related compounds, is also a stable source of bioactive flavonoids.