Antioxidant capacity of extracts and isolated compounds from Stryphnodendron obovatum Benth
Antioxidant capacity of extracts and isolated compounds from Stryphnodendron obovatum Benth
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DOI：
10.1590/s1984-82502009000300009
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发表时间：
2009-09-01
影响因子：
1.3
通讯作者：
Mello, João Carlos Palazzo de
中科院分区：
文献类型：
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作者：
Zocoler, Analice Martins Daleffi;Sanches, Andréia Cristina Conegero;Mello, João Carlos Palazzo de
从倒卵叶马钱子茎皮中分离得到9个化合物，分别为没食子酸（GA）、对羟基苯甲酸（PHB）、没食子儿茶素（GC）、表没食子儿茶素（EPG）、4 ′-O-甲基没食子儿茶素（MGC）、表没食子儿茶素（EPG）、没食子酸（GA）、对羟基苯甲酸（PHB）、没食子儿茶素（GC）、表没食子儿茶素（EPG）、4 ′-O-甲基没食子儿茶素（MGC）、表没食子儿茶素（MGC）、没食子酸（GA）、对羟基苯甲酸（PHB）、没食子儿茶素（GC）、表没食子儿茶素（EPG）。（4 β-> 8）-表没食子儿茶素（EPEP）、表没食子儿茶素-（4 β-> 8）-没食子儿茶素（EPGC）、洋槐替尼醇-（4 α-> 8）-没食子儿茶素（ROGC）和洋槐替尼醇-（4 β-> 8）-表没食子儿茶素（ROEP）。通过DPPH自由基（IC 50 μ g/mL）和还原磷钼络合物（RAC）的方法评价体外抗氧化能力得到以下结果，分别为粗提物4.52和0.8242，乙酸乙酯部分4.04和0.9537，水部分5.58和0.9275。粗提物和乙酸乙酯馏分显示具有与维生素C（4.93和1.0）相当的抗氧化能力。通过DPPH自由基方法获得的分离化合物的值为IC 50（μ M）。GA=8.89，PHB=10.12：GC=16.46，EPG=13.20，MGC=21.00，EPEP=6.89，EPGC=4.91，ROGC=7.78和ROEP=6.20。维生素C和trolox分别为30.11和30.10。二聚体具有较强的清除自由基的活性，可能与羟基的数量有关。然而，化合物没有羟基在位置5的A-环（5-脱氧pranthocyamdins）没有改变的DPPH自由基的抗氧化活性，在这里评估的第一次。在单体中，由于化合物的立体化学，似乎在清除自由基方面存在直接关系。甲基自由基的存在下的B-环显着降低了清除自由基的没食子儿茶素。所有化合物的清除自由基能力均强于维生素C和曲洛酮，且两种化合物之间无显著差异。
The extract from stem bark of Stryphnodendron obovatum Benth was chromatographed on a Sephadex (R) LH-20 column, and yielded nine compounds, gallic acid (GA), p-hydroxybenzoic acid (PHB), gallocatechin (GC), epiagallocatechin (EPG) 4'-O-methylgallocatechin (MGC), epigallocatechin- (4 beta -> 8)-epigallocatechin (EPEP), epigallocatechin-(4 beta -> 8)-gallocatechin (EPGC), robinetinidol- (4 alpha -> 8)-gallocatechin (ROGC) and robinetinidol-(4 beta -> 8)-epigallocatechin (ROEP). Evaluation of the antioxidant capacity in vitro by the methods of DPPH free radical (IC50.mu g/mL) and reduction of the phosphomolybdenum complex (RAC) gave the following results, respectively crude extract 4.52 and 0.8242, ethyl-acetate fraction 4.04 and 0.9537; aqueous fraction 5.58 and 0.9275. The crude extract and ethyl-acetate fraction were shown to possess an antioxidant capacity comparable to that of vitamin C (4.93 and 1.0). The values obtained by the DPPH free-radical method for the isolated compounds were IC50 (mu M). GA=8.89, PHB=10.12: GC=16.46, EPG=13.20, MGC=21.00, EPEP=6.89, EPGC=4.91, ROGC=7.78 and ROEP=6.20. Vitamin C and trolox showed 30.11 and 30.10, respectively. Dimers showd greater activity in scavenging free radicals, possibly related to the number of hydroxyls. However, compounds without a hydroxy at position 5 of the A-ring (5-deoxy-pranthocyamdins) did not change the antioxidant activity of the DPPH free radical, as evaluated here for the first time. Among the monomers, there appeared to be a direct relationship in scavenging of free radicals because of the stereochemistry of the compounds. The presence of a methyl radical on the B-ring significantly reduced the scavenging of free radicals of gallocatechin. All compounds showed greater scavenging of radicals than vitamin C and trolox, and these two compounds showdd no significant difference from each other.