大叶冬青叶的化学成分及其抗氧化活性研究

Chemical Constituents from the Leaves of Ilex Latifolia Thunb. and their Antioxidant Activity

目的:研究大叶冬青叶的化学成分及其抗氧化活性。方法:采用薄层色谱、硅胶及凝胶柱色谱法对大叶冬青叶进行分离纯化,经理化性质和波谱数据鉴定化合物结构;采用DPPH法测定抗氧化活性。结果:从大叶冬青叶乙醇提取物的乙酸乙酯部位分离得到10个化合物,分别为棕榈酸(1)、羽扇豆醇(2)、β-谷甾醇(3)、白桦脂酸(4)、24-羟基羽扇豆醇(5)、齐墩果酸(6)、胡萝卜苷(7)、槲皮素(8)、熊果苷(9)和槲皮素-3-O-α-L-鼠李糖苷(10)。其中化合物8和10抗氧化活性IC_(50)值分别为12.31±0.27,22.30±0.42μmol·L^(-1),优于阳性药维生素C(IC_(50)值为39.18±0.51μmol·L^(-1))。结论:化合物9和10为首次从该植物中分离得到;化合物8和10具有显著的抗氧化活性。

Objective： To determine the chemical constituents in the leaves of Ilex latifolia Thunb. and study their antioxidant activity. Methods： The compounds were isolated by silica gel, gel chromatograph and TLC, and then the structures were eheidated by physicochemical properties and spectrum analysis. The antioxidant activity was tested by DPPH radical scavenging assay. Results： Nine compounds were obtained from the ethyl acetate fraction of ethanol extract and identified as palmitic acid （ 1 ）, hipeol （2）, β-sitosterol （3）, betulinic acid （4）, 24-hydroxyhipeol （5）, oleanalie acid （6）, daucesterol（7）, quercetin （8）, arbutin （9） and quercetin-3-O-α-rhamnopyranoside（10）. The antioxidative ICs0 value of compounds 8 and 10 was 12.31±0.27 μmol·L^-1 and 22.30 ± 0.42 μmol·L^-1, respectively, which were better than that of the positive control Vitmin C （ 39.18±0.51μmol·L^-1）. Conclusion： Compounds 9 and 10 are isolated from llex latifolia Thunb. for the first time. Compounds 8-10 all exhibit significant antioxidant activi- ty.