紫花地丁化学成分分析及其体外抗氧化活性考察

目的:对堇菜科堇菜属植物紫花地丁中的化学成分及其抗氧化活性进行研究.方法:取紫花地丁5 kg,加3倍量95％乙醇回流提取3次,合并提取液,过滤,减压浓缩得总浸膏,上60～100目硅胶柱色谱,用石油醚、二氯甲烷、二氯甲烷-甲醇(50:1,10:1,5:1,2:1)及甲醇洗脱,得到7个相应馏分.各部位依次运用正相硅胶柱色谱...

Analysis of Chemical Constituents in Violae Herba and Investigation of Its Antioxidant Activity in Vitro

Objective: To investigate the chemical constituents and antioxidant activities of Violae Herba from the Violaceae. Method: The 5 kg of Violae Herba was refluxing extracted with 3 times the amount of 95% ethanol for three times,then the extracting solution was combined,filtrated,concentrated under vacuum to get the total extract. Seven corresponding fractions were eluted with petroleum ether,dichloromethane,dichloromethane-methanol(50∶1,10∶1,5∶1,2∶1)and methanol by silica gel column chromatography(60-100 mesh)on the total extract. Each fraction was isolated and purified by normal phase silica gel column chromatography,octadecylsilane chemically bonded silica(ODS)column chromatography,Sephadex LH-20 column chromatography and preparative high performance liquid chromatography(HPLC),respectively. The structures of the obtained compounds were identified by spectroscopic methods of nuclear magnetic resonance(NMR),mass spectroscopy(MS)and infrared spectroscopy(IR). Meanwhile,some of these compounds isolated from Violae Herba were carried on the 1,1-diphenyl-2-picrylhydrazyl(DPPH)free radical scavenging experiment. Result: Fourteen compounds were isolated from the 95% ethanol extract of Violae Herba,including N-acetyl-1-ethyl ester glutamic acid(1), N-acetyl glutamic acid-1-ethyl-5-methyl ester(2),aurantiamide(3),rel-(2α,3β)-7-O-methylcedrusin(4),oleanolic acid(5),α-tocopherol-quinone(6),tectochrysin(7),isoscopoletin(8),esculetin(9),24-ethylcholesta-4,24(28)Z-dien-3-one(10),stigmasta-4,25-dien-3-one(11),β-sitostenone(12),β-sitosterol(13),(24 R)-3β-hydroxy-ethylcholest-5-en-7-one(14).Conclusion: Compound 2 is a new natural product,compounds 1,4,6,7,10-12 are isolated from the genus Viola for the first time. Compound 9 has significant antioxidant activity,while compounds 2,6 and 8 have certain DPPH free radical scavenging activity.