Liu Xiaoli, Cui Chun, Zhao Mouming, Wang Jinshui, Luo Wei, Yang Bao, Jiang Yueming
College of Light Industry and Food Science, South China University of Technology, Guangzhou 510640, People's Republic of China.
College of Light Industry and Food Science, South China University of Technology, Guangzhou 510640, People's Republic of China.
Food Chem. 2008 Aug 15;109(4):909-15. doi: 10.1016/j.foodchem.2008.01.071. Epub 2008 Feb 15.
An activity-directed fractionation and purification process was used to identify the antioxidative components of emblica fruit. Dried fruit of emblica was extracted with methanol and then partitioned by ethyl ether, ethyl acetate, butanol and water. The ethyl acetate fraction showed the strongest 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity among four fractions. The ethyl acetate fraction was then subjected to separation and purification using Sephadex LH-20 chromatography and reverse-phase high-performance liquid chromatography (HPLC). Six compounds were identified to be geraniin (1), quercetin 3-β-d-glucopyranoside (2), kaempferol 3-β-d-glucopyranoside (3), isocorilagin (4), quercetin (5), and kaempferol (6), respectively, by spectral methods, (1)H and (13)C nuclear magnetic resonance (NMR) spectroscopy, ultraviolet-visible (UV-Vis) spectrophotometry and mass spectroscopy (MS), and comparison with literatures. Compounds 2-4 and 6 were identified from emblica fruit for the first time. Furthermore, the antioxidant activities of purified compounds were screened for their antioxidative potential using lipid peroxidation and DPPH systems. All the purified compounds showed strong antioxidant and radical scavenging activities. Amongst, geraniin showed the highest antioxidant activity (4.7 and 65.7μM of IC50 values for DPPH and lipid peroxidation assay, respectively) than other purified compounds.
采用活性导向的分离纯化工艺来鉴定余甘子果实的抗氧化成分。将余甘子干果用甲醇提取，然后依次用乙醚、乙酸乙酯、正丁醇和水进行分配。乙酸乙酯萃取物在四个萃取物中表现出最强的1,1-二苯基-2-苦基肼（DPPH）自由基清除活性。随后，采用葡聚糖凝胶LH-20柱色谱和反相高效液相色谱（HPLC）对乙酸乙酯萃取物进行分离纯化。通过光谱法、氢核磁共振（¹H NMR）和碳核磁共振（¹³C NMR）光谱、紫外可见（UV-Vis）分光光度法和质谱（MS），并与文献对照，分别鉴定出六种化合物，依次为诃子鞣质（1）、槲皮素3-β-D-吡喃葡萄糖苷（2）、山柰酚3-β-D-吡喃葡萄糖苷（3）、异诃子鞣质（4）、槲皮素（5）和山柰酚（6）。化合物2-4和6首次从余甘子果实中鉴定得到。此外，利用脂质过氧化和DPPH体系筛选纯化化合物的抗氧化活性。所有纯化化合物均表现出较强的抗氧化和自由基清除活性。其中，诃子鞣质的抗氧化活性最高（DPPH和脂质过氧化试验的IC50值分别为4.7和65.7μM），高于其他纯化化合物。
