大叶冬青苦丁茶多糖提取、纯化与抗氧化活性研究

大叶冬青苦丁茶经85%乙醇溶液脱脂、热水提取、S-8大孔树脂脱色、醇沉、干燥,得到大叶冬青苦丁茶粗多糖。粗ILPS经DEAE-52纤维素阴离子交换层析柱分离,得到4个多糖组分ILPS-1,ILPS-2,ILPS-3和ILPS-4。采用化学法分别测定了粗多糖及其纯化组分的体外清除自由基（DPPH.自由基,O2^-.自由基,.OH自由基）能力、还原能力以及螯合金属离子能力。结果表明,大叶冬青苦丁茶多糖具有较强的体外抗氧化活性,并且抗氧化能力与多糖浓度之间存在良好的相关性。

Extraction,Purification and Antioxidant Activity in Vitro of Polysaccharides from Kudingcha Made from Ilex latifolia Thunb

Kudingcha made from Ilex latifolia Thunb was defatted with 85% ethanol,and then extracted with hot water,decolored by S-8 macroporous resin,precipitated by ethanol,and dried to afford crude polysaccharide（ILPS）.Four purified polysaccharides,ILPS-1,ILPS-2,ILPS-3 and ILPS-4,were gained from crude ILPS by DEAE-52 anion-exchange chromatography.Furthermore,the antioxidant activities in vitro of the crude ILPS and its purified fractions were evaluated by determinations of scavenging activities on 1,1-diphenyl-2-picrylhydrazyl（DPPH·） free radicals,superoxide anion radicals（O2-·）,hydroxyl radicals（·OH）,ferric reducing-antioxidant power（FRAP） and chelating capacity to Fe2＋.The results indicated that ILPS exhibited strong antioxidant activity,and the antioxidant activity was significantly correlated with its concentration.