大叶冬青苦丁茶多糖提取、纯化与抗氧化活性研究

摘要

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.%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.