盐肤木叶多酚提取及抗氧化活性初探

Extraction of Polyphenols from Leaves of Rhus chinensis Mill and Its Antioxidant Activity

比较了热浸提、超声波辅助提取、微波辅助提取3种方法和水、乙醇、甲醇、丙酮4种不同溶剂对盐肤木叶多酚提取的影响。选择乙醇溶液和热浸提作为基本提取方法,在单因素试验基础上进行正交试验对提取工艺进行优化,结果显示盐肤木叶多酚的最佳提取条件是料液比1∶15(g∶mL),提取时间60 min,提取温度60℃,乙醇体积分数60%。提取的粗多酚溶液离心后直接干燥得到粗多酚粉末或经过乙酸乙酯萃取分离,烘干分别得到乙酸乙酯相干粉和水相粗多酚干粉,接着对获得的粗提物进行了多酚纯度测定和抗氧化等生物学功能检测。结果显示,3种粗多酚纯度分别为:直接干燥的37.53%,水相的为19.26%,乙酸乙酯相的为59.44%。提取物体外清除DPPH自由基能力大于维生素C,略小于商品化茶多酚。

Three extraction methods （ heat, ultrasound-assisted, microwave-assisted） and four different solvents （ water, ethanol, methanol and acetone） were used to compare the extraction efficiencies of polyphenols from leaf tissues of Rhus chinensis Mill. The thermal extraction and ethanol solvent was chosen as the basic method for further study. By using single factor test and orthogonal test, the optimized extraction conditions were as follows： solid-liquid ratio 1 ： 15, extraction time 60 min, extraction temperature 60 ℃ and 60 % ethanol solvent. Crude pelyphenol powder was obtained from solution of direct centrifugation, ethyl acetate phase or water part after ethyl acetate extraction. The polyphenol purity was determined as 37.53 % by direct dry, 19.26 % in water phase, 59.44 % in ethyl acetate phase. Their radical-scavenging activities in vitro were slight lower than to commercial tea polyphenol with 98% purity, but more than that of Vc.