牡丹叶多糖的提取纯化、分级制备及抗氧化性能研究

Extraction,purification,classific preparation and antioxidant activities of polysaccharides from peony leaves

以牡丹叶为实验对象,建立牡丹叶多糖的提取及分离纯化方法,再采用不同体积分数(25%、45%、65%、85%)乙醇分级沉淀,得牡丹叶多糖PW-25、PW-45、PW-65、PW-85,采用红外光谱分析各组分的光谱学特征,并通过DPPH自由基和羟自由基清除实验对各组分体外抗氧化活性进行研究。结果表明:采用ZTC1+1-Ⅱ型天然澄清剂法脱蛋白和过氧化氢脱色法联用进行牡丹叶粗多糖的分离纯化,在此方法下牡丹叶粗多糖中蛋白脱除率为89.66%,色素脱除率为79.35%,多糖保留率为61.41%,得到PW-25多糖纯度达91.23%,得率为1.29%;4种牡丹叶多糖组分均具有一定体外抗氧化能力,其中PW-25对DPPH自由基和羟自由基具有明显清除能力,且半数抑制浓度(IC50)分别为15.36、65.77μg/m L,但均略差于VC(IC50分别为7.89、46.46μg/m L)。研究结果为牡丹叶多糖开发和应用提供基础。

A method for extracting, isolating and purifing polysaccharides from peony leaves was established,and four polysaccharides from peony leaves( PW-25、PW-45、PW-65、PW-85) were obtained by ethanol graded precipitation method with 25% 、45% 、65% and 85% ethanol. The spectral characteristics of the four polysaccharides were determined by FTIR and the in vitro antioxidant activities were studied by DPPH free radical and hydroxyl free radical scavenging experiments. The results showed that the polysaccharides from peony leaves were isolated and purified by a combined method of ZTC1 +1-II natural clarifying agents for removing protein and decolorization with hydrogen peroxide,and under this method,the removal rates of protein and pigment and retention rate of polysaccharides in crude polysaccharides from peony leaves were 89. 66%,79. 35% and 61. 41% respectively;the purity of polysaccharides PW-25 was 91. 23%,and its yield was 1. 29%;four polysaccharides from peony leaves showed certain in vitro antioxidant activities,and the IC50 of PW-25 by scavenging DPPH free radical and hydroxyl free radical were 15. 36、65. 77 μg/m L respectively,which were slightly worse than VC( IC507. 89、46. 46 μg/m L). The results could provide foundation for the development and application of polysaccharides from peony leaves.