虎杖多糖乙醇分级纯化及其抗氧化性

Ethanol Fractional Purification and Antioxidant Activities of Polysaccharides from Polygonum cuspidatum

本文采用热水浸提及不同浓度乙醇(30%、50%、70%、90%)分级沉淀制得4组虎杖多糖(PCP-30、PCP-50、PCP-70、PCP-90),分别测定其得率、总糖含量及糖醛酸含量,采用红外和紫外光谱比较其光谱学性质差异,利用DPPH自由基清除实验及还原力实验考察其抗氧化性差异,并考察总糖含量、糖醛酸含量与抗氧化活性的相关性。结果显示,不同组分间多糖得率及含量有较大差异,PCP-70总糖含量(557.03 mg/g)及糖醛酸含量(284.85 mg/g)最高,且在DPPH自由基清除实验及还原力实验中表现出最高的抗氧化性,4组虎杖多糖红外检测都具有多糖的典型基团,紫外图谱波形近似,相关性研究表明总糖含量、糖醛酸含量与上述抗氧化模型均有一定的线性关系,表现出较强的相关性。因此,70%乙醇更适宜沉淀制备虎杖多糖,且所得虎杖多糖抗氧化性强。

The Polygonum cuspidatum polysaccharides were extracted with hot water and deposited by different gradient concentrations of ethanol (30%,50%,70%,90%)into four precipitation fractions,named PCP-30,PCP-50,PCP-70and PCP-90.The yield of polysaccharide,the contents of sugar and uronic acid were determined,FTIR and UV spectroscopy were analyzed to determine their spectroscopy properties.The DPPH radical and reducing power were tested.The correlation of sugar content and uronic acid content with antioxidant activities were further studied.The results indicated that the composition contents of the four Polygonum cuspidatum polysaccharides were significantly different.PCP-70 showed the highest content of sugar(557.03mg/g)and uronic acid (284.85mg/g),and also exhibited the highest antioxidant activity in DPPH radicalscavenging test and ferric reducing power test.Four different polysaccharide fractions all had the typical groups of polysaccharides by infrared analysis,and they had almost no difference in the UV scanning spectra.The results of correlation coefficients showed that the sugar content and uronic acid content correlated highly with DPPH radical scavenging and ferric reducing power.Therefore 70% ethanol was considered appropriate for precipitating Polygonum cuspidatum polysaccharide,and the PCP-70showed high antioxidant activities.