马齿苋多糖组分的分离纯化及抗氧化活性研究

Study on Separating and Antioxidative Activity of Polysaccharides Extrated from Portulaca oleracea L.

本文对马齿苋总多糖进行了纯化分离,得到了POLⅠb、POLⅡa、POLⅢ’三种单一的多糖组分,分子量分别为18kD、56kD和410kD;均是非单一组分多糖,POLⅠb、POLⅢ’主要由葡萄糖、半乳糖组成,含有α-糖苷键;POLⅢ含有六种单糖,分别是阿拉伯糖、木糖、果糖、甘露糖、半乳糖和葡萄糖,含有β-糖苷键。三种多糖体外实验证明均有一定的抗氧化功能,POLⅢ对于·OH有较高的灭活作用。

In this paper, the polysaccharides(POL) from Portulaca oleracea L. is separated into three fractions(POLⅠ,POL Ⅱand PoLⅢ) by DEAE-cellulose chromatography. They are purified by sephadex G-200 gel chromatography into POLⅠb, POL Ⅱa and PoLⅢ′. Purity identification by cellulose acetate electrophoresis and sephadex G-200 gel chromatography implies that they are homogeneous components. Typical absorption of nucleic acid or protein can not be observed in UV spectrum. Molecular weight of the polysaccharide which is determined by gel filtration are 18kD, 56kD and 410kD respectively. By means of GC, POL Ⅰb is composed of glucose and galactose, POLⅡa is composed of arabinose, xylose, fructose, mannitose, galactose and glucose and the main compositions of PoLⅢ′ are glucose and galactose. The infrared ray spectrum of the polysaccharides indicates α- glucosidal bond in POLⅠb and POLⅡa, β-glucosidal bond in PoLⅢ′. The experiment results of antioxidative activities shows POLⅠb can abolish OH and O2, the activities and amount are relative; PoLⅢ′is effective in abolishing ·OH, but it can not inhibit O2·.