西藏雪莲多糖初步分离和清除自由基活性研究

Study on Preliminary Purification and Scavenging Free Radical Activity of Polysaccharide of Tibetan Saussurea

为合理利用西藏雪莲提供一定依据,对西藏雪莲多糖进行提取分离纯化。西藏雪莲经热水浸提,乙醇沉淀得粗多糖。粗多糖凯氏定氮法测得蛋白质含量为4.38%,苯酚-硫酸法测定多糖含量为25.8%,硫酸-咔唑法测半乳糖醛酸含量为38.18%。粗多糖经Sevage法和酶法联合脱蛋白,得初步纯化的多糖。纸层析和气相色谱分析表明西藏雪莲多糖由7种单糖组成:木糖,阿拉伯糖,鼠李糖,半乳糖,葡萄糖,半乳糖醛酸,甘露糖,物质的量比为:1.0∶2.8∶2.6∶2.6∶2.0∶7.6∶1.6。西藏雪莲多糖对阴离子自由基和羟自由基具有明显的清除效果,且初步纯化后多糖的清除效果比粗多糖好。西藏雪莲多糖对脂质自由基的清除效果不明显。

The crude polysaccharide was extracted from Tibetan Saussurea with hot water ,and precipitated by ethanol. Then some identifiable properties of the crude polysaccharide were studied. It contained of no starch ,The contents of protein was 4.38%, the contents of Tibetan Saussure polysaccharide（TSP） was 25.8% on phenolvitriol method and the contents of GAL-A was 38.18%. The refined polysaccharide was prepared after protein being separated. Based on PC analysisand GC analysis,it showed that TSP was composed of seven different kinds of sugar .Xyl,Ara,Rha,Gal,Glc,Gal-A,Man,proportion of mol：1. 0 ： 2.8 ： 2.6 ： 2.6 ： 2.0 ： 7.6 ： 1.6. Both crude and refined TSP were effective in scavenging superoxide radical and hydroxyl radical. The scavenging capacity for superoxide radical and hydroxyl radical of refined TSP had higher than that of crude TSP. Furthermore, TSP had only a little effect in scavenging lipid radical.