桦褐孔菌多糖的分离纯化及其抗氧化活性测定

以桦褐孔菌为原料，测定其化学组分，并采用水提醇沉法提取桦褐孔菌粗多糖（IOP）。将获取的桦褐孔菌粗多糖进行脱蛋白、脱色素的初步纯化，然后利用DEAE-52纤维素层析柱及Sephadex-100凝胶柱对多糖提取液进行分离纯化，通过抗氧化活性筛选出活性较高的多糖组分，并通过高效液相色谱分析多糖组分的纯度。实验结果表明，桦褐孔菌子实体的化学成分组成丰富，其中多糖13.10%±0.31%、还原糖4.21%±0.40%、蛋白质2.70%±0.71%、灰分9.60%±0.31%。通过对桦褐孔菌粗多糖脱蛋白、脱色素的试验方法进行筛选，得到聚酰胺层析法为最佳的脱除方法。蛋白质的脱除率为93.1%、脱色率为75.8%，多糖的保留率为90.3%。IOP经过DEAE-52纤维素柱层析后得到四个单糖组分:IOP-1、IOP-2、IOP-3、IOP-4。对四个多糖组分进行抗氧化实验发现，IOP-2对DPPH自由基的清除率最高，清除率为81.9%。IOP-2经过Sephadex-100层析柱后获得两个多糖组分:IOP-2a、IOP-2b。对比其抗氧化活性，筛选出活性较高的多糖组分为IOP-2a。采用高效液相色谱法鉴定多糖组分IOP-2a，只检查出一个对称峰，说明IOP-2a为均一性多糖。

Isolation,Purification and Antioxidant Activity of Inonotus obliquus Polysaccharide

The chemical compositions of Inonotus obliquus were analyzed and crude polysaccharides (IOP)were isolated from Inonotus obliquus by water extraction. The component of polysaccharides were purified by DEAE-52, and Sephadex G-100 column chromatography, and the highly active polysaccharide component was screened out through antioxidant activity, and the purity of the polysaccharide component was analyzed by high-performance liquid chromatography.The experimental results showed that the chemical composition of Inonotus obliquus was rich, including polysaccharide 13.10%± 0.31%, reducing sugar 4.21%±0.40%, protein 2.70%±0.71%, ash 9.60%±0.31%.After IOP undergoes DEAE-52 cellulose column chromatography, four monosaccharide components were obtained: IOP-1, IOP-2, IOP-3, and IOP-4. Antioxidation experiments on four polysaccharide components found that IOP-2 had the highest scavenging rate for DPPH free radicals. After passing through Sephadex-100 chromatography column, IOP-2 obtained two polysaccharide components: IOP-2a and IOP-2b. Compared with its antioxidant activity, the polysaccharide component with higher activity was selected as IOP-2a. Using high performance liquid chromatography to identify the polysaccharide component IOP-2a, only one symmetrical peak was detected, indicating that IOP-2a was a homogeneous polysaccharide.