茯苓多糖的分离纯化、组成及其抗氧化活性研究

目的分离纯化得到带电性不同的茯苓多糖组分,分析其化学组成性质,比较多糖粗提物和其不同组分的抗氧化活性。方法采用水提醇沉法提取茯苓多糖粗提物(Poria cocos Polysaccharide,PCP),利用二乙氨基乙基(diehlaminowthy,DEAE)-纤维素阴离子交换色谱柱法对多糖粗提物进行分离纯化,得到不同带电性的多糖组分PCP-1(水洗糖)和PCP-2(盐洗糖)。结合紫外-可见光分光光度测定法、傅里叶红外光谱法、高效液相色谱-衍生化法、高效凝胶渗透色谱法和扫描电子显微镜法等方法对多糖粗提物和2种不同组分的化学组成性质进行研究。以多糖的1,1-二苯基-2-三硝基苯肼自由基、2,2-联氨-双(3-乙基苯并噻唑啉-6-磺酸)二胺盐自由基和羟基自由基的清除能力作为评估体外抗氧化活性指标。结果PCP、PCP-1和PCP-2的多糖含量分别为78.16%、93.53%、90.84%,红外光谱出现相似吸收峰,均有多糖的典型吸收。3种多糖均为主要由甘露糖、鼠李糖、葡萄糖、半乳糖和岩藻糖按照不同比例组成的杂多糖,分别由不同分子量的多糖片段构成,微观形态没有显著差异。体外抗氧化实验提示PCP-2的体外抗氧化活性最高。结论经过分离纯化后的不同茯苓多糖组分的化学结构性质不同,相较于茯苓多糖粗提物体外抗氧化活性更强,其中PCP-2的活性最强。

Isolation,Purification,Composition,and Antioxidant Activity of Poria cocos Polysaccharides

Objective To investigate the chemical composition and properties of different components of Poria Cocos polysaccharides with different charge properties obtained by isolation and purification,as well as the antioxidant activity of the crude extract versus different components of polysaccharides.Methods Poria Cocos polysaccharide(PCP)was extracted by water extraction and alcohol precipitation,and PCP was isolated and purified on a diethylaminoethyl-cellulose anion exchange chromatographic column to obtain the polysaccharide components with different charge properties,PCP-1(water-washed polysaccharide)and PCP-2(salt-washed polysaccharide).The chemical composition and properties of the crude extract and the two components of polysaccharides were analyzed by various methods including ultraviolet-visible spectrophotometry,Fourier transform infrared spectroscopy,high-performance liquid chromatography-derivatization,high-performance gel-permeation chromatography,and scanning electron microscopy.The in vitro antioxidant activity of polysaccharides was evaluated based on their scavenging activity against 1,1-diphenyl-2-trinitrophenylhydrazine radical,2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)diammonium salt radical,and hydroxyl radical.Results The content of PCP,PCP-1,and PCP-2 was 78.16%,93.53%,and 90.84%,respectively,and similar absorption peaks were observed on infrared spectrometry,with the typical absorption characteristics of polysaccharides.All three types of polysaccharides were heteropolysaccharides mainly composed of mannose,rhamnose,glucose,galactose,and fucose in different proportions,which were composed of polysaccharide fragments with different molecular weights,with no significant difference in micromorphology.The in vitro antioxidant experiment showed that PCP-2 had the highest in vitro antioxidant activity.Conclusion Different components of Poria cocos polysaccharides obtained after isolation and purification have different chemical and structural properties,with a stronger antioxidant activity than the crude extract of polysaccharides,and PCP-2 has the strongest activity.