安徽产地桑叶多糖分离纯化、结构鉴定与抗氧化活性研究

Purification, characterization and antioxidant properties of polysaccharides of Anhui mulberry leaves

利用水提醇沉法提取桑叶多糖,采用DEAE-52-纤维素阴离子交换树脂和Sephadex G-100葡聚糖凝胶柱层析分离纯化桑叶多糖(MLP),得到2种纯化多糖MLP-1和MLP-2,并对其结构和抗氧化活性进行研究。结果表明,MLP-1分子量为9.31×104 Da,单糖组成包括甘露糖、鼠李糖、葡萄糖、半乳糖、木糖和阿拉伯糖,其摩尔比为0.26∶0.36∶1.00∶0.41∶1.34∶1.02。MLP-2的分子量为2.22×106 Da,由甘露糖、鼠李糖、葡萄糖、半乳糖和阿拉伯糖组成,其摩尔比为0.18∶1.22∶1.00∶0.14∶1.72。红外光谱分析表明,MLPs各组分具有典型的糖特征吸收峰。超氧阴离子(O2·-)、H2O2自由基清除能力和还原力测定体外抗氧化活性研究表明,MLP-1和MLP-2均具有一定抗氧化能力,强弱顺序依次为VC>MLP-1>MLP-2。

Mulberry leaf polysaccharide(MLP)was extracted by ethanol extraction and further purified by DEAE-52-cellulose and Sephadex G-100 column chromatography.Two main purified polysaccharides(MLP-1 and MLP-2)were obtained.The purified polysaccharides were characterized,and their antioxidant properties were investigated.The molecular weight of MLP-1 was 9.31×104 Da,and it was composed of mannose,rhamnose,glucose,galactose,xylose,and arabinose in a molar ratio of 0.26∶0.36∶1.00∶0.41∶1.34∶1.02.The molecular weight of MLP-2 was 2.22×106 Da,and its monosaccharide constituents are mannose,rhamnose,glucose,galactose,and arabinose in a molar ratio of 0.18∶1.22∶1.00∶0.14∶1.72.Infrared spectroscopy showed that each MLP had a typical sugar characteristic absorption peak.Both MLP-1 and MLP-2 had certain antioxidant capacity from in vitro experiments on superoxide anion(O2·-),H2 O2 scavenging and reducing power.Compared with Vc,the order of antioxidation is VC>MLP-1>MLP-2.