莲子红衣多糖的分离纯化及结构表征

Separation, Purification and Structural Characteristics of Polysaccharides from Red Skin of Lotus Seeds

以莲子红衣为实验对象,将其中的多糖进行分离、纯化并表征结构。采用酶提醇析法提取莲子红衣粗多糖,选择DEAE-C阴离子交换树脂和Sephadex G-25凝胶柱层析,从莲子红衣粗多糖中分离纯化得到中性多糖和酸性多糖两种组分。经凝胶渗透色谱测定,中性和酸性多糖的重均分子质量分别为3.78×104 D和4.94×104 D,纯度分别为91.16%和90.24%。中性多糖组分由葡萄糖、木糖、甘露糖、半乳糖4种单糖组成;酸性多糖组分由葡萄糖、木糖、半乳糖、岩藻糖、阿拉伯糖5种单糖组成。红外光谱证明两种多糖中均含有糖类特征吸收峰,且为α构型的吡喃型多糖。核磁共振氢谱检测又进一步证实了两种多糖均为α构型。

The crude polysaccharides isolated from the red skin of lotus seeds by enzymatic extraction and ethanolprecipitation were separated into neutral and acidic polysaccharides by DEAE-C column chromatography and subsequentSephadex G-25 gel column chromatography. Gel permeation chromatography （GPC） analysis showed that the molecularweights of the neutral and acidic polysaccharides were 3.78 × 10^4 D and 4.94 × 10^4 D with a purity of 91.16% and 90.24%,respectively. The neutral polysaccharide was composed of 4 monosaccharides including glucose and xylose, while theacidic polysaccharide was mainly composed of 5 monosaccharides including glucose, xylose and galactose. Infrared spectrapreliminarily confirmed that both purified fractions were pyranoses with α configuration. This conclusion was further provedby nuclear magnetic resonance.