金针菇锌多糖分离纯化及其结构特征

目的：以金针菇为原料，经过逐步分离纯化得到两个锌多糖组分并研究其理化性质、光谱学特性及结构特征。方法：金针菇锌多糖采用热水浸提的方法提取，经DEAE纤维素-52和Sephadex G-100凝胶色谱柱逐步分离纯化后通过火焰原子吸收法测定多糖中锌的含量，高效凝胶过滤色谱法鉴定组分的均一性，并测定其分子质量及单糖组成，采用紫外光谱、红外光谱和刚果红实验对锌多糖的结构特征进行相关研究。结果：通过分离纯化得到两个锌多糖组分CF1、CF2，纯品提取率分别为20.97%与12.25%，其中锌含量分别为191、429 μg/g，平均分子质量分别为890、1 244 kD。CF1组分由葡萄糖、半乳糖等6 种单糖组成；CF2组分主要由甘露糖、葡萄糖、岩藻糖等8 种单糖组成，且两个多糖组分均具有三股螺旋分子结构。

Separation,Purification and Structure Characteristics of Zn-Binding Polysaccharides from Flammulina velutipes

Objective: To obtain two Zn-binding polysaccharide fractions from Flammulina velutipes and characterizetheir physiochemical, spectroscopic and structural properties. Methods: The Zn-binding polysaccharides were extractedfrom Flammulina velutipes with hot water, purified sequentially by DEAE cellulose-52 and Sephadex G-100 gelcolumn chromatographies and analyzed for Zn contents by flame atomic absorption spectrometry (FAAS) and forhomogeneity by high-performance size-exclusion chromatography (HPSEC). Moreover, their relative molecular weights(Mw) and monosaccharide composition were determined, and the structural characterization was carried out by ultravioletspectroscopy, infrared spectroscopy (FT-IR) and Congo red test. Results: Two major purified fractions named CF1 and CF2were obtained with yields of 20.97% and 12.25%, Zn contents of 191 and 429 μg/g, and average molecular weights of 890and 1 244 kD, respectively. CF1 was composed of 6 monosaccharides such as glucose and galactose, while CF2 was mainlycomposed of 8 monosaccharides such as mannose, fucose and glucose. Both polysaccharide fractions were three helixmolecular structures.