苦丁茶冬青多糖乙醇分级纯化及其理化性质研究

为了研究苦丁茶冬青多糖醇沉规律及产物理化性质。通过热水浸提和不同浓度乙醇分级沉淀，得到乙醇终浓度为20%、40%、60%和80%的4种苦丁茶冬青多糖组分，即ICP-1、ICP-2、ICP-3和ICP-4。比色法检测各多糖组分总糖、糖醛酸、蛋白质和总酚含量；高效凝胶渗透色谱法进行相对分子质量的测定；紫外和红外光谱扫描考察各组分的光谱性质。结果表明：ICP-1、ICP-2、ICP-3和ICP-4总糖含量分别为19.21%、34.91%、37.70%和30.21%，糖醛酸含量分别为5.04%、44.90%、24.20%和5.84%；凝胶渗透色谱图表明：ICP-2和ICP-3为高纯度均一组分，分子量为440.440与348.279 ku；4种多糖组分在280 nm处均有吸收峰，说明均为糖蛋白质化合物。红外结果显示，各组分均为吡喃糖环构型。以上结果表明，乙醇分级沉淀的方法可用于分级纯化制备组分均一、纯度较高的苦丁茶冬青多糖组分。

Ethanol Fractionation and Physico-chemical Properties of Soluble Polysaccharides from Ilex kudingcha C.J. Tseng

Ilex kudingcha C.J. Tseng was extracted with hot water and then fractionated with ethanol to produce different concentrations of water-soluble polysaccharides, and the physico-chemical properties of these polysaccharides was analyzed. The polysaccharides were fractionated and purified into fractions with concentrations of 20%, 40%, 60% and 80%, and were named ICP-1, ICP-2, ICP-3 and ICP-4, respectively. The polysaccharides were detected by using colometrics in terms of total sugar, protein, alduronic acid and total phenol; their molecular weight (Mw) was determined by using high performance gel permeation chromatography, and their spectroscopic properties by using UV and IR spectra analysis. The polysaccharides fractions ICP-1, ICP-2, ICP-3 and ICP-4 were detected to contain 19.21%, 34.91%, 37.70% and 30.21% of total sugar, respectively, and their alduronic acid contents were 5.04%, 44.90%, 24.20% and 5.84%, respectively. The gel permeation chromatograph showed that ICP-2 and ICP-3 were of high and uniform purity, their Mw being estimated about 440.440 and 348.279 ku. The UV spectra showed that these four fractions all had a characteristic absorption peak at near 280 nm. The IR spectrum indicated that all the fractions had a structure of pyranose ring. These results showed that this extraction and fractionation method can be used to produce uniformly pure water-soluble polysaccharides with higher concentrations from I. kudingcha C.J. Tseng.