文献类型： 外文期刊

作者： Zhang, LN ¹ ; Ding, Q ² ; Meng, DY ² ; Ren, LW ² ; Yang, G ² ; Liu, YG ² ;

作者机构： 1.Wuhan Univ, Dept Chem, Wuhan 430072, Peoples R China

2.Wuhan Univ, Dept Chem, Wuhan 430072, Peoples R China; Hubei Acad Agr Sci, Agr Testing Ctr, Wuhan 430064, Peoples R China

关键词： Poria cocos;carbohydrates;preparative chromatography;glucan

期刊名称：JOURNAL OF CHROMATOGRAPHY A （ 影响因子：4.759； 五年影响因子：4.302 ）

ISSN： 0021-9673

年卷期： 1999 年 839 卷 1-2 期

页码：

收录情况： SCI

摘要： beta-D-Glucan PC3 (weight-average molecular mass = 9.15. 10(4), polydispersity = 1.6), a linear glucan from Poria cocos sclerotium, was fractionated by a preparative size-exclusion chromatography (SEC) column packed with regenerated cellulose gels using dimethyl sulfoxide (DMSO) as mobile phase. The molecular masses and aggregation of the fractions were investigated by using analytical SEC, viscometry and membrane osmometry under different conditions. The results of SEC analysis proved that glucan PC3 forms partial aggregates in 0.25 M LiCl/DMSO (namely, 0.25 M LiCl in DMSO) at 40 degrees C, showing a new shoulder peak of a higher-molecular-mass component in the chromatogram, and dissolves as a single-stranded chain at 80 degrees C, giving a sharper peak. The mean apparent aggregation number (N-ap) of the fractions in 0.25 M LiCl/DMSO at 40 degrees C was 1.9, and much smaller than that of glucan PC3 in 20% cadoxen. It is indicated that the analytical SEC is more sensitive and direct in detection of the aggregates than other methods, and aggregation can be avoided by carrying out SEC measurement at 80 degrees C. The Mark-Houwink equation for glucan PC3 in DMSO at 25 degrees C was established as [eta] = 0.107M(w)(0.50) in the M-w range of 7-11 . 10(4), suggesting that it behaves as a flexible coil. (C) 1999 Elsevier Science B.V. All rights reserved.