白花蛇舌草中一葡聚糖的结构鉴定(英文)

Structural Characterization of A Glucan Isolated from Hedyotis diffusa Willd

通过乙醇沉淀、透析、离子交换和凝胶色谱等分离方法,我们从白花蛇舌草中分离得到一种葡聚糖HD-27,ESI-MS检测其分子量为1800。利用化学及光谱分析方法进行结构研究,确定HD-27是由11个葡萄糖残基组成,其结构为α-D-G lc-(1→4)-[-αD-G lc-(1→4)]9-β-D-G lc。

A natural glucan HD-27 was isolated from Hedyotis diffusa Willd by alcohol precipitation, dialysis, anionexchange and gel-permeation chromatography, The molecular weight of the glucan was 1800 as determined by ESIMS and showed [ α] D^20 ＋ 165.5°（c0. 50, H2O）. Its structure was investigated by a combination of sugar composition analysis, methylation analysis, NaIO4 oxidation, and IR and NMR spectroscopy. The results showed HD-27 contained 11 glucose residues, which mainly composed of α-D-（ 1→4）-glucose with one β configuration reduced terminal residue.