Raju T S, Davidson E A
Department of Biochemistry and Molecular Biology, Georgetown University Medical School, Washington, D.C. 20007.
Carbohydr Res. 1994 May 20;258:243-54. doi: 10.1016/0008-6215(94)84090-3.
Two water-soluble polysaccharide fractions, WSTP-IA and WSTP-IB were purified from the leaves of Tridax procumbens Linn. with graded ethanol precipitation followed by mild delignification and size-exclusion chromatography. WSTP-IA contained L-Araf and D-Galp in approximately 1:3 molar proportions, and WSTP-IB contained only D-Galp as the major sugar component. The results of methylation linkage analysis, and 1H and 13C NMR studies on the native and modified polysaccharides, indicated that WSTP-IA is an L-arabino-D-galactan with a beta-(1-->6)-D-galactan main chain in which at least one in every two D-Galp residues carries single residues of either L-Araf (alpha-/beta-) or beta-D-Galp end-group as substituents at O-3. WSTP-IB is a linear beta-(1-->6)-D-galactan. This is the first report of polysaccharides containing a beta-(1-->6)-D-galactan main chain isolated from plant sources.
从三叶鬼针草叶片中通过分级乙醇沉淀、轻度脱木质素和尺寸排阻色谱法纯化得到两种水溶性多糖级分，即WSTP - IA和WSTP - IB。WSTP - IA中L - Araf和D - Galp的摩尔比例约为1:3，而WSTP - IB仅含有D - Galp作为主要糖成分。对天然和改性多糖进行的甲基化连接分析以及1H和13C NMR研究结果表明，WSTP - IA是一种L - 阿拉伯糖基 - D - 半乳聚糖，其主链为β - (1→6) - D - 半乳聚糖，其中每两个D - Galp残基中至少有一个在O - 3位带有L - Araf（α/β）或β - D - Galp端基的单残基作为取代基。WSTP - IB是一种线性β - (1→6) - D - 半乳聚糖。这是首次报道从植物来源分离得到的含有β - (1→6) - D - 半乳聚糖主链的多糖。
