苎麻水溶性碳水化合物的分离和分析

Study on separation and analysis of water-soluble carbohydrate from ramie

用冷、热水分级抽提苎麻水溶性碳水化合物，然后分离出多糖、低聚糖和单糖。苎麻水溶性多糖和低聚糖用酸水解成单糖，再将水解所得的中性糖和酸性糖分别制备成糖腈乙酰酯和二硫缩醛硅烷化衍生物，作气相色谱分析。分析结果表明，苎麻水溶性多糖的糖基主要是D-半乳糖、L-鼠李糖、D-葡萄糖、L-阿拉伯糖、D-甘露糖和D-半乳糖醛酸。此外，尚有少量的L-岩藻糖、L-来苏糖、D-木糖和D-半乳糖醛酸甲酯。苎麻低聚糖的糖基组成与苎麻水溶性多糖的相似。苎麻游离单糖主要有D-赤鲜糖和七碳糖，还有少量的D-半乳糖、L-阿拉伯糖和D-半乳糖醛酸。

The water-soluble carbohydrate was gradually extracted from ramie, then thepolysaccharides, oligosaccharides and monosaccharides were separated. The water-solublepolysaecharides and oligosaccharides were hydrolyzed with acid. The neutral and acid sugarsin the hydrolyzate were convented into acetylated aldononitriles and diethyl dithioacetaltrimethylsilylates separately. Results analyzed by GC show that the sugar components in thehydrolyzate of water-soluble polysaccharides from ramie are mainly D-galactose,L-rhamnose, D-glucose, L-arabinose, D-mannose, D-galacturonic acid, with some L-fu-cose, D-xylose , L-lyxose and D-galacturonic methyl ester. The sligar components inhydrolyzate of oligosaccharides mixture are similar to that of water-soluble polysaccharides.The free monosaccharides of water extract from ramie are mainly D-erythrose and heptose,with traces of D-galactose, L-arabinose and D-glacturonic acid.