中文摘要：

目的：对网脊石耳（Umbilicaria decussate（Vill.）Zahlbr.）和淡肤根石耳（Umbilicaria virginis Schaer.）多糖中的单糖组成进行研究。方法：两种石耳经水提、醇沉、冷冻干燥得水溶性多糖,经DEAE-52离子交换层析柱和SephadexG-150凝胶柱进行分离纯化得纯化多糖。气相色谱分析所得多糖的单糖组成。结果：淡肤根石耳精制多糖的单糖组为甘露糖、葡萄糖、半乳糖,其含量之比为16.00：50.96：6.17、淡肤根石耳纯化多糖的单糖组成为甘露糖、葡萄糖、半乳糖,其含量之比为2.97：17.70：1.52;网脊石耳精制多糖的单糖组成为甘露糖、葡萄糖、半乳糖,其含量之比为3.90：38.086：2.00、网脊石耳纯化多糖只含葡萄糖,含量为5.37%。结论：网脊石耳和淡肤根石耳都含有葡萄糖,含有少量的甘露糖和半乳糖。

英文摘要：

Objective：To analyze the monosaccharide composition of polysaccharides extracted from two Umbilicaria species： Umbilicaria decussate（Vill.） Zahlbr and Umbilicaria virginis Schaer..Methods： Water-soluble polysaccharides from both Umbilicaria species were obtained by water extraction,ethanol precipitation and freeze-dried and purified into fractions SUv and ZUd,respectively by sequential column chromatography on DEAE-52 and Sephadex G-150.Gas chromatography（GC） was used to analyze their monosaccharide composition.Results： The monosaccharide composition of crude Umbilicaria virginis polysaccharides was composed of mannose,glucose and galactose at a ratio of 16.00：50.96：6.17.The monosaccharide composition of SUv was comprised of mannose,glucose and galactose at a ratio of 2.97：17.70：1.52.The monosaccharide composition of crude Umbilicaria decussate polysaccharides was made up of mannose,glucose and galactose at a ratio of 3.90：38.086：2.00.ZUd contained only 5.37% glucose.Conclusion： Both Umbilicaria decussata and Umbilicaria virginis contain glucose and a small amount of mannose and galactose.