大花红景天多糖RCPS分离纯化及单糖组成分析

采用水提醇沉方法提取大花红景天粗多糖RCP(rhodiola crenulata polysaccharide)，并通过乙醇分级沉淀，Sevag法脱除蛋白，葡聚糖凝胶柱色谱纯化等手段，得到一种多糖RCPS。采用苯酚-硫酸法测定了总糖含量，UV和IR等方法考察了多糖性质，凝胶渗透色谱-示差检测法测定多糖的纯度及分子量范围及分布，GC法鉴定单糖组成及其摩尔比值。结果表明,多糖RCPS为淡黄色粉末状物质，易溶于水，总糖含量为99.11%。紫外光谱分析显示，在195 nm 波长处有明显吸收峰,在260和280 nm等处无吸收峰,说明被测物为多糖,且不含核酸及蛋白质；红外吸收光谱分析表明,在3 424.83，2 934.10，1 742.11，1 438.96，1 261.40， 1 103.54，832.86 cm-1处均有明显的多糖特征吸收，主要由鼠李糖，阿拉伯糖，木糖，甘露糖，葡萄糖，半乳糖和半乳糖醛酸组成，其摩尔比值为1∶2.96∶0.21∶0.26∶0.08∶0.58∶0.15。

Purification and Composition Analysis of Polysaccharide RCPS from Rhodiola Crenulata

Hot water extracting and ethanol precipitating method was employed to isolate polysaccharides.RCP(Rhodiola crenulata polysaccharide) was fractionally precipitated with EtOH.RCP3(Rhodiola crenulata polysaccharide 3)was one of the three fractions.RCPS was obtained after RCP3 was purified by deproteination;decolourization and gel chromatography on Sephadex G-100.The homogeneity and molecular masses of RCPS were proved by HLGPC.The amount of total carbohydrates of RCPS was measured with phenol-sulfuric acid method.IR spectrometry and UV-spectrophotometer were used to determine the characteristic absorption of RCPS.The monosaccharides contained in the RCPS were analyzed by GC.The amount of total carbohydrates in RCPS is 99.11 %.The molecular weight was 27 876.IR spectrometry analysis indicated that RCPS showed typical signals of acid polysaccharide,including signals at 3 424.83,2 934.10,1 742.11,1 438.96,1 261.40,1 103.54 and 832.86 cm-1;UV-spectrophotometer analysis indicated that RCPS showed a signal of polysaccharide at 195 nm and no signals of protein,nucleic acid at 260 and 280 nm.The monosaccharide constituents of RCPS were Rha,Ara,Xyl,Man,Glu,Gal and GalA,and their molar proportions were 1:2.96:0.21:0.26:0.08:0.58 and 0.15,respectively.