基于柱前衍生化HPLC分析8种石斛精制多糖的单糖组成及含量

Analysis of monosaccharide composition and content of eight kinds of dendrobium refined polysaccharides based on pre-column derivatization HPLC

目的:分析8种石斛精制多糖的单糖组分及含量,为石斛资源的合理利用以及探讨石斛产区影响石斛多糖品质的形成提供依据。方法:采用水提醇沉法提取石斛多糖,Sevage法除蛋白并透析纯化多糖;采用柱前1-苯基-3-甲基-5-吡唑啉酮(PMP)衍生化高效液相色谱(HPLC)法对来自不同产地的8种石斛进行精制多糖中的单糖组分和含量分析。结果:8种石斛的单糖由甘露糖、葡萄糖、半乳糖和木糖组成,但含量存在一定的差异。单种石斛的单糖含量比较,均以甘露糖为最高组分;且8种石斛的甘露糖占比,属紫皮石斛最高,达到84.35%,而葡萄糖仅含2.36%。相似度评价、聚类分析及主成分分析结果显示,不同产区石斛单糖含量差异较大,同一产区不同种石斛单糖含量差异小。结论:石斛多糖的单糖组分及含量与其品种和产区有关,上述结果从单糖含量及组成摩尔比的角度为鉴别紫皮石斛提供了新思路。

Objective: To analyze the effects of monosaccharide components and content differences of polysaccharides from eight Dendrobium species, to provide the basis for rational utilization of Dendrobium resources and to explore the influence of Dendrobium production area on the formation of polysaccharide quality. Methods: Dendrobium polysaccharides were extracted by water extraction and alcohol precipitation, and purified by dialysis after protein removal by the Sevage method. The composition and content of monosaccharides in purified polysaccharides of 8 species of Dendrobium from different areas were analyzed by HPLC with 1-phenyl-3-methyl-5-pyrazolone(PMP) derivatization before column. Results: The monosaccharides of 8species of Dendrobium were composed of mannose(Man), glucose(Glu), galactose(Gal), and xylose(Xyl), but there were some differences in content. In a comparison of monosaccharide content of single Dendrobium species, Man was the highest component.Besides, the proportion of Man in the eight species of Dendrobium was the highest in Dendrobium devonianum Paxt, reaching 84.35%, while Glu content was only 2.36%. The results of similarity evaluation, cluster analysis, and principal component analysis showed that the monosaccharide content of Dendrobium from different producing areas had great differences, while the monosaccharide content of different species of Dendrobium from the same producing area had little differences. Conclusion: The monosaccharide composition and content of Dendrobium polysaccharides are related to their varieties and regions, and the above results provide a new idea for the identification of Dendrobium devonianum Paxt. from the perspective of monosaccharide content and molar ratio.