铁皮石斛多糖提取工艺优化及其成分分析

Optimized Extraction and Compositional Analysis of Polysaccharides from Dried Stems of Dendrobium officinale

采用响应面法优化铁皮石斛多糖的提取工艺,并对经优化提取得到的多糖基本理化性质进行分析。结果表明:铁皮石斛多糖提取的最佳工艺条件为水料比30:1(mL/g)、提取温度90℃、提取时间2h,在此条件下多糖得率为30.56%。铁皮石斛多糖中糖含量为78.21%、淀粉含量为18.64%、蛋白含量为5.8%、灰分含量为1.28%,主要由甘露糖、葡萄糖组成,两者的物质的量比为5.2:1。铁皮石斛多糖富含Ca(1.07%)、Mg(0.11%)、Fe(0.0012%)、Zn(0.0039%)等元素。高效凝胶渗透色谱结果显示铁皮石斛多糖呈单一色谱峰,均一性较好。通过本方法制得的铁皮石斛多糖的糖含量较高,除淀粉和蛋白外无其他含量较高的杂质成分;该多糖均一性较好,并且富含Ca、Mg、Fe、Zn等矿物质,研究成果可为日后铁皮石斛多糖活性研究以及构效关系讨论提供基础。

Response surface methodology was utilized to optimize the extraction process of polysaccharides from dried stems of Dendrobium officinale （DOP）. The physiochemical properties of DOP obtained by the optimized process were analyzed. The optimal extraction conditions were found to be an extraction duration of 2 h at 90 ℃ with a water/material ratio of 30：1 （mL/g）. The yield of polysaccharides under the optimized conditions was 30.56%. In the resulting extract, 78.21% of neutral polysaccharide, 18.64% of starch, 5.8% of protein and 1.28% of ash were contained, with mannose and glucose being the major monosaccharides at a molar ratio of 5.2：1. DOP was rich in Ca （1.07%）, Mg （0.11%）, Fe （0.0012%） and Zn （0.0039%）. HPGPC analysis demonstrated that the polysaccharide was homogeneous with a single peak. This polysaccharide-rich extract may be useful for future studies on its activity and structure-activity relationship.