板蓝根多糖提取工艺及对活性成分影响的研究

Extract technology of total polysaccharides and active components effect from root of Isatis indigotica

目的:考察板蓝根总多糖提取的影响因素,确定总多糖制备最佳工艺。方法:采用3因素3水平正交试验设计,考察温度、液料比和提取次数对总多糖得率、糖含量、相对分子质量分布以及单糖组成的影响。同时考察不同提取温度对总多糖理化性质的影响。采用苯酚-硫酸法测定糖含量;乙酸酯衍生-气相色谱法测定单糖组成;凝胶渗透高效液相色谱法测定多糖相对分子质量。结果和结论:①正交试验结果表明,影响总多糖得率的因素次序:提取温度>液料比>提取次数,提取温度是最大影响因素。②单因素考察结果表明,随着提取温度的升高,总多糖得率、大分子多糖以及总多糖中葡萄糖相对摩尔比均显著增加,而其中二种活性多糖含量明显减少,特别是提取温度≥70℃效果更显著。因此提示板蓝根总多糖的最佳提取工艺为:温度≤60℃,液料比15∶1,提取2次。该提取工艺条件有利于2个活性多糖的浸出,同时又经济可行。

Objective： To investigate the suitable extract technology for extracting the total polysaccharides and two active components from root of Isatis indigotica. Methods： Orthogonal experiment was carried out using a three factors and three levels design to investigate the effects of temperature, water volume and extracting times on the yield, sugar content, molecular weight and monosaccharide ratio of the total polysaccharides. The sugar content was determined by phenol-sulfuric acid method. Monosaccharide compositions were analyzed with the alditol acetates by gas chromatography. Molecular weights of polysaccharides were determined by gel filtration chromatogra- phy. Results and Conclusion： The orthogonal experiments showed that the three influent factors were in this se- quence ： extract temperature 〉 ratio of solid to liquid 〉 extract frequency. The extract temperature was the most im- portant factor. When the extract temperature was raised gradually, the yields, large molecular polysaccharides and the ratios of glucose in the total polysaccharides were significantly increased. However, the two active polysaccha- rides were markedly less at extract temperature ≥ 70℃. The optimal conditions were that ratio of solid to liquid was 1： 15, extract temperature was ≤60℃, and extract frequency was two times. This extract technology is economical and in favor of two active polysaccharides.