甘草多糖超声辅助提取工艺优化及分子表征

Ultrasonic Assisted Extraction Optimization of Glycyrrhiza Polysaccharide and Its Molecular Characterization

优化超声辅助提取甘草多糖的条件,并对甘草多糖的分子量和结构进行了研究。单因素实验确定最佳提取条件为:设定超声功率500 W时,液料比为20∶1(m L/g),超声时间60 min,温度60℃。应用GC/MS对甘草多糖进行单糖组分分析,得出人工与野生甘草多糖的单糖组分主要是甘露糖和葡萄糖,另外还含有阿拉伯糖、核糖、木糖、半乳糖、葡萄糖醛酸和半乳糖醛酸,说明人工与野生甘草多糖均为酸性多糖。最后利用Sepharose CL-6B层析柱对甘草多糖进行分离纯化,测得人工甘草两个多糖组分相对分子量分别为212 ku和25.1 ku,野生甘草多糖两个组分的相对分子量分别为34.1 ku和0.1 ku。本研究为甘草多糖的生物活性研究和应用提供了理论基础。

In this study,the ultrasonic assisted extraction conditions of glycyrrhiza polysaccharides were optimized and its molecular weight and structure were investigated. The single-factor experiment was used to deter mine the optimum conditions：ultrasonic power 500 W,liquid/solid ratio 20 ∶ 1（m L/g）,ultrasonic time 60 min,temperature 60 ℃. The monosaccharide composition of glycyrrhiza polysaccharide was analyzed by GC/MS. The result showed that the artificial and wild glycyrrhiza monosaccharide components was primarily contained mannose and glucose,also including arabinose,ribose,xylose,galactose,glucuronic acid and galacturonic acid,indicating that artificial and wild glycyrrhiza polysaccharides were acidic polysaccharides. Finally,the glycyrrhiza polysaccharides were purified and two fractions was obtained. The relative molecular weight of artificial glycyrrhiza polysaccharides were 212 ku and 25.1 ku,respectively,while relative molecular weight of wild glycyrrhiza polysaccharides were 34.1 ku and 0.1 ku,respectively. This study provides a theoretical basis for the bioactivity investigation and application of glycyrrhiza polysaccharide.