超声-微波协同提取大青叶多糖及其分子特性和免疫活性研究

为研究大青叶多糖的分子特性和免疫活性,采用超声-微波协同提取大青叶多糖并测定其化学组成,衍生化后利用气质联用分析仪检测单糖组成和链接方式,用HPSEC-MALLS-RI联机系统测定分子质量及分布情况,最后利用RAW264. 7细胞分析大青叶多糖的免疫活性。结果表明,多糖最佳提取参数:料液比25∶1(V/m),温度90℃,蒸馏水浸提70 min,超声-微波提取50 min,微波功率500 W,超声功率50 W,多糖得率为10. 49%。大青叶多糖化学组成包括63. 8%总糖、13. 1%蛋白质、14. 2%硫酸根和12. 6%糖醛酸,单糖组成主要包括半乳糖、阿拉伯糖、鼠李糖和葡萄糖,分子质量为7. 85×105u,回转半径为183. 3 nm。同时分析了大青叶多糖的链接方式,体外生物活性实验表明大青叶多糖可以促进RAW264. 7细胞增殖并产生一氧化氮。

Ultrasound-microwave assisted extraction,molecular properties and immunomodulatory activities of the polysaccharide from Folium isatidis

The molecular properties and immunomodulatory activities of the polysaccharide were investigated in this study,which was extracted from Folium isatidis by the distilled water with the assistance of ultrasound-microwave.Firstly,the chemical compositions of the polysaccharide were analyzed,and its monosaccharide composition and glycosidic linkage were investigated by GC-MS after derivatization.The molecular weight assay was conducted using HPSEC-MALLS-RI system.Finally,the immunomodulatory activities of the polysaccharide were carried out using RAW264.7 cells.In conclusion,the optimal extraction parameters studied by the orthogonal experiment,were as follows,ratio of liquid to solid 25∶1(V/m),temperature 90℃,distilled water extraction 70 min,ultrasound-microwave extraction time 50 min,microwave power 500 W,ultrasound power 50 W,with the yield of polysaccharide 10.49%.The polysaccharide contained 63.8%neutral sugar,13.1%protein,14.2%sulfate and 12.6%uronic acid.Its major monosaccharide units were galactose,arabinose,rhamnose and glucose.The Mw and Rg of the polysaccharide were 7.85×10^5 u and 183.3 nm,respectively.The glycosidic linkage of polysaccharide was also investigated.According to the results of immunomodulatory activities,the polysaccharide can enhance the proliferation of RAW264.7 to produce NO.