桔梗多糖的分离纯化与含量测定

Purification and Content Determination of the Polysaccharides from Platycodon grandiflorum

利用离子交换凝胶柱层析法分离纯化桔梗多糖,并对纯化组分进行纯度鉴定和糖含量及蛋白质含量测定。桔梗饮片经热水浸提、乙醇分步沉淀得桔梗粗多糖PPS80,Sevage法脱蛋白后,通过DEAE-Sepharose FF离子交换和Sephadex G-75凝胶柱层析进行纯化鉴定。分别采用苯酚-硫酸法和考马斯亮蓝染色法测定纯化后各组分的糖和蛋白质含量。试验结果表明,从桔梗粗多糖PPS80中分离得到2个均一性组分PPS80-I和PPS80-Ⅱ,糖含量分别为90.32%和86.75%,蛋白质含量分别为0.48%和1.96%。该试验首次采用DEAE-Sepharose FF离子交换柱层析结合Sephadex G-75凝胶柱层析有效分离纯化出桔梗多糖均一性组分,为桔梗多糖的进一步研究提供基础。

To purify the polysaccharide fromPlatycodon grandiflorum via ion-exchange chromatography and detect the contents of saccharide and protein, the crude polysaccharide named PPS80 was extracted from Platycodon grandiflorum using hot water-ethanol fractional precipitation. After removing the protein by Sevage method, the polysaccharide was purified and identified with DEAE-Sepharose FF ion-exchange chromatography and Sephadex G-75 gel chromatography, respectively. The contents of saccharide and protein were determined by phenol-sulfate acid method and Coomassie brilliant blue staining assay, respectively. The results showed that two homogeneous constituents were isolated from PPS80 named as PPS80-I and PPS80-II. It was determined that PPS80-I contained 90.32% saccharides and 0.48% proteins, while PPS80-II contained 86.75% saccharides and 1.96% proteins, respectively. Two homogeneous constituents of polysaccharides were efficiently purified from the crude polysaccharide PPS80 via DEAE-Sepharose FF ion-exchange chromatography and Sephadex G-75 gel chromatography. These results laid an experimental foundation for further research on the polysaccharides fromPlatycodon grandiflorum .