太白蓼多糖的硫酸化修饰及其体外抑菌活性分析

Sulfate Modification of Polygonum taipaishanease Kung Polysaccharide and Antibacterial Activity of Modified Products in Vitro

建立并优选太白蓼多糖(Polygonum taipaishanease Kung polysaccharide,PTKP)硫酸化修饰的条件,探讨硫酸化修饰对太白蓼多糖抑菌活性的影响。以硫酸根取代度为指标,采用氯磺酸-吡啶法对太白蓼多糖进行修饰,以氯磺酸-吡啶比、反应时间和反应温度为因素水平,采用L9(34)正交试验对修饰条件进行优选。用氯化钡-明胶浊度法测定修饰产物的硫酸基取代度(DS),傅里叶红外变幻光谱法测其结构,微量法测定硫酸化太白蓼多糖(sulfated Polygonum taipaishanease Kung polysaccharide,sPTKP)对大肠杆菌和志贺氏菌的最小杀菌浓度。太白蓼多糖硫酸化修饰的最佳条件为氯磺酸与吡啶体积比为1∶10,反应温度为80℃,反应时间为1h,sPTKP的硫酸基取代度为1.57。红外光谱检测到S=O的伸缩振动峰。PTKP和sPTKP对大肠杆菌和志贺氏菌均有抑制作用,它们对志贺氏菌的抑制作用优于大肠杆菌。硫酸化修饰能提高太白蓼多糖对大肠杆菌和志贺氏菌的体外抑菌活性。

To create the condition of sulfated modification of Polygonum taipaishanease Kung polysaccharide （PTKP） and explore the influence of sulfation on antibacterial activity of PTKP, based on index of sulfate substitution degree,Polygonurn taipaishanease Kung polysaccharide was modified by chlorosulfonic acid pyridine method. The modification conditions were optimized with L9 （34） orthogonal experiment by using the ratio of chlorosulfonic acid to pyridine, reaction time and reaction temperature as the factor levels. Barium sulfate -gelatin turbidity method was used to determine the degree of substitution （DS）. Then, the structure of modified products were detected by Fourier infrared spectroscopy. The minimum bactericidal concentrations of sulfated Polygonurn taipaishanease Kung poly- saccharide（sPTKP） on E. coli and Shigellosis were also examined by micro broth dilution method. The best conditions of sulfated modification on Polygonum taipaishanease Kung polysaccharide were as followings： the volume ratio of chlorosulfonic acid to pyridine was 1 ： 10,reaction temperature was 80 ℃ ,reaction time was 1 h,and the degree of substitution was 1.57. S=O stretching vibration peaks were detected in the infrared spectrum. Both PTKP and sPTKP could inhibit E. coli and Shigellosis in vitro,and their inhibitory effects on Shigella was better than on E. coli. In conclusion, sulfated modification could improve the antibacterial activity of Polygonum taipaishanease Kung in vitro.