LiCl/DMAc均相法制备高取代度硫酸酯化改性凝胶多糖

Preparation of Sulfated Modified Curdlan with High Degree of Substitution by LiCl/DMAc Homogeneous Method

凝胶多糖作为一种细菌胞外多糖食品添加剂,对其进行各种化学修饰意义深远。为了探究更绿色、更高取代度的硫酸酯化方法,采取了LiCl/DMAc的均相体系,将凝胶多糖溶解后用三氧化硫-吡啶复合物对凝胶多糖进行改性,与传统碱性溶解体系相比,取代度和得率均大大提高,当凝胶多糖与SO——(3)·Py物质的量比为1∶12、反应时间为2 h时,反应效果最佳。通过FTIR、XRD、^(13)C NMR和XPS等方法对所制备的材料进行表征,结果表明C-6位优先被取代,且产物中的S元素主要以—SO——(3)^(-)形式存在。

Curdlan is a kind of bacterial polysaccharide food additive.Its chemical modification is far-reaching significance.In order to explore a more green and higher degree of substitution sulfation method,LiCl/DMAc homogeneous system was used in this study.After dissolving the gel polysaccharide,the gel polysaccharide was modified by three sulfur oxide pyridine complex,and the degree of substitution and yield were both compared with the traditional alkaline dissolution system.When the ratio of Curdlan to SO_(3)·Py is 1∶12,and the reaction time is 2 h,and the reaction effect is the best.The prepared materials are characterized by FTIR,XRD,NMR and XPS.The results show that C-6 is replaced first,and the S element in the product mainly exists in the form of—SO_(3)^(-).