本课题在前期研究证明硫酸化修饰能够显著提高当归多糖和枸杞多糖的抗病毒和增强免疫活性的基础上，分别从枸杞和当归中提取总多糖和分级多糖，分离纯化，用正交试验优选修饰条件，建立两种多糖的硫酸化修饰方法，对各多糖进行硫酸化修饰，测定多糖及其衍生物的一级结构及硫酸根取代度，从体内、体外试验系统比较不同结构和取代度的硫酸化多糖的抗肿瘤及免疫增强活性的变化，分别筛选出1～2种抗肿瘤活性及免疫增强活性较好的硫酸化多糖，然后从分子水平方面阐明其作用机制，并探讨硫酸化多糖的构效关系。本研究不仅对多糖类药物的开发和应用具有重要意义，而且对研制开发抗畜禽免疫增强剂具有实用价值。

Based on the previous research which proved that sulfation modification could significantly improve the antiviral and immune-enhancing activities of lycium barbarum polysaccharide and Chinese angelica polysaccharide, in this study, total and grade polysaccharides will be extracted from lycium barbarum L and Chinese angelica, respectively, isolated and purified. After modification conditions are optimized by orthogonal design, these polysaccharides will be sulfatedly modified according to optimum sulfation conditions of two polysaccharides and their primary structures and the degree of sulfate group (DS) will be determined. The antitumor and immune-enhancing activities of sulfated polysaccharides with different structures and DS will be compared through the tests in vitro and vivo and 1-2 sulfated polysaccharides with better antitumor and immune-enhancing activities will be selected,respectively. Their molecular mechanisms and structure -activity relationships will be investigated. The present study not only plays an important role of developing and utilizing polysaccharides, but also improves the utility value of preparing immunopotentiators of animals.