活性多糖的结构表征与功能性质以及二者之间构效关系机制的研究是目前生命科学研究的热点，而苦豆子多糖的研究缺乏系统性。本项目在苦豆子多糖前期制备的基础上，分析苦豆子多糖组分的物化性质，应用医学和生物学方法研究多糖组分体外和体内抗肿瘤活性，确定活性多糖组分。通过现代仪器分析结合部分酸水解和甲基化分析等化学方法表征活性多糖的一级结构，确定糖苷键连接方式以及多糖主链上的取代等。采用仪器分析和计算机模拟推理获得多糖分子链的特征参数如对称性、螺距等，观察多糖分子的形貌、凝胶网络和糖的亚细胞结构，揭示活性多糖的高级结构。通过光散射技术确定多糖分子尺寸和流体动力学半径等参数，从分子水平上研究多糖分子在溶液中的空间构象。通过分子修饰技术研究多糖链的聚合度、取代方式、支链分布及分子构象等对多糖抗肿瘤活性的影响，诠释多糖的功能机制和结构与功能之间的构效关系，明确多糖的活性部位和影响活性的关键因素。

The studies on structural characterization and functional property of bioactive polysaccharides and relationships between them are hot points in food and life science at present. However, there is a lack of systematic study of polysaccharides from Sophora alopecuroides L., a traditional Chinese herb, mainly distributed in northwest China. The spatial structure, melecular configuration and functional mechanism of bioactive polysacchrides from Sophora alopecuroides L. are investigated and determined in this project. The physicochemical properties of polysaccharide fractions from Sophora alopecuroides L. are analyzed and antitumor bioactivities of fractions both in vitro and in vivo are carried out using medical and biological methods based on preparation of polysaccharides using extracting alkaloids waste as material. The primary structure of bioactive fractions are determined using partial acid hydrolysis and methylation analysis, combined with HPAEC-PAD, GC-MS and 1D & 2D NMR spectroscopy techniques. The monosaccharide compositions, linkages of glycosidic bonds and side chains attached to the polysaccharide backbone are obtained. Advanced structural characterizations of bioactive polysaccharides are described by reasoning the characteristic parameters of polysaccharide chains, such as symmetry and screw pitch. The morphology, gel network and subcellular structure of fraction molecules are investigated using the atomic force microscope (AFM). The spatial configurations of polysaccharide molecules in solution are investigated in the molecular level by dynamic and static light scattering techniques. The weight average molecular weight (Mw), radius of gyration (Rg), the second virial coefficient (A2) and hydrodynamic radius (Rh) of the molecules are derived, and molecular conformations are obtained. The effects of degree of polymerization, substitution pattern and distribution of side chains and configuration of polysaccharide molecules on antitumor bioactivities are studied by molecular modification techniques. The functional mechanisms and relationships between structure and function of bioactive polysaccharides are elucidated, and meanwhile the important elements and bioactive sites of polysaccharide molecules are determined.