本文以光果甘草叶为原料,提取得到水溶性多糖GC C,采用DEAE-Sepharose Fast Flow柱层析法对GC C进行分离纯化,得到一种中性多糖(GC I),两种酸性多糖(GC II和GC III),选择DPPH自由基清除能力、氧自由基吸收能力(ORAC)强的中性多糖GC I,对其进行结构特征分析。采用高效凝胶渗透色谱法(GPC)、红外光谱法(FT-IR)、PMP柱前衍生-高效液相色谱法(HPLC)、甲基化-气相色谱质谱法(GC-MS)测定GC I的分子量、单糖组成以及糖苷键连接方式。GC I含有两个分子量分布不同的多糖,它们的平均分子量分别为980 ku及20 ku;红外光谱中4000~500 cm-1波数范围内出现了多糖的特征峰;GC I由5种单糖组成,包括:甘露糖、鼠李糖、葡萄糖、半乳糖和阿拉伯糖;GC I中→2)-Araf-(1→、→6)-Galp-(1→和→6)-Glcp-(1→残基含量最高。 In this paper, Ginkgo biloba leaves were used as raw materials to extract water-soluble polysaccharide GC C, GC-C was separated and purified by DEAE-Sepharose Fast Flow column chromatography to obtain a neutral polysaccharide (GC I), two kinds of acid polysaccharides GC II and GC III), and GC I, a neutral polysaccharide with strong DPPH radical scavenging ability and strong oxygen free radical absorption capacity (ORAC), were selected for structural characterization. The GC I was determined by high performance gel permeation chromatography (GPC), infrared spectroscopy (FT-IR), PMP column derivatization-high performance liquid chromatography (HPLC-MS) and gas chromatography-mass spectrometry The molecular weight, monosaccharide composition and glycosidic bond. GC I contains two polysaccharides with different molecular weight distributions, and their average molecular weights are 980 ku and 20 ku, respectively. The characteristic peaks of polysaccharides appear in the range of 4000-500 cm -1 in the infrared spectrum. GC I consists of five kinds of monosaccharides , Including: mannose, rhamnose, glucose, galactose and arabinose; GC I → 2) -Araf- (1 →, → 6) -Galp- (1 → and → 6) -Glcp- The highest content of residues.