枸杞子经提取,醇沉,得到枸杞水溶性多糖粗品(LBP)。最佳乙醇沉淀添加量为50 m L浓缩液中添加80 m L体积分数95%乙醇;最佳乙醇醇沉时间为12 h;Sevag法除蛋白次数为6次,脱除率为83.45%。枸杞粗多糖经DEAE-52纤维素(OH-)色谱柱、Sephedex G-50柱层析纯化后,得到LBP1和LBP2。采用紫外光谱扫描和Sephedex G-100柱层析鉴定LBP1和LBP2均为分子质量相对均一的组分。高效液相色谱检测LBP1和LBP2的相对分子质量分别为367和358。苯酚-硫酸法测得:LBP1和LBP2的中性糖含量分别为82.20%和74.50%;咔唑-硫酸法测得LBP1和LBP2的半乳糖醛酸含量为7.50%和14.30%。气相色谱测得LBP1的单糖组成摩尔比为半乳糖∶甘露糖∶葡萄糖=1.79∶1.00∶3.08;LBP2的单糖组成的摩尔比为半乳糖∶甘露糖∶葡萄糖=1.32∶1.00∶7.38。红外光谱测定结果显示,LBP1和LBP2均由吡喃糖构成。β消去反应检测得LBP1和LBP2与氨基酸是通过O-糖苷键相连。刚果红实验证明LBP1和LBP2均不存在三股螺旋结构。粒度实验表明,溶液酸碱度会影响枸杞多糖的粒度分布。

Crude polysaccharide( LBP) was obtained by extraction and ethanol precipitation from fruit bodies of Lycium barbarum. The best precipitated condition was adding 80 m L ethanol to 50 m L concentrated solution for 12 h.The process of removing protein was Sevag method repeating 6 times with the removal rate of 83. 45%. Two groups LBP1 and LBP2 were separated by DEAE-52 Cellulose column and Sephedex G-50 column chromatography using different solvent. After UV spectra imageand Sephedex G-100 column chromatography determination,LBP1 and LBP2 were regarded as homogeneous components. The average molecular weights of LBP1 and LBP2 determined by HPLC were estimated to be 367 k Da and 358 k Da,respectively. The results from Phenol-sulfuric acid and Carbazole-sulfuric acid determination showed that the neutral sugar of LBP1 and LBP2 were 82. 20% and 74. 50%,the uronic acid of LBP1 and LBP2 were 7. 50% and 14. 30%,respectively. The results of GC showed that monosaccharide compositions of LBP1 contained D-galactose,D-mannose and D-glucose with molar ratio of 1. 79∶ 1. 00∶ 3. 08,and LBP2 contained D-galactose,D-mannose and D-glucose with molar ratio of 1. 32 ∶ 1. 00 ∶ 7. 38. β-elimination reaction suggested that there are O-glueosidie linkage between sugars and amino acids in LBP1 and LBP2. The FT-IR detection showed that glycosidic bond was pyranosetype in both LBP1 and LBP2. Congo red test show that LBP1 and LBP2 do not exist the triple helix structure. Particle experiments show that solution p H could change particle distribution of LBP1 and LBP.