沙枣多糖结构的初步研究

Purification and preliminary analysis of Elaeagnusangustifolia L.polysaccharide-1a

采用热水浸提法从沙枣中提取沙枣多糖,经Sevage法除蛋白,乙醇沉淀,离心、流水透析、DEAE-cellulose52和Sephadex G-100纯化、浓缩、冻干后得沙枣多糖(EAP-1a),并利用苯酚-硫酸法、紫外、红外、气相色谱、刚果红实验、核磁共振技术及原子力显微镜进行多糖组分、含量、结构的分析研究。结果表明:沙枣多糖主要由阿拉伯糖、木糖、葡萄糖及半乳糖组成,还含有少量的鼠李糖和甘露糖,其摩尔比为0.029∶0.74∶0.51∶0.039∶1.0∶5.19。高效液相色谱计算多糖数均分子量约61421u;红外光谱及核磁共振图谱表明沙枣多糖具有α-吡喃葡萄糖环,具有糖类物质的结构特征;AFM观测结果表明EAP-1a呈长链状形态,可缠绕形成棒状纳米聚集体且具有三股螺旋结构。

Polysaccharide of Elaeagnusangustifolia L. （EAP）was extracted by hot water.And EAP-1a was made by investiguted deproteinization with sevage method, ethanol precipitation, centrifugation, diasylis, DEAE- cellouse 52 and Sephadex G- 100, concentration and lyophilization. Meanwhile, the composition, content and structure of EAP-1a was investigated through phenol- sulfuric acid method, UV, I R, gas chromatography （ GC）, Congo- red test,NMR and AFM. The results showed that, EAP-1a was mainly composed of rhamnose, arabinose, xylose, mannose, glucose and galactose with a molar ratio of 0.029：0.74：0.51：0.039：1.0：5.If.The molecular weight of EAP- 1a was 61421u; I R spectra and NMR showed EAP-1a had α-glucose which was structural characteristic of the polysaccharide.AFM showed EAP-ia had long chain,which could be winded rod-shaped nano aggregation and no triple helix conformation.