[关键词]
[摘要]
目的 马兰多糖类组分为其抗实验性胃溃疡作用的物质基础之一,为了探讨马兰多糖结构与功能之间的关系,对马兰多糖进行了分离纯化和结构分析。方法 以马兰为原料,采用热水提取,酶法结合Sevag法除蛋白,经DEAE-52纤维素柱精制得纯品马兰多糖(KIP-1)。采用凝胶色谱、红外光谱(FTIR)、GC、GC-MS甲基化分析等方法对其化学结构进行初步分析,并通过原子力显微镜(AFM)观察其微观结构。结果 KIP-1是一重均分子质量(Mw)为11 592,由甘露糖(Man)、葡萄糖(Glc)、半乳糖(Gal)以物质的量比2.523∶1.162∶l组成的多糖。主链为1, 3→连接的Glc和1, 2→连接的Gal,Man构成糖链的末端,该糖链的分枝点残基为1, 3, 6→Man,分枝点应在O-3上。KIP-1结构为颗粒状,不规则圆形及椭圆形,平均粒径大小1~2 nm,空间中同样呈现不规则形状,高度起伏约1 nm。结论 KIP-1由甘露糖、葡萄糖、半乳糖组成,具有分枝结构,为首次从马兰中分离得到。
[Key word]
[Abstract]
Objective The polysaccharide from Kalimeris indica (KIP) has been proved to be one of effective parts with anti-gastric ulcer action. In order to accurately define the structure and structure-activity relationship of KIP, the purification and structural analysis of KIP were carried out. Methods A water-soluble polysaccharide (KIP-1) was obtained from K. indica by hot water extraction, deproteination with enzymolysis and Sevag methods, and fractionation through DEAE cellulose (DE-52) column. The molecular weight of KIP-1 was determined by gel chromatography (Sephadex G-200). The structure was characterized with FTIR, GC, and GC-MS methylation analysis. The microstructure of KIP-1 was observed by atomic force microscope (AFM). Results The results indicated that KIP-1 had a molecular weight of 11 592 and was mainly composed of mannose, glucose, and galactose with the ratio of 2.523∶1.162∶l. Methylation analysis showed that KIP-1 had a backbone of 1, 3-linked glucose and 1, 2-linked galactose, of which the branch point was at O-3 composed of a 1, 3, 6-linked mannose residue and terminated with mannose residue. The microstructure study showed that KIP-1 with an average particle size of 1-2 nm was granular, irregular-rounded, and ellipsoidal. Irregularly shaped structure was found together in cubic image of KIP-1 with the height about 1 nm. Conclusion KIP-1 with branch structure is mainly composed of mannose, glucose, and galactose. It is the first time to get the polysaccharide from K. indica.
[中图分类号]
[基金项目]
四川省科技支撑计划项目(2010SZ0245,2011SZZ030,2012ZZ0007);四川省教育厅自然科学研究项目(10ZC030)