牛蒡寡糖的分离纯化及结构研究

Separation, Purification and Structure of Burdock Oligosaccharide

以菊科植物牛蒡(A rctium lapp a L.)的等外根为材料,经热水浸提、木瓜蛋白酶-Sevag法脱蛋白、乙醇沉淀和SephadexG-50凝胶柱层析分离纯化,得到水溶性的牛蒡寡糖(BO S-2).采用化学分析方法研究了BO S-2的理化性质,并通过TLC,GC-M S,HP-GPC,UV,IR,1H NM R及13C NM R等对BO S-2的纯度、结构和组成进行表征.结果表明,BO S-2由果糖和葡萄糖组成,摩尔比约为12∶1,纯度较高,为均一性组分;由12个呋喃型的果糖以β(2→1)糖苷键相连,1个吡喃型的葡萄糖以α(1→2)糖苷键连接在果糖末端的线性直链结构,是一种菊糖构型的低聚果糖.

A kind of soluble oligosaccharide, Burdock oligosaccharide(BOS-2), was extracted by hot water, deproteinized by enzymolysis and Sevag method, precipated by ethanol, separated and purified by Sephadex G-50 column chromatography from burdock sub-standard root. Its purification, physical and chemical properties and structure were studied by means of some chemical reactions assay and instrumental analysis. The results show that BOS-2 is composed of D-fructose and D-glucose in a molar ratio of about 12∶1, which is confirmed by the composition of 12 fructose residues linked by -{β(2→1)-} glucoside bond and 1 glucose residue linked by α(1→2) glucoside bond at the end of linear straight sugar chain. It is shown to be a single homogeneous component.