大苞鞘石斛中多糖DWW-1的提纯及其结构与性质分析

Purification and Analysis of DWW-1 from Dendrobium wardianum

从大苞鞘石斛Dendrobium wardianum中分离纯化得到一种均一多糖组分DWW-1,采用化学和光谱学的方法对其理化性质及初步结构进行研究。首先采用水提醇沉方法制备大苞鞘的粗多糖,经过Sevag法除蛋白,DEAE-Cellulose和SephadexG-75柱层析分离纯化得到均一多糖DWW-1纯品。其次利用化学法、高效凝胶过滤色谱法、液相色谱法,并结合红外光谱,对DWW-1进行性质及结构分析。结果显示DWW-1为白色絮状固体,易溶于水,分子量为6.479×10~4,糖基组成为葡萄糖、糖醛酸、甘露糖、岩藻糖四种单糖;多糖糖苷键以1→4连接键为主,1→3为次;其次DWW-1具有较强DPPH自由基清除活性。初步研究结果表明从大苞鞘石斛中分离到的是一种具有抗氧化活性多糖,并简称为DWW-1。

Crude polysaccharides from Dendrobium wardianum were extracted by water and precipitated by ethanol.Deproteinization with Sevage method,DWW-1 was separated and purified by DEAE-Cellulose and Sephadex G-75 column chromatography.Analysis of properties and structure was performed by using chemical method,HPGPC,HPLC,GC-MS and IR.The results showed that DWW-1 was a white flocculent solid after vacuum freeze-drying,soluble in water,with relative molecular mass of 6.479×104.It was composed of glucose,glucuronic acid,mannose and fucose.DWW-1 showed strong scavenging ability on DPPH free radicals.