东北红豆杉多糖的化学研究

利用水提醇沉提取东北红豆杉多糖TP,经超滤得到超滤外液TP-1和内液TP-2。TP-2进行部分酸水解和凝胶柱层析分离纯化,得到TP-2-1a。通过对理化性质、分子量、单糖组成和甲基化测定结果分析,确定其分子量分布在7.0 kDa左右,糖组成由Rha、Man、Gal、Glu、GalA和GlcA构成,摩尔比为:16.9∶1.0∶15.5∶1.3∶9.9∶2.5,中性糖以Gal的1→3、1→4连接为主,在1→3连接的O-6位上有分支;Rha以1→2连接为主,在O-4位上有分支;Man以1→4、1→6连接为主;Glu以1→3、1→4连接为主;非还原末端主要是Gal及少量的Man、Glu和Rha。酸性糖以1→4连接GalA为主,无分支。该多糖为首次从东北红豆杉中分离得到。

Chemical Analysis of Polysaccharides from Taxus cuspidate

TP was obtained by water extraction and alcohol precipitation from Taxus cuspidate.TP was filtrated through a cellulose ultrafiltration system to give the extra-ultrafiltrate with TP-1 and intro-ultrafiltrate with TP-2.TP-2 was treated with partially acid hydrolysis,then purified by Sephadex G-75 column to obtain the polysaccharides TP-2-1a.TP-2-1a was studied,including the physical and chemical properties,molecular weight,sugar compositions,glycosidic linkage analysis and so on.The molecular weight of TP-2-1a was about 7.0×103 kDa.Suger compositions were Rha,Man,Gal,Glu,GalA and GlcA,in molar ratio of 16.9∶ 1∶ 15.5∶ 1.3∶ 9.9∶ 2.5.The backbone of TP-2-1a were(1→3) and(1→4)-linked galactosyl,(1→4) and(1→6)-linked mannosyl,(1→3) and(1→4)-linked glucosyl,and(1→4)-linked galacturonide,There were side chains attached to O-6 of(1→3)-linked galactoside and O-4 of(1→2)-linked rhamnoside.And the non-reducing terminals were mostly galactose and a few mannose,glucose and rhamnose.This is the first time to obtain the polysaccharides from T.cuspidate.