二维核磁共振对羊栖菜褐藻糖胶DJL的结构研究

Structure Elucidation of Fucoidan DJL Originated from Hizikia fusiforme by 2D NMR

羊栖菜是我国的特色海藻,褐藻糖胶是其主要生物活性成分.葡萄糖醛酸甘露聚糖(DJL)是羊栖菜褐藻糖胶经脱硫和部分酸水解后的产物,本文采用2D NMR和甲基化分析等方法,对DJL的结构进行了研究.结果显示,DJL主要由甘露糖(46.4%)和葡萄糖醛酸(50.5%)组成,另外还含有少量的半乳糖,相对分子质量为11 KDa,其可能具有的一种结构为:-βD-GlcA(1→[2)--αD-Man(1→4)--βD-GlcA(1→]n1→4)--βD-Gal(1→[4)--βD-GlcA(1→2)-α-D-Man(1→]n2→4)--βD-GlcA(1→2)--αD-Man.

Fucoidan is the primary bio-active component in Hizikia fusiforme, an algae widely distributed in China. DJL is a product of Hizikia fusiforme-originated fucoidan after desulfation and partial hydrolysis. In this study, the structure of DJL was elucidated using 2D NMR spectroscopy and methylation analysis, The result shows that DJL has a molecular weight of 11 KDa and is composed of mannose （Man） and glucouronic acid （GlcA） with a composition ratio of about 1：1. Its possible structure was also determined to be β-D-GlcA（1→[2）-α-D-Man（1→4）-β-GlcA（1→]n1 →4）-β-D-Gal （ 1→[4）-β-D-GlcA （1→2）-α-Man（ 1→]n2→4）-β-D-GlcA（1→2）-α-D-Man.