羊栖菜岩藻聚糖硫酸酯的甲基化分析

Methylation Analysis of Fucoidan from Sargassum fusiforme

测定褐藻羊栖菜中的岩藻聚糖硫酸酯 (F 2 )的中性单糖组成和硫酸基含量 ,发现F 2主要由岩藻糖、半乳糖、葡萄糖、甘露糖和少量的木糖、鼠李糖等组成 ,硫酸基含量为 3 4.6%。采用温和的溶剂法将F 2脱硫 ,比较其脱硫前后硫酸基含量和中性单糖组成的差异 ,其脱硫产物F 2d的硫酸基含量为 5 .6% ,除岩藻糖含量略有降低外 ,其他中性单糖组成相似 ,测定结果表明脱硫基本完全且效果较好。另外 ,本文选用改良的甲基化方法 ,并通过红外光谱扫描验证了甲基化反应完全。对F 2脱硫前后部分甲基化糖醇乙酸酯的GC MS进行分析比较 ,得出F 2的结构信息 ,包括其主链和支链的构成、连接方式和硫酸基取代位置等。

The neutral monosaccharide constituents and sulfate ester content in fucoidan F-2 from brown seaweed Sargassum fusiforme were determinated. F-2 was composed mainly of fucose, galactose, glucose, mannose and a small amount of xylose and rhamnose. The sulfate ester content was 34.6%. A mild solvolytic desulfation method was used. Compared with F-2, the sulfate ester content in desulfated derivative F-2d was 5.6% and the monosaccharide composition was similar, except that the fucose content decreased slightly. The results suggested that the desulfation was complete and effective. In addition, the optimized methylation method was used and the methylation reaction was proved to be complete by IR spectra. The comparison of GC-MS analysis of partially methylated alditol acetates made before and after the desulfation of F-2 presents useful structural information on F-2, including the composition of its main chains and side chains, the linkage pattern and sulfation positions.