半乳糖基葡聚糖的制备与结构表征  

Synthesis and characterization of galactose-branched dextran

作　　者：徐开俊[1] 杜彬[1] 巩沛鑫 彭树华 何建平 范敏敏[1] 王克[1] 

机构地区：[1]四川大学高分子研究所,四川成都610065 [2]京昆油田科技开发公司,江苏昆山215300

出　　处：《化学研究与应用》2015年第5期573-577,共5页Chemical Research and Application

摘　　要：本文提出了一种在固态条件下,通过磷酸(5 mol%)催化半乳糖与葡聚糖共聚合成了半乳糖基葡聚糖的方法。采用1H NMR确定了不同条件下产物的摩尔取代度,发现当投料比为2:1,反应时间为9h,反应温度为110℃时,MS最大为0.43。还通过凝胶渗透色谱考察了不同反应时间条件下产物分子量,发现随反应时间延长,分子量逐步减小。最后使用甲基化分析法确定了MS=0.27的半乳糖基葡聚糖糖单元连接结构,发现半乳糖基葡聚糖的主链仍然由(1→6)-连接的葡萄糖组成,支化度为11.5%,其中位于主链糖单元C3的支链比例最大。支链半乳糖均为线型连接,并且其中(1→6)-连接比例最大,平均链长约为3个糖单元。Copolymerization of galactose and dextran took place in the presence of H3PO4（5 mol%）at 110℃ under a N2 flow and in solid-state,resulting a branched polysaccharide, galactose-branched dextran. The structural characterization of galactose-branched dextran are investigated. The effect of the dosage of galactose, reaction temperature and reaction time on molar substitution （ MS measured by 1 H NMR） of galactose-branched dextran were investigated. The galactose-branched dextran with the MS of 0. 43 could be obtained under conditions of the molar ratio of galactose to the AGU 2,at 110℃ for 9h. The molecular weight（measured by SEC） of galactose-branched dextran decreased while the reaction time increased. The methylation analysis of galactose-branched dextran with the MS of 0. 27 revealed that it contained 68. 6%（ 1→6 ）-glucosidic linkages in the main linear chain and remained 11. 5%branched linkages. The branched chains consisted of galactose units with varied linkages,it could be deduce that the average length of the branching galactose is about 3 units according the data of methylation analysis.

关 键 词：葡聚糖 半乳糖 共聚 糖链结构 

分 类 号：O636.1[理学—高分子化学]