寡聚乳酸改性葡聚糖的合成及表征

Dextran Modified by L-lactic Acid Oligomers

设计了两种基于寡聚L-乳酸(OLL)改性葡聚糖的工艺路线:路线Ⅰ为OLL末端羟基活化后接枝葡聚糖;路线Ⅱ为在亲核试剂及偶合剂的存在下,OLL末端羧基接枝葡聚糖。研究表明,固定OLL与葡聚糖摩尔比,延长反应时间有利于提高路线Ⅰ的产品得率,而对路线Ⅱ中的产品得率几乎没有影响。1HNMR,IR,UV表征改性后产物显示OLL在葡聚糖上的接枝率(葡聚塘的100个葡萄糖单元上OLL的数目)可以通过调节反应物摩尔比得到有效的控制。

Two different strategies were developed to graft L - lactic acid oligomers （OLL） to dextran ： Route Ⅰ, OLL grafted to dextran via its terminal activated -hydroxyl group;Route Ⅱ,OLL grafted to dextran via its terminal carboxylic acid group with the presence of nucleophilic reagent and coupling reagent. Under given molar ratio of OLL and dextran,the yield of the dextran grafted by OLL increased with the increased reaction time in route Ⅰ,while almost constant yield was observed under various reaction time in route Ⅱ. The characterization of the product by 1HNMR, IR,UV revealed that dextan could be modified by OLL and the grafting rate（the number of oligomers per 100 glucopyranose units of dextran）could be effectively controlled by molar ratio of the reactants.