葡聚糖的环氧化修饰与表征

以1，4-丁二醇二缩水甘油醚（BDE）为环氧化试剂，对葡聚糖（Dex）进行功能化修饰，探讨了投料比、pH值、反应时间等条件对环氧取代度的影响。通过核磁共振氢谱（1HNMR）表征产物的结构，采用多角激光光散射与尺寸排阻色谱联用分析系统（MALLS-SEC）考察产物的分子量及其分布。采用Axen方法测定产物的环氧取代度，并通过检测产物中环氧量随时间的变化情况考察了产物的稳定性。结果表明。环氧基团被成功地引入到葡聚糖的单元节上。并且通过改变反应条件可以对环氧取代度进行调控，得到稳定的环氧化葡聚糖产物；在反应温度为37℃、投料比n（Dex）：n（BDE）=1；30、pH=12．6、反应时间为12h的条件下，环氧取代度高达16％，且4℃的低温下环氧化葡聚糖在水中的稳定性良好。

Synthesis and Characterization of Epoxy-Activated Dextran

The epoxy-activated dextran was synthesized by ring-opening reaction using dextran （20 kDa） and 1,4-butanediol diglycidyl ether （BDE） as respective reagent. Various factors,including the ratio of react ants,pH value, reaction time,on epoxy degree of epoxy-activated dextran were investigated. The structure of epoxy-activated dextran was characterized by 1 HNMR. The molecular weight and its distribution of epoxy-acti- vated dextran were determined by MALLS-SEC. The epoxy degree of epoxy-activated dextran was measured by Axen method. The stability of epoxy-activated dextran was determined in terms of changes of its epoxy amount with time. The results showed that epoxy groups were successfully introduced into sephadex units section,and the stable epoxy-activated dextran was obtained by controlling epoxy degree through changing the reaction con- ditions. The epoxy degree of epoxy-activated dextran reached 16 % under following conditions：the reaction tem- perature of 37 ℃,the molar ratio of dextran to BDE of 1 ： 30,the pH value of 12.6,the reaction time of 12 h. Storage stability experiment uncovered that the aqueous solution of the product was stable at lower temperature of 4 ℃.