离子液体中6-O-(11-十二烯酸)葡萄糖酯的脂肪酶催化合成及其表征

为了探索脂肪酶在离子液体中选择性地催化葡萄糖与11-十二烯酸乙酯的转酯化反应,通过不同脂肪酶在不同离子液体中进行转酯化反应,并用单因素法研究离子液体种类、温度、底物的比例、体系含水量和脂肪酶含量对反应产率的影响,优化反应条件。反应产物的结构通过红外光谱、高效液相色谱、质谱和核磁共振等表征。结果表明:脂肪酶Novozym-435在离子液体1-正丁基-3-甲基咪唑氟硼酸盐BMIM]BF4]中,当反应温度为55℃、酶浓度20mg/mL、葡萄糖/11-十二烯酸乙酯的摩尔比1∶2、体系的水含量为2%时,获得糖酯的产率最高,Novozym-435可以重复使用7次。脂肪酶Novozym-435在离子液体BMIM]BF4]中选择性转酯化反应的产物为6-O-(11-十二烯酸)葡萄糖单酯。

Lipase-catalyzed synthesis and characterization of 6-O-(11-dodecenoic)-glucose ester in ionic liquids

In order to investigate the lipase-catalyzed selective transesterification of glucose with 11-dodecenoic ethyl ester in ionic liquids,the single-factor method was used to optimize the reaction conditions and determined various factors on the yield such as ionic liquids,temperature,molar ratio,water content and enzyme concentration.The synthetic product structure was characterized by FT-IR,HPLC,MS and NMR.The results showed that the highest yield of sugar ester was obtained in 1-butyl-3-methyl imidazolium tetrafluoroborate under such conditions as the reaction temperature at 55 ℃,the enzyme concentration at 20 mg/mL,the mole ratio of glucose over 11-dodecenoic ethyl ester at 1∶ 2,and the water content of the system at 2%.Lipase Novozym-435 can be used 7 times repeatedly.The catalyzed product by Novozym-435 lipase in selective transesterification in BF4 was 6-O-(11-dodecenoic)-glucose ester.