Regioselective acylation of pyridoxine catalyzed by immobilized lipase in ionic liquid  

作　　者：Shu BAI Mengyuan REN Lele WANG Yan SUN 

机构地区：[1]Department of Biochemical Engineering,School of Chemical Engineering and Technology,Tianjin University,Tianjin 300072,China

出　　处：《Frontiers of Chemical Science and Engineering》2008年第3期301-307,共7页化学科学与工程前沿（英文版）

基　　金：supported by the National Natural Science Foundation of China(Grant No.20636040);the Program for Changjiang Scholars and Innovative Research Team in University from the Ministry of Education of China.

摘　　要：The regioselective acylation of pyridoxine catalyzed by immobilized lipase(Candida Antarctica)in 1-butyl-3-methylimidazolium hexafluorophosphate([BMIM]PF_(6))has been investigated,and compared with that in acetonitrile(ACN).The acetylation of pyridoxine using acetic anhydride in[BMIM]PF6 gave comparable conversion of pyridoxine to 5-monoacetyl pyridoxine with considerably higher regioselectivity(93%-95%)than that in ACN(70%-73%).Among the tested parameters,water activity(aw)and temperature have profound effects on the reaction performances in either[BMIM]PF6 or ACN.For the reaction in[BMIM]PF6,higher temperature(50℃-55℃)and lower aw(<0.01)are preferable conditions to obtain better conversion and regioselectivity.Mass transfer limitation and intrinsic kinetic from the ionic nature of ionic liquids(ILs)may account for a different rate-temperature profile and a lower velocity at lower temperature in[BMIM]PF_(6)-mediated reaction.Moreover,consecutive batch reactions for enzyme reuse also show that lipase exhibited a much higher thermal stability and better reusability in[BMIM]PF_(6)than in ACN,which represents another advantage of ILs as an alternative to traditional solvents beyond green technology.

关 键 词：PYRIDOXINE ionic liquid LIPASE ACYLATION regioselectivity 

分 类 号：O64[理学—物理化学]