摘要
研究了1-丁基-3-甲基咪唑六氟磷酸盐[BMIM]PF6/缓冲液两相体系中,热带假丝酵母104细胞催化3,5-双三氟甲基苯乙酮不对称还原制备(S)-1-[3,5-双(三氟甲基)苯基]乙醇的反应过程。通过考察影响生物还原反应的主要因素,如离子液体浓度、辅助底物种类和浓度、底物浓度、菌体浓度和转化时间等,发现上述因素对产率影响较大,但基本不影响产物手性醇的光学纯度。优化得到的较佳还原反应条件为:[BMIM]PF6体积分数5%,辅助底物为60 g L 1异丙醇,底物3,5-双三氟甲基苯乙酮浓度70 mmol L 1,菌体浓度350 g L 1,转化时间24 h。在优化条件下,产率达82.5%,产物(S)-1-[3,5-双(三氟甲基)苯基]乙醇的对映体过量值大于99.9%。与水相转化相比,采用[BMIM]PF6/缓冲液两相体系进行3,5-双三氟甲基苯乙酮的生物不对称还原可有效提高底物浓度和产率,且反应时间缩短了6 h。
An ionic liquid-buffer biphasic system was employed to improve the asymmetric reduction of 3,5-bis（trifluoromethyl） acetophenone to （S）-1-[3,5-bis（trifluoromethyl）phenyl] ethanol catalyzed by Candida tropicalis 104 cells. Some key reaction parameters, such as [BMIM]PF6 content, co-substrate and its concentration, substrate concentration, cell concentration and reaction time, were investigated, respectively. The results show that these factors obviously affect the yield of the prepared product, but the optical purity of the corresponding （S）-1-[3,5-bis（trifluoromethyl）phenyl] ethanol keep intact. The optimum values of [BMIM]PF6 content, co-substrate concentration, substrate concentration, cell concentration and reaction time are 5 %, 60 g.L- 1（isopropanol）, 70 mmol.L-1, 350 g.L-1 and 24 h, respectively. Under above optimal conditions, the best yield of 82.5 % and over 99.9 % of product e.e. were obtained. The results also demonstrate that the bioconversion is more efficient in [BMIM]PF6/buffer biphasie systems than that in monophasic aqueous system, the substrate concentration and the yield can be markedly increased, and the reaction time is shorter for 6 h.
出处
《高校化学工程学报》
EI
CAS
CSCD
北大核心
2012年第2期279-284,共6页
Journal of Chemical Engineering of Chinese Universities
基金
国家自然科学基金项目(21076193)
浙江省制药重中之重学科开放基金(20100609)
浙江工业大学"大学生创新性实验计划"项目(2010034)
