کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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70688 | 48842 | 2009 | 5 صفحه PDF | دانلود رایگان |
The kinetic resolution of racemates constitutes one major route to manufacture optically pure compounds. The enzymatic kinetic resolution of (R,S)-1-phenylethanol over Candida antarctica lipase B (CALB) by using vinyl acetate as the acyl donor in the acylation reaction was chosen as model reaction. A systematic screening and optimization of the reaction parameters, such as enzyme, ionic liquid and substrates concentrations with respect to the final product concentration, were performed. The enantioselectivity of immobilized CALB commercial preparation, Novozym 435, was assayed in several ionic liquids as reaction media. In particular, three different ionic liquids: (i) 1-butyl-3-methylimidazolium hexafluorophosphate [bmim][PF6], (ii) 1-butyl-3-methylimidazolium tetrafluoroborate [bmim][BF4] and (iii) 1-ethyl-3-methylimidazolium triflimide [emim][NTf2] were tested. At 6.6% (w/w) of Novozym 435, dispersed in 9.520 M of [bmim][PF6] at 313.15 K, using an equimolar ratio of vinyl acetate/(R,S)-1-phenylethanol after 3 h of bioconversion, the highest possible conversion (50%) was reached with enantiomeric excess for substrate higher than 99%.
Journal: Journal of Molecular Catalysis B: Enzymatic - Volume 58, Issues 1–4, June 2009, Pages 24–28