UNCORRECTED PROOF BEJ 4189 1–6 Biochemical Engineering Journal xxx (2005) xxx–xxx Lipase-catalyzed enantioselective acylation of 3-benzyloxypropane-1,2-diol in supercritical carbon dioxide 3 4 Ildik´ o Kmecz a,∗ , B´ ela Sim´ andi a , L´ aszl´ o Poppe b , Zolt´ an Juvancz c , Katalin Renner a , Vikt´ oria B ´ odai b , Enik ˝ o R. T ˝ oke b , Csaba Csaj´ agi a , J´ anos Sawinsky a 5 6 a Department of Chemical Engineering, Budapest University of Technology and Economics, M˝ uegyetem Rakpart 3, H-1111 Budapest, Hungary 7 8 b Institute for Organic Chemistry and Research Group for Alkaloid Chemistry, Budapest University of Technology and Economics, Szt. Gell´ ert t´ er 4, H-1111 Budapest, Hungary 9 10 c VITUKI Ltd., Kvassay Jen˝ o´ ut 1, H-1095 Budapest, Hungary 11 Received 11 February 2005; received in revised form 19 September 2005; accepted 11 November 2005 12 Abstract 13 Lipase-catalyzed acylation of 3-benzyloxypropane-1,2-diol with vinyl acetate as acyl donor using different lipases [porcine pancreas lipase (PPL), Lipase AK “Amano”, Lipase PS “Amano”, and crude enzymes from Trichoderma reesei RUT-C30, Thermoascus thermophilus (NRRL5208), Talaromyces emersonii (NRLL3221)] was studied in supercritical carbon dioxide (scCO 2 ). In the reactions catalyzed by different lipases different amounts of monoacetate and diacetate products along with minor amounts of cyclic acetals forming from the diol and acetaldehyde were obtained. 14 15 16 17 Application of Lipase AK led to the highest conversion (84.7%) and the highest enantiomeric excess values (ee monoacetates = 38%, ee diacetate = 85%). Effect of water content of scCO 2 on the productivity and the enantiomer selectivity of the reactions with Lipase AK was also investigated. 18 19 © 2005 Published by Elsevier B.V. 20 Keywords: Supercritical carbon dioxide; Enantioselective; Acylation; Water activity; Lipase; Filamentous fungi 21 22 1. Introduction 1 According to the regulation of FDA production of chiral 2 drugs, agrochemicals, fine chemicals has been allowed in enan- 3 tiomerically pure form, because it is often happens that only one 4 of the two enantiomers shows the required therapeutical effect 5 [1]. The inactive enantiomer represents 50% impurity, that often 6 leads to harmful side effects or to environmental pollution. 7 Since Pasteur carried out the first resolution based on diastere- 8 omeric salt formation, several resolution methods – such as 9 chromatographic separations or chemical and biochemical reac- 10 tions – have been developed. 11 Over the last decade the enzyme-catalyzed kinetic resolution 12 of racemic mixtures has become a common tool for preparation 13 of enantiomerically pure compounds. Conventionally enzymatic 14 reactions are performed in aqueous solutions, but many exam- 15 ples indicate that enzymes are also active in organic solvents. 16 ∗ Corresponding author. Tel.: +36 1 463 2246; fax: +36 1 463 3197. E-mail address: kmetz@mail.bme.hu (I. Kmecz). Since the pioneering works of Randolph et al. [2], Hammond et 17 al. [3] and Nakamura et al. [4], who described in the mid 1980s 18 that enzymes are stable and active in supercritical solvents, there 19 is a growing number of studies on the applications of supercrit- 20 ical fluids, especially carbon dioxide, as solvent for different 21 types of enzyme-catalyzed reactions [5–7]. Supercritical carbon 22 dioxide provides environmentally benign reaction media; its low 23 critical temperature makes it an ideal solvent for heat sensitive 24 substances. By changing the pressure and the temperature of 25 carbon dioxide, the separation of the reaction mixture becomes 26 possible, and the final product is free from residual solvent. 27 Chiral glycerol derivatives are important C 3 intermediates of 28 several biologically active substances such as phospholipids [8], 29 phospholipase A 2 inhibitors [9] and platelet activating factors 30 (PAF) [10]. 31 Herradon et al. studied the regio- and enantioselectivity of 32 the lipase catalyzed acylation of racemic 3-benzyloxypropane- 33 1,2-diol in organic solvents such as CHCl 3 , tetrahydrofuran and 34 1:1 mixture of hexane and tetrahydrofuran. The investigated 35 enzymes were lipases from Pseudomonas fluorescens and Pseu- 36 domonas cepacia. The best result was achieved by using P. fluo- 37 1 1369-703X/$ – see front matter © 2005 Published by Elsevier B.V. 2 doi:10.1016/j.bej.2005.11.010