The use of organic solvents/ionic liquids mixtures in reactions catalyzed by lipase from Burkholderia cepacia immobilized in different supports

Abstract

In this study, lipase originating from Burkholderia cepacia (BCL) was immobilized in three different supports, starch film (SF), agar gel (AG) and loofa sponge (LS), and used to obtain two aroma esters (1-octyl acetate and 1-pentyl octanoate) and a monoepoxide derived from β-caryophyllene. Seven organic solvents with different log P values were evaluated in transesterification, esterification and epoxidation reactions. Subsequently, two solvents were chosen for the preparation of the organic solvent/ionic liquids mixtures in order to investigate the influence of the medium on these reactions. A series of imidazolium (BMIM) derivatives was used for this purpose. The ester 1-octyl acetate was obtained (>99% conversion) when BCL was immobilized in starch film and LS, using n-hexane or ethyl ether in mixtures with [BMIM][PF6], [BMIM][BF4] and [BMIM][SCN]. With regard to the preparation of 1-pentyl octanoate the best results (conversions >99%) were obtained using MTBE in mixtures with [BMIM][PF6], [BMIM][BF4] and [BMIM][SCN] or using ethyl ether/[BMIM][BF4] when BCL was immobilized in LS. The highest degree of conversion of β-caryophyllene to the respective monoepoxide was 87%, with the use of BCL immobilized in agar gel and employing acetonitrile/[BMIM][PF6] as the organic medium.