Enantioselective desymmetrization of meso-cyclopent-2-en-1,4-diacetate to 4-(R)-hydroxycyclopent-2-en-1-(S)-acetate using enzyme immobilized superparamagnetic nanocomposites

M. Eizadi Sharifabad, T. Sen
University of Central Lancashire, UK

Keywords: nanocomposites, enzymes


Enzymes are well established as catalysts for various bio-transformations. However, it is difficult to remove the expensive enzymes from the reaction mixtures. Hence, immobilization of enzymes on solid support is a very important step for the recovery and recycling of the enzymes. Magnetisable solid support could have an additional benefit in separation of catalysts from the reaction mixture by the influence of external magnetic field. In this context, magnetic nanocomposites and nanoparticles have been previously used to immobilize lipases for ester hydrolysis.1-3 The use of immobilized enzymes is particularly important as they exhibit increased stability and catalytic activity compared with free enzymes.4,5 Bio-transformations catalysed by immobilised enzymes or microbial cells have tremendous potential in the industrial production of fine chemicals.6,7 For example, in the pharmaceutical industry enantiomerically pure (1R,4S)-(+)-4-Hydroxycyclopent-2-ene-1-acetate (2a) or its enantiomer (2b) are starting materials (see scheme 1) for the synthesis of prostaglandins8,9 prostacyclins and thromboxanes10. These starting materials can be synthesized bio-catalytically by either the enzymatic hydrolysis of the diacetate (3) or transesterification of diol (1) using lipases. Considering the large market demand for high cost chiral intermediates, like 2a and 2b in reaction scheme 1, development of economically viable enzymatic technology for their large-scale preparation represents an important synthetic objective. Herein, we report a preliminary study of three different enzymes (PFL, PPL, CRL) immobilised two solid supports (i.e. HOPMN and SPIONs) for the performance in model catalysis (hydrolysis of p-nitro phenyl palmitate) and acylation of diol (1). Commercial PFL immobilized immobed has been used for the comparison purpose. See full PDF.