2. Department of Chemistry, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India.
The use of enzymes in nearly anhydrous organic solvents generally results in low initial rates/percentage conversions. The current review focuses on some biocatalyst designs like immobilization on nanomaterials, enzyme precipitated and rinsed with organic solvents (EPROS), crosslinked enzyme crystals (CLEC), crosslinked enzyme aggregates (CLEA), protein coated microcrystals (PCMC) and crosslinked protein coated microcrystals (CLPCMC) which show much better catalytic efficiency in such media as compared to other kinds of biocatalyst preparations. The basic methodology and principle behind these efficient designs are described. The relatively recent results on catalytic promiscuity as seen in low water media have also been covered. It is hoped that this will further encourage wider applications of enzymes in neat organic solvents in organic synthesis.
Keywords: Transesterification reactions, aldol condensation, kinetic resolution, enantioselective reactions, regioselectivity, nanobiocatalysts, enzyme catalysis in low water media, enzyme promiscuity