Kinetic resolution of rac-1,2-diols using the biocatalyst Burkholderia cepacia lipase (BCL) immobilized on a biodegradable binary blend support of hydroxypropyl methyl cellulose(HPMC)/polyvinyl alcohol (PVA) has been investigated. The immobilization technique improved enzyme activity significantly and it has excellent recyclability with good yield and enantiomeric excess values up to the studied range of nine cycles. At optimum reaction conditions, conversion of 45-50% with excellent enantiomeric excess (up to 99% ee) were obtained. It was observed that BCL shows enantio-preference to R form of primary hydroxyl group for acylation, whereas S form is preferred for diacetate formation. The resultant products were characterized with the help of different analytical techniques such as 1H and 13C NMR, chiral HPLC, IR and GC-MS. In order to understand the effect of solvent as well as various derivatives of substrates, combined molecular dynamics and docking simulations were carried out. Explanation related to experimentally observed enantio-selectivities have been provided based on transition state structures of acylated complexes.
Keywords: Burkholderia cepacia lipase; Chiral resolution; Diols; Immobilized; Molecular dynamics.
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