Enantioselective acylation of some secondary alcohols by biocathalise with lipase from pseudomonas fluorescens immobilised using sol-gel method

Kinetic resolution of secondary alcohols: 2-butanol, 2-pentanol, 2-hexanol and 2-octanol was accomplished by acylation with vinyl acetate, using sol-gel entrapped lipase preparations. Amano AK lipase (from Pseudomonas fluorescens) was immobilized in hydrophobic sot-gel materials derived from tetraetoxysilane and alkyl- or phenyl-triethoxysilane precursors. Phenyl-group containing matrixes exhibited the highest enzyme activity recoveries at 1:1 precursor molar ratio, 22-42% (depending on the alcohol) related to the free enzyme activity. The enantioselectivity followed the Kazlauskas rule. Both enantiomeric excess of the ester product (ee(p)) and enantiomeric ratio (E) increased following the entrapment, reaching 86% and 17.3, respectively, by using methyltriethoxysilane and tetraethoxysilane at 3:1 molar ratio as precursors and 2-hexanol as substrate.