LIPASE-CATALYZED ACYLATION OF MENTHOL WITH VINYL ACETATE IN ORGANIC MEDIA

Menthyl acetate was prepared using vinyl acetate with lipase PS-30 from Pseudomonas sp . as biocatalyst in organic media. Immobilization of the lipase by adsorption onto 0.5 mm diameter glass beads and the presence of molecular sieves improved the yield of menthyl acetate from 24 to 50%. Approximately 40% yield of menthyl acetate was achieved after 48 h incubation with the immobilized lipase. Equimolar ratio of substrates gave higher yields of product compared to higher mole ratios. Synthesis of menthyl acetate increased as the reaction temperature increased from 20 to 60C. An acceptable yield of menthyl acetate was achieved with 400 units of immobilized lipase PS. Less polar solvents appeared to be better than polar solvents for the enzymatic synthesis of menthyl acetate by transesterification.