Ln. Yee et Cc. Akoh, ENZYMATIC-SYNTHESIS OF GERANYL ACETATE BY TRANSESTERIFICATION WITH ACETIC-ANHYDRIDE AS ACYL DONOR, Journal of the American Oil Chemists' Society, 73(11), 1996, pp. 1379-1384
Pseudomonas sp. lipase (PS) was immobilized by adsorption technique on
to glass beads and tested for its ability to synthesize geranyl acetat
e by transesterification with acetic anhydride as the acyl donor. Reac
tions were carried out in n-hexane containing 0.1 M geraniol, 0.1 M ac
etic anhydride, and 200 units of lipase PS. Enzyme load, effect of sub
strate concentration, added water, temperature, time course, organic s
ol vent, pH memory, and enzyme reuse were studied. Yields of up to 96%
were obtained with 200 units (approximately 11% w/w of reactants) of
enzyme. Increasing amounts of geraniol inhibited lipase activity, whil
e excess acyl donor concentration enhanced ester production. Yields as
high as 97% were obtained at 50 degrees C, 24 h incubation, with no a
dded water. Solvents with log P values greater than or equal to 3.0 sh
owed the highest conversion yields. Solvent-free samples also performe
d well. The pH range of 4-9 gave good yields (92-98.4%). Enzyme reuse
studies showed the lipase remained active after 15 runs.