Kinetic Studies on Lipase-Catalyzed Acetylation of 1-Alkanol with Vinyl Acetate in Organic Solvent

Abstract

Lipase-catalyzed acetylation of 1-alkanol with vinyl acetate to give alkyl acetate has been studied kinetically using Burkholderia cepacia lipase, six alcohols and different organic solvents. The rate constants k_A and k_B with respect to vinyl acetate and 1-alkanol determined from the double reciprocal plots, v^-1 vs. [vinyl acetate]^-1 and v^-1 vs. [1-alkanol]^-1 respectively, where v is the initial rate of the reaction. The rate ratio k_B/k_A was larger than unity except some cases: the rate in acetylation of active serine residue in the lipase with vinyl acetate was slower than that of 1-alkanol with the acetyl-enzyme intermediate. The rate constant k_A was independent of the solvent hydrophobicity log P (where P is a partition coefficient of a given solvent between octanol and water), however, k_B increased with log P. Both rate constants were different depending on the structure (carbon number CN) of 1-alkanol.