Study on Reaction Kinetics of Lipase-catalyzed Synthesis of Vanillyi Nonanoate in Acetone Media

摘要

The reaction kinetics for synthesis of vaniilyi nonanoate (VN) by lipase-catalyzed transesterification of vaniilyi alcohol and methyl nonanoate in acetone was investigated in this study. The reaction catalyzed by lipase was carried out as follows: A reaction mixture containing given concentration of substrates (1ml) and lipase Novozyme 435 (20mg) in acetone (1ml) was shaken at 30 °C for 10min. The initial velocity of the reaction was calculated according to the concentration of VN detected by high performance liquid chromatography (HPLC), and the kinetic equation was obtained by analysis of the double reciprocal plot of initial velocity versus substrate concentration. The data calculated by the kinetic equation were basically in agreement with the experimental data with a correlation coefficient at 0.997. The inhibitory action of methanol (by-product) in the reaction was also investigated and the results indicated that the concentration of methanol influences both slope and intercept of y-axis of the double reciprocal curve, and the lines intersect on the X-axis. These results revealed that this transesterification follows the Ping-Pong reaction mechanism.