Enzymatic synthesis of cinnamyl propionate from cinnamyl alcohol and propionic acid in a solvent free condition

Abstract

This work illustrates the synthesis of cinnamyl propionate in the presence of lipase biocatalyst. The esterification reaction was performed in a solvent free condition with cinnamyl alcohol and propionic acid using fermase CALB™ 10000, a commercial lipase. Experiments were conducted to study different operating parameters such as enzyme loading, temperature, mole ratio, speed of agitation, and reusability of enzyme. Various kinetic parameters affecting esterification reaction were evaluated to synthesize cinnamyl propionate. It has been observed that the data obtained follows random bi-bi mechanism with inhibition by both acid and alcohol substrate. The highest conversion of cinnamyl propionate obtained is 87.89% after 7 h at optimum parameters: enzyme loading 2% (w/v), temperature 60 °C, acid to alcohol ratio 1:3, molecular sieves 6% (w/v) and agitation speed 200 rpm. Limitation of diffusion mass transfer between the enzyme surface and substrate does not show a significant effect on reaction kinetics. The study of repeated use of enzyme shows that it maintains 90% of its catalytic activity after six successive batches.