Optimized enzymatic synthesis of caffeic acid phenethyl ester by RSM.

In this study, optimization of enzymatic synthesis of caffeic acid phenethyl ester (CAPE), catalyzed by immobilized lipase (Novozym 435) from Candida antarctica was investigated. Novozym 435 was used to catalyze caffeic acid and 2-phenylethanol in an isooctane system. Response surface methodology (RSM) and 5-level-4-factor central-composite rotatable design (CCRD) were employed to evaluate the effects of synthesis parameters, such as reaction temperature (30-70 degrees C), reaction time (24-72 hours), substrate molar ratio of caffeic acid to 2-phenylethanol (1:10-1:90) and enzyme amounts (100-500 PLU) on percentage conversion of CAPE by direct esterification. Reaction temperature and time had significant effects on percent conversion. On the basis of ridge max analysis, the optimum conditions for synthesis were: reaction time 59 hours, reaction temperature 69 degrees C, substrate molar ratio 1:72 and enzyme amount 351 PLU. The molar conversion of predicted values and actual experimental values were 91.86+/-5.35% and 91.65+/-0.66%, respectively.