Optimized synthesis of lipase-catalyzed octyl caffeate by Novozym® 435

In this study, optimization of the enzymatic synthesis of octyl caffeate (OC), catalyzed by an immobilized lipase (Novozym (R) 435) from Candida antarctica was investigated. Novozym (R) 435 was used to catalyze the caffeic acid and octanol in an isooctane system. Response surface methodology (RSM) and 5-level-4factor central-composite rotatable design (CCRD) were employed to evaluate the effects of the synthesis parameters, such as reaction temperature (40-80 degrees C), reaction time (24-72h), substrate molar ratio of caffeic acid to octanol (1:20-1:100), and enzyme amounts (100-500 PLU) on the percentage conversion of OC by direct esterification. Reaction temperature and time had significant effects on the percent conversion. Based on ridge max analysis, the optimum conditions for synthesis were: reaction time of 55 h, reaction temperature of 75 degrees C, substrate molar ratio of 1:78, and enzyme amount of 317 PLU. The molar conversions of predicted and actual experimental values were 93.79% and 90.34 +/- 1.38%. respectively. (C) 2010 Elsevier B.V. All rights reserved.