Optimization of Alkyldiethanolamides Synthesis from Terminalia catappa L. Kernel Oil through Enzymatic Reaction

Abstract

Alkyldiethanolamides (fatty acid diethanolamides) synthesis from Terminalia catappa L. kernel oil was optimized using lypozyme as a catalyst. The result showed that the optimal reaction conditions were 2 hours reaction time, with a ratio of oil mass (g) to diethanolamine (mmol) of 1:5, a ratio of oil mass to enzyme (g) of 1: 0.075, and a temperature of 40°C. The percentage of alkyldiethanolamides at optimum condition was 56-60%. The synthesis results were also analyzed by FTIR. FTIR spectra revealed specific absorption at several wave numbers (3434 cm^-1, 1655 cm^-1, 1280 cm^-1), indicating that amide and alcohol bonds (C=O, C-N, and O-H) were formed. GC-MS was employed to identify the types of fatty acid diethanolamides that were successfully synthesized. The fatty acid diethanolamides formed were palmitoyldiethanolamide (R_t = 32.96 min) and oleyldiethanolamide (R_t = 35.57 min). The total nitrogen content of alkyldietanolamides was 0.26%, or 0.19 mmol of the amide group in 1 g of sample.

Keywords: Terminalia catappa L. kernel oil; alkyldietanolamide; enzymatic reaction; optimization.