Optimization of TBAB-Assisted Lipase-catalyzed Synthesis of L-Ascorbyl Myristate

H. LI, L. Zhang, R. Shen and Y. Liu

Abstract
The synthesis of l-ascorbyl myristate through esterification of l-ascorbic acid and myristic acid catalyzed by lipase was studied. The effect of different parameters including lipase, molecular sieve 4 Å, organic solvent, and tetrabutyl ammonium bromide (TBAB) was evaluated. The results showed excellent yield in the presence of Novozyme435 as catalyst, 10 % (w/w of l-ascorbic acid) of 4 Å molecular sieve and 10 % (w/w of l-ascorbic acid) of TBAB as additives in 1,4-dioxane. Furthermore, response surface methodology (RSM) and 5-level-4-factor central composite design (CCD) were employed to evaluate the effects of parameters on the yield of l-ascorbyl myristate. According to the analysis result of ridge max, the optimal synthesis conditions were predicted, as follows: reaction time 27.1 h, temperature 54.1 °C, enzyme amount 25.9 % (% w/w of l-ascorbic acid), substrate molar ratio 5, and the optimal actual yield was 85.0 %. (This work is licensed under a Creative Commons Attribution 4.0 International License.)

This work is licensed under a Creative Commons Attribution 4.0 International License

Keywords
L-ascorbyl myristate, Novozyme435, TBAB, Response Surface Methodology.