Enzymatic synthesis of fatty acid ascorbyl esters

• Published in: Journal of molecular catalysis. B, Enzymatic Enzymatic, 1998-09, Vol.5 (1), p.19-23
• Main Authors: Humeau, C, Girardin, M, Rovel, B, Miclo, A
• Format: Article
• Language: English
• Subjects: Ascorbyl palmitate; Bioconversions. Hemisynthesis; Biological and medical sciences; Biotechnology; Candida antartica; Fundamental and applied biological sciences. Psychology; Life Sciences; Lipase B; log P; Low-water media; Methods. Procedures. Technologies; Polyunsaturated fatty acid ascorbyl esters; Transesterification; Water activity
• ISSN: 1381-1177; 1873-3158
• DOI: 10.1016/S1381-1177(98)00090-3

Lipase B from the yeast Candida antartica was used to catalyze the enzymatic synthesis of fatty acid ascorbyl esters, in 2-methyl-2-butanol as a solvent. The influence of water activity ( a w) and reaction medium hydrophobicity on the synthesis of 6- O-palmitoyl l-ascorbic acid were investigated through a transesterification reaction involving l-ascorbic acid and palmitic acid methyl ester as substrates. The catalytic activity of the enzyme and the production at equilibrium were affected by the pre-fixed a w, best results being obtained for the lowest a w values. The activation of the lipase was promoted by an increase in the methyl palmitate/ascorbic acid molar ratio ( R) up to 9, leading to 19 g/l of ascorbyl ester after a 5 h reaction time. That performance was not reached in a reaction medium of equal log P level, where methyl palmitate was partly substituted by a hydrophobic solvent. Results were applied to the syntheses of polyunsaturated fatty acid ascorbyl esters such as ascorbyl eicosapentaenoate, leading to a production range from 11 to 15 g/l, after a 3 h reaction time.