Lipase-catalyzed synthesis of conjugated linoleyl ascorbic acid in organic media

Abstract

The synthesis of conjugated linoleyl ascorbic acid was achieved by lipase-mediated esterification in organic media, using immobilized Candida antartica lipase from Roche. This enzyme was perfectly regioselective. The product was extracted and subjected to HPLC. The yield was greatly influenced by the kinds of solvents, reaction temperature, the initial water activity $(a_w)$ and the molar ratio of L-ascorbic acid to conjugated linoleic acid (CLA). Highest conversion of the esterification was obtained with the initial water activity $(a_w)$ 0.43 after 48 hours at 50℃ in 68mmol of the acetone using 50㎎ of enzyme, when molar ratio of L-ascorbic acid to CLA was 1:11. The selected solvent was both easily eliminated and accepted by European Community for use in the manufacture of foods and/or food additives. At that moment, maximum yield was 64.6%.