TRANSESTERIFICATION OF LACTULOSE WITH ETHYL BUTANOATE CATALYZED BY CANDIDA-ANTARCTICA LIPASE

The enzyme-catalysed acylation of lactulose by ethyl butanoate was inv estigated. A slow conversion to a complex mixture of esters was observ ed at 40 degrees C in tert-butyl alcohol in the presence of a number o f lipases and a protease. With Candida antarctica B lipase, esterifica tions could also be performed at 82 degrees C (reflux) to increase the rate. The reaction could be accelerated by a factor of 5 when 1,2-dim ethoxyethane was used as solvent. In this way, a nearly quantitative c onversion to a mixture of esters was accomplished within 24 h. (C) 199 8 Elsevier Science B.V. All rights reserved.