Lipase-catalyzed esterification of unusual substrates: Synthesis of glucuronic acid and ascorbic acid (vitamin C) esters

The synthesis of n-butanol and cinnamic alcohol esters of glucuronic acid and the esterification of ascorbic acid (vitamin C) with phenylbutyric acid was performed with lipase from Candida antarctica B (CAL-B, SP435) in a mainly solid-phase system. Products were obtained in 15 to 22 % yield. Computer modelling based on the structure of CAL-B was used to elucidate the access of glucuronic acid to the catalytic site of the lipase. A fixation of glucuronic acid via H-bonds to Q157, D134 and H224 during the transition state was observed. © Rapid Science Ltd. 1998