Study towards the improvement of the enantioselective hydrolysis of Naproxen esters by sheep liver acetone powder

Liver acetone powders (LAPs) have been suggested as easy to handle and low cost crude esterase sources, which can be used to carry out estereoselective biotransformations involving carboxylic acids, esters and alcohols. (S)-Naproxen [(S)-2-(6-methoxy-2-naphtyl)-propionic acid] is 28-fold more active than the corresponding (R)-enantiomer as antiinflamatory agent, for this reason (R,S)-naproxen is a suitable commercial candidate as a model for the study of the application of crude sheep liver acetone powder (SLAP) for its resolution. After the evaluation of the effect of pH, reaction time, co-solvents, substrate/SLAP ratio and temperature we concluded that the best results (72% ee and 21% conversion) were obtained when the reaction was performed at room temperature for 48h at pH 7, with dioxane (15%), utilizing 1:1 substrate/SLAP ratio.