Enantioselective Hydrolysis ofd,l-Menthyl Benzoate toL-(-)-Menthol by RecombinantCandida rugosa Lipase LIP1

Abstract

The stereoselective synthesis of L-menthol is an attractive process in the flavor and fragrance industry. One promising way to obtain optically pure menthol is the enantioselective hydrolysis of menthol esters under enzymatic catalysis. We developed an effective and highly enantioselective method for the synthesis of L-(−)-menthol (>99% EE) by hydrolyzing the key industrial starting compound, d, l-menthyl benzoate. The enzyme of choice was the lipase from Candida rugosa (CRL). While commercially available preparations of this lipase showed only minor selectivity (E=15), excellent enantiomeric purity (E>100) was achieved using the heterologously expressed isoenzyme LIP1.