ENANTIOSELECTIVE HYDROLYSIS OF ESTERS OF SECONDARY ALCOHOLS USING LYOPHILIZED BAKERS-YEAST

A number of acetoxycarboxylic acid esters were hydrolyzed enantioselectively by Saccharomyces cerevisiae Hansen leading to chiral hydroxycarboxylic acid esters of high optical purity. The scope and limitations of this method with respect to the substitutional pattern of substrates were investigated. Subcellular localization of the hydrolytic activity on the plasma membrane led to the assumption that unspecific carboxyl esterases are responsible for hydrolysis of this type of substrate. Comparative experiments using viable cells and lyophilized cells as enzyme sources revealed the latter to be superior with respect to enantioselection and ease of handling.