Enzyme-catalyzed resolution of chlorinated esters.

Abstract

It has been found that lipase from the yeast Candida rugosa (formerly C. cylindracea) will stereoselectively hydrolyze racemic mixtures of the partially water soluble methyl-2- chloropropionate. This will not occur in an aqueous reaction medium, so the substrate was made less water soluble by dissolving it in a water-immiscible organic solvent. The complete reaction mixture was a biphasic system comprising the water immiscible organic solvent plus reactant and an aqueous phase containing the enzyme and buffer component. The hydrolysis products were ideally present in the aqueous phase. The course of the reaction could be followed by the determination of the proportions of D- and L-(a)-chloropropionic acid using a triple-linked enzyme assay. The resolutions of the racemic ester were of a practical or pre-pilot scale. Screening of the 5 soil samples was undertaken in an attempt to isolate some microor ganisms that may possess some unusual or enantiospecific lipase or esterase enzymes. Individual microbes were isolated but not identified, several of which were shown to be secreting an exolipase capable of hydrolysing an olive oil emulsion.