Substrate selectivity of lipases in the esterification of cis/trans-isomers and positional isomers of conjugated linoleic acid (CLA)

The substrate selectivity of several microbial lipases has been examined in the esterification of the conjugated linoleic acid (CLA) isomers cis-9,tra ns-11-, cis-9,cis-11-, trans-9,trans-11- and trans-10,cis-12-octadecadienoi c acid with n-butanol in n-hexane. Lipases from Candida cylindracea and Muc or miehei had a preference for the cis-9,trans-11-octadecadienoic acid, whi le Chirazyme L-5, a Candida antarctica lipase A, accepted the trans-9,trans -11-fatty acid with a high selectivity. Moreover, lipase from Candida cylin dracea and Chirazyme L-5 catalysed the esterification of the cis-9,trans-11 -octadecadienoic acid with n-butanol faster than the corresponding reaction of the trans-10,cis-12-fatty acid.