STEREOSPECIFICITY OF LINOLEIC-ACID HYDROPEROXIDE ISOMERASE FROM CORN GERM

Linoleic acid hydroperoxide isomerase from corn germ inverted the stereoconfiguration of its substrate. 9-D(S)-Hydroperoxy-trans-10, cis-12-octadecadienoic acid was converted to 10-oxo-9-L(R)-hydroxy-cis-12-octadecenoic acid. Presumably, the H2O solvent of OH- acted as a nucleophile. In the presence of another nucleophile, linoleate, the 9-D(S)-hydroperoxide was transformed into 9-L(R)-linoleoyloxy-10-oxo-cis-12-octadecenoic acid. The substitution of nucleophiles from the incubation solution and the inversion of stereoconfiguration at carbon-9 are consistent with a bimolecular nucleophilic substitution (SN2) mechanism. © 1979 American Oil Chemists' Society.