[Hydroperoxide degradation by oat isomerase. Investigation of the reaction mechanism (author's transl)].

Oat isomerase is inhibited by hydroxyoctadecadienoic acids (monohydroxy acids) to a degree comparable with inhibition by linoleic acid hydroperoxides (LHPO). Hydroxy acids seem to combine with the enzyme like LHPO do. In an experiment on LHPO breakdown by isomerase 1-14C-hydroxy acids were added and it was examined whether the epoxyhydroxy acids are formed by an intermolecular or intramolecular mechanism. In this experiment 1-14C-labeled trihydroxy acids were formed; they arise from the hydrolysis of epoxyhydroxyoctadecenoic acids formed on their part by isomerase effected LHPO-breakdown. It was determined that at least 70% of LHPO are converted by intermolecular reaction.