Vernonia anthelmintica (L.) Willd. enzyme studies conversion of epoxyoleic acid to (+)‐threo‐12,13‐dihydroxyoleic acid

Vernonia anthelmintica (L.) Willd. seed was found to contain enzymes that were active only after the seed was ground. By deactivation of the enzymes, an oil rich in trivernolin (the triglyceride of epoxyoleic acid) was produced, and pure trivernolin was isolated. Acceleration of the enzyme activity altered the composition of the oil as evidenced by changes in free fatty acid content, iodine values, and oxirane oxygen (epoxy) content. Investigation showed that these changes were due, at least partially, to the conversion of epoxyoleic acid to (+)‐threo‐12,13‐dihydroxyoleic acid, which was isolated in pure form. Pure (蜢)‐threo‐12,13‐dihydroxyoleic acid was prepared by acetolysis ofV. anthelmintica seed oil. Neither of these isomers had been obtained previously from mature,V. anthelmintica seed.