Oxygenated Trans-3-olefinic acids in a Stenachaenium seed oil

Abstract

Interesting differences were found in oils from two samples of Stenachaenium macrocephalum (Compositae) seed with dissimilar storage histories. One contained significant amounts of epoxy acids (6.5%) and hydroxy conjugated dienoic acids (5.6%), but the other contained no more than 1% of these oxygenated acids. Characterization of components in the former oil established that the principal epoxy acid (4.0%) is the previously unknown cis-9, 10-epoxy-trans-3, cis-12-octadecadienoic acid. The conjugated dienols include two additional new acids with Δ3 unsaturation (2.5%): 9-hydroxy-trans-3,-trans-10, cis-12-octadecatrienoic and 13-hydroxy-trans-3, cis-9, trans-11-octadecatrienoic acoids. The nonoxygenated acids, except for the large amount (40%) of trans-3, cis-9, cis-12-octadecatrienoic, are those that commonly occur in seed oils. © 1971 American Oil Chemists' Society.