Identification of conjugated fatty acids in the seed oil of Acioa edulis (Prance) syn. Couepia edulis (Chrysobalanaceae)

Abstract

The oil of Acioa edulis has the fatty acid composition: palmitic acid 28.3%, palmitoleic acid 1.3%, stearic acid 6.8%, oleic acid 26.5%, vaccenic acid 1.3%, linoleic acid 8.8%, arachidic acid 0.7%, a-eleostearic acid 7.3% and a-licanic acid 19%. The oil was analyzed and components were identified by ultraviolet (UV), infrared (IR), nuclear magnetic resonance OH-NMR,13C-NMR), gas chromatography/mass spectrometry (GC/ MS) and chemical methods. For transesterification the tetramethylguanidine reagent was used and it was shown that the method is very suitable for conjugated fatty acids. The equivalent chain lengths of α-eleostearic acid and a-licanic acid and their all-trans isomers were determined on DB 23 and OV-1. The electron impact (El) and chemical ionization (CI) (with isobutane) mass spectra of licanic acid, eleos-tearic acid and the El mass spectrum of 4-oxo-azelaic acid are presented and discussed. Furthermore, a comparison of literature data of seeds with the same common name is presented. © 1990 American Oil Chemists' Society.