The oil ofAcioa 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 (IH-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 co~ugated fatty acids. The equivalent chain lengths of aeleostearic acid and ~-licanic acid and their all-trans isomers were determined on DB 23 and OV-1. The electron impact (EI) and chemical ionization (CI) (with isobutane) mass spectra of Hcanic acid, eleostearic acid and the EI mass spectrum of 4-oxo-azelalc acid are presented and discussed. Furthermore, a comparison of literature data of seeds with the same common name is presented.
KEY WORDS: Acioa edulis, Chrysobalanaceae, conjugated fatty acids, eleostearic acid, gas chromatography/mass spectrometry (GC/MS), licanic acid, 4-oxo-azelaic acid.Acioa edulis syn. Couepia edulis is a member of the family Chrysobalanaceae found in the basin of the Rio Purus and the central Solimoes of Amazonia, Brazil. The tree is 25 m tall and its stone-fruits are 8-9 cm long and 4.5-cm broad. The kernel is eaten raw by the habitants of the described region or is crushed and added to tapioca cakes. The oil of the seeds is used for cooking and soapmaking (1).The common name "Cotia Chestnut (Castanha de Cotia)" obviously is not unique for this fruit. This curious designation is derived from the name of a tailless animal called "Cotia, "which feeds on these kernels (2). There obtained by argentation thin-layer chromatography was converted to the bis-(methylthio) derivates as described previously (10).