Structure analysis of an allene‐containing estolide tetraester triglyceride in the seed oil of Sebastiana commersoniana (Euphorbiaceae)

The seed oil of Sebastiana commersoniana (Euphorbiaceae) was separated into triglyceride and an estolide fraction by preparative thin-layer chromatography. The triglyceride band was characterized by spectroscopic methods, and its fatty acids have been analyzed by gas chromatography (GC) and GC-mass spectrometry (MS) as their methyl esters. Linolenic acid was the main fatty acid (65%). The estolide band was examined by a combination of spectroscopic and chromatographic methods (ultraviolet, infrared, nuclear magnetic resonance, fast atom bombardment-MS, GC-MS of the fatty acids before and after silylation) and was identified as a tetraglyceride, where one alpha-carbon of the triglyceride backbone was esterfied with 8-hydroxy-5,6-octadienoic acid, which itself was esterfied with trans-2,cis-4-decadienoic acid. The remaining positions of the triglyceride backbone were occupied by common fatty acids.