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 a triglyceride and an estolide fraction by preparative thin-laye r chromatography. The triglyceride band was characterized by spectrosc opic methods, and its fatty acids have been analyzed by gas chromatogr aphy (CC) and CC-mass spectrometry (MS) as their methyl esters. Linole nic acid was the main fatty acid (65%). The estolide band was examined by a combination of spectroscopic and chromatographic methods (ultrav iolet, infrared, nuclear magnetic resonance, fast atom bombardment-MS, CC-MS of the fatty acids before and after silylation) and was identif ied as a tetraglyceride, where one alpha-carbon of the glyceride backb one was esterfied with 8-hydroxy-5,6-octadienoic acid, which itself wa s esterfied with trans-2,cis-4-decadienoic acid. The remaining positio ns of the glyceride backbone were occupied by common fatty acids.