The seed oil of Bernardia pulchella (Euphorbiaceae) - A rich source of vernolic acid

Abstract

The fatty acids from the seed oil of Bernardia pulchella (Euphorbiaceae) have been analyzed by gas chromatography (GC) and GC-mass spectrometry (MS) analysis of their methyl esters. Vernolic acid is the main compound (91%), along with other usual fatty acids. In addition to the quantitation by GC analysis, H-1-nuclear magnetic resonance (NMR) signals from the seed oil have been used to estimate the total epoxy fatty acid content. The structure of vernolic acid has been proven by spectroscopic methods (infrared, H-1, and C-13-NMR) and by GC-MS analysis of the corresponding silylated hydroxy-methoxy derivative. The 4,4-dimethyloxazoline derivatives of the fatty acid mixture have also been examined by GC-MS, and it was shown that this derivatization reaction is not suitable for the structure analysis of vernolic acid.