Acid-catalyzed alcoholysis ofVernonia galamensis oil

Abstract

We have demonstrated the potential ofVernonia galamensis seed oil as a source of hydroxy alkoxy fatty esters. Reaction of the oil with various alcohols (methanol, ethanol, 1-propanol and 2-propanol), under acidic conditions, resulted in transesterification as well as epoxy ring opening in all cases. The major products, the hydroxy alkoxy fatty esters, constituted approximately 80% of the product mixtures, of which the 12-hydroxy-13-alkoxy isomers were the major constituents. These derivatives were isolated by solvent extraction and/or column chromatography to afford 78–80% of pure isomers. Alcoholysis with butanol resulted in a poor yield of the hydroxy butoxy esters. A discussion of the isolation and mass-spectrometric characterization of these new esters is provided.