HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY OF THE TRIACYLGLYCEROLS OF VERNONIA-GALAMENSIS AND CREPIS-ALPINA SEED OILS

The triacylglycerols of Vernonia galamensis and Crepis alpina seed oil s were characterized because these oils have high concentrations of ve rnolic (cis-12,13-epoxy-cis-9-octadecenoic) and crepenynic (cis-9-octa decen-12-ynoic) acids, respectively. The triacylglycerols were separat ed from other components of crude oils by solid-phase extraction, foll owed by resolution and quantitation of the individual triacylglycerols by reversed-phase high-performance liquid chromatography with an acet onitrile/methylene chloride gradient and flame-ionization detection. I solated triacylglycerols were characterized by proton and carbon nucle ar magnetic resonance and by capillary gas chromatography of their fat ty acid methyl esters. The locations of the fatty acids on the glycero l moieties in the oils were obtained by lipolysis. The Vernonia galame nsis oil contained 50% trivernoloyl and 21% divernoloyllinoleoyl glyce rols along with 20% triacylglycerols with one vernolic and two other f atty acids. The Crepis alpina oil contained 36% tricrepenynoyl and 33% dicrepenynoyllinoleoyl glycerols, 17% triacylglycerols with two crepe nynic and one other fatty acid and 7% triacylglycerols with one crepen ynic acid and two other fatty acids. Vernolic acid was found at both t he 1(3)- and 2-glycerol carbons but was more abundant at the 1,(3)-pos ition in the Vernonia galamensis oil. Crepenynic acid was found at bot h glycerol carbon positions but was more abundant at the 2-position in the Crepis alpina oil.