Gaschromatographische Analyse des Samenfettes der mittelamerikanischen Fevillea Cordifolia (Cucurbitaceae)

Abstract

The fat of the seeds of Fevillea cordifolia was extracted under exclusion of oxygen and light and then characterized by 13C-NMR in regard to the contained unsaturated acid moieties. The total fat was separated by HPLC to yield one major fraction (˜ 45%), one medium fraction (˜ 18%) and some minor fractions. All substantial fractions showed the chromophore of a conjugated triene. According to MS-analysis the major fraction consists of distearyleleostearylglycerol. The total fat was converted by transesterification to a mixture of fatty acids methyl esters, which was analyzed by subsequent HPLC and GC: Main fatty acids were found to be stearic acid (53%) and the triple conjugated α-eleostearic acid (31%). Interestingly, punicic acid, which is isomeric to α-eleostearic acid and contained in various seed fats of Cucurbitaceae plants, could not be detected.Se extrajo la grasa de las semillas de Fevillea cordifolia bajo condiciones de ausencia de oxígeno y de luz y se caracterizaron mediante espectroscopía 13C-NMR. La grasa total fue separada en fracciones por HPLC. Todas las fracciones muestran el cromóforo de los trienos conjugados. La grasa total se transesterificó para dar una mezcla de ésteres metílicos que fueron luego analizados por HPLC y cromatografía de gases. Los ácidos grasos principales resultaron ser el ácido esteárico (53%) y el ácido alfa-eleoesteárico (31%). No se encontró la presencia del ácido punícico, contenido en la grasa de las semillas de varias Cucurbitaceas.