Constitution of the surface lipid from the leaves of Brassica oleracea (var. capitata ) ( Winnigstadt )) - III. Nonacosane and its derivatives

Abstract

The constitution of the hydrocarbon fraction has been determined by gas/liquid chromatography. Ten alkanes containing both odd and even numbers of carbon atoms have been found. Nonacosane (93 %) and hentriacontane (3 %) are the main components. The constitution of the nonacosane derivatives has been elucidated by subjecting each fraction to modified Baeyer-Villiger oxidation and identifying the key fragments by a combination of adsorption and reversed-phase partition chromatography on films of adsorbent supported on glass plates. A pair of isomers has been found in each group. Those from the ketone and secondary alcohol are derived by substitution of oxygen atoms in the 10- and 15-positions. In the ketol the oxygen substituents are also in the 10- and 15-positions and the isomers are derived by interchanging the positions of the hydroxyl and carbonyl groups.