Composition of cuticular waxes on Osmunda regalis fronds

The chemical composition of rodlet-shaped wax crystals on fronds of Osmunda regalis was analyzed. In all, 139 compounds belonging to 14 homologous ser ies were detected in the surface extract. They included typical plant wax c onstituents: alkanes (C-25-C-33), alkyl esters (C-38-C-50), primary alcohol s (C-22-C-32), secondary alcohols (C-27 and C-29), ketones (C-27-C-33), ald ehydes (C-24-C-34), fatty acids (C-24-C-32), and beta-sitosterol. Additiona lly, bifunctional C-29 compounds (alpha-diketone, ketols, diols) were ident ified. Nonacosan-10-one as the most abundant single compound, together with its bifunctional derivatives, is likely to form the wax crystals found on O. regalis fronds. Hence, a new type of wax crystals is defined morphologic ally and chemically. The occurrence of comparable wax aggregates on surface s of higher plants is discussed.