CHEMISTRY OF THE SUDANESE FLORA

Abstract

The yields and composition, but not the components, of the volatile oil of the Sudanese medical plant Cymbopogon proximus varied widely at different stages of development and in different habitats. The main components were piperitone (22 to 88 %), elemol (0.4 to 39 %) and β-eudesmol (2 to 20 %). In contrast, Cymbopogon excavatus, C. nervatus and C. commutatis yielded oils containing low (< 6 %) proportions of sesquiterpenes and piperitone; the main constituents were now unusual p-menthadienols (up to 89 %).

Studies of uptake of carbon dioxide – [ ¹⁴ C] into the oil of C. proximus revealed significant incorporation of tracer into both mono– and sesqui-terpenoids in short term (ca 24 hr) periods of methabolism and indicated the suitability of the species for biosynthetic studies on elemane and eudesmane-type sesquiterpenes. A brief discussion of the biogenesis and biological significance of these oils is appended.