Essential oils in the spiny-fruited umbelliferae

Abstract

The fruits of some 24 species of the tribe Caucalideae of the Umbelliferae were surveyed for essential oils by GLC. The patterns obtained are particularly useful for separating the tribe into genera. Daucus, by far the richest taxon in essential oils, is distinguished by the presence of carotol, geranyl acetate and two unidentified components as major constituents. Within Daucus, the overall pattern is relatively similar, although the seven species studied can easily be separated on the basis of qualitative and quantitative variations in oil components. Carotol was also found in Torilis and Turgenia but only in trace amounts. Daucus and Pseudorlaya, which are morphologically fairly similar, are chemically related in containing four compounds in common, α- and β-pinene, limonene and myristicin. The genus Torilis is characterized by the presence of an unidentified sesquiterpene C 15H 22. Furthermore, the five Torilis species examined can be distinguished from each other by the presence/absence of biphenyl, carotol and four unidentified components. The genera Caucalis and Turgenia also have their distinctive oils, while Artedia can be separated by its lack of volatile oil in the fruit. Finally, the essential oil patterns correlate well with other chemical differences which distinguish the genera within the tribe.