Essential oil composition of stems and fruits of Caralluma europaea N.E.Br. (Apocynaceae).

The essential oil of the stems and fruits of Caralluma europaea (Guss.) N.E.Br. (Apocynaceae) from Lampedusa Island has been obtained by hydrodistillation and its composition analyzed. The analyses allowed the identification and quantification of 74 volatile compounds, of which 16 were aromatic and 58 non-aromatic. Stems and fruits contained 1.4% and 2.7% of aromatic compounds respectively, while non-aromatic were 88.3% and 88.8%. Non-aromatic hydrocarbons were the most abundant compounds in both organs, followed by fatty acids. Data showed differences in the profiles between stems and fruits which shared only eighteen compounds; stems accounted for 38 compounds while fruits for 53. Fruits showed a higher diversity especially in aromatic compounds with twelve versus four in stems. Among the volatiles identified in stems and fruits of C. europaea 26 are present in other taxa of Apocynaceae, 52 are semiochemicals for many insects, and 21 have antimicrobial activity. The possible ecological role of the volatiles found is briefly discussed.