Chemical composition of essential oil of Senecio coincyi, an endemic species of the Central Iberian Peninsula.

The essential oil has been studied of leaves of Senecio coincyi Rouy, an endemic species of Spain restricted to a very small area of the Central Iberian Peninsula. Samples from five locations were obtained by hydrodistillation and extraction and analysed by gas chromatography-mass spectrometry. The main compound was 1-tridecene (28.1 +/- 8.5%). The presence of unsaturated hydrocarbons (1-undecene, 1-dodecene and 1-tridecene) seems to indicate a chemotaxonomic relationship between Senecio coincyi and S. congestus.