Essential oil composition of four Psiadia species from Reunion Island: A chemotaxonomic study

The essential oils of four wild species of Psiadia (Psiadia anchusifolia, Psiadia argentea, Psiadia boivinii, Psiadia salaziana; Asteraceae) endemic to Reunion Island were obtained by hydrodistillation and subjected to detailed GC/MS analysis in order to determine possible similarities among them and also the differences in their chemical compositions depending on the stage of the life cycle (vegetative and flowering). A total of 57 compounds were identified including two unusual components 7,7-dimethyl-2-methylenebicyclo[3.3.1]heptan-6-ol acetate (1) and 6,6,8,9-tetramethyltricyclo[3.3.3.0]-undec-7-en-2-ol (2) which, until now, have been found only in species of the genus Psiadia. For P. anchusifolia, P. argentea and P. salaziana, the qualitative and quantitative composition of the oils appeared to be constant in the different stages of their development. In contrast, considerable differences were found to exist in the composition of essential oils of P. boivinii.