Chemical composition and variability of the essential oil of Inula graveolens from Corsica.

The essential oil of Inula graveolens was investigated by GC, GC-MS and 13C-NMR spectroscopy. First, a commercial sample was repeatedly chromatographed and analysis of the fractions led to the identification of 89 components. The main constituents were bornyl acetate (56.8%), borneol (7.6%) and τ-cadinol (7.8%). In the second part, six samples of I. graveolens essential oil, obtained at different stages of development of the plant, were investigated. Bornyl acetate and borneol were always the two major compounds. Then, in order to study the chemical variability, we analysed 22 samples obtained from several plants collected in a restricted area in different localities during the flowering stage. Bornyl acetate (43.1-73.1%) and borneol (3.7-32.2%) were the main compounds for 20 samples. Sample 21 exhibited borneol (41.9%) and bornyl acetate (16.6%) as the major components, while the composition of sample 22 was atypical (borneol 41.9% and τ-cadinol 23.8%). Copyright © 2004 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]