Chemical composition of Vernonia albicans essential oil from India.

The chemical composition of the hydro-distilled essential oil obtained from the flowering aerial parts of Vernonia albicans DC. (Asteraceae) was analyzed by gas chromatography equipped with a flame ionization detector (GC-FID) and gas chromatography coupled with a mass spectrometry (GC/MS). Thirty-nine compounds have been identified, representing 97.5% of the total oil. The major constituents were beta-caryophyllene (34.3%), gamma-amorphene (19.5%), 9-epi-beta-caryophyllene (6.9%), and a-pinene (6.9%). The oil was found to be rich in sesquiterpene hydrocarbons (73.9%).