Abstract

Essential oil yield and chemical composition of fresh leaves of Chromolaena odorata obtained by hydro-distillation collected from five different sites in Abidjan were investigated. The chemical composition of the essential oil was analyzed by gas chromatography (GC) and gas chromatography/mass spectrometry (GC/MS). From each locality, leaves were collected during sunny period to look for some correlation between composition and geographical variation. As a result, fifty four components were characterized, representing between all essential oil samples. From five investigated sample, all of the essential oil presented seven major components: germacrene D (15 to 20%), geijerene (14 to 17%), pregeijerene (11 to 12%), α-pinene (7 to 10%), β-caryophyllene (7 to 10%), β-pinene (4 to 5%) and δ-cadinene (3 to 5%). All essential oils considered were characterized by a clear predominance of hydrocarbon compounds chiefly sesquiterpenes (71.92 to 77.68%) and monoterpenes (15.71 to 18.38%). With only one exception, storage of the material plant, seasonal and geographical variation have no effect on the yield. Antibacterial activities of the oils from one location were tested against seven bacteria. The inhibition zones and minimum microbial concentration (MIC) for bacterial strains, which were sensitive to C. odorata essential oil, were in the range of 8 to 16 mm and 64 to 256 µg/ml, respectively. The oils showed moderate activity against all tested bacteria.

Key words: Chromolaena odorata, essential oil, chemical composition, germacrene D, geigerene, pregeigerene, antimicrobial activity.