Variation in chemical composition and antibacterial activity of the essential oil of fresh and dry leaves and dry stem of Tarchonanthus camphoratus

Abstract

The essential oils of the fresh leaves, dry leaves and dry stem of Tarchonanthus camphoratus from Kwa-Zulu Natal, South Africa, were obtained by hydro-distillation and analyzed by gas chromatographymass spectrometry (GC-MS). The essential oils were evaluated for their antibacterial activity against 4Gram positive and 5 Gram negative bacteria using the disc diffusion method and the minimuminhibitory concentration (MIC) method. A total of 33, 27 and 25 compounds were identified representing85.9, 73.01 and 72.66% of the total oil composition from the fresh leaves, dry leaves and dry stem, respectively. Sesquiterpene hydrocarbons dominated the essential oil of the fresh leaves (36.46%) and of the dry leaves (59.18) whereas an aldehyde, butanal (35.77%) dominated the essential oil of the drystem. The oils showed a broad spectrum of antibacterial activity. The zones of inhibition of the freshleaves, dry leaves, dry stem and chloramphenicol ranged from 7.3 to 14.0, 7.3 to 16.7, 13.5 to 20.4 and0.00 to 17.5 mm, respectively. The lowest MIC value for the oils was 125 µg/ml.