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

摘要

The essential oils of the fresh leaves, dry leaves and dry stem ofTarchonanthus camphoratusfrom Kwa-Zulu Natal, South Africa, were obtained by hydro-distillation and analyzed by gas chromatography mass spectrometry (GC-MS). The essential oils were evaluated for their antibacterial activity against 4 Gram positive and 5 Gram negative bacteria using the disc diffusion method and the minimum inhibitory concentration (MIC) method. A total of 33, 27 and 25 compounds were identified representing 85.9, 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 dry stem. The oils showed a broad spectrum of antibacterial activity.The zones of inhibition of the fresh leaves, dry leaves, dry stem and chloramphenicol ranged from 7.3 to 14.0, 7.3 to 16.7, 13.5 to 20.4 and 0.00 to 17.5 mm, respectively. The lowest MIC value for the oilswas 125 µg/ml.