Evaluation of Antibacterial Activity of the Essential Oils of Zataria multiflora, Carum copticumand Thymus vulgarisby a Thin Layer Chromatography-Bioautography Method

AbstractBioautography is a method to localize antimicrobial activity on a chromatogram. A modified agar overlay bioautographic method was used to investigate the antibacterial activities of essential oils of Zataria multiflora, Carum copticumand Thymus vulgaris.The essential oils of all the plants exhibited activity against Bacillus subtilisand Escherichia coliat RF~ 0.4 which represented the RFfor Thymol and carvacrol in petroleum ether chloroform (50:50 as solvent system). Twenty two components were identified in the essential oil of Carum copticum.The main compounds consisted of Thymol (71.07%), terpinolene (13.08%) and cymene (10.20%). It could be concluded that the observed antibacterial activity was mainly due to the presence of Thymol and carvacrol in the essential oils.