Thymus caucasicus and Thymus transcaucasicus (lamiaceae) at the flowering stage were collected, from Ardabil province (No. 41and 87 at Central Herbarium of Institute of Medicinal Plants, ACECR).
The essential oil aerial parts of T. caucasicus and T. transcaucasicus were collected by Hydrodistillation in a Clevenger type apparatus and Steam distillation method. The essential oils were dried over anhydrous sodium sulphate and after filtaration, stored at +4oC until tested and GC/MS analyzed.
The essence of T. caucasicus which was collected by hydrodistillation, 44 compounds were identified which most important ones were Nerolidol (52.31%), Geraniol (7.02%), Geranyl acetone (5.64%).
In steam distillation essence of T. caucasicus, 58 compounds were identified which most important ones were Nerolidol (53.58%), Geranyl acetone (6.57%), Geraniol (7.02%).
At T. transcaucasicus, the major components were thymol (33.31%), 1,8 cineol (11.56%) and linalool (8.08%), in hydro distillation method and the major components were thymol (24.85%), bronyl acetate (14.65%), linalyl acetate (8.57%), thymol methyl ether (7.71%), linalool (5.63%) and neryl acetate (5.14%) in hydro distillation method.
In vitro antimicrobial activities of T. caucasicus and T. transcaucasicus was performed against eight standard bacterial strains using agar dilution method. Result showed that was effective against Staphylococcus aureus, Staphylococcus epidermidis, Bacillus subtilis, Escherichia coli, Klebsiella pneumonia, Pseudomonas aeruginosa and Meticillin Resistant Staphylococcus aureus.