Determination of the chemical composition and antimicrobial activity of the essential oils of Teucrium polium and Achillea millefolium grown under North Anatolian ecological conditions

The chemical composition and antimicrobial effect of essential oils derived from Teucrium polium L. and Achillea millefolium subsp. millefolium Afan. in in vitro conditions were investigated in the present study. The results from the gas chromatography - mass spectrometry analysis showed that the obtained (Z)-beta-farnesene from T. polium was with the highest percentage (15.49%), whereas beta-pinene from the same plant was with the lowest percentage (0.74%). The 1,8-cineole in A. millefolium subsp. millefolium was with the highest percentage (22.83%), whereas p-cymene in the same plant was with the lowest percentage (0.93%). In the antimicrobial studies, the essential oils' effect against methicillin-resistant Staphylococcus aureus (MRSA), S. aureus ATCC 6538, Pseudomonas aeruginosa, Escherichia coli Q157:H7 and Bacillus cereus CCM 99 were investigated using the agar well method. P. aeruginosa and MRSA showed the biggest inhibition zones (15 mm), whereas E. coli Q157: H7 showed the smallest inhibition zone (11 mm), each generated by using T. polium essential oils. MRSA showed the biggest inhibition zone (21 mm), whereas P. aeruginosa showed the smallest inhibition zone (10 mm), both obtained by using A. millefolium subsp. millefolium essential oils. Therefore, it was concluded that the essential oils obtained from the two plant species had an inhibition effect on resistant micro-organisms.