Faranak Elmi - Biology Dept., University of Tabriz, Tabriz, I.R. Iran
Asad Kazemi - Departement of Medical Biotechnology, school of Advanced Technologies in Medicine, Tehran university of Medical Sciences, Tehran, Iran

aims: The aim of this study was to characterize the chemical composition and antimicrobial activity of Achillea biebersteinii essential oil (EO).Methods: The chemical composition of samples obtained from Marand city in East Azerbaijan, was assessed using gas chromatography-mass spectrometry (GC-MS). The antimicrobial activity was evaluated by disc diffusion method against methicillin-resistant Staphylococcus aureus (MRSA), other extended-spectrum beta-lactamases(ESBLs) producing, as well as Gram-negative and Gram-positive bacteria. The minimum inhibitory concentration (MIC) value of EO was assessed using agar dilution method.Results: In A. biebersteinii the major compounds were α-terpinen (41.42%), 2-carene (13.96%), m-cymene (13.41%) and 1,8-cineole(8.91%).The EO showed antimicrobial activity against ten microorganisms, especially Streptococcus sanguis, S. aureus (MRSA strain), and Klebsiella pneumoniae(ESBL-producing strain), which was potentially better than tetracycline and kanamycin.Conclusion: This study confirmed that EO of A. biebersteinii has in vitro antimicrobial activity against Gram-negative and Gram-positive bacteria, which has made it an alternative antibacterial agent.

Phytochemicals, Achillea biebersteinii, Essential Oil, GC/MS