Phytochemical composition and antibacterial properties of the essential oil of Achillea biebersteinii Afan. (Asteraceae)

   Background and aims: The aim of this study was to characterize the chemical composition and antimicrobial properties 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 properties were evaluated by the 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 the agar dilution method. Results: In A. biebersteinii the major compounds were α-terpinene (۴۱.۴۲%), ۲-carene (۱۳.۹۶%), m-cymene (۱۳.۴۱%) and ۱,۸-cineole(۸.۹۱%).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.