Abstract Essential oils of the flowers and fruits of Achillea kotschyi Boiss. subsp. kotschyi (Asteraceae) growing wild in Lebanon were, for the first time, screened for their antimicrobial inhibitory activity. The composition of the essential oils was analyzed by GC and GC-MS; 37 compounds and 14 compounds representing 68.3%, and 95.5% of total oils, were found in the essential oils of flowers and fruits, respectively.
Also, nerolidol 2 (14%), β-terpinene (13.6%), β-myrcene (9.2%), trans-β-farnesene (4.1%), α-bisabolol (3.2%), α-farnesene (3.2%), α-phellandrene (3.2%), and piperitone (3.2%) were the major components found in the extracted essential oil of flowers. Whereas, dominance of β-thujone (58.5%) followed by 1,8-cineole (8.3%), camphene (7.3%), β-selinenol (5%), sabinene (3.7%), α-pinene (2.8 %) and α-selinene (2.8%) characterized the fresh fruits essential oil.
The essential oils showed significant inhibitory antibacterial and antifungal activity mainly on Gram negative S. enteritidis and both Gram positive S. aureus and E. faecalis as well as the fungus A. fumigatus. The results of the study showed an interesting antimicrobial profile which could provide promising pharmaceutical and economical benefits of the potential use of the plant essential oils.