Background and Aims: The present study has evaluated the chemical composition and antimicrobial activity of
the essential oils of five Iranian ecotypes of fennel.
Methods: The Essential oils of five Iranian ecotypes of fennel have obtained from dried seeds using hydro
distillation method.Variations in the essential oil compositions were determined using Gas chromatography
coupled to mass spectrometry (GC-MS). Antimicrobial activities were tested against the strains Staphylococcus
aureus, Bacillus cereus, Pseudomonas aeruginosa, Escherichia coli, Candida albicans using disc paper and broth
microdilution methods.
Results: Our results show that all essential oils have a broad spectrum of antimicrobial activity against all the
tested bacterial strains. The essential oils have more sensitivity to gram-positive than gram-negative bacteria,
however, some difference in antimicrobial activities of essential oils was observed for several microorganisms,
which was attributed to the variation in percentage of the components. The most important identified
compounds in all samples of fennel volatile oils were trans-anethole, estragole, fenchone, limonene, alphapinene
and gamma-terpinene.
Conclusions: This plant showed desire antibacterial effects and therefore is a good candidate for future
investigation of development of new bactericidal and bacteriostatic agent investigation was developed to purify
the essential component and estimate their effects