In the present research, the chemical composition of the essential oils from Ferulago angulata and Tetrataenium
lasiopetalum were analyzed by the gas chromatography-mass spectrometry (GC-MS). The antibacterial activity of
the extracts and essential oils of both species was also evaluated against Staphylococcus aureus and Enterococcus
faecalis (Gram-positive bacteria) and Escherichia coli and Pseudomonas aeruginosa (Gram-negative bacteria), using
agar disk diffusion and micro-dilution methods. Our results showed that essential oil from F. angulata was a rich
source of cis-β-ocimene, α-pinene and α-phellandrene and can be used in industries such as pharmaceutical,
cosmetic and food. Additionally, T. lasiopetalum essential oil had high percentage of camphene, germacrene-D,
and 1,8-cineole. Gram positive bacteria were more susceptible than Gram-negative bacteria to all oils and extracts. The results of our study showed that in both species, especially T. lasiopetalum, the extract and essential
oils exhibited reliable inhibitory activity against both Gram-positive and Gram-negative bacteria and have the
potential to be considered as natural alternatives for food preservatives.