Objective: To evaluate the essential oil composition and the antibacterial activity of an Algerian endemic plant, Launaea lanifera Pau (L. lanifera), grown in arid steppe regions.
Methods:L. lanifera essential oil was isolated from aerial parts by steam distillation and its chemical composition was evaluated by gas chromatography-flame ionization detector and gas chromatography with electron impact mass spectrometry. Furthermore, its in vitro antibacterial activity against four bacterial strains was tested following the agar disk diffusion method.
Results: This species had a very low essential oil yield (0.005%). Twenty-four (92.6%) individual components were identified. The main constituents were hexahydrofarnesyl acetone (31.6%), (E)-β-ionone (8.5%), (E)-β-damascenone (7.0%), 2-methyltetradecane (3.8%), n-heptadecane (3.8%), limonene (2.8%) andβ-caryophyllene (2.8%). No noteworthy antimicrobial activity was observed on the tested bacteria, neither Gram negative nor Gram positive.
Conclusions:This is the first report on the volatile constituents and antibacterial activity of L. lanifera. The studied essential oil does not possess significant activity against the tested microorganisms.

Objective: To evaluate the essential oil composition and the antibacterial activity of an Algerian endemic plant, Launaea lanifera Pau ( L. lanifera), grown in arid steppe regions. Methods: L. lanifera essential oil was isolated from aerial parts by steam distillation and its chemical composition was evaluated by gas chromatography-flame ionization detector and gas chromatography with electron impact mass spectrometry. Furthermore, its in vitro antibacterial activity against four bacterial strains was tested following the agar disk diffusion method. Results: This species had a very low essential oil yield (0.005%). Twenty-four (92.6%) individual components were identified. The main constituents were hexahydrofarnesyl acetone (31.6%), (E)-β-ionone (8.5%), (E)-β-damascenone (7.0%), 2-methyltetradecane (3.8%), n-heptadecane (3.8%), limonene (2.8%) and β-caryophyllene (2.8%). No noteworthy antimicrobial activity was observed on the tested bacteria, neither Gram negative nor Gram positive. Conclusions: This is the first report on the volatile constituents and antibacterial activity of L. lanifera. The studied essential oil does not possess significant activity against the tested microorganisms.