Artemisia arborescens essential oil composition, enantiomeric distribution and antimicrobial activity from different wild populations from the Mediterranean Area

Aerial parts of Artemisia arborescens were collected from different sites of the Mediterranean area (southwestern Algeria and southern Italy) and the chemical composition of their essential oil (EO) extracted by hydrodistillation was studied by both gas chromatography (GC) equipped with an enantioselective capillary column and GC/mass spectrometry (GC/MS). The EOs obtained were tested against several Listeria monocytogenes strains. Using GC and GC/MS, 41 compounds were identified, accounting for 96.0 – 98.8% of the total EO. All EOs showed a similar terpene profile, which was rich in chamazulene, b-thujone, and camphor. However, the concentration of such compounds varied among the EOs. A. arborescens EO inhibited up to 83.3% of the L. monocytogenes strains, but the inhibitory spectrum varied among the EOs, with those from Algeria showing a higher inhibition degree than the Italian EOs. Such effect likely depended on the ketone (b-thujone + camphor) content of the EO. The differences in the EO composition support the hypothesis that A. arborescens has at least two different chemotypes: a b-thujone and a chamazulene type. The EO inhibitory spectrum indicates the A. arborescens EO as a valuable option in the control of the food-borne pathogens.