Effect of the Phenological Stage on the Antioxidant and Antimicrobial Activity of Artemisia Herba-Alba and Artemisia Campestris Essential Oils

The essential oils obtained by hydrodistillation from the aerial parts of two endemic species of Artemisia (Asteraceae) collected from the Center of Tunisia (Maknessi), was analysed by GC-MS. Twelve to fourteen components were identified representing more than 80% of the total oil. The essential oil composition and yield showed a variation related to the harvest period. The yield of the essential oils of A. campestris harvested on December was 0.44 % and the one of May was 0.30 %. For A. herba-alba it was 0.5 % for air dried leaves harvested on December and 0.8 % for the one of May. It is observed that the major component in the essential oils for both species is α-thujone followed by cis-sabinol and β-thujone for the extract of December. However, the major compound is β-pinene followed by p-cymen for Artemisia campestris extract of May. The major component of A. campestris α-thujone was absent in the essential oil of the seed stage. This variability could be explained by the phenological stage of the plant. The essential oils of two Artemisia species showed significant antifungal activity against a weak antimicrobial activity.