Variations in Tunisian wormwood essential oil profiles and phenolic contents between leaves and flowers and their effects on antioxidant activities

This study is the first to investigate the chemical characterization of leaves and flowers essential oils and methanolic extract of Artemisia absinthium L. in Tunisia and their effect on the antioxidant activities. The yield of essential oil was higher in flowers (2.98%) than in leaves (1.87%). Qualitative and quantitative differences among the analyzed organ parts were revealed. 38 compounds in flower oils and 19 components in leaves oils were identified representing, respectively, 93.95% and 98.5% of the total oil composition. The two types of oils were dominated by chamazulene (flowers: 29.9%, leaves: 30.41%) and β-thujone (flowers: 19.66%, leaves: 25.75%). Flowers oils are characterized by camphor (16.16%) whereas leaves essential oils are distinguished by bornan-2-one (17.33%). According to our results chamazulene chemotype is probably specific to North African region for essential oil of Artemisia absinthium L. Essential oils show important antioxidant activities; however the highest antioxidant activities were recorded for methanol extract. In both cases leaves extract highlighted higher antioxidant capacity. Significant correlations were observed between the total phenols or flavonoid contents in methanol extracts and antioxidant activity estimated for both used tests even for leaves or for flowers extracts.

► The highest yield of the essential oils was recorded for flowers whereas leaves exhibited an important but lower yield.
► According to our results, Chamazulene chemotype is probably specific to North African region.
► Leaves had the highest contents of phenolic and flavonoid contents.
► The highest antioxidant activities were recorded for methanol extract.
► Significant correlations were observed between the total phenols or flavonoid contents and antioxidant activities.