Antioxidant and antiacetylcholinesterase activities of essential oils from Cymbopogon schoenanthus L. Spreng. Determination of chemical composition by GC–mass spectrometry and 13C NMR

Cymbopogon schoenanthus L. Spreng, is an aromatic herb consumed in salads and used to prepare traditional meat recipes in Tunisia. The chemical composition, antioxidant activities and acetylcholinesterase inhibitory properties of the essential oils from fresh leaves, dried leaves and roots collected from three different locations in southern Tunisia, were evaluated. Essential oils were analysed by GC–mass spectrometry and 13C NMR. The major components were limonene (10.5–27.3%), β-phellandrene (8.2–16.3%), δ-terpinene (4.3–21.2%) and α-terpineol (6.8–11.0%). Antioxidant activity was measured by DPPH assay. The results ranged from 36.0% to 73.8% (2 μl of essential oil per mL of test solution).The antioxidant activity was also assayed using β-carotene–linoleic acid bleaching method. The best results (IC50 = 0.47 ± 0.04 mg mL−1) were obtained with the fresh leaves of plants collect in the desert region.The greatest acetylcholinesterase inhibitory activity (IC50 = 0.26 ± 0.03 mg mL−1) was exhibited by the essential oil of the fresh leaves from the mountain region.