Chemical Composition and Antioxidant Activities of Essential Oils from Different Organs of Tunisian Pituranthos chloranthus (Apiaceae)

Abstract

The present study reports the variability of the chemical composition and the antioxidant properties of essential oils from an endemic species of North Africa “Pituranthos chloranthus”, collected from two locations of the South-East of Tunisia (Boughrara and Naffatia) at the fruiting stage. The essentials oils extracted from the seeds and stems by hydrodistillation were analysed by gas chromatography/flame ionization detector (GC/FID) and gas chromatography/mass spectrometry (GC/MS). Sixty-eight compounds were identified accounting for 90.4 to 99.7 % of the whole essential oil showing the predominance of monoterpene hydrocarbons. The most abundant compounds of the seeds oils of Boughrara and Naffatia were α-pinene (32.2 %; 37.7 %) and β-pinene (27.8 %; 30.7 %), respectively. β-Phellandrene (17.2 %; 11 %), α-phellandrene (14.1 %; 7.2 %), α-pinene (11 %; 8.9 %), β-pinene (8.1%; 6.5 %) and p-cymene (5.8 %; 8.7 %) were found to be the major compounds in the stems oils of Boughrara and Naffatia, respectively. The antioxidant activities of essential oils were evaluated by reducing power assay and metal chelating activity. The obtained results revealed that the stems oils collected from Naffatia showed the highest reducing power with an EC50 value of 192 μg/ml. However, the important metal chelating activity was measured for the stems essential oils collected from Boughrara (IC50= 43 μg/ml).