Chemical Variability and Antioxidant Activity of Stems and Seeds Essential Oils of Pituranthos chloranthus Benth. and Hook Collected from Tunisia.

Plants of the genus Pituranthos are well-known in folk medicine. Of particular interest, Pituranthos chloranthus bears interesting properties such as disinfectant of drinking water stored in cisterns and distinctive aroma and taste. The variability in the chemical composition of the essential oils (EO) of two organs (seeds and stems) of P. chloranthus collected from three regions of Tunisia (Gafsa, Sidi Bouzid and Kasserine) was investigated in this study. Therefore, dried seeds and stems of P. chloranthus were hydro-distilled and EO were analyzed by Gas chromatography/flame ionization detection (GC/FID) and Gas chromatography/mass spectroscopy (GC/MS). A total of thirty-one compounds were identified of which the main components of the stems EO were found as elemicin (7.4 - 47.1%) and apiol (15.8 - 25.3%) followed by myristicin (11.3 - 23.0%) and terpinen-4-ol (7.7 - 18.5%) whereas elemicin (45.5 - 54.0%), apiol (19.3 - 28.0%) and myristicin (6.6 - 9.0%) were identified as the most abundant compounds of the seeds' EO. Interestingly, while the stems and seeds essential oils from Majoura displayed similar chemical composition, EO of stems and seeds of both locations Regueb and Sbeitla exhibited different ones. Besides, 1-allyl-2,3,4,5-tetramethoxybenzene was identified for the first time in the EO of the genus Pituranthos, and with a relatively high rate in the stems EO from Sidi Bouzid. The antioxidant activity of EO samples was evaluated by their reducing power. Our results show clearly that the seeds EO from Gafsa exhibited the highest reducing power with an EC50 = 0.42 mg/ml. [ABSTRACT FROM AUTHOR]