Characterization of Aromatic Compounds and Antioxidant Activity of Essential Oils from Tunisian <i>Pituranthos tortuosus</i> (Coss.) Maire (Apiaceae)

Abstract

The essential oils compositions from different parts of Pituranthos tortuosus (Coss.) Maire collected at the flowering and the fruiting stages were investigated. The essential oils were extracted by hydrodistillation and analyzed by GC/FID and GC/MS techniques. A total of 53 compounds representing 95.7 to 99.6% of the total oil were identified, showing large qualitative and quantitative differences. The analyzed oils were characterized by a very high percentage of monoterpenes, in which the monoterpene hydrocarbons constituted the predominant class especially in the stems (79.1%) at the fruiting stage. The major compounds in the flowers and the seeds were dillapiole (33.9; 37.2%), limonene (14.9; 10%), sabinene (8.8; 10.9%) and 3- n-butylphtalide (14.2; 6.7%), respectively. The antioxidant activity of the essential oils was evaluated by the metal (Fe2+) chelating and Fe3+ reducing power assays. The stems and seeds essential oils showed an important reducing power (EC50 : 0.06-0.08 mg/ml). Our findings demonstrated that P. tortuosus growing wild in the South-East of Tunisia could be considered as an interesting source of natural antioxidants.