Abstract Mentha Pulegium L. and Thymus capitatus are acknowledged as an important aromatic and medicinal plants thanks to their richness in a variety of bioactive phytochemical components. The purpose of the study was to investigate the chemical composition of the essential oil and the antioxidant activity for Mentha Pulegium L. and Thymus capitatus species cultivated in Tunisia. The essential oil for both species was obtained by means of hydrodistillation method and analyzed by GC/FID and GC/MS. The essential oil yield varied considerably according to the harvest time and species processed (1.37 – 3.1 %). The Mentha Pulegium L. essential oil was characterized by the predominance of oxygenated monoterpenes. Pulegone (39.15 %), menthone (35.66%), piperitenone (3.98%) and piperitone (3.55%) were found to be the main constituents. Moreover, the oil of Thymus capitatus, gathered in two different months from Tunisia origin, was dominated by oxygenated monoterpenes. Major components were Thymol (76.50- 82.48%), with p-cymene (3.17- 4.01 %), with β- caryophyllene (1.39- 2.78%) and γ -terpinene (1.41-2.07%). Thus, Mentha Pulegium L. and Thymus capitatus species could be considered a good source of oxygenated monoterpenes. Furthermore, the antioxidant activity was assessed by two different methods such as DPPH. and FRAP. Results showed that T. capitatus species collected in March exhibit the uppermost activity, followed by EO of the same species gathered in August. Whereas, the M. pulegium oil possess the lowest activity. The antioxidant activity varied according to the phytochemical constituent of the investigated essential oil.
Keyword: Mentha Pulegium L.; Thymus capitatus species; chemical composition; GC/MS; antioxidant activity.