Etude d’activité antioxydante et insecticide de l’huile essentielle de thymus fontanesii.

Abstract

In order to in hence the Algerian plant resources, the essential oils from plants of the lamiaceae family, namely T. fontanesii harvested in the Ain Dafla region were the subject of this study. EOs was extracted out by hydrodistillation. The chemical analysis of EOs was performed by CPG and CPG / MS and the antioxidant activities of EOs was done by two methods namely the DPPH and FRAP method, and insecticidal activity by contact and by inhalation. The hydro distillation of the aerial parts of T. fontanesii allowed us to obtain the oil with a yield of 3.125%. The chemical analysis of the EO of T. fontanesii showed the presence of 27 compounds, the most important components were thymol (67.8%), p-cymene (13%) and γ-terpinene (15.9 %) low in carvacrol (1.7%). The results of antioxidant activity depend on the phenolic constituents present in thyme which are responsible for the scavenging of DPPH radicals and the reduction of Fe3+ to Fe2+. The previous activity appeared as inhibition of concentration value (IC50) which represents the effective concentration of the substrates which causes the loss of 50% of the activity. IC50 values ranged from 57.3 ± 1.4 to 236.7 ± 1.4 μg / mL The insecticidal activity results of the contact tests are very essential, with 50% 57.5% 70% and 85% death recorded of adults after 24 hours which match respectively to doses of 2μL 4μL 8μL 16μL. The inhalation test confirms the results obtained or for a dose of 8 μl there was a mortality rate greater than 50% after 3 days.