Chemical Composition, Antioxidant, Antifungal and Herbicidal Activities of Essential Oils from Three Thymus Species

Abstract

The current study aimed to research the chemical composition, antioxidant, herbicidal and antifungal effect three essential oils, as obtained from Thymus canoviridis Jalas., Thymus eriocalyx (Ronni.) Jalas. and Thymus fallax Fisch. et C.A. Mey. Antioxidant capacities of essential oils were determined by 1.1dipheny1-2-picrylhydrazyl (DPPH) method. The antifungal potential was tested in-vitro against Fusarium equiseti (Corda) Sacc., Fusarium graminearum Schwab., Fusarium moniliforme J. Sheld and Fusarium oxysporum Schlec. Bioherbicidal effect was studied in-vivo and in-vitro against weed seeds of Amaranthus retroflexus L., Convolvulus arvensis L. and Chenopodium album L. Essential oils were assayed in laboratory three concentrations (5, 10 and 20 µL/petri) and one (20 µL/pot) concentration in the greenhouse. The chemical composition of essential oils was analyzed by (GC) and (GC/MS). The major constituents were p-cymene, 1,8-cineole and γ-terpinene. As a result of the antioxidant study, it was determined that Thymus essential oils had remarkable antioxidant activity. On the other hand, oils decreased mycelial growth of pathogens at different rates due to increasing doses and inhibited 9.33-100% in-vitro conditions. In the bioherbicidal study assays showed that tested essential oils had inhibitory effects on the seed germination and seedling growth of weeds. The study concludes that Thymus essential oils might has the potential use as bioherbicide and biofungicide can constitute an alternative process of weed control and fungus.