Phytochemical profile of fennel essential oils and possible applications for natural antioxidant and controlling Convolvulus arvensis L.

The natural compounds such as essential oils are getting more attention due to their potential usage in pharmaceuticals and possibly as natural herbicides. This study was conducted to identify the chemical compositions of essential oils from Foeniculum vulgare Mill. populations collected from different regions of Iran, Turkey, and Germany, and their antioxidant (DPPH·, ABTS·⁺ and reducing power methods) and phytotoxic activity (against Convolvulus arvensis L.). The results exhibited a significant variation in essential oils content (1.74-2.97%). The main compounds in essential oils were trans-anethole (15.23%-90.11%), estragole (4.00-63.72%), fenchone (0.03-12.62%) and limonene (1.05-13.04%). The results revealed that the essential oils have considerable antioxidant (IC₅₀ values in the range of 11.83-36.90 mg mL^-1 in DPPH, 7.65-20.13 mg mL^-1 in ABTS^·+ and EC₅₀ values in the range of 3.65-15.24 mg mL^-1 in reducing power assay) and phytotoxic activity. The results of this study can help in the development of natural antioxidants and herbicides.