Essential oil of : Chemical characterization, antioxidant activity, and allelopathic effect on the weed .

The essential oil (EO) of shoots was extracted via hydro-distillation and then investigated by gas chromatography-mass spectrometry. Thirty-four compounds were recognized for the first time from this plant, representing 100% of the total mass. Terpenoids represented the major components with 69.17% of the total mass, containing oxygenated sesquiterpenes (53.18%), oxygenated monoterpenes (9.77%), sesquiterpene hydrocarbons (5.03%), and diterpenes (1.19%). Additionaly, 6-methoxy-1-acetonaphthone was the only aromatic compound represented in a high percentage of the total identified compounds with 22.35%. Additionally, a percent of 8.48% of the total mass was hydrocarbons. Only one oxygenated sesquiterpene namely hexahydrofarnesyl acetone representing 47.35% of the total mass was identified. It was followed by methoxy-1-acetonaphthone (19.92%), -dotriacontane (3.58%), -borneol (3.24%), 6-methy--ionone (3.04%), and -gurjunene (2.65%). The EO exhibited moderate antioxidant activity comparable with ascorbic acid as a standard, where it attained IC value of 20.70 µL L and 16.32 µL L, for DPPH and ABTS. The EO of significantly reduces the germination and seedling development of the weed . The EO showed an IC value of 175.60 µL L, 246.65 µL L, and 308.33 µL L for root growth, shoot growth, and germination, respectively. Therefore, this EO could be a good green resource for the control of weeds.