Chemical Composition and Antioxidant Activity of Algerian Juniperus phoenicea L. Extracts

Abstract

Essential oils of Algerian Juniperus phoenicea L. obtained from leaves and berries by hydrodistillation (HD) and from berries by Solvent Free Microwave Assisted Extraction (SFMAE) were investigated using both capillary GC and GC-MS techniques. The monoterpene hydrocarbons constituted the most prominent group of constituents (43.2-86.5 %) in the three essential oils with α-pinene (34.4-80.8 %) as the main compound. Leaves ethanol extract was analyzed in terms of the dosage in total phenolic and flavonoids contents. Gallic acid equivalent representing total phenolic constituents of the extract was 308 mg GAE/g; and quercetin equivalent representing total flavonoids was 20 mg QE/g. The antioxidant potential of the samples was evaluated using two separate methods, inhibition of free radical 2,2-diphenyl-1-picrylhydrazyl (DPPH) and reducing power. All essential oils showed a relatively weak antioxidant capacity. No improvement of the antioxidant activity by SFMAE technique has been detected. J. phoenicea ethanol extract was found to be remarkably effective toward DPPH inhibition, compared to chemical antioxidant BHT (IC = 9.8±0.1 and 28±0.7 mg/l, respectively); for reducing power test it has also exhibited high activity in comparison with all studied essential oils and the chemical standard (BHT).