Antioxidant activity and chemical composition of essential oils of three aromatic plants from La Rioja province

AbstractContext: The use of many traditional medicinal plants is often hampered by the absence of a proper biochemical characterization, which is essential to identify the bioactive compounds present in it. The essential oils (EOs) of three native species from the La Rioja province were analyzed: Lippia turbinata Griseb and Lippia integrifolia (Griseb.) Hieron (Verbenaceae), and Clinopodium gilliesii (Benth.) Kuntze (Lamiaceae).Objective: The aim of this study was to evaluate their EOs antioxidant activity (AA) and their chemical composition.Materials and methods: EOs were analyzed by gas chromatography-mass spectrometry (GC-MS). To enhance the aqueous solubilization of the EOs, EO–water emulsions were prepared (concentration range of 0.1–6 mg mL−1). AA was determined using ABTS, DPPH, and peroxyl radical scavenging assays, as well as by the β-carotene bleaching test.Results: Piperitenone oxide was a major constituent in L. turbinata, pulegone and piperitenone oxide in C. gilliesii, and β-caryophyllene in...