Total Phenolic Content, Radical Scavenging Properties, and Essential Oil Composition of Origanum Species from Different Populations

The aim of this work was to compare the antiradical activity, total phenol content (TPC), and essential oil composition of Origanum vulgare spp. virens, Origanum × applii, Origanum × majoricum, and O. vulgare spp. vulgare cultivated in Argentina in different localities. The experiment was conducted in the research station of La Consulta (INTA-Mendoza), the research station of Santa Lucia (INTA-San Juan), and Agronomy Faculty of National University of La Pampa, from 2007 to 2008. The composition of the essential oils of oregano populations was independent of cultivation conditions. In total, 39 compounds were identified in essential oils of oregano from Argentina by means of GC−MS. Thymol and trans-sabinene hydrate were the most prominent compounds, followed by γ-terpinene, terpinen-4-ol, and α-terpinene. O. vulgare vulgare is the only Origanum studied which is rich in γ-terpinene. Among tested oregano, O. × majoricum showed the highest essential oil content, 3.9 mg g−1 dry matter. The plant extract of O. ...