Chemical composition and antioxidant activity of Marrubium vulgare L. essential oil from Tunisia

In this study, the essential oil of the aerial parts of Marrubium vulgare L. obtained by hydrodistillation was analyzed by gas chromatography coupled to mass spectrometry (GC-MS) in order to determine their chemical composition. Thirty-four (34) components in the oil of M. vulgare were identified. The results demonstrated that the major components of the essential oil were y-eudesmol (11.93%),β - citronellol (9.90%), citronellyl formate (9.50%) and germacrene D (9.37%). Antioxidant effectiveness was examined by three different methods: The DPPH (1,1-diphenyl-2-picrylhydrazyl) assay, the β-carotene bleaching test and the reducing power assay. The results showed that this oil can be considered an effective source of antioxidants of natural origin. This is the first report on chemical composition of M. vulgare essential oil cultivated in Tunisia and the original study on the antioxidant activity of M. vulgare essential oil.Key words: Marrubium vulgare, essential oil, chemical composition, antioxidant activity

Chemical composition and in vitro antioxidant activities of Thymelaea hirsuta L. essential oil from Tunisia

This study was designed to examine for the first time, the chemical composition and in vitro antioxidant activities of the essential oil obtained from the aerial parts of Thymelaea hirsuta L. The essential oil was subjected to hydrodistillation and was analyzed by GC-FID and GC-MS. The chemical composition was dominated by the presence of hydrocarbon sesquiterpenes (26.91%) with germacrene D (12.98%) as the major component, while oxygenated sesquiterpenes and monoterpenes amounted to 13.82 and 13.29%, respectively. The antioxidant properties of the studied essential oil were determined by three methods: diphenylpicrylhydrazyl (DPPH) assay, -carotene bleaching assay and reducing power test and the results were compared to the reference BHT (butyl hydroxy toluene). In the three earlier mentioned assays, the essential oil demonstrated a potential antioxidant which may be considered as potent agent in food preservation and drug discovery.Key words: Thymelaea hirsuta, essential oil, antioxidant activities