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Browsing by Author "Sebei, H."

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  • Chemical variability of the essential oils from Rosa canina L. and Rosa sempervirens L. flowers collected at Tunisia
    Publication . Ghazghazi, H.; Miguel, Maria Graça; Weslati, M.; Hasnaoui, B.; Sebei, H.; Barroso, J. G.; Pedro, L. G.; Figueiredo, A. C.
    The chemical variability of the essential oils of Rosa canina L. and R. sempervirens L. flowers collected at seven localities from northern Tunisia was investigated by gas chromatography (GC) and GC-mass spectrometry (GC-MS). The essential oils yields ranged between 0.7% and 1.4% (v/f.w.) for R. canina and R. sempervirens, respectively. Forty-one components were identified in R. canina and twenty-six in R. sempervirens oils. Rosa canina essential oil, from plants collected at Ain Draham, was dominated by beta-caryophyllene (32%) and geraniol (21%), whereas in the oils from plants collected at Boussalem n-heneicosane (29%), p-cymene (12%) and beta-caryophyllene (11%) predominated. However, the oil isolated from the samples collected at Fernana was dominated by 2,4,6-trimethyl-octane (9%), n-undecane (8%) and geraniol (8%). p-Cymene (14%), limonene (11%) and gamma-terpinene (11%) were the main components of the oil isolated from Feija samples. Rosa sempervirens oils, from plants collected at Ain Draham and Fernana, were characterized by a high 2-phenylethyl alcohol content (29% and 93%, respectively). The major components of the oil isolated from Tabarka samples were p-cymene (16%) and gamma-terpinene (12%). Cluster analysis of the essential oils composition from the studied populations, confirmed the major chemical variability.
    2012Journal article Restricted access Show more
  • Phenols, essential oils and carotenoids of Rosa canina from Tunisia and their antioxidant activities
    Publication . Ghazghazi, H.; Miguel, Maria Graça; Hasnaoui, B.; Sebei, H.; Ksontini, M.; Figueiredo, A. C.; Pedro, L. G.; Barroso, J. G.
    The antioxidant activity of leaf extracts of Rosa canina from diverse localities of Tunisia were evaluated by ABTS and DPPH methods, whereas in those of essential oils and carotenoids extracts such activity was determined only by the ABTS method. Total phenols determined by the Folin method revealed that at Aindraham, samples showed a great variability of phenol content in contrast to those from Feija. After chemical analysis of the essential oils by gas chromatography (GC) and gas chromatography coupled to mass spectra (GC-MS), revealed that the oils of Feija were predominantly composed of palmitic acid, vitispirane, linoleic acid, lauric acid, myristic acid and phytol acetate, while in those samples from Aindraham predominated vitispirane, palmitic acid, linoleic acid and phytol acetate. Higher concentrations of beta-carotene and lycopene were found in the samples from Aindraham after determination by high performance liquid chromatography (HPLC). All samples possess antioxidant activity, nevertheless much more significant in phenol extracts in contrast to the carotenoid extracts, which possess the lowest activity.
    2010Journal article Open access Show more