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Younsi F.,University of Carthage | Trimech R.,University of Carthage | Boulila A.,National Institute of Research and Physico chemical Analyses | Ezzine O.,National Water Research Institute | And 3 more authors.
International Journal of Food Properties | Year: 2016

Total phenols, flavonoids, flavonols, and flavanols of the methanolic extract of the aerial part of Artemisia herba-alba were determined. The extract was analyzed by liquid chromatography with photodiode array coupled with electrospray ionisation mass spectrometry and allowed to identify of 10 phenolic compounds. Apigenin-6-C-glycosyl flavonoids and caffeoylquinic acids were identified. Chlorogenic acid and 1,4 dicaffeoylquinic acid being the major constituents. The essential oil obtained by hydrodistillation was analyzed by gas chromatography-mass spectrometry. Twenty-three compounds, representing 97.8% of the total oil, were identified. The most abundant components were β-thujone (41.9%), α-thujone (18.4%), and camphor (13.2%). Methanolic extract and essential oil exhibited a considerable antioxidant activity as evaluated by 2,2-diphenyl-pycrilhydrazil hydrate scavenging activity, reducing power, β-carotene bleaching test, and chelating ability. The methanolic extract was found to be more efficient, while the essential oil exhibited the highest acetylcholinesterase inhibitory activity. Analysis of the antibacterial activity showed that A. herba-alba methanolic extract and essential oil are efficient against gram positive and gram negative bacteria. Copyright © Taylor & Francis Group, LLC. Source


Boulila A.,National Institute of Research and Physico chemical Analyses | Sanaa A.,Tunisian National Institute of Applied Sciences and Technology | Salem I.B.,Research Unit | Rokbeni N.,National Institute of Research and Physico chemical Analyses | And 3 more authors.
Industrial Crops and Products | Year: 2015

The phenolic profile of six wild growing Marrubium vulgare L. (Lamiaceae) collected from different bioclimatic zones was investigated. Ethanol, ethyl acetate and residual water fractions were investigated for their antioxidant activity using DPPH assay. Ethyle acetate (EtOAc) fraction showed the highest antioxidant capacity with IC50 values ranging from 68.98 to 118.15μg/mL.Eight phenolic acids and five flavonoids were detected in the ethyle acetate fraction and quantified by high performance liquid chromatography (HPLC) coupled to a diode array detector (DAD), among them the concentration of quercetin-3-. d-O-galactoside (5.84-14.46. mg/g DW) was the highest. Metabolic profile, consisting of glycosylated flavonoids and phenolic acids, was very regular with only quantitative differences and absences limited to minor components. A remarkably significant quantitative variation for the major components was noted. On the basis of chemical composition, principal component analysis and cluster analysis, M. vulgare was classified into two groups. Population grouping was not concordant with bioclimatic appurtenance.These results indicate that M. vulgare can be used in dietary applications with a potential to reduce oxidative stress. The pronounced chemical diversity between populations is discussed to possibly be linked to the variation of soil properties and microclimate conditions. © 2015 Elsevier B.V. Source


Abdennacer B.,National Institute of Research and Physico chemical Analyses | Karim M.,National Institute of Research and Physico chemical Analyses | Yassine M.,National Institute of Research and Physico chemical Analyses | Nesrine R.,National Institute of Research and Physico chemical Analyses | And 2 more authors.
Food Chemistry | Year: 2015

A comparative analysis of methanol extracts from fruit and leaves of Lycium intricatum Boiss., a Solanaceous shrubbery with the potential to become a high-value crop, was performed by means of liquid chromatography with photodiode array and electrospray ionisation mass spectrometric detection (LC/PDA/ESI-MS). The total phenolic (TPC), anthocyanin (TAC) and flavonoid (TFC) contents as well as the antioxidant capacity measured by four complementary methods were performed for each sample. The results showed the tested extracts to be rich sources of phenolics; in leaves polyphenols and flavonoids dominate, while in fruit anthocyanins dominate. Nineteen phenolic compounds were detected and fifteen were identified or tentatively characterised based on Photodiode-array ultraviolet visible (PDA) UV-Vis spectra, ESI-MS spectrometric data and spiking experiments with authentic standards. Rutin and chlorogenic acid are the major constituents of the leaves and fruit, respectively. Results obtained in this study have revealed that leaves exhibit better performance in all antioxidant assays. From these results it has been shown that extracts of L. intricatum have great potential as a source of phenolics for natural health products. © 2014 Elsevier Ltd. All rights reserved. Source


Rokbeni N.,National Institute of Research and Physico chemical Analyses | M'Rabet Y.,National Institute of Research and Physico chemical Analyses | Dziri S.,National Institute of Research and Physico chemical Analyses | Chaabane H.,National Institute of Research and Physico chemical Analyses | And 3 more authors.
Chemistry and Biodiversity | Year: 2013

The essential oils of Daucus carota L. (Apiaceae) seeds sampled from ten wild populations spread over northern Tunisia were characterized by GC-FID and GC/MS analyses. In total, 36 compounds were identified in the D. carota seed essential oils, with a predominance of sesquiterpene hydrocarbons in most samples (22.63-89.93% of the total oil composition). The main volatile compounds identified were β-bisabolene (mean content of 39.33%), sabinene (8.53%), geranyl acetate (7.12%), and elemicin (6.26%). The volatile composition varied significantly across the populations, even for oils of populations harvested in similar areas. The chemometric principal component analysis and the hierarchical clustering identified four groups, each corresponding to a composition-specific chemotype. The in vitro antimicrobial activity of the isolated essential oils was preliminarily evaluated, using the disk-diffusion method, against one Gram-positive (Staphylococcus aureus) and two Gram-negative bacteria (Escherichia coli and Salmonella typhimurium), as well as against a pathogenic yeast (Candida albicans). All tested essential oils exhibited interesting antibacterial and antifungal activities against the assayed microorganisms. Copyright © 2013 Verlag Helvetica Chimica Acta AG, Zürich. Source

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