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Salah N.B.,University of Monastir | Salah N.B.,Laboratoire Of Chimie Organique Structurale | Casabianca H.,CNRS Institute of Analytical Sciences | Jannet H.B.,University of Monastir | And 4 more authors.

A phytochemical investigation of Diplotaxis virgata DC. and D. erucoides (L.) D.C. (Brassicaceae) offered to the isolation of two new flavonoids isorhamnetin-3-O-α-L-glucopyranoside (1) and rhamnetin-3,3'-di-O-β-D-glucopyranoside (2), respectively. Their structures have been elucidated from the extended spectroscopic methods, including 1D- and 2D-NMR, UV and mass spectrometry analysis and by comparison with literature data. The fatty acid composition of the hexane extracts of the two species was also investigated by using GC-MS. The antioxidant activity of ethanol, ethyl acetate, n-butanol extracts and the isolated compounds from the two species was evaluated using DPPH and ABTS+ scavenging assays. All the tested samples showed an efficient radical scavenging ability, with IC50 values ranging from 16-40 μg/mL for the DPPH and from 17-44 μg/mL for the ABTS+ assays. In addition, the antibacterial activity of the prepared extracts and compounds 1 and 2, determined by well diffusion agar method against two Gram positive and five Gram negative bacteria, was evaluated and the results showed significant effects against all strains used. © 2015 by the authors; licensee MDPI, Basel, Switzerland. Source

Mzani O.,Laboratoire Of Chimie Organique Structurale | Ben Romdhane H.,Laboratoire Of Chimie Organique Structurale | Baklouti M.,Unite de Recherche Synthese et Analyse de Materiaux | Mercier R.,French National Center for Scientific Research
Designed Monomers and Polymers

The synthesis and characterization of novel polyimides obtained by Diels-Alder reaction of bis-pyrones and bismaleimides are studied. The present cycloadducts contain CO2 bridges, which can be eliminated by subsequent heat treatment, thereby generating stable aromatic systems. The CO2 released acts as blowing agent, leading to porous structures that are in high demand in the manufacture of heat-resistant foams. However, in this type of material, one should always seek a good compromise between the temperatures of polymerization and decarboxylation of early degradation. All polymers are analyzed with 13C-, solid-state NMR and coupling ATG/IR. The studies of their thermal behaviour, examined by thermogravimetric analysis and differential scanning calorimetric analysis, show that these polyimides have a good thermal stability and are mainly amorphous. © 2010 Koninklijke Brill NV, Leiden. Source

Ben Salah N.,University of Monastir | Ben Salah N.,Laboratoire Of Chimie Organique Structurale | Casabianca H.,CNRS Institute of Analytical Sciences | Essaidi I.,Laboratoire Of Chimie Organique Structurale | And 5 more authors.
Industrial Crops and Products

The present work constitutes a contribution to the phytochemical investigation of Hedysarum carnosum aiming to search for novel bioactives secondary metabolites. In this context, the fractionation of the butanolic extract of H. carnosum flowers afforded two new flavonoid glycosides quercetin 3-O-β-d-glucopyranosyl-(1→2)-α-l-rhamnopyranosyl-(1→6)-α-l-rhamnopyranoside 1 and kaempferol 3-O-β-d-glucopyranosyl-(1→2)-α-l-rhamnopyranosyl-(1→6)-α-l-rhamnopyranoside 2 together with a the known rutin 3 indicated for the first time in this species. Their structures were determined on the basis of spectroscopic evidences (UV, HRMS and NMR) and comparison with literature. The fatty acid composition of the hexane extract of this species was also investigated by using GC-MS. The n-butanol extract and the isolates were assessed for their antioxidant potential using DPPH and ABTS+ scavenging assays and ferric reducing power (FRAP). The n-butanol extract and its fractions exhibited efficient radical scavenging activity with IC50 values ranging from 16 to 37μg/mL for the DPPH assay. The obtained results suggest that the isolated compounds 1 and 3 could be promising antioxidant agents. © 2015 Elsevier B.V. Source

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