Les peintures de terres cuites à Carthage. Identification des pigments de figurines et de fruits

Le développement de l'artisanat punique à Carthage a fait l'objet de nombreuses études mais un très petit nombre concerne les matériaux utilisés dans les terres cuites et leur décor. L'article présente les analyses de pigments décorant deux types d'objets, fruits à usage funéraire et statuettes. Elles ont été réalisées sur des micro-prélèvements, essentiellement par microspectrométrie Raman, complétée dans quelques cas par des analyses élémentaires. Elles montrent l'utilisation seulement de produits inorganiques. A l'époque punique, la palette de l'artiste comporte des oxydes de fer jaune et rouge, composés très largement répandus dans la nature et du bleu égyptien, comme dans l'ensemble du bassin méditerranéen. Deux pigments sont particulièrement intéressants car les matières premières ne sont pas d'origine locale : la présence de sulfure de mercure, qui pourrait provenir de la péninsule ibérique, et le carbonate basique vert de cuivre, la malachite, qui suppose un approvisionnement en cuivre. Les engobes blancs sont à base de kaolinite. Pour tous les engobes de fruit, un oxyde de titane, l'anatase, a été identifié et pourrait être une indication d'origine géographique de la kaolinite. L'engobe d'une statuette contient un composé phosphoré, vraisemblablement un phosphate de calcium, pour en renforcer la couleur blanche.The punie craftsmanship development in Carthage was the subject of numerous studies, however, a few of them dealt with the materials used in baked clay and its decoration. The report shows the analysis of pigments decorating two types of objects, fruits for funeral uses and statuettes. These analysis have been achieved on microsamples, essentially by Raman micro-spectrometry and sometimes completed by elementary ones. No organic colored product was detected. During the punic cra, the artist's palette comprises yellow and red iron oxides, components widely spread in nature, and also Egyptian blue, like the one in the Mediterranean world. Two pigments arc particularly interesting because their raw materials arc not from a local origin : mercury sulfide which may originate from Iberian peninsula and malachite which engenders the need for a supply in copper. The white coatings arc kaolinit basis. For all the fruit coatings, a titanium oxide, anatase, has been identified and might be an indication of kaolinite geographic origin. The coating of a statuette contains a phosphorus component, which could be calcium phosphate, in order to reinforce white colour

A New and Efficient Method for the Synthesis of Novel 3-Acetyl Coumarins Oxadiazoles Derivatives with Expected Biological Activity

This paper presents the design of some novel 3-acetylcoumarin derivatives, based on minimal inhibitory concentration values (MICs) previously obtained against some microorganism cultures, Gram positive and negative bacteria and fungi. Some of these molecules exhibited antibacterial activity against S. aureus, comparable to that of the standard used (impinem). The in vitro antioxidant activities of the novel 3-acetylcoumarin oxadiazoles were assayed by the quantitative 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity method. The compounds 5c,d proved to be the most active, showing the highest capacity to deplete the DPPH radicals. Structure elucidation of the products has been accomplished on the basis of IR, 1H-NMR, 13C-NMR, NOESY and HMBC NMR data

Identification par microscopie Raman des tessons et pigments de glaçures de céramiques de L'Ifriqiya (Dougga, XI-XVIIIèmes siècles)

Raman (micro)spectrometry is used as a technique for the understanding and identification of the fabrication technology of ancient faience and glazed terra cotta from Dougga, north-west of Tunisia. Studied samples are assigned to zirides (XI-XIIth), almohades (XIII-XVth), hafsides and ottomane (XVII-XVIIth) periodes. Cassitérite (SnO2) white, (Pb2Sb,O7) Naples yellow, black and (Fe/Mn ?) brown spinels, haematite (Fe2O3) black and unassigned blue pigment have been characterized. Green colour results from glaze doping (by Cu ?), except for recent samples where woUastonite phase, easely colored in green by chrome, is found. A cassiterite-free overglaze is often present. Cassitérite amounts appear too low in ancient samples to really opacify the enamel.L'analyse par (micro)spectroscopie Raman est utilisée pour comprendre et identifier les technologies employées pour l'élaboration de faïences/terres cuites émaillées provenant de Dougga (Nord-ouest de la Tunisie). La chronologie proposée se répartit sur les périodes : ziride, almohade, hafside et ottomane : XI-XIIème siècles, XIII-XVème siècles et XVII-XVIIIème siècles. Le blanc de cassitérite (Fe 2O3), le jaune de Naples (Pb2Sb2O7), des spinels (Fe/Mn ?) pour les noirs et bruns, l'hématite (Fe2O3) pour un noir, ainsi que d'autres phases pour le bleu, sont clairement observés. Le vert résulte d'une coloration dans la masse de l'émail (sans doute du cuivre) sauf pour certains échantillons tardifs (XVII-XVIII th) où la présence de wollastonite rend possible une coloration par le chrome. Un émail de surface exempt de cassitérite est souvent observé. La cassitérite semble avoir été utilisée dans les productions du haut Moyen Age en quantité trop faible pour être un opacifiant efficace.Colomban Philippe, Sagon Gérard, Louhichi Adnan, Binous Housam, Ayed Naceur. Identification par microscopie Raman des tessons et pigments de glaçures de céramiques de L'Ifriqiya (Dougga, XI-XVIIIèmes siècles). In: Revue d'Archéométrie, n°25, 2001. pp. 101-112

Valorization of Tunisian alfa fibres and sumac tannins for the elaboration of biodegradable insulating panels

Alfa leaves are important renewable raw materials in Tunisia where they are used basically in handcrafts and paper industry. Sumac is also an abundant species in Tunisia known for its high tannin content and is basically used in traditional medicine. To valorize these natural resources, we studied, for the first time, the possibility of making insulating panels based on alfa fibres and sumac tannins based adhesive. Firstly, alfa leaves were treated with an alkali solution as it is one of the standard procedures commonly used in the paper industry to extract cellulosic fibres. Mercerization effects were studied by characterizing fibres thermal properties and fibres surface morphology. Secondly, the sumac tannin based resin was formulated and characterized. Finally, the insulating panel was elaborated and characterized by determining its thermal conductivity. The thermal gravimetric analysis results show improvement in the thermal stability of fibres after alkali treatment. Environmental Scanning Electron Microscopy showed changes on treated alfa surface which could promote the fibre-matrix adhesion. The reactivity of sumac tannins to formaldehyde test (Stiasny number) showed the possible use of sumac tannins in wood adhesive formulation. Thermomechanical analysis and strength analysis of sumac tannin/hexamin based resin highlighted acceptable bonding properties. The thermal conductivity measurement showed an average value equal to 0.110 W/m K

Synthesis and Characterization of New Thiazolidinones Containing Coumarin Moieties and Their Antibacterial and Antioxidant Activities

New coumarin derivatives, namely (2-(4-methyl-2-oxo-<em>2H</em>-chromen-7-yloxy)-<em>N</em>-(4-oxo-2-phenylthiazolidin-3-yl)acetamide, <em>N</em>-(2-(3-methoxyphenyl)-4-oxothiazolidin-3-yl)-2-(4-methyl-2-oxo-<em>2H</em>-chromen-7-yloxy)acetamide, 2-(4-methyl-2-oxo-<em>2H</em>-chromen-7-yloxy)-<em>N</em>-(4-oxo-2-(2,3,4trimethoxyphenyl)thiazolidin-3-yl)acetamide and <em>N</em>-(2-(4-bromophenyl)-4-oxothiazolidin-3-yl)-2-(4-methyl-2-oxo-<em>2H</em>-chromen-7-yloxy)acetamide) were synthesized starting from 4-methyl-7-hydroxycoumarin. The structures of the obtained compounds were confirmed by analytical IR and NMR spectra to elucidate the different positions of protons and carbons and as well as theoretical studies (DFT/B3LYP). The new compounds were screened for antibacterial activity. Most of them are more active against <em>E. coli S. aureus </em>and <em>B. subtilis</em> than standard references

MALDI-TOF Analysis of Aleppo Pine (Pinus halepensis) Bark Tannin

Matrix-assisted laser desorption/ionisation time of flight (MALDI-TOF) mass spectrometry is a suitable method for examining polyflavonoid tannin oligomers because it has the capability to determine aspects of their oligomeric structure and characteristics that are too difficult to determine by other techniques. For non-purified industrially extracted Aleppo pine polyflavonoid tannin, it was possible to determine by MALDI-TOF that: (i) oligomers formed by catechin/epicatechin are present in tannin, as are mixed oligomer units with fisetinidin and robinetinidin units; the presence of flavonoid gallate and other structures was confirmed; (ii) oligomers up to 12 to 13 repeating monoflavonoid units, in which the repeating unit is at 264 Da, have been confirmed; and (iii) oligomers of the two types covalently linked to each other also occur. The presence of a small proportion of hydrolysable tannins by chemical analysis can also be explained by gallate residues attached to some of the flavonoid oligomers

Efficient in situ N-heterocyclic carbene palladium(ii) generated from Pd(OAc)2 catalysts for carbonylative Suzuki coupling reactions of arylboronic acids with 2-bromopyridine under inert conditions leading to unsymmetrical arylpyridine ketones: synthesis, characterization and cytotoxic activities

International audienceN,N-Substituted benzimidazole salts were successfully synthesized and characterized by 1H-NMR, 13C {1H} NMR and IR techniques, which support the proposed structures. Catalysts generated in situ were efficiently used for the carbonylative cross-coupling reaction of 2 bromopyridine with various boronic acids. The reaction was carried out in THF at 110 °C in the presence of K2CO3 under inert conditions and yields unsymmetrical arylpyridine ketones. All N,N-substituted benzimidazole salts 2a–i and 4a–i studied in this work were screened for their cytotoxic activities against human cancer cell lines such us MDA-MB-231, MCF-7 and T47D. The N,N-substituted benzimidazoles 2e and 2f exhibited the most cytotoxic effect with promising cytotoxic activity with IC50 values of 4.45 μg mL−1 against MDA-MB-231 and 4.85 μg mL−1 against MCF7 respectively