Copper(II) interaction with 3,5-diisopropylsalicylic acid (Dips): New insights on its role as a potential .OH inactivating ligand

International audienceThe purpose of this study was to identify the low-molar-mass complexes formed between copper(II) and 3,5-diisopropylsalic acid (Dips) in physiological conditions. Copper(II)-Dips complex equilibria were determined using glass electrode potentiometry and their solution structures checked by UV-visible spectrophotometry. Because of the low solubility of Dips in water, the equilibria were investigated in different water/ethanol mixtures. Formation constants were extrapolated to 100% water and then compared with the values obtained for the other anti-inflammatory drugs previously studied. Given the prime role of histidine as the copper(II) ligand in blood plasma, copper(II)-histidine-Dips ternary equilibria were studied under similar experimental conditions. Computer simulations of copper(II) distribution relative to different biofluids, gastrointestinal (g.i.) fluid and blood plasma, show that like salicylic and anthranilic acids, Dips favors g.i. copper absorption, but cannot exert any significant influence on plasma copper distribution. Moreover, Dips can mobilize increasing fractions of copper(II) as the pH decreases. In conclusion, Dips seems to correspond to the notion of .OH-inactivating ligand (OIL) as determined for anthranilic acid

Copper(II) interaction with 3,5-Diisopropylsalycilic acid (DIPS), a non-steroidal antiinflammatory agent as a potential .OH inactivating ligand (OIL)

International audienceLike iron, copper can trigger Fenton-type reactions which produce in vivo .OH radicals responsible of inflammation. However, it is known that copper(II) is used in the treatment of antiinflammatory diseases [1]. Indeed, the paradox that copper can play both anti-inflammatory and pro-oxidant role is not only apparent. Its pro-oxidant action in Fenton chemistry may result in anti-inflammatory effect if a ligand bound to the Cu2+ ions is involved in the Haber-Weiss reaction, which corresponds to the definition of an .OH inactivating ligand (OIL) [2]. In this kind of action, to be active, a potential OIL must firstly mobilise copper at the inflamed site. Presently, several hundred copper complexes have been proposed as potential antiinflammatory agents. The results of these studies have been reviewed [1, 3], and confirm that many complexing agents, which are pharmacologically inactive by themselves, display antiinflammatory properties in association with copper(II) [1], such as anthranilic acid [4] and its derivatives [5] Among inactive substances activated by copper(II), 3,5-diisopropylsalicylic acid (Dips) has attracted great interest because of its radioprotectant, antiinflammatory, anticancer, antimutagenic, antidiabetic, analgesic, antineoplastic and anticonvulsant activities. The purpose of this study was to identify the low-molar-mass complexes formed between copper(II) and Dips in physiological conditions. Copper(II)-Dips complex equilibria have been determined using glass electrode potentiometry and their solution structures have been checked by UV-vis spectrophotometry. Because of the low solubility of Dips in aqueous solution, the investigation of the equilibria was done in different water/ethanol mixtures. Formation constantshave been determined extrapolating these values at 100% water and then compared with the values obtained for the other anti-inflammatory drugs previously studied. Given the prime role of histidine as copper(II) ligand in blood plasma, copper(II)-histidine-Dips ternary equilibria have also been studied in such similar experimental conditions. Computer simulations of copper(II) distribution relative to different biofluids, gastrointestinal fluid (g.i), blood plasma and synovial fluid have been run and the results will be discussed on the presentation. [1] J. R.J. Sorenson in: G. Berthon (Ed.), Handbook of Metal-Ligand Interactions in Biological Fluids; Bioinorganic Medicine, vol. 2, Marcel Dekker, New York, 1995, pp. 1318. [2] G. Berthon, Agents Actions 39 (1993) 210. [3] J. E. Weder, C. T. Dillon, T. V. Hambley, B. J. Kennedy, P. A. Lay, J. R. Biffin, H. L. Regtop, N. M. Davies, Coord. Chem. Rev., 232 (2002) 95. [4] H. Miche, V. Brumas and G. Berthon, J. Inorg. Biochem,. 68 (1997) 27. [5] B.Halova-Lajoie, V. Brumas, M. Fiallo and G. Berthon, J. Inorg. Biochem., 100 (2006) 362

Copper(II) interaction with 3,5-Diisopropylsalycilic acid (DIPS), a non-steroidal antiinflammatory agent as a potential .OH inactivating ligand (OIL)

International audienceLike iron, copper can trigger Fenton-type reactions which produce in vivo .OH radicals responsible of inflammation. However, it is known that copper(II) is used in the treatment of antiinflammatory diseases [1]. Indeed, the paradox that copper can play both anti-inflammatory and pro-oxidant role is not only apparent. Its pro-oxidant action in Fenton chemistry may result in anti-inflammatory effect if a ligand bound to the Cu2+ ions is involved in the Haber-Weiss reaction, which corresponds to the definition of an .OH inactivating ligand (OIL) [2]. In this kind of action, to be active, a potential OIL must firstly mobilise copper at the inflamed site. Presently, several hundred copper complexes have been proposed as potential antiinflammatory agents. The results of these studies have been reviewed [1, 3], and confirm that many complexing agents, which are pharmacologically inactive by themselves, display antiinflammatory properties in association with copper(II) [1], such as anthranilic acid [4] and its derivatives [5] Among inactive substances activated by copper(II), 3,5-diisopropylsalicylic acid (Dips) has attracted great interest because of its radioprotectant, antiinflammatory, anticancer, antimutagenic, antidiabetic, analgesic, antineoplastic and anticonvulsant activities. The purpose of this study was to identify the low-molar-mass complexes formed between copper(II) and Dips in physiological conditions. Copper(II)-Dips complex equilibria have been determined using glass electrode potentiometry and their solution structures have been checked by UV-vis spectrophotometry. Because of the low solubility of Dips in aqueous solution, the investigation of the equilibria was done in different water/ethanol mixtures. Formation constantshave been determined extrapolating these values at 100% water and then compared with the values obtained for the other anti-inflammatory drugs previously studied. Given the prime role of histidine as copper(II) ligand in blood plasma, copper(II)-histidine-Dips ternary equilibria have also been studied in such similar experimental conditions. Computer simulations of copper(II) distribution relative to different biofluids, gastrointestinal fluid (g.i), blood plasma and synovial fluid have been run and the results will be discussed on the presentation. [1] J. R.J. Sorenson in: G. Berthon (Ed.), Handbook of Metal-Ligand Interactions in Biological Fluids; Bioinorganic Medicine, vol. 2, Marcel Dekker, New York, 1995, pp. 1318. [2] G. Berthon, Agents Actions 39 (1993) 210. [3] J. E. Weder, C. T. Dillon, T. V. Hambley, B. J. Kennedy, P. A. Lay, J. R. Biffin, H. L. Regtop, N. M. Davies, Coord. Chem. Rev., 232 (2002) 95. [4] H. Miche, V. Brumas and G. Berthon, J. Inorg. Biochem,. 68 (1997) 27. [5] B.Halova-Lajoie, V. Brumas, M. Fiallo and G. Berthon, J. Inorg. Biochem., 100 (2006) 362

L'environnement du plan d'eau Sidi Bouraroua: Physico-chimie des eaux et sédimentation actuelle (région d'Ouezzane, Maroc)

International audienceIn order to characterise the actual environment oof Sidi Bouraoua, a deam lake situated in the Ouezzane region, seasonal investigation and sampling of water and superficial sediments have been achieved during the year 2003-2004. The physico*chemical analysis shows that fresh water is bicarbonated calco-chloro-sodics. The climatic influence is characterized by a dilution of waters from the hot season (summer) to the cold season (winter). The granulometric data of the superficial sediments shows on a detritical upstream resulting from the soil erosion of the catchment basin. The weak contents in organic matter and in carbonates are correlated with low biological water productivity and to the low autochthonous carbonates precipitation.Dans l'objectif de caractériser l'environnement actuel d'un lac de barrage situé dans la région d'Ouezzane (plan d'eau Sidi Boudaroua) des campagnes saisonnières d'études et d'échantillonnage d'eau et de sédiments d'interface ont été réalisées au cours de l'année 2003-2004. L'analyse physico-chimique montre que les eaux douces sont bicarbonatées calco-chloro-sodiques. L'influence climatique se caractérise par une dilution des eaux de la saison chaude (été) à la saison froide (hiver). La granulométrie des sédiments d'interface renseigne sur un alluvionnement en amont du plan d'eau résultant de l'érosion du sol du bassin versant. Les faibles teneurs en matière organique et en carbonates sont en liaison avec une faible productivité biologique du plan d'eau et une faible précipitation des carbonates

L'environnement du plan d'eau Sidi Bouraroua: Physico-chimie des eaux et sédimentation actuelle (région d'Ouezzane, Maroc)

International audienceIn order to characterise the actual environment oof Sidi Bouraoua, a deam lake situated in the Ouezzane region, seasonal investigation and sampling of water and superficial sediments have been achieved during the year 2003-2004. The physico*chemical analysis shows that fresh water is bicarbonated calco-chloro-sodics. The climatic influence is characterized by a dilution of waters from the hot season (summer) to the cold season (winter). The granulometric data of the superficial sediments shows on a detritical upstream resulting from the soil erosion of the catchment basin. The weak contents in organic matter and in carbonates are correlated with low biological water productivity and to the low autochthonous carbonates precipitation.Dans l'objectif de caractériser l'environnement actuel d'un lac de barrage situé dans la région d'Ouezzane (plan d'eau Sidi Boudaroua) des campagnes saisonnières d'études et d'échantillonnage d'eau et de sédiments d'interface ont été réalisées au cours de l'année 2003-2004. L'analyse physico-chimique montre que les eaux douces sont bicarbonatées calco-chloro-sodiques. L'influence climatique se caractérise par une dilution des eaux de la saison chaude (été) à la saison froide (hiver). La granulométrie des sédiments d'interface renseigne sur un alluvionnement en amont du plan d'eau résultant de l'érosion du sol du bassin versant. Les faibles teneurs en matière organique et en carbonates sont en liaison avec une faible productivité biologique du plan d'eau et une faible précipitation des carbonates

L'environnement du plan d'eau Sidi Bouraroua: Physico-chimie des eaux et sédimentation actuelle (région d'Ouezzane, Maroc)

International audienceIn order to characterise the actual environment oof Sidi Bouraoua, a deam lake situated in the Ouezzane region, seasonal investigation and sampling of water and superficial sediments have been achieved during the year 2003-2004. The physico*chemical analysis shows that fresh water is bicarbonated calco-chloro-sodics. The climatic influence is characterized by a dilution of waters from the hot season (summer) to the cold season (winter). The granulometric data of the superficial sediments shows on a detritical upstream resulting from the soil erosion of the catchment basin. The weak contents in organic matter and in carbonates are correlated with low biological water productivity and to the low autochthonous carbonates precipitation.Dans l'objectif de caractériser l'environnement actuel d'un lac de barrage situé dans la région d'Ouezzane (plan d'eau Sidi Boudaroua) des campagnes saisonnières d'études et d'échantillonnage d'eau et de sédiments d'interface ont été réalisées au cours de l'année 2003-2004. L'analyse physico-chimique montre que les eaux douces sont bicarbonatées calco-chloro-sodiques. L'influence climatique se caractérise par une dilution des eaux de la saison chaude (été) à la saison froide (hiver). La granulométrie des sédiments d'interface renseigne sur un alluvionnement en amont du plan d'eau résultant de l'érosion du sol du bassin versant. Les faibles teneurs en matière organique et en carbonates sont en liaison avec une faible productivité biologique du plan d'eau et une faible précipitation des carbonates

Effect of silicon on reducing cadmium toxicity in durum wheat (Triticum turgidum L. cv. Claudio W.) grown in a soil with aged contamination

International audienceAgricultural soil contamination and subsequently crops still require alternative solutions to reduce associated environmental risks. The effects of silica application on alleviating cadmium (Cd) phytotoxicity in wheat plants were investigated in a 71-day pot experiment conducted with a historically contaminated agricultural soil. We used amorphous silica (ASi) that had been extracted from a diatomite mine for Si distribution at 0, 1, 10 and 15 ton ASi ha−1. ASi applications increased plant biomass and plant Si concentrations, reduced the available Cd in the soil and the Cd translocation to shoots, while Cd was more efficiently sequestrated in roots. But ASi is limiting for Si uptake by plants. We conclude that significant plant-available Si in soil contributes to decreased Cd concentrations in wheat shoots and could be implemented in a general scheme aiming at controlling Cd concentrations in wheat

Comparaison des résultats analytiques obtenus après fusion alcaline au métaborate avec ceux obtenus après fusion alcaline au tétraborate dans les niveaux d'altération des grès de l'Inkisi (secteur de Brazzaville, République du Congo) : applications dans l

In comparing the analytical results obtained by ICP-AES after alkali fusion with lithium metaborate and with lithium tetraborate in the analysis of samples from a weathering profile of Inkisi sandstone (south of Brazzaville, Republic of Congo), we notice important differences, notably in the upper levels of the profile. Those differences are either positive or negative. For Some element, like Al, differences are very small. That can due to the precision of the analysis. On the other hand, other elements, like Si, present important differences, sometimes positive, sometimes negative. In order to evaluate these fluctuations, we have defined a coefficient of variation Ki, as follows :Ki(%) = 100 * ((oxidei (tf)-oxidei (mf)) / oxidei (mf))(with tf: result obtained after tetraborate alkaline fusion and mf : result obtained after metaborate alkaline fusion for the i oxide analyzed).The Ki curves in function of the depth established for three chemical elements (K, Na, Si) permit to locate on the weathering profile the levels more fusible to tetraborate (positive Ki) and those more fusible to metaborate (negative Ki) for each element. So, by this way, we can know if a chemical element released from a primary mineral has integrated more or less refractory secondary mineral structures. By comparing these curves with mineralogical evolution along the weathering profile, as showed by X ray diagrams, we have obtained the following results:-Sodium and potassium Ki curves can be correlated with the weathering level respectively of albite and potassium feldspars.-The silicon Ki curve can be connected with the type of secondary minerals formed successively along the weathering profile.So, the Ki coefficient associated with other analytical methods like X ray diffraction, can be used in weathering studies. According to our knowledge, it is the first time that such geochemical approach is used in weathering profile study

Comparaison des résultats analytiques obtenus après fusion alcaline au métaborate avec ceux obtenus après fusion alcaline au tétraborate dans les niveaux d'altération des grès de l'Inkisi (secteur de Brazzaville, République du Congo) : applications dans l'étude des profils d'altération

We have compared the analytical results obtained by ICP-AES after alkali fusion with lithium metaborate and with lithium tetraborate in the analysis of samples from an arkosic sandstone from «Inkisi» (Congo, Central of Africa) along a weathering profile. The observation of some differences of behaviour of the two fluxes at the upper levels has conduce us to assume that this differences was in relationship with the degree of weathering process on potassic feldspars and sodic feldspars (albite) contained in those sandstones. In order to locate easily the weathering front on the weathering profile we have defined a coefficient of variation Ki:Ki (%) = 100 * ((oxidei (tf) - oxidei (mf)) / oxidei (mf))(with tf : result obtained after tetraborate alkaline fusion and mf : result obtained after metaborate alkaline fusion for the i oxide analyzed).The study of the Ki curves obtained for three chemical elements (K, Na, Si) typical of alteration of sandstones in function of the depth permits to show that the variations of the Ki curves was able to locate precisely the alteration levels of the different minerals. So, sodium from albite is the first released at a quite deep level of the profile. It is followed by the potassium from potassic feldspars. We have also showed that, according to the positive or negative sign positive of Ki variations, the chemical element released will integrate more or less refractory mineral structures. All of those results have been confirmed by the study of the X-ray diagrams of the same weathering profile. So, in case of arkosic sandstone our method would permit to locate with precision the weathering front on the profile. This method might be used for the study of other kind of rocks.Les résultats analytiques obtenus en ICP-AES après fusion alcaline au métaborate de lithium sont comparés à ceux obtenus après fusion alcaline au tétraborate de lithium sur un profil d’altération des grès de l’Inkisi (Sud de Brazzaville, Congo). Les teneurs obtenues montrent des différences parfois importantes, notamment dans les niveaux supérieurs de l’altération. Ces différences sont, soit positives, soit négatives. Elles varient selon l'élément chimique analysé. Certains éléments chimiques, comme l'aluminium, présentent des différences très faibles attribuables à la précision des analyses; pour d'autres, par contre, comme le silicium, elles sont importantes et fluctuantes. Nous avons conçu un coefficient Ki de la manière suivante: Ki (%) = 100 * ((oxydei (tf) - oxydei (mf)) / oxydei (mf))(tf : résultat obtenu après fusion alcaline au tétraborate et mf : résultat obtenu après fusion alcaline au métaborate, pour un oxyde i analysé). Les courbes de variation du Ki en fonction de la profondeur, établies de la base au sommet du profil d’altération permettent de localiser les niveaux plus fusibles au tétraborate (Ki positif) et les niveaux plus fusibles au métaborate (Ki négatif). En comparant ces courbes avec l’évolution minéralogique au cours de l’altération, montrée par les diagrammes rayons X, nous avons obtenu les résultats suivants: -les variations des courbes du Ki du sodium et du potassium ont pu être corrélées, respectivement, avec les niveaux d'altération de l’albite et ceux d'altération des feldspaths potassiques.-les variations des courbes du Ki du silicium ont pu être corrélées avec la nature des minéraux secondaires apparaissant successivement le long du profil d'altération. Ainsi l’utilisation du coefficient Ki, tel que nous l’avons déterminé, peut contribuer, en appui avec d'autres méthodes comme la diffraction RX, à l’étude des processus d’altératio

New Computerized Method for the Geochemical Classification of Precambrian Carbonate Rocks: Case of a Set of African Cap Carbonates

International audiencePost-sedimentary transformations have masked or completely obliterated the structures and textures of Precambrian carbonate rocks. Therefore, methods of classification of the carbonate rocks founded on the observation of primary structures or textural characteristics are ill-adapted. Consequently, only certain geochemical classification methods al- low us to distinguish the various rock-types in the case of Neoproterozoic carbonates. After presenting the most suit- able geochemical classifications, we propose a new classification into 14 groups based on a regular ternary diagram with computerized data input. For each sample of carbonate rock, analysis of calcium and magnesium contents allows us to calculate the input data for our diagram i.e. the percentages of Calcite, Dolomite and Insoluble Residue. To auto- mate the application of this diagram, input parameters are created in a descriptive file "Roches.ternaires.txt" using an option called "Ternaires" in the "Diagrammes" software developed by Roland Simler. Thirty cap carbonates of Africa are used to validate this new method