Étude in vitro de l’effet antifalcémiant des globules rouges et de l’activité antioxydante d’extraits de la poudre de racines de Maytenus senegalensis Lam (Celestraceae)

La drépanocytose est une hémoglobinopathie largement répandue chez les populations africaines noires. Actuellement, très peu de traitements conventionnels existent sur le marché, d’où le recours à la médecine traditionnelle. Maytenus senegalensis est une plante prescrite par les tradipraticiens dans la prise en charge de la drépanocytose. L’activité antifalcémiante des extraits de la poudre de racines de Maytenus senegalensis a été étudiée dans ce travail. Après obtention de l’extrait hexanique par extraction à l’aide d’un Soxhlet, le marc est macéré dans de l’acétate d’éthyle puis dans du méthanol pour donner les extraits correspondants. L’activité des fractions a été évaluée sur des drépanocytes de type SS. Les activités antifalcémiantes les plus importantes ont été observées pour les fractions polaires du méthanol et de l’acétate d’éthyle avec des taux d’inversion de la falciformation respectivement de 77% et de 65% à 10 mg/mL. Les activités antioxydantes de M. senegalensis (CI50 = 0,195 ± 0,004 mg/mL) et de l’acide ascorbique (CI50 = 0,078 ± 0,002 mg/mL) ont été déterminées. Les pouvoirs antioxydants (PA) montrent que l’activité antiradicalaire de l’acide ascorbique (PA = 12,85) est 2,5 fois meilleure que celle de M. senegalensis (PA = 5,14). Les résultats de l’étude justifient l’utilisation traditionnelle des racines de Maytenus senegalensis dans la prise en charge de la drépanocytose.Mots clés : Hémoglobine, drépanocytose, Maytenus senegalensis, activité antifalcémiante, stress oxydant, radicaux libres, activité antioxydante

Etude physico-chimique et minéralogique comparative des attapulgites de Mbodiène (Sénégal) et de Mormoiron (France)

La valorisation des ressources locales constitue un impératif afin d’atteindre des objectifs de développement durable. Cette étude a consisté à évaluer les caractéristiques physiques, chimiques et minéralogiques d’une argile provenant de Mbodiène (Sénégal), l’attapulgite, comparativement avec un médicament antidiarrhéique, constitué d’attapulgite, dénommé Actapulgite®. L’échantillon d’attapulgite brute a été purifié avec une solution de HNO3 1M. Une étude morphologique effectuée par visualisation à la Microscopie Electronique à Balayage a montré pour les deux argiles étudiées, une structure fibreuse caractéristique de la palygorskite, représentant le minéral dominant. L’analyse chimique par la spectrométrie à fluorescence X a donné pour l’attapulgite purifiée : 65,69% Si, 7,89% Al, 5,92% Fe, 17,90% Mg, 0,43% Ca et 0,93% K contre respectivement 63,98 % Si, 12,92% Al, 10,32% Fe, 6,20% Mg, 2,48% Ca et 2,25% K pour l’Actapulgite®. La diffraction aux rayons X a montré une présence de palygorskite, quartz et carbonates dans les échantillons étudiés. L’étude des isothermes d’adsorption a montré une surface spécifique nettement plus élevée pour l’attapulgite purifiée, 138,96 m2.g-1 contre 98,72 m2.g-1 pour l’Actapulgite®. Ces résultats ont montré que l’attapulgite de Mbodiène pourrait être utilisée comme antidiarrhéique orale après lavage à l’eau et séchage.© 2016 International Formulae Group. All rights reservedMots clés: Argile, attapulgite, antidiarrhéique, SénégalEnglish Title: Physico-chemical and mineralogical comparative study of attapulgites Mbodiène (Senegal) and Mormoiron (France)English AbstractThe development of local resources is imperative to achieve sustainable development goals. This study was to assess physical, chemical and mineralogical characteristics of a clay from Mbodiène (Senegal), named attapulgite, compared with Actapulgite® (antidiarrheal drug), composed of attapulgite. A sample of attapulgite from Mbodiène was purified with a 1M HNO3 solution to remove impurities including carbonates. A morphological study using Scanning Electron Microscopy showed for both types of clay studied, a fibrous structure characteristic of palygorskite which represent major mineral. Chemical analysis by XRF spectrometry gave for purified attapulgite: 65.69% Si, 7.89% Al, 5.92% Fe, 17.90% Mg, 0.43% Ca and 0.93% K against respectively 63.98% Si, 12.92% Al, 10.32% Fe, 6.20% Mg, 2.48% Ca and 2.25% K for Actapulgite®. X-ray diffraction showed the presence of palygorskite, quartz and carbonates for both samples studied. The study of adsorption isotherms showed a significantly higher surface area for purified attapulgite, 138.96 m2.g-1 versus 98.72 m2.g-1 for Actapulgite®. These results have shown that Mbodiène attapulgite compared to Actapulgite®, could be used as an oral antidiarrheal after washing with water and drying.© 2016 International Formulae Group. All rights reserved.Keywords: Clay, attapulgite, antidiarrheal, Senega

Evaluation of Mineral Elements Content of Senegal Fruits

International audienc

Crystal structure of N'-[4-(dimethylamino)benzyl-idene]furan-2-carbohydrazide monohydrate

The condensation of 2-furoic hydrazide and 4-dimethyl aminobenzaldehyde in ethano yielded a yellow solid formulated as the title compound,C14H15N3O2H2O. The crystal packing is stabilized by intermolecular O(water)—H···O,N(carbohydrazide) and N—H···O(water) hydrogen bonds,which form a two-dimensional network along the bc plane. Additional C—H···O interactions link the molecules into a three-dimensional network. The dihedral angle between the mean planes of the benzene and the furan ring is 34.47 (6)º. The carbohydrazide moiety, i.e., the C=N—N—C=O fragment and the benzene ring are almost coplanar, with an angle of 6.75 (9)º between their mean planes

Crystal structure of N,N′-[(ethane-1,2-diyl)bis(azanediylcarbonothioyl)]bis(benzamide)

The reaction of benzoyl chloride and ethylendiamine in the presence of potassium thiocyanate yielded a white solid, C18H18N4O2S2, which consists of two benzoylthioureido moieties connected by an ethylene chain. The asymmetric unit consists of one half of the molecule, the complete molecule being generated by crystallographic inversion symmetry. Both thiourea moieties are in a trans conformation. An intramolecular N—H...O hydrogen bond occurs. In the crystal, C—H...S and C—H...O hydrogen bonds link the molecules, forming layers parallel to the ac plane

Synthesis, characterization and crystal structure of 1-(2-benzamidophenyl)-3-benzoylthiourea Hemihydrate

The dissymmetric compound C21H17N3O2S.0.5H2O obtained by a reaction of 1,2-diaminobenzene, potassium thiocyanate and benzoyl chloride in 1/1/2 ratio is characterized by elemental analyses, IR, and NMR spectroscopies. The structure is elucidated by X-ray diffraction technic. The compound crystallizes in the monoclinic system with a space group of I2. The asymmetric unit contains one hemihydrate organic molecule. The title thiourea derivative, features an almost planar, C2N2S (S1/N1/N2/C7/C8) moiety, with a maximum deviation from the least-squares plane of 0.0422 (3) Å. This moiety is flanked by a disubstituted and a monosubstituted phenyl rings. The dihedral angles between the thiourea and the monosubstituted phenyl ring and the thiourea and the central disubstituted phenyl ring are respectively 10.418 (7)° and 60.292 (2)°, indicating twist in the molecule. On the other arm, a phenyl ring supported by an amide function, which is linked to the central ring through the nitrogen atom, is present. The dihedral angle between this phenyl group and the central disubstituted phenyl is 76.862 (7)° showing that their mean planes are not coplanar. Intramolecular S(thiono)—H…O(water) hydrogen bonds which close in S(6) and S(7) rings consolidate the conformation. Intermolecular N(amido)—H…O(carbonyl) which form layers parallel to the ac plane stabilized the structure

Alkaline Leaching of Metals from Cathodic Materials of Spent Lithium-Ion Batteries

International audienceThe aim of this study was to recover metals from the positive electrode material for recycling in lithium-ion batteries. It was focused on research to optimize the hydrometallurgical pretreatment process of cathode materials for Li-ion batteries by varying parameters such as NaOH concentration, the ratio of solvent volume to mass of the test sample (liquid-solid ratio (L/S)) and reaction time. Thus, from used batteries collected in a local market (Colobane, Senegal), cathodic materials dried in an oven at 50°C for 24 hours, submitted to alkaline leaching with NaOH 2, 3 or 4N, followed by filtration, all at room temperature. The filtrates obtained were analyzed by atomic absorption spectrophotometry. The results obtained were showed that Al collectors could be better extracted with 4N NaOH for 5 hours at a ratio liquid/solid (L/S) = 10/1, with small quantities of the metals Co, Mn, Ni and Li found in the filtrates

Mineralogical and physico-chemical characterization of Mbodiene palygorskite for pharmaceutical applications

International audienc

Antioxidant and antiglycation properties of two mango (Mangifera indica L.) cultivars from Senegal

Objective: To evaluate the total phenolic contents, antioxidant and antiglycation activities of leaves, barks, roots and kernels from two cultivars of Mangifera indica (Anacardiaceae). Methods: Total phenolic contents were determined by using Folin-Ciocalteu's method. The antioxidant activities were assessed by three different protocols including DPPH, oxygen radical absorbance capacity and iron (II) chelation assays. In addition, in vitro bovine serum albumin/D-ribose assay was chosen to evaluate the antiglycation properties of the extracts. Results: All the investigated extracts were found to contain high level of total phenols as well as potent antioxidant activities. Kernel extracts showed the highest total phenol contents and DPPH radical scavenging activities whereas higher oxygen radical absorbance capacity values were observed for leave, root and bark extracts. Besides, extracts from leaves, roots and barks from both cultivars exhibited potent inhibitory effects against the formation of advanced glycation end products, with IC50 values lower than the standard positive control aminoguanidine. Conclusions: The potent antiglycation and antioxidative activities of these two Mangifera indica cultivars suggest a possible role in targeting aging, diabetic complications and oxidative stress related diseases

Chemical Constituents and Antimicrobial and Antioxidant Activities of Essential Oil from Dried Seeds of Xylopia aethiopica

The study aimed to investigate the chemical composition and antimicrobial and antioxidant activities of the essential oil from dried seeds of Xylopia aethiopica. The essential oil was obtained by hydrodistillation and analyzed by GC/FID and GC/MS. The essential oil yield was 1.35%. Forty-nine compounds were identified in the essential oil with 1,8-cineole (16.3%), β-pinene (14.8%), trans-pinocarveol (9.1%), myrtenol (8.3%), α-pinene (5.9%), and terpinen-4-ol (5.6%) as major components. The antimicrobial activity of this essential oil was studied using disk diffusion and broth microdilution methods on four bacteria (Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, and Pseudomonas aeruginosa) and one fungus (Candida albicans). The essential oil exhibited excellent activity against S. aureus, E. faecalis, and C. albicans and moderate activity against E. coli. Among all strains tested, C. albicans showed the best sensitivity with a MIC of 50 mg/mL. The antioxidant activity was examined using a DPPH-free radical scavenging assay. The essential oil of X. aethiopica showed low antioxidant activity (IC50 = 784.604 ± 0.320 mg/mL) compared to that of ascorbic acid and the reference compound (IC50 = 0.163 ± 0.003 mg/mL). The results indicate that consumption of X. aethiopica seeds can reduce the virulence of food-borne pathogens and their resistance to antibiotics