Gold Mineralisation in the Intiédougou Prospect (Diébougou District) in Southwest Burkina Faso, West African Craton

The Intiédougou located in the Houndé Birimian greenstone belt has been the subject of several mining and geoscience studies that have led to the discovery of mineralized gold targets. One of these mineralized targets has prompted work that raises the issue of control factors for the gold mineralization of the prospect. The methodology used in this study combines a study of core drill hole data located in the area and laboratory studies. The Intiédougou sector is based on andesito-basaltic, andesitic interstratified volcanoclastite rocks and Tarkwaïen type detrital sedimentary rocks caught in a vice in the volcano-sedimentary unit. Lithostructural analysis of the sector shows that the subvolcanic rocks bearing gold mineralization are subjected to heterogeneous ductile to brittle deformations and affected by hydrothermalism evolving at stages marked by large fissure fillings. These hydrothermal phases evolve in the zones of expansion created by the brittle deformations that have contributed to the deposits of different types of gold-enriched sulphides. These different phases of hydrothermal destabilization generally of low degree accompany the tardi to post-eburnean brittle tectonics. This deformation system is favorable to the establishment of gold mineralization in the form of vein bodies. The overimposition of deformed and altered areas suggests a genetic relationship between deformation and hydrothermal activity. In conclusion, the mineralization of Intiédougou in vein styles, set up in a volcanic arc environment with a paragenesis of gold-pyrite deposit ± chalcopyrite would be controlled by the structural aspect and accompanied by hydrothermal alteration.

Co-Occurring Plant Species of the West African Critically Endangered Aubregrinia taïensis Heine, in Côte d’Ivoire

The Upper Guinea Forest is subject to heavy deforestation. In this context, many endemic and/or rare plant species are threatened with extinction. This is the case of Aubregrinia taïensis (Aubrév. & Pellegr.) Heine, a critically endangered Sapotaceae species, endemic to Côte d’Ivoire and Ghana. After 3 years of investigation in and around the Tai National Park (TNP) in the West of Côte d’Ivoire, only one individual of this species was located and no sexual reproductive organs (fruits, seeds) were observed. Woody plant species around this individual were inventoried in order to know the species that can co-occur with Aubregrinia taïensis. For that a plot of 30 m of diameter was established around the individual and all of the woody species of this circle were inventoried. Then, the taxonomic diversity, the chorology of the species, the conservation status and their life-form were recorded. A total of 130 woody plant species belonging to 51 families were collected in the site. The most represented families are Euphorbiaceae (12 spp.), Rubiaceae (10 spp.), Annonaceae (7 spp.), Fabaceae, Moraceae, Malvaceae (6 spp. each) while the most represented genera are Diospyros L. (4 spp.), Cola Schott & Endl. and Vitex L. (3 spp.). Species from the Guineo-Congolese Region (GC) are the most abundant (72%). They are followed by West African endemic species (GCW, 19%). Microphanerophytes (mp) are the most abundant and represent more than 40% of the species. Three vulnerable species were found in this plot: Campylospermum amplectens, Placodiscus boya and Trichoscypha cavalliensis. Thus, the preservation of this forest is more than necessary.

Synthesis, Characterization and Biological Activity Evaluation of Schiff Bases Derived from 1,8-Diaminonaphtalène

The compounds have been synthesized and characterized by routine MS, IR and NMR spectrometry methods. The compounds are all active on bacterial strains with the exception of Salmonella typhimirium, with a MIC value of 7.5 mg/mL. They show a percentage of anti-radical activity of 75.476 ± 5.070 for the compound DAN-S and of 68.142 ± 6.539 for the compound DAN-OV. The compounds are sensitive to the two champions used. DAN-S compound is then the most active.

Former Botanical Garden of ORSTOM(Côte d’Ivoire):What Remain after Thirty Years of Abandonment and Forest Restoration

Botanical gardens represent important places for ex situ conservation.One of these botanical gardens has been abandoned in Côte d’Ivoire for 30 years.This is the former botanical garden of ORSTOM.This study was conducted to determine the level of diversity of this former garden in order to assess the opportunity for its rehabilitation.The authors carried out inventories in 18 quadrats of 500 m2 through the vegetation to collect woody species.Dendrometric measurements(height,diameter)were also recorded to assess the structure of the site.A total of 190 species have been identified.They belong to 141 genera and 47 families.This former botanical garden contains important species because of their origin,status or particularity(threatened,endemic,rarity,etc.).A total of 19 threatened species including 2 endangered and west African endemic(Chrysophyllum azaguieanum J.Miège,Placodiscus pseudostipularis)were found at the site.Also,Chrysophyllum azaguieanum is declared extinct from Côte d’Ivoire.Four species are rare in the flora of Côte d’Ivoire:Balanites wilsoniana,Chrysophyllum azaguieanum,Gilletiodendron kisantuense and Loesenera kalantha.The most abundant species is Hopea odorata.Although this introduced species is considered globally vulnerable,it presents a risk of invasion in the forest of Côte d’Ivoire.The diameter and height structures show that all the stages of development are presented indicating a good regeneration on the site.Ultimately,this botanical garden deserves to be rehabilitated and especially urgent management of Hopea odorata is needed to prevent an invasion of this species.

Facile Synthesis Route of Au-Ag Nanostructures Soaked in PEG

A nanostructured gold-silver soaked in polyethylene glycol 400 (Au-Ag@PEG) is designed using gold(I) chloride and silver nitrate (AgNO3) as precursors and, polyethylene glycol 400 (PEG) as capping agent. The result of the structure characterization using Selected Area Electron Diffraction (SAED) has showed that the synthesized nanomaterial has a good crystallinity while Transmission Electron Microscopy (TEM), energy dispersive X-ray spectrometry (EDX) and Dynamic Light Scattering (DLS) measurements suggest mixed Au-Ag nanoparticles with an average diameter size of around 7 nm and 30 nm for Au and Ag respectively.

Synthesis and Antibacterial Activities of New 2-(Benzylthio)pyrimidines and 2-(Benzimidazolylmethylthio)pyrimidines Derivatives

A series of 2-(benzylthio)pyrimidines (6a-l) and 2-(benzimidazolylmethylthio)-pyrimidines derivatives (6m and 6n) analogues of ethyl 2-(benzylthio)-6-methyl-4-phenyl-1,4-dihydropyrimidine-5-carboxylates and ethyl 2-(((1H-benzimidazol-2-yl)methyl)thio)-6-methyl-4-phenyl-1,4-dihydropyri-midine-5-carboxylates were prepared and evaluated for antibacterial activity. These compounds were obtained by condensation of 2-thiopyrimidines (4) with benzyl halides or 2-(chloromethyl)-1H-benzimidazole (5) in the presence of a base. All compounds were characterized by 1H, 13C and HRMS spectra. Out of fourteen, only eight compounds were screened against multi-resistant strains of Escherichia coli and Staphylococcus aureus. The results revealed that all of them were found to possess significant antibacterial activity against the germs tested. Compounds 6c, 6d, 6h and 6m were more active on S. aureus and compounds 6h and 6m more active on E. coli.

Studies of the Chemical Reactivity of a Series of Rhodanine Derivatives by Approaches to Quantum Chemistry

This theoretical chemical reactivity study was conducted using the Density Functional Theory (DFT) method, at computational level B3LYP/6-31G (d). It involved a series of six (06) 5-arylidene rhodanines and allowed to predict the chemical reactivity of these compounds. DFT global chemical reactivity descriptors (HOMO and LUMO energies, chemical hardness, softness, electronegativity) were examined to predict the relative stability and reactivity of rhodanin derivatives. Thus, the compound 6 which has an energy gap between the orbitals of ΔEgap = 3.004 eV is the most polarizable, the most reactive, the least stable, the best electron donor and the softest molecule. Calculation of the local indices of reactivity as well as dual descriptors revealed that the sulfur heteroatom of the Rhodanine ring is the privileged site of electrophilic attack in a state of sp3 hybridization and privileged site of nucleophilic attack in a state of sp2 hybridization.

Photocatalytic and Antimicrobial Properties of [AgTiO₂]:[Clay] Nanocomposite Prepared with Clay Different Ratios

This work aimed to synthesis a novel material that would be able to efficiently remove both organic and microbiological pollutants from wastewater. Through the hydrothermal process, we first doped titanium dioxide, a semiconductor possessing excellent photocatalytic properties with silver nanoparticles having good antibacterial properties. The obtained material was then associated with clay known for its good adsorbent properties to form [AgTiO2]:[clay] type nanocomposites. The different mass composition of [AgTiO2]:[clay] considered in this work were 1:1;1:0.5;1:0.1;1:0.05 and 1:0.01. The prepared nanocomposites were characterized by means of XRD, FTIR and SEM techniques. Results revealed the presence of TiO2 anatase and Ag on the surface of the clay mainly composed of kaolinite and quartz. The photocatalytic activities of the nanocomposites were tested in the presence of synthetic Orange II (25 mg/L) wastewater under visible light irradiation. The experiments demonstrated that organic pollutants were effectively photodegraded when the proportion of clay in the mixture (AgTiO2)-(Clay) was inferior or equaled to 50%. The use of commercial TiO2, for comparison purpose, showed a lower degradation efficiency of the Orange II solution (η < 30%). The antibacterial properties of the nanocomposites [AgTiO2]:[clay] were also assessed in the presence of two types of bacteria E. coli (Gram negative) and S. aureus (Gram positive). The antibacterial activities of the nanocomposites were characterized with and without UV irradiation. In dark conditions, the antibacterial activities of nanocomposites (AgTiO2)-(Clay) against S. aureus gradually increased with increasing the clay amount. Under visible light irradiation, the nanocomposites showed a significant antimicrobial activity against E. coli and S. aureus.

Combining Experimental and Quantum Chemical Study of 2-(5-Nitro-1,3-Dihydro Benzimidazol-2-Ylidene)-3-Oxo-3-(2-Oxo-2H-Chromen-3-yl) Propanenitrile as Copper Corrosion Inhibitor in Nitric Acid Solution

Due to acidic solutions aggressiveness, corrosion inhibitors use is considered to be one the most practical methods to delay metals dissolution in the said solutions. In this study benzimidazolyl derivative namely 2-cyanochalcones 2-(5-nitro-1,3-dihydrobenzimidazol-2-ylidene)-3-oxo-3-(2-oxo-2H-chromen-3-yl) propanenitrile which was synthesized was then applied as a corrosion inhibitor for copper in 1 M HNO3 solution. The inhibition action of this molecule was evaluated by gravimetric and density functional theory (DFT) methods. It was found experimentally that this compound has a better inhibition performance and its adsorption on copper surface follows Langmuir adsorption isotherm. This adsorption evolves with temperature and inhibitor concentration, it is endothermic and occurs spontaneously with an increase in disorder. Corrosion kinetic parameters analysis supported by Adejo-Ekwenchi model revealed the existence of both physisorption and chemisorption. DFT calculations related that compound adsorption on copper surface is due to its electron donating and accepting capacity. The reactive regions specifying the electrophilic and nucleophilic attack sites were analyzed using Fukui and dual descriptor functions. Experimental results obtained were compared with the theoretical findings.

Design, Synthesis and <i>in Vitro</i>Antibacterial Activity of 2-thiomethyl-benzimidazole Derivatives

A series of novel substituted benzimidazole (7a - n) derivatives were synthesized and characterized by 1H, 13C Nuclear Magnetic Resonance (NMR) spectra and High Resolution Mass Spectrometry (HRMS). The substitution was done in position -1 and -2 by appropriate groups. These compounds are obtained by N-alkylation reaction with thiomethyl-1H-benzimidazole intermediates (5a - g). Design of intermediates (5a - g) was made by condensation reaction between 2-methylbenzimidazole thiourunium salt (3) and functionalized halides (4) in the presence of sodium hydroxide (NaOH). Among the twenty-one compounds synthesized, ten were evaluated for their antimicrobial activity on three bacterial strains namely: Escherichia coli ATCC 25922, Staphylococcus aureus ATCC 25923 and Pseudomonas aeruginosa ATCC 27853. Only E. coli ATTC 25922 was susceptible to the synthesized derivatives 5g, 7f and 7h with a significant antibacterial activity (CMI is between 250 and 500 μg/mL).

Anti-Hemorrhoidal Medicinal Plants of the Department of Issia: Inventory and Cytotoxicity on HFF Cells of the Ethanolic Extract 70% of Landolphia utilis A. Chev. (Apocynaceae)

Objective: To identify the anti-hemorrhoidal medicinal plants of the Department of Issia and evaluate the cytotoxic activity of the most requested species. Methods: The plants used in hemorrhoid recipes in the Department of Issia (C?te d’Ivoire) were obtained using a semi-structured survey based on a questionnaire sheet. To assess the use of plants on the disease, Informant Consensus Factors (ICF) for each species were calculated. The harvested species were identified at the Centre National de Floristique (CNF) of the Félix Houphou?t Boigny University (C?te d’Ivoire). Cytotoxicity tests were performed on HFF cells with the 70% ethanolic extract, prepared from the aqueous extract of the most cited species. Results: A total of twenty four medicinal species in eighteen families were recorded. Among these taxa are ten woody and fourteen herbaceous. Only three species gave an ICF greater than 0.5. The ethanolic extract 70% of the frequently requested medicinal plant did not reveal any toxicity on HFF cells. Conclusion: These results revealed that the flora of the Department of Issia is rich in anti-hemorrhoidal medicinal plant species. Their use without side effects is revealed by the absence of toxicity in one of the most solicited plants.

Antioxidant Activity Evaluation in a Series of Heterocyclic Compounds Derived from 1,8-Diaminonaphthalene

From (2,3-dihydro-1H-perimidin-2-yl)-phenyl, the substitution of OH group in ortho or para position on the phenyl ring, allows us to synthesize the studied compounds. These three compounds have been characterized by conventional spectroscopic methods (NMR and MS). The interest of this work is to review the antioxidant activity of our compounds. The antioxidant activity screening carried out according to FRAP and DPPH methods revealed significant anti-free radical properties for compounds 1 and 2 even at low concentrations. In contrast to the compound 2, compound 3 for which the OH group is substituted in para position has the lowest activity in both cases. Therefore the para position seems to be the least sensitive position to increase the antioxidant activity of this pharmacophore.

Nutritional and Anti-Nutrient Composition of Three Kola Nuts(Cola nitida,Cola acuminata and Garcinia kola)Produced in Benin

Kola nuts were regularly chewed by West Africans and Beninese in particularly. The aim of this study was to investigate nutritional and anti-nutrient content of three Benin’s kola nuts (Cola nitida, Cola acuminata and Garcinia kola). Proximate composition of the three species of kola nuts was assessed using standard analytical AOAC methods. Phenolics and flavonoids contents were determined by Folin-Ciocalteu and aluminum trichloride methods, respectively. Mineral composition was determined by Atomic Absorption Spectrometry method. Free and total amino acids were separated and quantified by HPLC. Protein content of the three kola nuts ranges from 4.95% (G. kola) to 10.64% (C. acuminata) whereas fat content ranges from 0.2 ± 0.00 (C. nitida) to 2.5 ± 0.42 (G. kola). Total phenolics abounded (2444.96 ± 81.56 μg Eq AG/100g) in C. acuminata, while flavonoids predominated (561.69 ± 22.10 μgEqQ/100g) in G. kola. The three species are a good source of magnesium and a copper provider was lowest in C. nitida (0.59 ± 0.08 mg/g) and in C. acuminata (0.65 ± 0.02 mg/g). The dominant total essential amino acids were threonine (C. acuminata) and methionine (C. acuminata and G. kola), while the predominant non-essential total amino acids according to species were arginine (C. nitida and G. kola), proline (C. acuminata) and cysteine (G. kola). For the anti-nutrients factors, saponins were in great proportion (8.33% ± 0.25%), while the oxalates were in small proportion (0.44% ± 0.04%). The three species have an interesting nutritional composition, but these seeds have the relatively lowest amino acids content.