118 research outputs found
2-[2-(Benzylsulfanyl)phenyl]-1,1,3,3-tetramethylguanidine
The molecular structure of the title compound, C18H23N3S, shows it to be a derivative of an aminothiophenol possessing a tetramethylguanidine group with a localized C=N double bond of 1.304 (2) Å and a protected thiol functional group as an S-benzyl thioether. The two aromatic ring planes make a dihedral angle of 67.69 (6)°
N-Trityl-2-(tritylsulfanyl)aniline
The title compound, C44H35NS, is a derivative of aminothiophenol and possesses a protected S-triphenylmethyl thioether and an N-triphenylmethylamine functional group. The trityl groups show an anti orientation, with C—C—N—C and C—C—S—C torsion angles of −151.0 (3) and −105.3 (2)°, respectively. There is an intramolecular N—H⋯S hydrogen bond
Traditional Practices and Medicinal Plants Use during Pregnancy by Anyi-Ndenye Women (Eastern Côte d'Ivoire)
The use of plants during pregnancy is a common practice in Africa. In Côte d’Ivoire, despite modern antenatal medical prescriptions, most pregnant women resort to traditional medicine to ensure foetus development and facilitate childbirth. Yet, there is not enough research on the African traditional medicine concerning this aspect of health. Therefore, the plants used by pregnant women need to be better known in order to offer integrated antenatal care. This study analyzes the salience of plants used, the associated practices and reasons of such practices by pregnant women in Yakassé-Féyassé, an Anyi-Ndenye town of the Eastern Côte d’Ivoire. Methodsinclude an ethnobotany survey (freelist method, interview with pregnant women during their antenatal consultation and with specialists). The survey led to a list of 75 plants distributed in 3 class of salience. In addition, 90.3 % of pregnant women use these practices which are nevertheless ignored by Midwives during antenatal visits (Afr J Reprod Health 2011; 15[1]: 85-93)
Wild edible plants in the Ehotilé, a fishing people around Aby lagoon (eastern littoral of Côte d'Ivoire): Knowledge and availability
This study is set within the important framework of the imperative need to safeguard traditional knowledge at historical, nutritional levels, and as an element of sustainable management of natural resources. Thus, it aimed to identify, through four ethnobotanical surveys (2007, 2009, 2015 and 2019), the wild edible plants used by the Ehotilé around the Aby Lagoon, on the Ivorian eastern littoral, to evaluate the use, preference and availability related to these plants and to discuss the evolution of food practices since the observations of missionaries three centuries earlier. The level of knowledge was analysed using Smith's Index and the availability of edible fruits was assessed with a new cognitive index. Compared to the era of the first settlement, the diet of the Ehotilé has undergone many modifications. Current observations showed that wild plants were rarely used in the diet which was essentially cassava-based. Thirty-nine edible ethnospecies corresponding to 40 scientific plants species were recorded for 46 uses, of which, wild fruits with 54.17 % were the most important. Edible fruits were available all year round, but irregularly and the availability index suggested that 10 species of the fruits sought were rare in the region. The study has shown that gathering plants are well known by the Ehotilé. However, they are not very present in their diet. In addition, they have a good knowledge of the availability of their edible plants and could therefore be key resource persons in any assessment of the dynamics of plants in their environment
Diversité Floristique Et Valeur De Conservation De La Forêt Classée De N’ganda-N’ganda (Sud-Est De La Cote D’ivoire)
L’étude a été entreprise en vue de contribuer à une meilleure connaissance de la flore de la forêt classée de N’ganda-N’ganda. Pour ce faire, la technique de relevés itinérants a été utilisée. Les inventaires itinérants ont permis d’obtenir une liste de 445 espèces de plantes réparties en 293 genres et 96 familles. Les familles les plus dominantes diffèrent d’un milieu à un autre. Les Rubiaceae sont parmi les familles prépondérantes, quel que soit le type de milieu. Les types biologiques sont dominés par les phanérophytes à plus de 60 %. Le spectre phytogéographique est marqué par une dominance des espèces Guinéo-Congolaises, dans les deux types de forêts. En savane, les hémicryptopytes sont les types biologiques les plus dominants. Le nombre élevé d’espèces endémiques de Haute Guinée (58) et ivoiriennes (09) couplé par la présence de 22 taxons classés de rares, devenus rares et en voie d’extinction pour la flore de la Côte d’Ivoire et de 20 taxons de la liste rouge de l’UICN (2015), représente sa caractéristique particulière. Les traits particuliers de cette flore doivent susciter plus d’attention de la part des gestionnaires de cette forêt.
This study focuses on providing a better knowledge of the flora of N'ganda-N'ganda forest. The itinerant survey technique was used, and this made it possible to obtain a list of 445 species which was distributed between 293 genera and 96 families. The most dominant families deffer by space. Rubiaceae was between dominated families and all types of spaces. The biological types are dominated more than 60% by the phanerophyts. Phytogeographic spectrum is marked by a strong dominance of species known as Guineo-Congolese in two types of forest. In Savanah, hemicryptophyts was the most dominated biological types. The high number of endemic species from Upper Guinea (58) and Ivorian (9), coupled with the presence of 22 taxa classified as rare and endangered for the flora of Côte d'Ivoire and 20 taxa of IUCN Red List (2015), represents its special character. Particular traits of this flora should attract more attention from managers of this forest
Unraveling the electrochemical and spectroscopic properties of neutral and negatively charged perylene tetraethylesters
A detailed investigation of the energy levels of perylene-3,4,9,10-tetracarboxylic tetraethylester as a representative compound for the whole family of perylene esters was performed. It was revealed via electrochemical measurements that one oxidation and two reductions take place. The bandgaps determined via the electrochemical approach are in good agreement with the optical bandgap obtained from the absorption spectra via a Tauc plot. In addition, absorption spectra in dependence of the electrochemical potential were the basis for extensive quantum-chemical calculations of the neutral, monoanionic, and dianionic molecules. For this purpose, calculations based on density functional theory were compared with post-Hartree–Fock methods and the CAM-B3LYP functional proved to be the most reliable choice for the calculation of absorption spectra. Furthermore, spectral features found experimentally could be reproduced with vibronic calculations and allowed to understand their origins. In particular, the two lowest energy absorption bands of the anion are not caused by absorption of two distinct electronic states, which might have been expected from vertical excitation calculations, but both states exhibit a strong vibronic progression resulting in contributions to both bands
Caractérisation phytosociologique des anciens sites de traitements sylvicoles et de la réserve naturelle dans le parc national du Banco (Abidjan-Côte d’Ivoire)
La perturbation des milieux est à l’origine de la destruction des habitats, elle contribue à la perte de la biodiversité et est une des causes du changement de la flore dans une localité. Elle entraine par conséquent la transformation des associations végétales. L’objectif principal de cette étude est de rechercher les associations végétales dans le parc national du Banco suite aux plantations villageoises et aux essais sylvicoles dus à la recherche d’une méthodologie propre à la sylviculture africaine. Pour ce faire, la caractérisation phytosociologique des anciens sites de traitements et de la réserve forestière a été réalisée. La méthode utilisée est celle de la phytosociologie synusiale. Les 91 relevés (82 dans les anciens sites de traitements sylvicoles et 9 dans la réserve forestière) ont permis de recenser 337 espèces de plantes réparties en 65 familles et 268 genres. Le dendrogramme issu de la classification hiérarchique ascendante des relevés a mis en évidence trois syntaxons dont deux sont constitués essentiellement des relevés des anciens sites de traitements et un des relevés de la réserve forestière. Aucun syntaxon ne renferme la totalité des espèces caractéristiques de l’association Turraeantho-Heisterietum. Cependant, dans deux syntaxons, la proportion des espèces caractéristiques de cette association est supérieure à 50%. 70,59% dans le syntaxon à Tarrietia utilis et Cola heterophylla (syntaxon des forêts secondaires), 52,94% dans le syntaxon à Cola chlamydantha et Drypetes chevalieri (syntaxon de la réserve forestière). Alors que dans le syntaxon à Dacryodes klaineana et Pleiocarpa mutica (syntaxon des forêts secondaires), 41% de ces espèces caractéristiques ont été enregistrées. Les espèces caractéristiques des autres formations forestières sont également peu représentées dans les syntaxons (moins de 40%). Il ressort donc de cette étude que le parc national du Banco demeure une forêt à Turraeanthus africanus et Heisteria parvifolia.
The disturbance of the environment is at the origin of the destruction of the habitats, it contributes to the loss of the biodiversity and is one of the causes of the change of the flora in a locality. It therefore leads to the transformation of plant associations. The main objective of this study is to research the plant associations in the Banco National Park following village plantations and silvicultural trials due to the search for a methodology specific to African silviculture. To do this, the phytosociological characterization of the former treatment sites and the forest reserve was carried out. The method used is that of synusial phytosociology. The 91 surveys (82 in the former silvicultural treatment sites and 9 in the forest reserve) made it possible to identify 337 species of plants divided into 65 families and 268 genera. The dendrogram resulting from the ascending hierarchical classification of the readings revealed three syntaxa, two of which essentially consist of the readings of the old treatment sites and one of the readings of the forest reserve. No syntaxon contains all the characteristic species of the Turraeantho-Heisterietum association. However, in two syntaxa, the proportion of characteristic species of this association is greater than 50%. 70.59% in the syntaxon to Tarrietia utilis and Cola heterophylla (syntaxon from secondary forests), 52.94% in the syntaxon to Cola chlamydantha and Drypetes chevalieri (syntaxon from the forest reserve). While in the Dacryodes klaineana and Pleiocarpa mutica syntaxon (secondary forest syntaxon), 41% of these characteristic species were recorded. Species characteristic of other forest formations are also poorly represented in the syntaxa (less than 40%). It therefore emerges from this study that Banco National Park remains a forest with Turraeanthus africanus and Heisteria parvifolia
Analyse de la distribution spatiale des Acanthaceae en Afrique Centrale et comparaison avec les théories phytogéographiques de Robyns, White et Ndjele.
Cette étude a pour but d\'analyser les modèles de distribution spatiale des Acanthaceae, récoltées en République Démocratique du Congo, au Rwanda et au Burundi et de comparer leur répartition spatiale avec les systèmes phytogéographiques qui couvrent cette zone. Elle porte sur 9181 échantillons regroupés en 48 genres et 310 espèces.
Un système d\'information géographique a été utilisé pour réaliser des cartes de distribution de chaque espèce. La méthode multi variée de classification, appuyée par deux indices de structure spatiale (équitabilité et fragmentation) a permis de stratifier la zone d\'étude afin de permettre une comparaison visuelle avec les systèmes phytogéographiques définis par Robyns, White et Ndjele. On note une large distribution spatiale pour certaines espèces sur l\'ensemble du territoire, alors que d\'autres sont inféodées à certains territoires phytogéographiques bien déterminés. Les savanes situées au Sud de l\'équateur contiennent des sites plus riches en Acanthaceae que celles situées au Nord. Les centres
d\'endémisme Guinéo-Congolais, Zambézien et Afromontagnard pourraient être les sources de migration des taxons. Les Acanthaceae suivent relativement bien le système phytogéographique de White et sont utilisables en tant que bioindicatrices afin de rapprocher la distribution spatiale des communautés végétales décrites par ce système.By means of 9181 samples representing 48 genus and 310 species, the spatial distribution models of the Acanthaceae family in Central Africa (Democratic Republic of Congo, Rwanda and Burundi) were analysed. Consequently, a comparison to existing phytogeographic systems for the study region was executed. Spatial distribution maps for
each species were created using a geographic information system. Subdivision of the study area was realised using a multivariate classification analysis. Using two indices of spatial pattern (fragmentation, class size evenness), the classification result was compared to the phytogeographic zones defined by Robyns, White and Ndjele. While certain
species showed a distribution throughout the study area, the presence of other species was found to be bound to one single phytogeographic territory in particular, or to a restricted number of them. The savannas situated in the southern part of the study area contained more Acanthaceae species than the zones situated north of the equator.
The Guineo-Congolian, the Zambezian and the Afromontane centre of endemism are suggested to be the origins of taxon migration. Since it was observed that the spatial pattern of the Acanthaceae species corresponded up a certain extent to the phytogeographic system proposed by White, it can be concluded that the Acanthaceae could be used as bio-indicators to proxy the spatial distribution of plant communities as described by this system. Keywords: phytogeography, spatial analysis, Acanthaceae, Central Africa, district, sector.Sciences & Nature Vol. 5 (2) 2008: pp. 101-11
Fundamental characterization, photophysics and photocatalysis of a base metal iron(II)-cobalt(III) dyad
A new base metal iron-cobalt dyad has been obtained by connection between a heteroleptic tetra-NHC iron(II) photosensitizer combining a 2,6-bis[3-(2,6-diisopropylphenyl)imidazol-2-ylidene]pyridine with 2,6-bis(3-methyl-imidazol-2-ylidene)-4,4′-bipyridine ligand, and a cobaloxime catalyst. This novel iron(II)-cobalt(III) assembly has been extensively characterized by ground- and excited-state methods like X-ray crystallography, X-ray absorption spectroscopy, (spectro-)electrochemistry, and steady-state and time-resolved optical absorption spectroscopy, with a particular focus on the stability of the molecular assembly in solution and determination of the excited-state landscape. NMR and UV/Vis spectroscopy reveal dissociation of the dyad in acetonitrile at concentrations below 1 mM and high photostability. Transient absorption spectroscopy after excitation into the metal-to-ligand charge transfer absorption band suggests a relaxation cascade originating from hot singlet and triplet MLCT states, leading to the population of the MLCT state that exhibits the longest lifetime. Finally, decay into the ground state involves a MC state. Attachment of cobaloxime to the iron photosensitizer increases the MLCT lifetime at the iron centre. Together with the directing effect of the linker, this potentially makes the dyad more active in photocatalytic proton reduction experiments than the analogous two-component system, consisting of the iron photosensitizer and Co(dmgH)(py)Cl. This work thus sheds new light on the functionality of base metal dyads, which are important for more efficient and sustainable future proton reduction systems
Fundamental Characterization, Photophysics and Photocatalysis of a Base Metal Iron(II)-Cobalt(III) Dyad
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