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Computational Chemistry 2018年第3期6卷 57-70页

作者： Affoué Lucie Bédé Amon Benjamine Assoma kicho denis yapo Mamadou Guy-Richard Koné Soleymane Koné Mawa Koné Boka Robert N’Guessan El-Hadji Sawaliho Bamba Laboratoire de Chimie Organique Structurale Université Félix Houphou&euml t-Boigny Abidjan C&ocirc te d’Ivoire Laboratoire de Thermodynamique et de Physico-Chimie du Milieu Université Nangui Abrogoua Abidjan C&ocirc te d’Ivoire

A theoretical study of the reactivity of quinoline-4-one derivatives is undertaken in order to understand the involved mechanisms. The calculations were carried out in gas phase and in N, N-Dimethylformamide (DMF) solution. The Density Functional Theory (DFT) with B3LYP functional associated to 6-311G (d) and 6-311+G (d) bases is used to perform these calculations. The results of the thermodynamic parameters showed that there is an equilibrium relation between the different tautomers. This equilibrium can be used to explain the failure to obtain tetrahydroquinoline from 5,8-dimethoxy-quinolin-4-one. Reactivity analysis from Frontier Molecular Orbitals theory and Fukui function calculations revealed that ketone forms are less reactive than enol ones. The methoxyl substituent decreases the acidity of the nitrogen and oxygen atoms of quinolin-4-one while the bromine increases the acidity of the same sites. These results foresee that nitrogen deprotonation in the case of the brominated compound is easier than in the case of methoxylated ones.

关键词： Quinolein-4-One Tautomers Equilibrium Constants Global Descriptors Dual Descriptors

Catechin and Epicatechin. What’s the More Reactive?

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Computational Chemistry 2022年第2期10卷 53-70页

作者： Essoh Akpa Eugène N’guessan Boka Robert Adenidji Ganiyou yapo kicho denis Adjou Ané Bamba El Hadji Sawaliho Laboratoire de Constitution et de Réaction de la Matière UFR SSMT Université Félix Houphou&#235 t-Boigny Abidjan C&#244 te d’Ivoire

Catechin and epicatechin are two isomeric flavonoids. Despite the vital properties highlighted by numerous scientific studies, very little data is available on the intrinsic reactivity of these compounds. To provide more details on the stability and reactivity of catechin and epicatechin, this study is performed by means of theoretical calculation methods. For this purpose, geometry optimizations and frequency calculations at the B3LYP/6-31 + G (d, p) level of theory has been carried out and Natural Bond Orbital (NBO) analysis and VEDA (Vibrational Energy Distribution Analysis). The geometric and energy parameters and NBO analysis show that catechin appears more stable than epicatechin. The hydroxyl group position on the ring C of the catechol structure represents a factor that influences this relative stability. The global and local reactivity parameters reveal that epicatechin becomes more reactive than catechin. They indicate that their hydroxyl groups correspond to their most receptive sites. Fukui indices, VEDA and acidity study establish that O28–H29 remains the most reactive.

关键词： Catechin Epicatechin NBO Acidity DFT Normal Modes

Structures, Lipophilicity, Dipole Moments, Acidity and Spectroscopic Properties of Non-Steroidal Anti-Inflammatory Drugs Diclofenac, Bromfenac and Amfenac: A Theoretical Study

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Computational Chemistry 2019年第4期7卷 95-105页

作者： Assoma Amon Benjamine Bede Affoué Lucie yapo kicho denis Bamba El Hadji Sawaliho Laboratoire de Chimie Organique et de Substances Naturelles Université Félix Houphou&#235 t-Boigny Abidjan C&#244 te d’Ivoire

This work is a contribution of theoretical chemistry to the classification of some non-steroidal anti-inflammatory drugs (NSAIDs). Indeed, research on the efficacy of NSAIDs has shown that no NSAID is recognized as the most efficient anti-inflammatory drug. We have made a theoretical study of diclofenac, bromfenac and amfenac, in order to compare their efficacy from some physicochemical properties. To do this, we used the DFT and TD-DTF methods at the B3LYP/6-311+G(d, p) level theory. The lipophilicity study shows that diclofenac and bromfenac are very lipophilic. Acidity study shows that diclofenac is more acid than bromfenac and amfenac. The results from molecular orbital and the TD-DFT calculations reveal that for the three NSAIDs, the lowest energy transition is due to the excitation from HOMO to LUMO. The absorption energy corresponding to H→L transition is comparable with the energy gap value. Our findings have shown that bromfenac is more reactive than amfenac, which is more reactive than diclofenac.

关键词： Diclofenac Bromfenac Amfenac DFT Spectroscopic Properties

Impacts of Field Harvesting and Conservation Practices on the Physical Quality of Yam “Kponan” (Dioscorea cayenensis-rotundata) of Côte D’Ivoire

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Open Journal of Applied Sciences 2022年第12期12卷 1979-1994页

作者： yapo Hypolithe Kouadio Kouakou Nestor Kouassi Daouda Nimaga Yao denis N’dri N’Guessan Georges Amani Laboratory of Food Biochemistry and Technology of Tropical Products Department of Food Science and Technology NANGUI ABROGOUA University Abidjan C&ocirc te D’Ivoire Swiss Center for Scientific Research in Cô te d’Ivoire (CSRS-CI) Abidjan C&ocirc te D’Ivoire Agronomic Forestry and Environmental Engineering Department University of Man Man C&ocirc te D’Ivoire

Yam “Kponan” (Dioscorea cayenensis-rotundata) is a popular staple food in Côte d’Ivoire. However, its rapid decay during conservation prevents regular supply of markets. The objective of this study was therefore to assess the impact of field cultivation and conservation practices on some physical quality parameters of “Kponan”. To this end, “Kponan” yam from three production areas (Bondoukou, Bouna, Kouassi-Kouassikro) was cultivated in each area. At maturity, physical parameters of yams at harvest and after 3 months of storage in field were analyzed. The results showed that injury was the most significant deterioration in yam harvest. The rate of injured yams was highest for hoe-harvested in Kouassi-Kouassikro area (16.67% - 22.22%) regardless of the origin of the cuttings. The main damage observed after the 3 months of storage was rots (22.86% - 60.00%) and weight loss (8.57% - 42.86%). However, yams stored in pits in Bouna zone had less damage (40% - 48.87%) than those stored under straw huts in Bondoukou locality (100%) and at shade under a tree in Kouassi-Kouassikro area (100%). In conclusion, the physical quality of “Kponan” in field is most affected by abusive use of herbicides during weeding and clearing, hoe harvesting and storage in the shade under a tree.

关键词： “Kponan” Yam Post-Harvest Loss Cultivation Practices Conservation Practices Physical Quality

Physico-Chemical Analysis of Eutrophication’s Parameters in a Coastal River(Cote D’ivoire)

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Journal of Environmental Protection 2014年第13期5卷 1285-1293页

作者： Koffi Sebastien Ouffoue Moreto Salla denis yapo kicho Dodiomon Soro Kouhete Philippe Da Zanahi Felix Tonzibo Laboratoire de Chimie Organique U.F.R.SSMTUniversite Felix Houphouet-BoignyAbidjanCote d’Ivoire Centre Ivoirien Anti-Pollution(C.I.A.POL.) AbidjanCote d’Ivoire Laboratoire de Botanique U.F.R.BiosciencesUniversite Felix Houphouet-BoignyAbidjanCote d’Ivoire

A study on some physico-chemical and biological variables of water quality was conducted on a coastal river in Ivory Coast. It’s the first assessment on water quality state. Those coastal rivers actually play an important role in the physical, biological and hydrological exchange between lagoons and the sea. Unfortunately, they are not taken into account by the national monitoring for water quality (RNO-CI). The samples were collected along Boubo River body through three stations, in the south of Cote d’Ivoire, during two years. Results show sharp fluctuations of the concentration N-NO3- nitrate, N-NH4+ ammonium and chlorophyll a with more than 20% variation. However, small fluctuations were noted for temperature, pH and conductivity with 4% - 20%. Measures are generally inferior to the threshold for hazardous water class. But respective average concentrations of N-NO3-, P-PO43-, COD and BOD5 are above natural water threshold, representing 67% of the analyzed samples of P-PO43- and 100% of the other. These results show that the river is not exempt of pollution: 0.2 mg/l of P-PO43- and 0.9 mg/l of N-NO3- are the limits of appropriate siege for the proliferation of invasive aquatic plants (IAP).

关键词： Water Quality Nutriments Chlorophyll A Pollution Eutrophication River Cote d’Ivoire