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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

Mechanism of Degradation of Rice Starch Amylopectin by Oryzenin Using OnIOM Quantum Calculations [DFT/B3LYP/6-31+G(D, P): AM1]

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Computational Chemistry 2022年第4期10卷 139-156页

作者： Bamba El Hadji Sawaliho n’guessan boka robert Laboratoire de Constitution et de Réaction de la Matière UFR SSMT Université Félix Houphou&euml t-Boigny Abidjan C&ocirc te d’Ivoire

Understanding the molecular factors of rice degradation during its aging concerns our research team. This article emphasizes oryzenin-amylopectin. It aims to reveal the mechanism of amylopectin deterioration during rice aging. The research exploits the natural Bond Analysis and OnIOn method at theory level DFT/B3LYP/6-31+G(d, p) and AM1. This methodological approach allows highlighting amylopectin transformation;oryzenin converts amylopectin into amyloidosis in continuous. This led to monosaccharides and disaccharides.

关键词： Amylopectin Hydrogen Bond Theoretical Method Starch Oryzenin

Hydrogen Bonds Sites of Amylose or Amylopectin from Starch at the OnIOn Level (B3LYP/6-311++G [d, p]: AM1)

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Computational Chemistry 2021年第1期9卷 85-96页

作者： Ablé Anoh Valentin n’guessan boka robert Bamba El Hadji Sawaliho Laboratoire de Constitution et de Réaction de la Matière UFR SSMT Université Félix Houphou&#235t-Boigny Abidjan C&#244te d’Ivoire

The research aims to help reduce the enormous post-harvest losses of rice or bananas in Cote d’Ivoire. It focuses on the breakdown mechanism of their starch. This process contributes to their decay. This study wants to elucidate it;to do this, it analyzes the tetra or penta saccharide reactions with the water or dioxide carbon. It calculates the geometric, energetic and spectroscopic parameters at the OnIOM level (B3LYP/6-311++G [d, p]: AM1). These quantities allow establishing that oxygen represents the privileged hydrogen bond (HB) site for amylose with four or five D-glucose building blocks. They suggest and are respectively those of amylopectin when the latter consists of four and five D-glucose synthons. They prove that amylose deteriorates before it;the degradation of starch begins with its alteration into disaccharides. It continues with that of amylopectin into tri or tetra-saccharides with four or five building blocks.

关键词： Hydrogen Bonds Glucose Amylose Amylopectin

The Oryzenin’s Effect on Di, Tri and Quadri-Saccharide Degradation. An Investigation by a Mixed Method: OnIOM (DFT/B3LYP/6 - 31 + G(d, p): AM1)

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Computational Chemistry 2022年第2期10卷 97-119页

作者： n’guessan boka robert Bamba El Hadji Sawaliho Koffi Kouassi Alain Laboratoire de Constitution et de Réaction de la Matière UFR SSMT Université Félix Houphou&#235 t-Boigny Abidjan C&#244 te d’Ivoire

The paddy rice degradation remains a concern for research;the chemical phenomena underlying this process persists unknown. This research aims to identify the mechanism of starch degradation. It determines the nature of the reactions between two, three and four synthons of amylose with oryzenin using theoretical methods. The OnIOM (DFT/B3LYP/6 - 31 + G(d, p): AM1) level of theory is performed on four monomers and eight complexes. Frequencies make it possible to obtain energy and spectroscopic quantities. Calculations after geometry optimization. Following this, a “single point” allows exploiting the “natural Bond Orbital (nBO)” analysis. The first three parameters suggest that the main interactions between oryzenin and amylose arise through O29-H30…O46 hydrogen bonds (HB). Furthermore, this result posits that the length of the amylose doesn’t influence this reaction. The nBO analysis shows that this component of starch degrades first at the end of the chain to produce monosaccharides;it can also alter in the middle of the chain to give disaccharides.

关键词： Paddy Rice Oryzenin Amyloidosis Hydrogen Bond

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

Management of Mandibular Fractures in Children in Ivory Coast: Experience of the Stomatology and Maxillofacial Surgery Department at the University Hospital of Cocody from 2000 to 2019

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Open Journal of Stomatology 2024年第7期14卷 341-349页

作者： Bakary Ouattara Camille Assouan Laurent boka Koffi Konan René Kouakou Ake Lucien Jonathan Yapo Annick Zoglo-Bro Ahi Morel Mounin Chapo Affoué Linda Marie Pierre Koffi Kahder Morel Diarra Atse Kobo n’guessan Konan Marc Koffi Department of Stomatology Maxillofacial Surgery University Flix Houphout-Boigny Abidjan Republic of Ivory Coast Department of Oral Pathology University Flix Houphout-Boigny Abidjan Republic of Ivory Coast

Introduction: Mandibular fractures in children are becoming increasingly common. Treatment of these fractures is difficult due to their anatomical and physiological complexity. Therefore, there is a need for well-codified management. Our main aim was to develop a decision algorithm for the management of mandibular fractures in children based on our experience. Materials and Methods: This was a retrospective descriptive study carried out in the Department of Stomatology and Maxillofacial Surgery at the University Hospital of Cocody over a period of 20 years (2000-2019). Results: We enrolled 58 patients. The mean age of the patients was 9.35 ± 2.3 years with a sex ratio of 2.22. Traffic accidents were the main cause of mandibular fractures (60.35%). Condylar fractures were the most common (46.87%). Treatment was orthopedic in 45.76% of cases, mixed (orthopedic and surgical) in 24.14% and surgical in 5.17%. Patients were followed up weekly for 1 month, then monthly for 6 months and annually for 3 years, with panoramic radiographs of the maxilla starting at 21 days. We observed 2 cases of complications: temporomandibular ankylosis and gingival stomatitis. Conclusion: Mandibular fractures are common in children. Management is difficult due to anatomical and physiological peculiarities. The choice of treatment depends on several criteria.

关键词： Fractures Mandible Children Treatment Ivory Coast