08 Mai 45 University
08 Mai 45 University
Bensouilah N.,University of Science and Technology Houari Boumediene |
Bensouilah N.,08 Mai 45 University |
Boutemeur-Kheddis B.,University of Science and Technology Houari Boumediene |
Bensouilah H.,May 8th 1945 University |
And 2 more authors.
Journal of Inclusion Phenomena and Macrocyclic Chemistry | Year: 2017
The aim of the present work is the investigation of the inclusion complex of nabumetone (NAB) and β-cyclodextrin (β-CD) using PM3, DFT, DFT-D and ONIOM2 methods. The results indicate that the most energetically favorable structure predicts a preference of the methoxy group to enter the cavity of β-CD from its wide rim. Consequently, the butanone moiety is positioned outside the cavity on the side of the secondary hydroxyls, with a total insertion of naphthalene group. The semi-empirical PM3 results are in good agreement with those obtained by the DFT optimization (with and without dispersion correction). The donor–acceptor interactions between drug and the cavity wall of the host, studied on the basis of natural bonding orbital (NBO) analysis, show the presence of weak intermolecular hydrogen bonds in addition to the most important van der Waals interactions. Furthermore, it is revealed that among the DFT and DFT-D techniques selected to quantify these interactions, WB97X-D functional provides the greatest values of stabilization energies E(2). Finally, a detailed topological charge density analysis based on the quantum theory of atoms in molecules (QTAIM), developed by Bader and co-workers, has been accomplished using the WB97X-D and B3LYP methods on the most favorable complexes. A good correlation between the structural parameters and the electronic density is found. © 2017, Springer Science+Business Media Dordrecht.
Benhamdi S.,08 Mai 45 University |
Seridi H.,Annaba University
2011 International Conference on Information Technology Based Higher Education and Training, ITHET 2011 | Year: 2011
For facilitating the use of e learning environments by teachers, we have proposed an approach that aid them to propose documents for learners taking in account their preferences and abilities, so allowing the personalization of these environments. This approach combines a pedagogical scenario design approach , using one of most used modelling languages IMS Learning Design (IMSLD), and taxonomy based one which is boosted-CSHTRL (Boosted Cold Start Hybrid Taxonomy Recommender for e Learning), developed to generate recommendation to learners, taking into consideration their preferences and abilities in order to motivate them, and consequently, improve efficiency and increase veracity of learner in the learning situation. © 2011 IEEE.
Seridi L.,08 Mai 45 University |
Boufelfel A.,08 Mai 45 University
Journal of Molecular Liquids | Year: 2013
We investigated the inclusion of Wogonin in β-cyclodextrin using several quantum mechanical models. Among the two considered modes of complexation, both PM3 and ONIOM2 results proved that the lowest energy structure is obtained from 'A' orientation. The most stable geometry presents a partial inclusion of Wogonin with the aromatic ring totally embedded in β-cyclodextrin hydrophobic cavity, while the di-hydroxy methoxy phenyl moiety is protruded out of the secondary rim. The statistical thermodynamic calculations at 1 atm and 298.15 K demonstrated that both in vacuum and in water, the complexation process is exothermic and enthalpically driven. However the nonspontaneous inclusion process in vacuum became spontaneous after explicit solvation of Wogonin:β-cyclodextrin complex in water. Furthermore, the quantification of the donor-acceptor interaction between host and guest molecules is performed via Natural Bond Orbital (NBO) analysis and we deduced that the main driving force stabilizing the inclusion complex are van der Waals interactions with a very weak contribution of hydrogen bonding, better estimated by the M05-2X and WB97X-D methods. Finally, 1H Nuclear Magnetic Resonance (NMR) chemical shifts of free and complexed Wogonin were calculated by the Gauge-Including Atomic Orbital (GIAO) method and compared with available experimental data. © 2013 Elsevier B.V.