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1,011 results on '"Daoud, J."'

25. New 1,2,3-Triazole Scaffold Schiff Bases as Potential Anti-COVID-19: Design, Synthesis, DFT-Molecular Docking, and Cytotoxicity Aspects

Author

Musa A. Said, Daoud J. O. Khan, Fawzia F. Al-blewi, Nadia S. Al-Kaff, Adeeb A. Ali, Nadjet Rezki, Mohamed Reda Aouad, and Mohamed Hagar

Subjects
1,2,3-triazole, Schiff base (SB), DFT-QSAR, COVID-19, molecular docking, cytotoxicity, Medicine
Abstract

Schiff bases encompassing a 1,2,3-triazole motif were synthesized using an efficient multi-step synthesis. The formations of targeted Schiff base ligands were confirmed by different spectroscopic techniques (FT-IR, 1H NMR, 13C NMR, and CHN analysis). The spectral data analysis revealed that the newly designed hydrazones exist as a mixture of trans-E and cis-E diastereomers. Densityfunctional theory calculations (DFT) for the Schiff bases showed that the trans-trans form has the lowest energy structure with maximum stability compared to the other possible geometrical isomers that could be present due to the orientation of the amidic NH–C=O group. The energy differences between the trans-trans on one side and syn-syn and syn-trans isomers on the other side were 9.26 and 5.56 kcal/mol, respectively. A quantitative structure-activity relationship investigation was also performed in terms of density functional theory. The binding affinities of the newly synthesized bases are, maybe, attributed to the presence of hydrogen bonds together with many hydrophobic interactions between the ligands and the active amino acid residue of the receptor. The superposition of the inhibitor N3 and an example ligand into the binding pocket of 7BQY is also presented. Further interesting comparative docking analyses were performed. Quantitative structure-activity relationship calculations are presented, illustrating possible inhibitory activity. Further computer-aided cytotoxicity analysis by Drug2Way and PASS online software was carried out for Schiff base ligands against various cancer cell lines. Overall, the results of this study suggest that these Schiff base derivatives may be considered for further investigation as possible therapeutic agents for COVID-19.

Published
2021
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28. Guidelines, “minimal requirements” and standard of care in glioblastoma around the Mediterranean Area: A report from the AROME (Association of Radiotherapy and Oncology of the Mediterranean arEa) Neuro-Oncology working party

Author

Belkacemi, Y., Bolle, S., Bourdeaut, F., Collin, P., Cornu, P., Delatre, J.-Y., Dhermain, F., Doz, F., Habrand, J.-L., Hoang-Xuan, K., Idbaih, A., Mammar, H., Martin-Duverneuil, N., Mokhtari, K., Roujeau, T., Acharqui, A., Atit Benali, S., Bakhti, S., Bena, F., Bendjaafar, N., Benider, A., Bouaouina, N., Bounedjar, A., Boussen, H., Bouyoucef, K., Bouzid, K., Chougai, Z., Daoud, J., Errihani, H., Essoudaigui, F., Gachi, F., Harif, M., Hilmani, S., Hsissen, L., Idali, B., Karkouri, M., Kerboua, E., Ouahabi, A., Sahraoui, S., Sadki, O., Sami, A., Samlali, R, and Terkmani, F.

Published
2016
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41. Design, Synthesis, Molecular Modeling, Anticancer Studies, and Density Functional Theory Calculations of 4-(1,2,4-Triazol-3-ylsulfanylmethyl)-1,2,3-triazole Derivatives

Author

Mohamed Reda Aouad, Nadjet Rezki, Fawzia F. Al-blewi, Mohamed Hagar, Adeeb A. Ali, Daoud J O Khan, and Arshi Naqvi

Subjects
chemistry.chemical_classification, 1,2,3-Triazole, Molecular model, biology, General Chemical Engineering, Alkyne, Active site, General Chemistry, Combinatorial chemistry, Article, Chemistry, chemistry.chemical_compound, chemistry, biology.protein, Side chain, Molecular orbital, Density functional theory, Target protein, QD1-999
Abstract

New conjugates of substituted 1,2,3-triazoles linked to 1,2,4-triazoles were synthesized starting from the appropriate S-propargylated 1,2,4-triazoles 7 and 8. Ligation of 1,2,4-triazoles to the 1,2,3-triazole core was performed through Cu(I)-catalyzed cycloaddition of 1,2,4-triazole-based alkyne side chain 7 and/or 8 with several un/functionalized alkyl- and/or aryl-substituted azides 9–15 to afford the desired 1,4-disubstituted 1,2,3-triazoles 16–27, using both classical and microwave methods. After their spectroscopic characterization (infrared, 1H, 13C nuclear magnetic resonance, and elemental analyses), an anticancer screening was carried out against some cancer cell lines including human colon carcinoma (Caco-2 and HCT116), human cervical carcinoma (HeLa), and human breast adenocarcinoma (MCF-7). The outcomes of this exploration revealed that compounds 17, 22, and 25 had a significant anticancer activity against MCF-7 and Caco-2 cancer cell lines with IC50 values of 0.31 and 4.98 μM, respectively, in relation to the standard reference drug, doxorubicin. Enzyme-docking examination was executed onto cyclin-dependent kinase 2; a promising aim for cancer medication. Synthesized compounds acquiring highest potency showcased superior interactions with the active site residue of the target protein and exhibited minimum binding energy. Finally, the density functional theory (DFT) calculations were carried out to confirm the outcomes of the molecular docking and the experimental findings. The chemical reactivity descriptors such as softness (δ), global hardness (η), electronegativity (χ), and electrophilicity were calculated from the levels of the predicted frontier molecular orbitals and their energy gap. The DFT results and the molecular docking calculation results explained the activity of the most expectedly active compounds 17, 22, and 25.

Published
2020

47. Developed procedure for Sn (II) extraction from hydrochloric acid medium with CYANEX 921 and its recovery from spent LCD screens.

Author

Rizk, S. E., Masry, B. A., and Daoud, J. A.

Subjects
TIN, LIQUID-liquid extraction, HAZARDOUS wastes, HYDROCHLORIC acid
Abstract

One of the sustainability goals is to resource and extracts valuable metals from different spent materials in which they are accumulated and become hazardous waste. A developed Liquid–Liquid extraction (LLE) procedure for Sn(II) extraction from HCl medium using CYANEX 921/kerosene and its recovery from spent LCD screens has been carried out. The effects of the different parameters on the extraction process such as shaking time, [HCl], [H+], [CYANEX921], [Cl−], [Sn+2], loading capacity and temperature were separately investigated. Based on the obtained results and using the slope analysis method, the extracted organic species is proposed to be SnCl2.2CY. 921 and the mean value of Kex for Sn (II) was found to be 23 × 104 M−3. The maximum loading capacity of the used extractant for the extraction of Sn+2 is 0.494 M Sn+2/mole CYANEX 921 and was reached after three extraction stages. The separation feasibility of Sn+2 from In+3 and other interfering ions such as Zn, Co, Ni, Ag and Mn was also investigated. The maximum stripping percentage was 99.5% and 86.2% for Sn+2 and In+3, respectively, and was achieved with 3 M HNO3 after one stripping stage. A developed process for the recovery of stannous from spent LCD screens using the investigated CYANEX 921/kerosene/HCl system is proposed and evaluated. [ABSTRACT FROM AUTHOR]

Published
2022
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50. New 1,2,3-Triazole Scaffold Schiff Bases as Potential Anti-COVID-19: Design, Synthesis, DFT-Molecular Docking, and Cytotoxicity Aspects

Author

Mohamed Reda Aouad, Mohamed Hagar, Daoud J O Khan, Adeeb A. Ali, Nadjet Rezki, Musa A. Said, Nadia S. Al-Kaff, and Fawzia F. Al-blewi

Subjects
Pharmacology, Schiff base, Hydrogen bond, Ligand, Stereochemistry, Immunology, COVID-19, molecular docking, Carbon-13 NMR, Article, Hydrophobic effect, chemistry.chemical_compound, Infectious Diseases, chemistry, Schiff base (SB), Docking (molecular), Drug Discovery, Proton NMR, Medicine, cytotoxicity, Pharmacology (medical), DFT-QSAR, 1,2,3-triazole, Cis–trans isomerism
Abstract

Schiff bases encompassing a 1,2,3-triazole motif were synthesized using an efficient multi-step synthesis. The formations of targeted Schiff base ligands were confirmed by different spectroscopic techniques (FT-IR, 1H NMR, 13C NMR, and CHN analysis). The spectral data analysis revealed that the newly designed hydrazones exist as a mixture of trans-E and cis-E diastereomers. Densityfunctional theory calculations (DFT) for the Schiff bases showed that the trans-trans form has the lowest energy structure with maximum stability compared to the other possible geometrical isomers that could be present due to the orientation of the amidic NH–C=O group. The energy differences between the trans-trans on one side and syn-syn and syn-trans isomers on the other side were 9.26 and 5.56 kcal/mol, respectively. A quantitative structure-activity relationship investigation was also performed in terms of density functional theory. The binding affinities of the newly synthesized bases are, maybe, attributed to the presence of hydrogen bonds together with many hydrophobic interactions between the ligands and the active amino acid residue of the receptor. The superposition of the inhibitor N3 and an example ligand into the binding pocket of 7BQY is also presented. Further interesting comparative docking analyses were performed. Quantitative structure-activity relationship calculations are presented, illustrating possible inhibitory activity. Further computer-aided cytotoxicity analysis by Drug2Way and PASS online software was carried out for Schiff base ligands against various cancer cell lines. Overall, the results of this study suggest that these Schiff base derivatives may be considered for further investigation as possible therapeutic agents for COVID-19.

Published
2021

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