http://depot.umc.edu.dz/handle/123456789/7647 2026-10-28T16:24:56Z http://depot.umc.edu.dz/handle/123456789/14862 Contribution à l’étude photochimique et à l’activité biologique de l’espèce hédysarum pallidum desf. et l’espèce LINAIRE PELISSERIANA. Dob ép. Douaa, Amina; Boumaza, Ouahiba This work is devoted to the phytochemical and biological study of two Algerian species: Hedysarum pallidum Desf. and Linaria pelisseriana that have not been previously subjected to any phytochemical study. The extraction of both species followed by chromatographic separation (CC, CCM) leads the isolation of 20 products. UHPLC-MS-DAD analysis identifies 28 products in the n-BUOH phase of Hedysarum pallidum. The GC-MS analysis of the two chloroform phases of the two species concede to identify 13 and 14 products of Hedysarum pallidum and Linaria pelisseriana respectively with structures identifies by comparison with literature data. Regarding biological activity, the n-BuOH extract presents the most satisfactory results. Seven in vitro tests were carried out to determine the antioxidant power (DPPH, ABTS, CUPRAC, reducing power, metal chelating effect, alkaline superoxide and phenanthroline); they have shown that it has very strong antioxidant power. In addition, the α-glucosidase inhibition test showed that the n-BuOH extract as well as the CHCl3 extract have interesting antidiabetic activity. For the inhibitory activity of acetylcholinesterase and buturylcholinesterase, the two species present a weak effect compared to standards. 2024-09-14T00:00:00Z http://depot.umc.edu.dz/handle/123456789/14861 Nouvelles synthèses d’hétérocycles Azotés et Oxygénés, évaluation biologique et étude théorique Zine, Yasmine; Boulcina, Raouf The objective of the work presented in this thesis is to develop new approaches to access a variety of nitrogen- and oxygen-containing polyheterocyclic compounds, as well as to evaluate their biological activity and conduct theoretical studies using DFT and molecular docking. The first chapter of the thesis is structured into three parts. In the first part of the first chapter, we investigated the effect of two new catalysts, Pyridinium-p-toluenesulfonate and triethylamine, for synthesizing derivatives of 2-amino-4-(aryl)-7-methyl-5-oxo-4H,5Hpyrano[4,3-b]pyran-3-carbonitrile, achieving high yields in reduced time. The structures of the compounds were confirmed by RMN and HRMS. The antibacterial tests on the synthesized compounds showed promising results. However, the tests for acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibition, as well as the evaluation of antioxidant activity, yielded limited performances. A DFT study was conducted on three representative molecules, and molecular docking assessed the antibacterial activity of the most promising compound. In the second part of the first chapter, we investigated a selective multi-component transformation of salicylaldehydes, 4-hydroxy-6-methyl-2H-pyran-2-one, and malononitrile in the presence of 10 mol% of PPTS. This reaction led to the formation of 2,4-diamino-5-[4- hydroxy-6-methyl-2-oxo-2H-pyran-3-yl]-5H-chromeno[2,3-b]pyridine-3-carbonitrile with excellent yields. The synthesized molecules showed promising potential in terms of biological activity. In the third part of the first chapter, we investigated the synthesis of several derivatives of tacrine successfully, with satisfactory yields. Spectroscopic analyses by RMN 1H and 13C confirmed the structures of the synthesized compounds, revealing characteristics consistent with expectations. In the second chapter, we developed a novel, simple, and effective method using DMAP as a catalyst without solvent to synthesize derivatives of 5-arylidene-thiazolidine-2,4-dione, obtained with excellent yields via Knoevenagel reaction. The compounds were characterized by RMN spectroscopy, and their physical properties were determined. Evaluation of antioxidant activity revealed the impact of substituents on their biological activity, with some compounds showing promising antioxidant activity. Computational simulations corroborated these observations. Additionally, we explored the potential of molecular docking for studying inhibition of PIM-1 kinase. In the third chapter, we investigated the synthesis of 4-arylmethylene-3-methylisoxazole- 5(4H)-ones using Na₂SO₃ as a catalyst. This choice of catalyst proved advantageous due to its non-hazardous and non-toxic nature, being a safe and easily handled food additive. The use of water as a solvent, environmentally friendly, allowed the reaction to proceed under mild conditions. The obtained products were pure with excellent yields. Additionally, all parts are accompanied by a recent, rich, and varied bibliography. 2024-11-10T00:00:00Z http://depot.umc.edu.dz/handle/123456789/14856 Structure, spectroscopie de molécules présentant un intérêt biologique. Akkache, Hibet Errahmane Meroua; Halimi, Ouahiba; Hamdouni, Noudjoud (E)-l-[-2-(2-fluorophenyl)diazan-l-ylidene] naphthalen-2(1H)-one (FPDN) and (E)-l-[2-(3-chlorophenyl) diazen-l-ylidene] naphthalen-2(1H)-one (3-ClPDN) are organic molecules belonging to the azo dye family. This thesis aims to study these two compounds experimen tally and theoretically, as well as explore their ptential biological applications in drug design. In the experimental part, the structures of these compounds were determined using single crystal X-Ray Diffraction (XRD). Hirshfeld surface (HS) analysis was performed to better understand the intermolecular interactions. The compounds were also characterized using Fourier-transform infrared (FT-IR) spectroscopy,and their biological activities were evaluated through antioxidant assays (DPPH, ABTS, CUPRAC, and phenanthroline). The theoretical calculations were performed using Density Functional Theory (DFT). The results were compared with experimental data for bond lengths, bond angles and IR spectra. Additionally, theoretical analyses included Frontier Molecular Orbitals (FMOs), Molecular Electrostatic Potential (MEP), Noncovalent Interactions (NCI), Electron Localization Func tion (ELF), and Localized Orbital Locator (LOL). To evaluate the potential biological applications, molecular docking simulation were performed against l l-beta-hydroxysteroid dehydrogenase l (11β-HSD1) and Absorption, Distri bution, Metabolism, Excretion, and Toxicity (ADMET) properties were predicted. 2025-11-13T00:00:00Z http://depot.umc.edu.dz/handle/123456789/14850 Estimation non paramétrique dans des modèles géométriques : applications. Djeniba, Hadjer; Leulmi, Sarra The purpose of this thesis is to investigate the nonparametric estimation of the classical and relative regression of the real valued random variable Y , conditional on a real valued covariate X, under independent and identically distributed data, as well as under strong mixing and η− weak dependence with a geometric rate. We established the necessary assumptions to prove the almost complete pointwise and uniform convergence of the proposed estimators, along with their rates of convergence. To illustrate and validate these theoretical results, a simulation study was conducted for both the i.i.d. case and the weakly dependent data with a geometric rate. 2025-11-19T00:00:00Z