http://depot.umc.edu.dz/handle/123456789/7647 2026-06-01T14:36:34Z http://depot.umc.edu.dz/handle/123456789/14830 Investigation phytochimique et biologique de la propolis Algérienne. Daikh, Amina; Segueni, Narimane Our study is interested in the investigation of the chemical composition and the biological activities of Algerian propolis. In the first part of our study we examined several propolis harvested from Algerian East in order to compare their antibiofilm and cytotoxicity activities, In addition, the UPLC-ESI-MS/MS analysis of the most active extracts was also evaluated. In the second part we studied the antioxidant capacity of two other propolis by five different methods. The total phenolic and flavonoid contents were evaluated. Propolis of Mila exhibited the highest antioxydant activity. This result encouraged us to study the cytotoxicity activity of the extracts of this propolis. This propolis acts on MDA-MB- 231 cells by inducing apoptosis by increasing the concentrations of Bax, caspase 3 and p53 proteins as well and decreasing Bcl2 and CDK-4 proteins. These results are confirmed by the study of mRNA and cDNA. In the last part of our work we were interested in the chemical composition of Algerian propolis. After extraction, separation and purification, we obtained 6 pure flavonoids 5,4'-dihydroxy-6,7-dimethoxyflavone (Cirsimaritine), 7-methoxy 3,5 dihydroxyflavonol (Galangine 7-methoxy), 4',5,7-trihydroxy-3-methoxyflavone (isokampferide), 5,7-dihydroxy-flavanone (Pinocembrine), Apigenin 7-methoxy (Genkwanin) and Apigenin. Our study demonstrated that all the studied propolis are probably of t poplar type. 2023-12-07T00:00:00Z http://depot.umc.edu.dz/handle/123456789/14828 Synthèse, caractérisation, etude structurale par diffraction des rayons X et réactivité thermique des carboxylates à base d’alcalino-terreux. Bendjellal, Nassima; Boudaren, Chaouki The main purpose of this thesis is based on the synthesis and characterization of new coordination compounds based on alkaline-earth metals. Two synthesis methods were used to prepare these materials: synthesis by way of chemistry in solution and by solvothermal route. The structural study and physico-chemical characterization of these compounds was achieved by several techniques such as: spctroscopie IR, UV spectroscopy, X-ray fluorescence, crystal structures of materials hybrids have been solved by X-ray single crystal and thermal behaviors were studied by thermogravimetry, has fully describe the mechanisms of the decomposition of the solid. Likewise, the influence of the bond strength within the hydrogen-bonding network on both the structure stability has been evidenced within these architectures. Initially, the synthesis and the structural characterization by X-ray diffraction as well as the study of the physico-chemical and photophysical properties and the thermal stability by the use of cinnamic acid associated with the Co-ligand 1, 10’-phenthroline led to the production of four coordination polymers. In a second step, we describe the preparation of a dicarboxylate ligand on imidazolium H(S,S-diLeuIm) and the synthesis of three complexes by aqueous solution method based on K, Sr, Ba and characterized by methods IR, RMN spectroscopy and EM-MS mass. 2023-06-20T00:00:00Z http://depot.umc.edu.dz/handle/123456789/14823 Généralisation de certaines inégalités intégrales non linéaires avec retard et applications. Kriket, Salah; Boudeliou, Ammar Gronwall-Bellman inequalities and their various generalizations that give explicit bounds on unknown functions provide a very useful and important device in the study of many qualitative properties of solutions of differential equations, integral equations and integrodifferential equations. The purpose of this work is to give an exposition of some classical and modern results about integral inequalities, and establish some new nonlinear integral inequalities with delay in two independent variables, which generalize some known inequalities recently obtained. These results can be used as handy tools to study the boundedness of solutions of Volterra integral equations. Applications are given to illustrate how our results can be applied to study the boundedness of the solutions of certain Volterra equations. The research on this topic is also large and continues until now, the impressive number of publications on this subject testifies to this. 2023-11-16T00:00:00Z http://depot.umc.edu.dz/handle/123456789/14819 Application des complexes organiques dans les procédés d’oxydation avancée pour la dégradation des polluants pharmaceutiques en solution aqueuse. Lekikot ép Kouicem, Bouchra; Mammeri, Lamia The catalytic activation of hydrogen peroxide (H2O2), persulfate (PS) and peroxymonosulfate (PMS) by organometallic FeIII and CuII complexes has been applied in the removal of several types of pharmaceutical pollutants in aqueous solution. The catalytic treatment processes were performed using different chelating agents to solubilize FeIII and CuII in a neutral aqueous solution. The first part of this work was devoted to the synthesis and characterization of organic complexes of FeIII and CuII in aqueous solution namely FeIII-GA and CuII-TA. In the second part, ibuprofen (IBP) and propranolol (PRO) were used as model molecules to study the activation of several oxidants by these organometallic complexes. A preliminary study of the complex/substrate mixture in the dark and at room temperature was performed and confirmed the absence of interaction between the substrate and the complexes. The effect of different factors, such as initial pH, oxygen, complex concentration, as well as substrate concentration, on the degradation of IBP and PRO was examined. The mineralization of IBP required more time than the degradation. The mechanistic aspect was also taken into account and shows the role of the oxidizing radicals involved in the modified Fenton-like process which would involve the •OH radical for both complexes whereas the combined effect of SO4•− and •OH radicals particularized the case of the PMS/complex. The application of these processes for the degradation of different pharmaceutical products has shown the superior catalytic capacity in comparison with other treatment processes. 2023-10-19T00:00:00Z