Browsing by Author "Silva, Artur M.S."

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Selectivity control in the reaction between 2-hydroxyarylaldehydes and 4-hydroxycoumarin. Antioxidant activities and computational studies of the formed products
(Elsevier, 2021) Ould Lamara, Kamilia; Makhloufi-Chebli, Malika; Benazzouz-Touami, Amina; Terrachet-Bouaziz, Souhila; Hamdi, Nejla; Silva, Artur M.S.; Behr, Jean-Bernard
A series of 6H,7H-7-(4-Hydroxy-3-coumarinyl)[1]benzopyrano[4,3-b][1]benzopyran-6-ones 4a-g and 3-(2-hydroxybenzoyl)-2H-chromen-2-ones 5a-g derivatives were synthesized by reaction of 4-hydroxycoumarin with 2-hydroxyarylaldehydes 2a-f or 2-hydroxynaphtaldehyde 2g using different solvents and acid/base catalysts. The approach relies on a regioselective cascade reaction involving one/two molar equiv of the 4-hydroxy coumarin iteratively acting as active methylene substrate in a Knoevenagel condensation and in a Michael addition. The structures of all compounds were established by IR, mass spectrometry, 1H-NMR and 13C-NMR. Antioxidant activity of the synthesized compounds were determined using the DPPH scavenging assay, best results being obtained with 5b (IC50 = 236 µg/mL). Computational studies showed that the compounds bind in the ATP-binding site of p38 MAPK, in a same manner than known polyaromatic potent inhibitors. The synthesized compounds might be considered further for cancer therapy
Study of the novel fluorescent 4-methyl-9-(3-oxobutanoyl)-2H,8H-pyrano[2,3-f]chromene-2,8-dione derivative. estimation of the ground- and excited-state dipole moments from a solvatochromic shift
(Elsevier, 2017) Al-Kawkabani, Ahmed; Makhloufi-Chebli, Malika; Benosmane, Nadjib; Boutemeur-Kheddis, Baya; Hamdi, Maamar; Silva, Artur M.S.
Transition-metal complexes of N,N′-di(4-bromophenyl)-4-hydroxycoumarin-3-carboximidamide : synthesis, characterization, biological activities, ADMET and drug-likeness analysis
(Elsevier, 2021) Belkhir-Talbi, Drifa; Ghemmit-Doulache, Naima; Terrachet-Bouaziz, Souhila; Makhloufi-Chebli, Malika; Rabahi, Amal; Ismaili, Lhassane; Silva, Artur M.S.
Coordination compounds of N,N’-di(4-bromophenyl)-4-hydroxycoumarin-3-carboximidamide (L1) were synthesized via the reaction of Cu (II), Co (II) and Zn (II) salts in molar ratio 1 : 1 in the presence of ammoniac as basic media. The Ligands and the complexes formed were characterized using FT-IR, UV–visible and fluorescence spectrophotometric analyses, mass spectrometry, elemental analyses and NMR spectroscopy. It was concluded that N,N’-di(4-bromophenyl)-4-hydroxycoumarin-3-carboximidamide (L1) coordinated as a mono ligand for all the complexes; it also coordinated via the –OH and –NH groups. The electrochemical behaviour of these compounds was determined by cyclic voltammetry. The synthesized compounds were screened for their antimicrobial and antioxidant activities. All the complexes except that of copper show good activities against the S. aureus and those of cobalt and zinc have very interesting diameters of inhibition but lower antioxidant activity than the ligand L1. Parameters drug-likeness and ADMET (Absorption, Distribution, Metabolism, and Excretion) properties have been calculated