Browsing by Author "Machado-Rodrigues, Carine"

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    Design, Synthesis, Biological evaluation of Isonicotinoyl-pyrazolyl-coumarin derivatives and computational study
    (Elsevier, 2022) Halit, Sabrina; Benazzouz-Touami, Amina; Makhloufi-Chebli, Malika; TerrachetBouaziz, Souhila; Ighilahriz, Karima; Robert, Anthony; Machado-Rodrigues, Carine
    A new series of 3-(5-Hydroxy-1-isonicotinoyl-3-methyl-4,5-dihydro-1H-pyrazol-5-yl)-2H-chromen-2-one derivatives 3a-g was efficiently synthesized under environmentally friendly reaction conditions by reaction of 3-acetoacetylcoumarin derivatives 1a-g with isoniazid 2. The reaction is conveniently performed at room temperature using Knorr pyrazole syntheses. The key features of this approach are its operational simplicity, the facile access to the desired products, and the good to excellent yields. The structures of the newly synthesized compounds were established by 1H, 13C, 2D NMR spectroscopy and mass spectrometry. 1H-15N HMBC experiments were also conducted to assess the regiochemistry of final compounds. All the synthesized compounds were evaluated for their in vitro antifungal activity against both Candida albicans and Aspergillus niger strains and compared to the standard drug Ketoconazole. Among all the compounds, 3d and 3e were the most effective, showing high potential antigungal inhibitory activities with respective MIC values of 15.62 µg ml−1 for 3e against Aspergillus niger. All the newly synthesized derivatives 3a-g are evaluated for their antioxidant activity and showed good activity. SAR studies demonstrated that the presence of nitro and hydroxyl groups in the aromatic ring of the coumarin and pyrazoline rings conferred enhanced antioxidant and antifungal activity. In addition, molecular docking studies were performed for compound 3e to evaluate its potential as an inhibitor of the fungal protein (Phytase A) from Aspergillus niger and the results suggested that our isonicotinoyl-pyrazolyl-coumarin may act as promising antifungal agent
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    Synthesis, biological activities of chalcones and novel 4-acetylpyridine oximes, molecular docking of the synthesized products as acetylcholinesterase ligands
    (Elsevier, 2022) Ould Lamara, Kamilia; Makhloufi-Chebli, Malika; Benazzouz-Touami, Amina; Terrachet-Bouaziz, Souhila; Robert, Anthony; Machado-Rodrigues, Carine; Behr, Jean-Bernard
    Heterocyclic chalcones were synthesized by reaction of 4-acetylpyridine with the corresponding aromatic aldehydes under Claisen Schmidt conditions. These chalcones were used as starting material for the synthesis of oximes in the presence of hydroxylamine hydrochloride. The structures of the synthesized compounds were confirmed by IR, 1H NMR, 13C NMR and ESI-MS, HRMS spectral analyses. All the synthesized compounds were evaluated for their antioxidant activity by DPPH• method and their in vitro antimicrobial activity by disk diffusion method against two Gram-negative bacteria, one Gram-positive bacteria and two fungal strains (C. albicans and A. niger). The results showed that the synthesized compounds did not display significant antioxidant activity. However, compounds 3b, 3d, 3f, 3h, 3i showed excellent antibacterial activity better than the standard drug against the bacterial strain S. aureus (ATCC 25923). The two compounds 3c, 3d proved very active against the fungal strain A. niger (MIC= 7.81 µg/ mL, 15.62 µg/mL respectively) while the antifungal drug used as reference (Fluconazole) was inactive. Molecular docking and molecular dynamics results revealed that the synthesized compounds, 4e, 4c, and 5j, were involved in a large number of favorable interactions with the active site residues of the acetylcholinesterase protein, which can stabilize the ligands in the active site and increase their affinities