RESUMEN
New pyrazolone-based Schiff bases were synthesized and characterized by various spectroscopic and analytical techniques such as 1H-NMR, FTIR, and UV − Vis spectroscopy and elemental analysis. Crystal structures of two of the Schiff-base (SB) compounds were obtained by single-crystal X-ray crystallography (SCXRC). The target Schiff bases were synthesized from the condensation of 4-acetyl-3-methyl-1-phenyl-5-pyrazolone with 1,2-diaminobenzene (SB1), 4-methyl-1,2-diaminobenzene (SB2), and 4,5-dimethy-1,2-diaminobenzene (SB3). Molecular docking modeling was used to study the interactions of these molecules with SARS-CoV-2 virus main proteases (PDB ids: 6LU7 and 7TLL). The estimated free binding energies (EFBE) for all the three SBs were better than the standard drugs favipiravir and dexamethasone. Besides, the order of EFBE was −7.68 (SB3)> −7.36 (SB1)> −7.06 kcal.mol−1(SB2) for 6LU7 and −10.42 (SB3)> −10.05 (SB1)> −9.69 kcal.mol−1(SB2) for 7TLL. SB3 showed the best interactions with both proteases that is discussed based on structure–function relationship.
RESUMEN
A new dinuclear Schiff-base complex, [Cu2L'2(μ-OAc)2], was synthesized and characterized by various spectroscopic methods and single-crystal X-ray diffraction (SCXRD). The symmetrical H2L ligand was synthesized from the reaction between 4-acetyl-3-methyl-1-phenyl-2-pyrazoline-5-one (or acylpyrazolone) with 1,3-propanediamine, but upon reaction with a metal salt, it gave the unsymmetrical HL'. The transition states and rates of interconversion between different tautomeric forms of HL' were studied by DFT computations. The imine-one (Z) in the gas phase and imine-ol (Z) in the solution were the most stable forms, most probably due to better hydrogen bonding. We also applied molecular docking modeling on the various tautomeric forms of the ligand as well as the complex with the main protease (6LU7) of the SARS-CoV-2 virus. Based on the obtained results, the complex had better interactions with the receptor. The order of the interactions was [Cu2L2(μ-OAc)2] > amine-one (Z) > imine-one (E) > imine-ol (Z) > amine-one (E) > imine-one (Z) > imine-ol (E). [ FROM AUTHOR] Copyright of Journal of Coordination Chemistry is the property of Taylor & Francis Ltd and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full . (Copyright applies to all s.)
RESUMEN
Three new mixed-ligand copper(II) complexes (1-3) with NN'O type unsymmetrical tridentate Schiff base ligands (SB) and N-donor heterocyclic co-ligands, with general formula [Cu(SB)(L)]ClO4, were synthesized and characterized using single crystal x-ray diffraction (SCXRD), FT-IR and UV-Vis spectroscopy and elemental analyses. The SB ligand is the half-unit form of the condensation of 1,3-propanediamine with 5-methoxysalicylaldehyde and the co-ligands (L) are pyridine (py in (1)), 2,2'-bipyridine (bpy in (2)) and 1,10-phenanthroline (phen in (3)). Crystal structures of (2) and (3) were obtained by SCXRD. Molecular docking and pharmacophore studies were performed to study the interactions between the synthesized complexes and SARS-CoV-2 virus main proteases (PDB IDs: 6LU7, 6WQF and 6W9C). Results revealed that complex (3) with phen co-ligand showed better docking scores with the three receptors, i.e. 6LU7 (-8.05 kcal.mol-1), 6W9C (-7.70 kcal.mol-1) and 6WQF (-7.75 kcal.mol-1). The order of the binding best energies for (3) was also as follows: 6LU7 > 6WQF > 6W9C. All of the studied complexes showed considerable performance, comparable to the standard drug, Favipiravir.
RESUMEN
Two new mixed-ligand complexes with general formula [Cu(SB)(L')]ClO4 (1 and 2) were synthesized and characterized by different spectroscopic and analytical techniques including Fourier transform infrared (FT-IR) and UV-Vis spectroscopy and elemental analyses. The SB ligand is an unsymmetrical tridentate NN'O type Schiff base ligand that was derived from the condensation of 1,2-ethylenediamine and 5-bromo-2-hydroxy-3-nitrobenzaldehyde. The L' ligand is pyridine in (1) and 2,2'-dimethyl-4,4'-bithiazole (BTZ) in (2). Crystal structure of (2) was also obtained. The two complexes were used as anticancer agents against leukemia cancer cell line HL-60 and showed considerable anticancer activity. The anticancer activity of these complexes was comparable with the standard drug 5-fluorouracil (5-FU). Molecular docking and pharmacophore studies were also performed on DNA (PDB:1BNA) and leukemia inhibitor factor (LIF) (PDB:1EMR) to further investigate the anticancer and anti-COVID activity of these complexes. The molecular docking results against DNA revealed that (1) preferentially binds to the major groove of DNA receptor whereas (2) binds to the minor groove. Complex (2) performed better with 1EMR. The experimental and theoretical results showed good correlation. Molecular docking and pharmacophore studies were also applied to study the interactions between the synthesized complexes and SARS-CoV-2 virus receptor protein (PDB ID:6LU7). The results revealed that complex (2) had better interaction than (1), the free ligands (SB and BTZ), and the standard drug favipiravir.