Synthesis, characterization, DFT calculations, and biological activity of copper(II) complexes with 1,1,1-trifluoro-4-(2-methoxyphenyl)butan-2,4-dione

In the present work, complex formation equilibria between copper(II) and 1,1,1-trifluoro-4-(2-methoxyphenyl)butan-2,4-dione (1) have been investigated by UV–vis spectroscopy in ethanol/0.01 M NEt4NO3 as an ionic strength adjuster at 25 °C. The composition of the complex in solution was determined using Job's plot and molar ratio method. Four single crystals of copper complexes CuL2(DMF) (2), CuL2 (3), CuL2(DMSO)2 (4) and CuL2(DMSO) (5), which include the ligand molecules in the cis- and trans-conformations, respectively, were obtained. The complexes were characterized with FT-IR spectroscopy, elemental analysis, and X-ray crystallography. In the complexes 2 and 5, the copper atoms adopt distorted square pyramidal coordination polyhedra formed by oxygen atoms, whereas the geometry around the copper atom in the complexes 3 and 4 can be described as square planar and square bipyramidal, respectively. Cu–O bond lengths were calculated within the density functional theory using two different functionals, viz., BP86 and B3LYP, in combinations with Ahlrichs and Pople basis sets to be compared with each other and with experimentally determined values. Compounds 1–4 were tested for their in vitro antimicrobial activity and found active to a variable extent. According to measured minimum inhibitory concentrations (MIC), the title complexes show comparable or higher activity against bacteria and yeast with respect to the free ligand. It was shown that the biological activity is induced by intact complexes and is not resulted from the complex decomposition into copper(II) ions and the free ligand. © 201

Unsymmetrical trifluoromethyl methoxyphenyl β-diketones: Effect of the position of methoxy group and coordination at cu(ii) on biological activity

Copper(II) complexes with 1,1,1-trifluoro-4-(4-methoxyphenyl)butan-2,4-dione (HL1) were synthesized and characterized by elemental analysis, FT-IR spectroscopy, and single crystal X-ray diffraction. The biological properties of HL1 and cis-[Cu(L1)2 (DMSO)] (3) were examined against Gram-positive and Gram-negative bacteria and opportunistic unicellular fungi. The cytotoxicity was estimated towards the HeLa and Vero cell lines. Complex 3 demonstrated antibacterial activity towards S. aureus comparable to that of streptomycin, lower antifungal activity than the ligand HL1 and moderate cytotoxicity. The bioactivity was compared with the activity of compounds of similar structures. The effect of changing the position of the methoxy group at the aromatic ring in the ligand moiety of the complexes on their antimicrobial and cytotoxic activity was explored. We propose that complex 3 has lower bioavailability and reduced bioactivity than expected due to strong intermolecular contacts. In addition, molecular docking studies provided theoretical information on the interactions of tested compounds with ribonucleotide reductase subunit R2, as well as the chaperones Hsp70 and Hsp90, which are important biomolecular targets for antitumor and antimicrobial drug search and design. The obtained results revealed that the complexes displayed enhanced affinity over organic ligands. Taken together, the copper(II) complexes with the trifluoromethyl methoxyphenyl-substituted β-diketones could be considered as promising anticancer agents with antibacterial properties. © 2021, MDPI. All rights reserved