Fluorophore tagged mixed ligand copper(II) complexes: synthesis, structural characterization, protein binding, DNA cleavage and anticancer activity

Two fluorophore tagged copper(II) complexes Cu(phen)(L)(ClO4)(2)] (1) and Cu(bpy)(L)(H2O)(ClO4)](ClO4) (2), (where L=2-amino-1H-benzode]isoquinoline-1,3-(2H)dione (L), phen=1,10-phenanthroline and bpy=2,2 `-bipyridine) have been synthesized and structurally characterized. Structures of the copper complexes 1 and 2 were confirmed by single-crystal X-ray structure determination. The coordination geometry around the copper center of complexes 1 and 2 is distorted octahedral. The plasmid DNA cleavage activity of the complexes has been investigated by agarose gel electrophoresis and the study reveals that both the complexes have high plasmid DNA photo-cleavage activity. The binding interaction ability of the metal complexes with bovine serum albumin (BSA) was investigated using fluorescence spectroscopy. The cytotoxicity of the complexes has been evaluated by MTT (3-4,5-dimethylthiazole-2-yl]-2,5-diphenyltetrazolium bromide) assay against A549 (adenocarcinoma human alveolar basal epithelial cells) and MCF-7 (breast cancer cell line) cell lines in comparison with cis-platin. Complexes 1 and 2 have exhibited better cytotoxic activity than cis-platin against A549 and MCF-7 cell lines. The cellular uptake study and localization of the complexes within the cells have been investigated by fluorescence microscopy. The cell staining and flow cytometry experiments suggest that complexes induce an apoptotic mode of cell death

Syntheses, structural characterization and evaluation of the anti-tubercular activity of copper (II) complexes containing 3-methoxysalicylaldehyde-4-methylthiosemicarbazone

In the present work three novel copper (II) complexes (CuL(CH3COO)] (1), CuL(phen)] (2) and CuL(bpy)] (3) (where phen=1,10-phenanthroline; bpy=2,2' bipyridyl)) containing 3-methoxysalicylaldehyde-4-methylthiosemicarbazone (HL) were synthesised and characterised. All the complexes were characterized using spectral techniques like FT-IR, ESI-MS, TGA-DTA, UV-Vis, ESR and VSM. The structure of complex 2 was confirmed by single-crystal X-ray structure determination. Complex 2 crystallized in a monoclinic crystal system and P 2(1)/n space group with a distorted square pyramidal geometry. In vitro anti-TB and cytotoxicity studies were also carried out using MABA (Microplate Alamar Blue Assay) and MIT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide) assay, respectively. All the copper (II) complexes have shown excellent anti-TB properties in the nano-molar concentration range and exhibit low cytotoxicity. (C) 2022 Elsevier B.V. All rights reserved