Antioxidant, DNA binding and nuclease activities of heteroleptic copper(II) complexes derived from 2-((2-(piperazin-1-yl)ethylimino)methyl)-4-substituted phenols and diimines

Thiosemicarbazone N-Heterocyclic Cu(II) complexes inducing nuclei DNA and mitochondria damage in hepatocellular carcinoma cells

The α-N-Heterocyclic thiosemicarbazones and their metal complexes have been widely investigated as anticancer and antibacterial agents for their broad spectrum of pharmacological properties. Thus, two thiosemicarbazone-based Cu(II) complexes, [Cu₂(ptpc)I₂] (1) and [Cu(qtpc)I] (2) with thiosemicarbazone ligand (ptpc = 2-(di(pyridin-2-yl)methylene)-N-(2-(trifluoromethyl)phenyl)-hydrazine-1-carbothioamide, qtpc = 2-(quinolin-8-ylmethylene)-N-(2-(trifluoromethyl)phenyl)hydrazine-1-carbothioamide) were synthesized and evaluated for their biological activities. Complexes 1 and 2 are superior to cisplatin in vitro antiproliferative activities toward hepatocellular carcinoma cell line with the half maximal inhibitory concentration value of 0.2 and 2 μM, respectively. A series of spectroscopic assays and the DNA cleavage experiments showed that both complexes can change and distort the conformation of DNA. Molecular docking experiment further demonstrated that complex 1 binds to DNA mainly in groove mode. Meanwhile, benefiting from their good liposolubility, complexes 1 and 2 could easily enter cells, which further triggers cell cycle arrest and apoptosis. Moreover, complexes 1 and 2 caused serious mitochondrial damage, associating with increased the level of reactive oxygen species (ROS) and Ca²⁺, decreased adenosine triphosphate (ATP) content and mitochondrial membrane potential (Δψ_m), and transformed mitochondrial morphology. These findings indicated that complexes 1 and 2 might exert their anticancer activity by inducing DNA and mitochondrial damage simultaneously.

Augmentation of photophysical features and Judd-Ofelt analysis of extensively green glowing terbium (III) complexes with nitrogen donor ancillary ligands

Six green glowing terbium (III) complexes were fabricated via grinding method utilizing a prime organic ligand (L) and nitrogen donor ancillary ligands. Characterization of synthesized complexes was accomplished through various spectroscopic techniques. The significant thermal stability was determined by thermogravimetric analysis while the energy bandgap and Urbach energy were investigated through diffused reflectance spectra of these complexes. The peak observed at 548 nm in emission spectra is responsible for the virescent color of these complexes. Color purity, decay time, quantum yield, and emission intensities of ternary complexes were significantly improved as compared to binary ones due to the synergistic effect of ancillary ligands. Judd-Ofelt parameters were determined by the NIR absorption spectrum, which claims the asymmetric environment around the terbium (III) ion. CCT values advocate the applicability of these complexes in green light-emitting materials as a cool light source. The biological assignments reveal the significance of these complexes as potent antioxidants and antimicrobial agents. The energy transfer process highlights the enhancement of luminescence in these complexes via the synergic effect of ligands. Our investigation portrays that these complexes can be employed in laser technology, display devices, semiconductors, biological fields, and optoelectronic devices.

Novel water-soluble Cu(ii) complexes based on acylhydrazone porphyrin ligands for DNA binding and in vitro anticancer activity as potential therapeutic targeting candidates

Three novel water-soluble Cu(ii) complexes featuring miscellaneous acylhydrazone tricationic porphyrin ligands (named Cu-Por1, Cu-Por2 and Cu-Por3) were successfully prepared and isolated.

Heteroleptic metal(II) complexes of hydrotris(methimazolyl)borate and diimines: Synthesis, theoretical calculations, antimicrobial, antioxidant, in vitro cytotoxicity and molecular docking studies

A series of heteroleptic metal(II) complexes of formulation [M(Tm)(diimine)](ClO₄) (1-8), [Tm = hydrotris(methimazolyl)borate, diimine = 2,2'-bipyridyl or 1,10-phenanthroline and M = Mn(II), Ni(II), Cu(II) or Zn(II)] have been synthesized and characterized by spectroscopic methods. The geometric parameters of the complexes were determined using UV-Vis spectroscopy and DFT calculations. The analyses of HOMO and LUMO have been used to explain the charge transfer within the molecule. Antimicrobial activity of the synthesized heteroleptic complexes were evaluated against two Gram (-ve) (Escherichia coli and Klebsiella pneumoniae) and two Gram (+ve) (Bacillus cereus and Staphylococcus aureus) bacterial, and three fungal (Candida albicans, Candida glabrata and Candida krusei) strains with respect to the standard drugs erythromycin and amphotericin-B. The copper(II) complex 6 showed better scavenging activity against DPPH when compared to other complexes. The cytotoxic activity of copper(II) complexes 5 and 6 against MCF-7 cell line was assessed by MTT assay, which showed exponential responses toward increasing concentration of complexes. In the molecular docking studies, the complexes showed π-π, σ-π, hydrogen bonding, van der Waals and electrostatic interactions with FGFR kinase receptor.

Ni(ii) and Co(ii) complexes of an asymmetrical aroylhydrazone: synthesis, molecular structures, DNA binding, protein interaction, radical scavenging and cytotoxic activity

The DNA/BSA binding, antioxidant and cytotoxic activity of Ni(ii) and Co(ii) complexes bearing aroylhydrazone were investigated to induce apoptosis in cancer cells.

Synthesis and crystal structure of new monometallic Ni(ii) and Co(ii) complexes with an asymmetrical aroylhydrazone: effects of the complexes on DNA/protein binding property, molecular docking, and in vitro anticancer activity

Cytotoxic nickel and cobalt complexes containing asymmetrical aroylhydrazone were synthesized and their interactions with HS–DNA and BSA protein were investigated, which was supported by molecular docking studies.

Oxidative DNA cleavage by Cu(II) complexes: Effect of periphery substituent groups

A series of structurally-related [Cu(R-benzyl-dipicolylamine)(NO3)2] complexes, where R=methoxy- (1), methyl- (2), H- (3), fluoro- (4), and nitro-group (5), were synthesized, and their activity on DNA cleavage was investigated by linear dichroism (LD) and electrophoresis. The addition of a benzyl group to the dipicolylamine ligand of the [Cu(dipicolylamine)(NO3)2] complex (A), i.e., the [Cu(benzyl-dipicolylamine)(NO3)2] complex (3), caused significant enhancement in the efficiency of oxidative cleavage of both super-coiled (sc) and double stranded (ds) DNA, as evidenced by the electrophoresis pattern and faster decrease in the LD intensity at 260nm. The efficiency in DNA cleavage was also altered with further modifications of the benzyl group by the introduction of various substituents at the para-position. The cleavage efficiency appeared to be the largest when the methyl group was attached. The order of efficiency in DNA cleavage was methyl>methoxy≈H>fluoro≈nitro group. When an electron-withdrawing group was introduced, the cleavage efficiency decreased remarkably. The reactive oxygen species involved in the cleavage process were the superoxide radical and singlet oxygen. A possible mechanism for this variation in the DNA cleavage efficiency was proposed.