Synthesis, crystal structure, DNA binding and antitumor studies of β-diketonate complexes of divalent copper, zinc and palladium

Synthesis and Structural Characterization of CaO-P2O5-CaF:CuO Glasses with Antitumoral Effect on Skin Cancer Cells

Copper is one of the most used therapeutic metallic elements in biomedicine, ranging from antibacterial approaches to developing new complexes in cancer therapy. In the present investigation, we developed a novel xCuO∙(100 − x) [CaF₂∙3P₂O₅∙CaO] glass system with 0 ≤ x ≤ 16 mol% in order to determine the influence of doping on the composition structure of glasses. The samples were characterized by dissolution tests, pH measurements, Fourier-transform infrared spectroscopy (FT-IR), electron paramagnetic resonance (EPR), Scanning Electron Microscopy with energy dispersive spectroscopy (SEM-EDX) and afterward, their antitumor character was assessed. The glasses were mostly soluble in the aqueous medium, their dissolution rate being directly proportional to the increase in pH and the level of doping up to x = 8 mol%. FT-IR spectra of glass samples show the presence of all structural units characteristic to P₂O₅ in different rates and directly depending on the depolymerization process. SEM-EDX results revealed the presence of an amorphous glass structure composed of P, O, Ca, and Cu elements. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) reduction assay showed strong cytotoxicity for tumoral cells A375 even in low concentrations for Cu-treatment. In contrast, the copper-free matrix (without Cu) determined a proliferative effect of over 70% viability for all concentrations used.

Synthesis, characterization and anti-cancer properties of water-soluble bis(PYE) pro-ligands and derived palladium(ii) complexes

The two cationic palladium(ii) complexes, [Pd(Len)2][OTf]2 (4) and [Pd(Lphen)2][OTf]2 (5), were synthesized by treatment of bis(benzonitrile)dichloropalladium(ii) with [H2Len][OTf]2 (2) or [H2Lphen][OTf]2 (3), respectively, in the presence of a weak base. The pro-ligands 2 and 3 were synthesized by melt reactions between N-methyl-4-chloropyridinium triflate (1) and the amines ethylenediamine or phenylenediamine, respectively. The water-soluble compounds 2-5 were fully characterized, including by single-crystal X-ray crystal structure determinations for 2-4. UV-Vis and fluorescence spectroscopy were used to study the binding interactions of 2-5 with CT-DNA. The spectroscopic data suggested the presence of intercalative and groove binding modes and this was supported by molecular docking studies. The in vitro cytotoxicity studies (IC50 values) showed that the human breast cancer cell lines MCF-7 and T47D were more sensitive towards 3, 4 and 5 than cisplatin. The cytotoxicity of the new compounds decreased in the order 5 > 4 > 3 > 2. Furthermore, the annexin V-FITC staining method strongly suggested the presence of phosphatidylserine (PS) on the outer membrane of the treated cells, which is a hallmark of apoptosis.

SN-Donor Methylthioanilines and Copper(II) Complexes: Synthesis, Spectral Properties, and In Vitro Antimicrobial Activity

Methylthioanilines, a series of sulfur-nitrogen donor ligands substituted with OCH3, CH3, Cl, and Br, and their copper(II) complexes have been synthesized and characterized by 1H and 13C NMR, elemental analysis, FTIR, UV-Vis and EPR spectra, molar conductance, and magnetic susceptibility measurements. The NMR spectra of the ligands revealed that the para/ortho protons and para carbon were sensitive to the electronic effect of substituents. The CHNS analysis presented CuLCl2 (L = OCH3, CH3, Cl) and CuL2Cl2 (L = Br) stoichiometries for the copper complexes. FTIR spectra showed that the bidentate ligands were coordinated to the copper ion through their nitrogen and sulfur atoms. The electronic spectra have suggested square planar and octahedral geometries for these complexes. The EPR spectra demonstrated that the solid state copper(II) complexes possess dx2–y2 orbital ground state and g∥ > g⊥ > 2.0023 in a tetragonal environment. The compounds were evaluated for in vitro antimicrobial activity against S. aureus, B. subtilis, E. coli, and C. albicans. The copper complexes showed higher activity than the parent ligands against S. aureus and B. subtilis; the electron-donating OCH3 and CH3 derivatives were more active than the withdrawing Br- and Cl-substituted compounds.

Nickel(II) bis(isatin thiosemicarbazone) complexes induced apoptosis through mitochondrial signaling pathway and G0/G1 cell cycle arrest in IM-9 cells

Three novel complexes (1, 3 and 4) ligating N-substituted isatin thiosemicarbazone derivatives have been synthesized and their structural and biological characteristics have been compared with those of the known analogs (2, 5-7 and 8). In addition, the structure of the representative ligands (L1, L3 and L4) and complex (4) was confirmed by single crystal X-ray diffraction method. All the complexes (1-8) were assessed for their cytotoxic property against a panel of four human cancer cells such as HepG-2 (liver), MOLM-14 (acute monocytic leukemia), U937 (histiocytic lymphoma). and IM-9 (myeloma). Complex 4 exhibited prominent cytotoxic property against MOLM-14, U937 and IM-9 cell lines. Moreover, the results were compared with the well-known anticancer drugs like doxorubicin, cisplatin and daunorubicin. Besides, complex 4 enhanced the apoptotic cell death in IM-9 cell line and induced cell cycle arrest at G1 phase. Western blot analysis revealed the down-regulation of Bcl-2 (b-cell lymphoma-2), up-regulation of Bax (bcl-2 associated X protein), release of cytochrome c and activation of caspases-3 in IM-9 cells by complex 4. Importantly, complex 4 was not toxic to the normal Vero cell line (IC₅₀ > 300 μM). In addition, complex 4 showed the concentration dependent cleavage of supercoiled (SC) DNA to its nicked circular (NC) form.