Designed Synthesis of Amino-Azo-Quinoline and Their Nickel(II) Complexes: Molecular Structure, Electrochemistry and an Insight Into Their In Vitro Anti-Cancer Activities

Amino-quinolines are potential candidates that may provide some insight into the current chemotherapeutic research due to their demonstrated anti-cancer activity. This led us to synthesize and explore a new amino-azo-quinoline ligand H2L 1 and its square planar nickel(II) complexes [Ni(HL) (OAc)], 2 and [Ni(HL)Cl], 3 and the structures were determined by Single Crystal X-Ray Diffraction. Theoretical investigation of redox orbitals of the complexes discloses that the reduction process is due to ligand reduction whereas both metal and ligand are contributing towards oxidation. The anti-cancer properties of the ligand and one of the nickel(II) complexes have been assessed by 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide assay, cell migration along with the generation of reactive oxygen species using human epithelial cancer cell line cells. The ligand 1 and complex 3 have been found to show effective anti-cancer activity and for the latter, it is more promising. This may be ascribed to the rigid and robust nature of square planar complex 3, which supports stronger binding with DNA than that of free ligands, possibly due to the flexible nature of the latter. This result has also been validated by molecular docking using nine conformers of the ligand and complex 3 via interaction with B-DNA (PDB ID: 1BNA) where the binding affinity with the complex has been found to be stronger.

Synthesis, characterization, solution chemistry and anticancer activity of [NiCl2(Ph2P-N(R)-PPh2)] (R = 2-CH2Py, CH2Ph and p-tol) complexes

In this work three Ni²⁺ complexes with general formula [NiCl₂(Ph₂P-N(R)-PPh₂)], R = 2-CH₂Py (Py = pyridine) - 1, CH₂Ph (Ph = phenyl) - 2 and p-tol (p-tol = p-tolyl) - 3, were synthesized and characterized. These complexes were obtained in high yield by the reaction of NiCl₂.6H₂O and the corresponding diphenylphosphinoamine ligand (Ph₂P-N(R)-PPh₂) in CH₂Cl₂/MeOH (1:1) solution, at room temperature (∼25 °C), and characterized by ¹H and ³¹P {¹H} NMR, vibrational spectroscopy in the infrared region, electronic spectroscopy in the UV-Vis regions, elemental analysis (%C, %H, %N) and single-crystal X-ray diffraction. The solution chemistry was studied in CDCl₃/dmso-d⁶ (dimethylsulfoxide) or neat dmso-d⁶ using complex 2 as a model. The complexes were evaluated as cytotoxic agents against two cancer cells lines, A549 (lung cancer cells), B16F10 (melanoma cells) and the health cells HaCaT (human epithelial keratinocytes).

Gold(III) Complexes: An Overview on Their Kinetics, Interactions With DNA/BSA, Cytotoxic Activity, and Computational Calculations

In the last few years, metallodrugs play a key role in the development of medicinal chemistry. The choice of metal ion, its oxidation state and stability, and the choice of inert and labile ligands are just some of the very important facts which must be considered before starting the synthesis of complexes with utilization in medicinal purpose. As a result, a lot of compounds of different transition metal ions found application for diagnostic and therapeutic purpose. Beside all, gold compounds have attracted particular attention. It is well-known that gold compounds could be used for the treatment of cancer, HIV, rheumatoid arthritis (chrysotherapy), and other diseases. This metal ion has unoccupied d-sublevels and possibility to form compounds with different oxidation states, from -1 to +5. However, gold(I) and gold(III) complexes are dominant in chemistry and medicine. Especially, gold(III) complexes are of great interest due to their structural similarity with cisplatin. Accordingly, this review summarizes the chemistry of some mononuclear and polynuclear gold(III) complexes. Special attention is given to gold(III) complexes with nitrogen-donor inert ligands (aliphatic or aromatic that have a possibility to stabilize complex) and their kinetic behavior toward different biologically relevant nucleophiles, mechanism of interaction with DNA/bovine serum albumin (BSA), cytotoxic activity, as well as computational calculations.