Antiproliferative activity of nickel(II), palladium(II) and zinc(II) thiosemicarbazone complexes

Synthesis, cytotoxicities, structural properties and comparison of dihalogeno-substituted-thiosemicarbazone ligands and mixed-ligand Ni(II) complexes

Three novel mixed-ligand Ni(ıı) complexes were synthesized from a 3,5-dihalogenosalicylaldehyde-S-methyl isothiosemicarbazone ligand (3,5-dichloro for Complex I, 3,5-dibromo for Complex II, and 3,5-diiodo for Complex III) and diethanolamine. The synthesized compounds were characterized by elemental analysis, FT-IR, UV-Vis and 1H-NMR spectroscopy. Solid-state structures of Complex I and Complex II were determined by the single-crystal X-ray diffraction technique. Both the complexes were found to have a distorted square planar geometry, with coordination of azomethine nitrogen, phenolate oxygen, terminal amine of the thiosemicarbazone ligand and amine nitrogen of diethanolamine. The cytotoxic effects of the ligands and the complexes were evaluated against two different types of cancer cells (THP-1 human leukaemia monocytic cell line and MDA-MB-231 aggressive breast cancer cell line) and healthy cells (HUVEC human umbilical vein endothelial cell line) by using the MTT method. The findings demonstrated that the chloro-derivatives exhibited better efficacy compared to cisplatin in targeting the monocytic leukemia cell line while displaying reduced toxicity towards healthy cells.

NiII and CoII binary and ternary complexes of 3-formylchromone: spectroscopic characterization, antimicrobial activities, docking and modeling studies

Reactions of 3-formylchromone (L) with Ni(ii) and Co(ii) ions having different anions (acetate, perchlorate, nitrate, and chloride) yielded a series of binary and ternary octahedral complexes with the general formula [ML n L' m X y (S) a ]Z y ·bS, where M = Ni or Co, n = 1-3, L' = auxiliary ligand = 8-hydroxyquinoline or 1,10-phenanthroline, m = 1 or 2, X = acetate or chloride, y = 0 or 2, S = H2O or MeOH, a = 0-2, Z = nitrate or perchlorate and b = 0-1.5. Elemental and thermal analyses and infra-red, electronic, mass, magnetic susceptibility and molar conductivity measurements were successfully utilized to characterize the structures of the chromone complexes. The chromone ligand acts as a neutral bidentate ligand through its formyl and γ-pyrone oxygen atoms. The obtained complexes were formed with molar ratios 1 : 2 and 1 : 3 M : L for the binary and 1 : 2 : 1 and 1 : 1 : 1 M : L : L' for the ternary complexes. The kinetic parameters of the thermal degradation steps were estimated and explained using the Coats-Redfern equations. The synthesized complexes showed antimicrobial activity with higher activity toward Candida albicans and Bacillus subtilis. Docking studies showed good agreement with the antimicrobial activity. Molecular modeling of the synthesized complexes was performed using Hyperchem at the PM3 level and the calculated structures correlate with the experimental data.