Divalent Organo-Bimetallic Chelates of Poly-Dentate O,N,O-dihydrazone Ligand as Effective Agents for Antitumor and Antimicrobial Assays, Interacting Modes With DNA

Abstract

Substituted hydrazones and dihydrazones, as polydenatate ligand, reported high coordination chemical behavior towards numerous transition metals of different oxidation states for alternated applicable interest. Therefore, with a facile condensed reaction of the salicylaldehyde with tartric dihydrazide, a chelated tartrato-dihydrazone ligand (H₂Ltz) was formed. The coordinated features of H₂Ltz versus two divalent metal ions of Cu (II) and Ni (II) ions were assumed to form two new bimetallic-organic framework complexes, assigning triagonal bipyramidal and tetrahedral geometries (CuLtz and NiLtz, respectively). Their structural elucidating was determined within the analytical tools spectroscopically. The effectiveness of the growth inhibition for H₂Ltz, CuLtz, and NiLtz against six named bacterial and fungal series, and three human cancer cell lines were examined discovering the reactive role of two central M (II) ions in CuLtz and NiLtz, respectively. The binding character of H₂Ltz, CuLtz, and NiLtz, with calf thymus DNA, that is, DNA, was estimated based on the variation in viscometric/spectrophotometric features. The two bimetallic-chelates represented more distinguished inhibitive attitudes than the regarded one of H₂Ltz assigning to the inhibitive zones (mm) and the half-inhibited concentration (IC₅₀, μM) of growth inhibition of the studied microbes and human tumor cells, respectively. The examination of the binding action of H₂Ltz, CuLtz, and CuLtz with DNA was approved according to the enhanced viscosity and the electronic spectral changes. Also, binding constants (14.09, 15.09, and 16.12 $\times$ 10⁷ mol⁻¹ dm³), Gibb's free energy (−42.06, −45.23, and −46.41 kJ mol⁻¹), and the chromism (mainly hypo modes) are assigned to estimate the binding modes. Rewardingly, the bimetallic-chelates MLtz displayed modified binding action more than that of H₂Ltz against DNA regarding their hydrophobicity/lipophilicity.