Effect of Cu+/2+ ions on the biological activity of their bis‐oxalyldihydrazone complexes: ctDNA interaction, antimicrobial and anticancer action

Abstract

Two bimetallic homoleptic complexes (CuL1 and CuL2) were synthesized from the coordination of Cu+/2+ ions with diisatin oxalyldihydrazone ligand (H2Lx), respectively. Confirmation of their chemical structures was based on the investigation of alternative spectroscopic tools. To distinguish the role of Cu+/2+ ion and its various charges on their complexes' reactivity, the bioreactivity of H2Lx, CuL1, and CuL2 was established on the spectral results against the growth of some microbial series (fungi and bacteria) and against three human cancer/normal cells. Furthermore, their behavior towards calf thymus DNA (ctDNA) was evaluated through viscometric and spectrophotometric titration. Both CuL1 and CuL2 complexes exhibited an amazing inhibiting effect against the growth of the titled microbial series and the human cancer cells, corresponded to the inhibited zone (mm), MIC (μM), and IC50 magnitudes (μM) and compared with those of their uncoordinated H2Lx ligand. CuL1 demonstrated a featured interacted behavior against ctDNA over that of CuL2 depending on the obtained intrinsic binding constants and the derived Gibbs' free energy values. The assigned nature of interaction could be built on the covalent and/or noncovalent modes, which supported by the electronegativity and electrophilicity of the titled studied compounds towards ctDNA.