Synthesis and biological evaluation of novel tetranuclear cyclopalladated complex bearing thiosemicarbazone scaffold ligand: Interactions with double‐strand DNA, coronavirus, and molecular modeling studies

Abstract

Threading intercalators are a novel class of materials that carry two substituents along the diagonal positions of an aromatic ring. When bound to DNA, these substituents project out in DNA grooves. Tetranuclear complexes appear to be promising threading intercalators for developing therapeutics against cancer and viral infections that require high nucleic acid binding affinity. The objective of this work was to prepare the thiosemicarbazone scaffold ligand [4-ClC 6 H 4 CHN=NC(S)NHPh] and tetranuclear cyclopalladated complex [Pd(4-ClC 6 H 4 CHN=NC(S)NHPh) 4 ] and to characterize the compounds by elemental analysis, 1D and 2D NMR, HRMS, and IR spectroscopy. The calf thymus DNA (CT-DNA) binding properties of the compounds were investigated in vitro under simulated physiological conditions using UV-vis spectroscopy, emission spectral titration, methylene blue competitive binding, circular dichroism, DNA thermal denaturation, DNA binding, and coronavirus interactions using molecular simulation.The compounds showed cytotoxic effect against both human breast (MCF-7) and colorectal (HCT116) cancer cells in a dose-dependent manner. We demonstrated that the compounds are promising for DNA threading intercalation binders with large DNA binding constants on the order of 10 7 M À1 magnitude.

Influence of the Reaction Conditions in the Crystal Structures of Zn(II) and Ni(II) Coordination Compounds with a Dissymmetric Bis(Thiosemicarbazone) Ligand

“…This, together with the control of protonation/deprotonation and the nature of auxiliary anions, lead to the formation of different structures such as monomers [10][11][12], dimers [13][14][15] or coordination polymers [16][17][18]. In addition to their fascinating structural properties, TSCs have a wide range of applications in different fields as catalysis [19][20][21], metal detoxification [22][23][24], metal sensing [25][26][27] or medicine [28][29][30][31].…”