New Cu(I) square grid-type and Ni(II) triangle-type complexes: synthesis and characterization of effective binders of DNA and serum albumins

Multivalent molecules are a potential group of bioactive compounds endowed with high affinity and specificity in innovative biomolecule-targeting therapeutic approaches. Herein, we report on a new and versatile N,N,N,N-donor ligand L (1R,4R)-N1,N4-bis(quinolin-2-ylmethylene)cyclohexane-1,4-diamine with two coordinating quinoline moieties connected with trans-1,4-diaminocyclohexane. It coordinates Cu+ forming a [2 x 2] square grid-type complex C1 [Cu4L4](4+) and Ni2+ giving a triangle-type complex C2 [Ni3L3](6+). We screened their potential as versatile metal-based Serum Albumin (SA), double helical and G-quadruplex DNA binders taking advantage of their shape, size and stability effects using different spectroscopic experiments (UV-Vis, fluorescence, circular dichroism). The findings of our work suggest the potential utility of the metal complexes herein described in the context of the new drug discovery.

Automated summary

This study reports on a new versatile ligand and its complexes with Cu+ and Ni2+. The metal complexes have potential utility as versatile metal-based protein and DNA binders in the field of new drug discovery.