Targeting G-quadruplex structures with Zn(II) terpyridine derivatives: a SAR study.

Area of Science:

• Coordination Chemistry
• Medicinal Chemistry
• Biophysical Chemistry

Background:

• Terpyridine ligands are known to interact with G-quadruplex DNA (G4) structures.
• Zinc (Zn) is an essential metal ion with significant biological roles.
• G4 structures are implicated in various cellular processes and diseases.

Purpose of the Study:

• To synthesize and characterize novel zinc-terpyridine complexes.
• To investigate the interaction of these complexes with G4 DNA.
• To evaluate their cytotoxicity and biological potential.

Main Methods:

• Synthesis and characterization of six Zn(II) complexes with functionalized terpyridine ligands.
• G4 DNA binding and stabilization studies (thermal denaturation).
• Cytotoxicity assays and cellular uptake studies (ICP-MS).

Main Results:

• Complexes with chloride leaving groups were more cytotoxic than nitrate analogues.
• Zn complexes with methylated imidazolylphenyl substituents (3Cl and 3(L)2) showed greatest G4 stabilization.
• Complexes 3Cl and 3(L)2 were internalized by SW480 cells and localized in the nucleolus.
• Complex 3Cl exhibited high cytotoxicity, G4 selectivity, and G4 affinity.

Conclusions:

• The leaving group and terpyridine ligand structure significantly influence cytotoxicity and G4 interaction.
• Complex 3Cl demonstrates promising biological activity and G4 targeting capabilities.
• Further investigation of 3Cl is warranted for its potential therapeutic applications.