Anticancer activity: synthesis, characterization and DNA binding of a 1,2,4-triazole-based Zn(ii) complex

Abstract

A new zinc(II) complex, [Zn(L)₂Cl₂], with a 1,2,4-triazole-based ligand (L) was synthesized, and its origin was validated. The ligand and complex were formulated using priming to explore their DNA binding and anticancer activity. Moreover, they were characterised via single-crystal X-ray analysis. The complex crystallized in the triclinic space group P and revealed a tetrahedral structure with 1 : 2 stoichiometry. Thermogravimetric analysis (TGA) conducted in a nitrogen environment at temperatures ranging from 25 °C to 500 °C revealed that the compound remained thermally stable up to almost 250 °C. DNA binding studies of the synthesised complex and its ligand with CT-DNA were conducted using fluorescence and UV-Vis spectroscopic techniques. The complex and ligand were bound to CT-DNA through intercalation, and their intrinsic binding constants (K_b) were 2.89 × 10³ and 1.05 × 10⁴ M⁻¹ and Stern–Volmer binding constants (K_SV) were 1.55 × 10² and 4.90 × 10³ M⁻¹, respectively. Additionally, the bio-efficacy of the ligand and its complex was examined in vitro against cancer cell lines—HeLa, MCF-7 and African green monkey kidney cells (Vero)—to assess their cytotoxicity.