Ru(ii)–thyminate complexes: new metallodrug candidates against tumor cells

Abstract

Herein, we used thymine (HThy) as a ligand to form two new ruthenium(II) complexes with formula [Ru(PPh₃)₂(Thy)(bipy)]PF₆ (1) and [Ru(Thy)(bipy)(dppb)]PF₆ (2). The complexes were characterized by spectroscopic, spectrometric and X-ray crystallography analyses. Complexes 1 and 2 can interact with ctDNA presenting binding constants, K_b, of 0.4 and 1.2 × 10³ M⁻¹, respectively. Their cytotoxic activities towards tumor cell lines (B16-F10, HepG2, K562 and HL-60) and non-tumor cells (PBMCs) were evaluated using the Alamar blue assay. Complex 1 exhibits high cytotoxicity against tumor cells, showing IC₅₀ values of 0.01 and 1.81 μM against the HL-60 and HepG2 cell lines, respectively. Therefore, compound 1 can be considered as a promising antitumor metallodrug.