Synthesis and anticancer activity evaluation of η5-C5(CH3)4R ruthenium complexes bearing chelating diphosphine ligands

Abstract

The complexes [RuCp*(PP)Cl] (Cp* = C₅Me₅; [1], PP = dppm; [4], PP = Xantphos), [RuCp^#(PP)Cl] (Cp^# = C₅Me₄(CH₂)₅OH; [2], PP = dppm; [5], PP = Xantphos) and [RuCp*(dppm)(CH₃CN)][SbF₆] [3] were synthesized and evaluated in vitro as anticancer agents. Compounds 1–3 gave nanomolar IC₅₀ values against normoxic A2780 and HT-29 cell lines, and were also tested against hypoxic HT-29 cells, maintaining their high activity. Complex 3 yielded an IC₅₀ value of 0.55 ± 0.03 μM under a 0.1% O₂ concentration.