Synthesis, characterization and anticancer activity of two Ru(II) polypyridyl complexes [Ru(dpq)2L](PF6)2 (L = maip, paip)

Abstract

Two new Ru(II) polypyridyl complexes, [Ru(dpq)2(maip)](PF6)2 (1) and [Ru(dpq)2(paip)](PF6)2 (2) (dpq = dipyrido [3,2-d:2′,3′-f]quinoxaline; maip = 2-(3-aminophenyl)imidazo[4,5-f][1,10]phenanthroline; paip = 2-(4-aminophenyl)imidazo[4,5-f][1,10]phenanthroline), were synthesized and characterized to investigate their antitumor activity. MTT assay showed that both complexes exhibit moderate antitumor activity against HeLa, A549, HepG2, MCF-7, and CNE-2 cell lines, but have lower cytotoxicity compared to cisplatin. Complex 1 exhibits higher toxicity than complex 2. Mechanism studies indicate that the two Ru(II) complexes were present in the cytoplasm after 10 h of incubation with HeLa cells and were selectively localized in the mitochondria. Additionally, the two complexes arrested the cell cycle in the G0/G1 phase, which suggests that both complexes can induce cancer cell death through reactive oxygen species (ROS)-dependent pathways.