Novel dinuclear arene ruthenium(II) complexes: synthesis, structure, anticancer activity and interaction with DNA

Abstract

Two new dinuclear Ru(II) arene M2L2 metallocycle complexes [Ru2(η 6-p-cymene)2(m-bitmb)2Cl2](SbF6)2 (1) and [Ru2(η 6-p-cymene)2(m-bitmb)2Cl2](CF3COO)2 (2) (m-bitmb=1,3-bis(imidazol-1-ymethyl)-2,4,6-trimethylbenzene) were synthesized and characterized by single crystal X-ray diffraction, 1 H NMR, ESI-MS and elemental analysis. Results revealed that complex 1 and 2 are M2L2 dinuclear Ru-arene complexes with unique "chair-like" conformation. Both of complexes 1 and 2 had certain anti-cancer activity, and complex 2 performed good cytotoxic effect on HeLa cells. The results of circular dichroism and agarose gel electrophoresis experiments indicated that complexes 1 and 2 could change the conformation of CT-DNA and PRB322 DNA. Moreover, compared with 1, 2 presented much stronger interaction with DNA, which was in accordance with their anti-cancer activities.