Evaluation of trimetallic Ru(II)- and Os(II)-Arene complexes as potential anticancer agents
Journal of Organometallic Chemistry
Department of Chemistry, University of Cape Town, Rondebosch, Cape Town, South Africa; Department of Biotechnology, University of the Western Cape, Bellville, Cape Town, South Africa
Schiff-base ligands, tris-2-(salicylaldimine ethyl)amine and tris-2-(2-pyridylimine ethyl)amine (1 and 2) were prepared and complexed to Ru(II) and Os(II) entities to form new trimetallic complexes (3-10). The complexes are air- and moisture-stable and have been characterized fully using elemental analysis, FT-IR and NMR spectroscopy as well as HR-ESI-TOF-MS spectrometry. Related mononuclear analogues (11-14) were also prepared via the Schiff-base condensation reaction of propyl amine and the appropriate aldehyde to form propysalicylaldimine and propyl-2-pyridylimine ligands. Upon complexation with the respective metal dimers, ([OsCl2(p-cym)]2 and [OsBr2(p-cym)]2) complexes (11-14) formed and were characterized by elemental analysis, NMR, FT-IR spectroscopy and mass spectrometry. The cytotoxicity of the trimetallic complexes (3-10) and their mononuclear analogues were established against human osteosarcoma (MG63), human ovarian (A2780cisR; cisplatin-resistant) cancer cells and model human non-cancerous cells (KMST6, fibroblast). All the complexes exhibited moderate to high anti-cancer activities and the most potent complexes were further evaluated for their ability to inhibit DNA topoisomerase I (Topo I) - an enzyme key to cellular genetic processes, such as DNA replication and transcription. © 2014 Elsevier Ltd. All rights reserved.
Iodine; Arene complexes; Cancer; Potential anticancer agents; Topoisomerases; Trimetallic; Cytotoxicity