Cytotoxicity of arene ruthenium metalla-rectangles incorporating bis-pyridyl diimide linkers

A series of tetranuclear arene ruthenium complexes of the general formula [Ru-4(p-cymene)(4)(mu(2)-L)(2)(mu(4)-OO boolean AND OO)(2)][CF3SO3](4) (L-1 = N,N'-bis(4-pyridylmethyl)-pyromellitic diimide, L-2 = N,N'-bis(4-pyridylmethyl)-naphthalene diimide) were obtained from the corresponding dinuclear arene ruthenium complexes Ru-2(p-cymene)(2)(mu 4-OO boolean AND OO)Cl-2 (OO boolean AND OO = oxalato (oxa), 2,5-dioxido-1,4-benzoquinonato (dobq), 2,5-dihydroxy-3-phenyl-1,4-benzoquinonato (dhpb), 2,5-dichloro-1,4-benzoquinonato (dClbq), 2,5-dioxido-3-undecyl-1,4-benzoquinonato (dubq), 2,5-dihydroxy-3,6-diphenyl-1,4-benzoquinonato (dhdb), 5,8-dioxido-1,4-naphtoquinonato (donq)) by reaction with the bidentate ligands (L-1 and L-2) and silver trifluoromethanesulfonate. The antiproliferative activity of the tetranuclear arene ruthenium metalla-rectangles was evaluated on cancerous (A2780 and A2780cisR) and non-cancerous (HEK293) cell lines, showing in all cases cancer cell selectivity. In general, the metalla-rectangles obtained with L-2 are more potent than those incorporating L-1, and with the exception of [Ru-4(p-cymene)(4)(mu(2)-L-1)(2)(m(4)-dClbq)(2)][CF3SO3](4), they are all more active than cisplatin on the cisplatin resistant A2780cisR cell line. (C) 2016 Elsevier B.V. All rights reserved.