Ruthenium(II/III)-Based Compounds with Encouraging Antiproliferative Activity against Non-small-Cell Lung Cancer

Hereby we present the synthesis of several ruthenium(II) and ruthenium(III) dithiocarbamato complexes. Proceeding from the Na[trans-Ru(III) (dmso)(2) Cl(4) ] (2) and cis-[Ru(II) (dmso)(4) Cl(2) ] (3) precursors, the diamagnetic, mixed-ligand [Ru(II) L(2) (dmso)(2) ] complexes 4 and 5, the paramagnetic, neutral [Ru(III) L(3) ] monomers 6 and 7, the antiferromagnetically coupled ionic alpha-[Ru(III) (2) L(5) ]Cl complexes 8 and 9 as well as the beta-[Ru(III) (2) L(5) ]Cl dinuclear species 10 and 11 (L=dimethyl- (DMDT) and pyrrolidinedithiocarbamate (PDT)) were obtained. All the compounds were fully characterised by elemental analysis as well as (1) H NMR and FTIR spectroscopy. Moreover, for the first time the crystal structures of the dinuclear beta-[Ru(III) (2) (dmdt)(5) ]BF(4) CHCl(3) CH(3) CN and of the novel [Ru(II) L(2) (dmso)(2) ] complexes were also determined and discussed. For both the mono- and dinuclear Ru(II) and Ru(III) complexes the central metal atoms assume a distorted octahedral geometry. Furthermore, in vitro cytotoxicity of the complexes has been evaluated on non-small-cell lung cancer (NSCLC) NCI-H1975 cells. All the mono- and dinuclear Ru(III) dithiocarbamato compounds (i.e., complexes 6-10) show interesting cytotoxic activity, up to one order of magnitude higher with respect to cisplatin. Otherwise, no significant antiproliferative effect for either the precursors 2 and 3 or the Ru(II) complexes 4 and 5 has been observed