Ru(III)-based compounds with sulfur donor ligands: synthesis, characterization, electrochemical behaviour and anticancer activity

In recent years, Ru(III) complexes have emerged as a new class of effective anticancer agents against tumors that proved to be resistant to all other chemotherapeutic drugs currently in clinical use. To extend our previous studies on metal complexes containing sulfur-donor ligands, we report here on the synthesis and characterization, by means of several spectroscopic and analytical techniques, some [Ru(RSDT)3] and [Ru2(RSDT)5]Cl complexes with dithiocarbamato ligands derived from methyl/ethyl/tert-butyl esters of sarcosine. Their electrochemical behaviour was also studied by cyclic voltammetry. All the complexes were tested for their cytotoxicity on a panel of human tumor cell lines showing highly significant antitumor activity. The chemical and biological properties of the newly synthesized complexes, were compared with those of [Ru(DMDT)3] and [Ru2(DMDT)5]Cl species (DMDT = N,N-dimethyldithiocarbamate) whose chemical (not biological) characterization has been already reported in literature.