New
platinum(II) complexes [PtCl(O,O'-acac)(L)] (1) and [Pt(O,O'-acac)(γ-acac)(L)] (2) (L =
DMSO, a; DMS, b) containing a single chelated (O,O'-acac) (1), or one chelated and one σ-bonded (γ-acac)
acetylacetonate (2) have been synthesized. The new Pt(II) complexes exhibited high in vitro cytotoxicity on
cisplatin sensitive and resistant cell lines and showed negligible reactivity with nucleobases (Guo and 5'-GMP) but selective substitution of
DMSO/DMS with soft
biological nucleophiles, such as
L-methionine. In order to assess the ability of the new complexes with respect to
cisplatin to induce apoptosis by interaction with nongenomic targets, the Ames' test, a standard reverse mutation assay, was carried out on two Salmonella typhimurium strains (TA98 and TA100). Interestingly, the new complexes did not show the well-known mutagenic activity exhibited by
cisplatin and are, therefore, able to activate apoptotic pathways without interacting with
DNA.