Synthesis, characterization and anticancer properties of (salicylaldiminato)platinum(II) complexes

Twelve new (salicylaldiminato)platinum(II) complexes have been prepared, characterized and examined for their in vitro cytotoxic properties against three human glioma cell lines LN18, LN405 and Hs683. Initial biotesting was done on platinum complexes 1–6, which display a wide range of physicochemical properties. Whereas introduction of aromatic rings in the complexes did not seem to have a significant impact on bioactivities, the length of the aliphatic group positively correlated with cytotoxicity in all cell lines. Complexes 2 and 3 were found to be particularly potent against LN18 cells as demonstrated by stronger cell growth inhibition when compared to cisplatin. These initial findings led us to develop an additional series of mono (salicylaldiminato)platinum(II) complexes 7–12, which were subjected to additional cytotoxicity studies but were less cytotoxic compared to the bis Schiff base complexes. These organometallic compounds could serve as interesting starting points for the development of novel therapeutic strategies to treat brain tumors.