Synthesis and comparative evaluation of the cytotoxic activity of cationic organometallic complexes of the type [Pt(η1-CH2-CH2-OR)(DMSO)(phen)]+ (R = Me, Et, Pr, Bu)

The new series of [Pt(η1-CH2-CH2-OR)(DMSO)(phen)]Cl {R = Me (1b), Et (2b), Pr (3b), Bu (4b), phen = 1,10-phenanthroline} complexes was synthesized starting from the corresponding [PtCl(η1-CH2-CH2-OR)(phen)] {R = Me (1a), Et (2a), Pr (3a), Bu (4a)} precursors. In the series only complex 1b was previously studied for its potential antitumor activity. In this work, the relative cytotoxicity of 1b-4b and cisplatin complexes was studied on HeLa, Hep-G2, SH-SY5Y and SK-OV-3 cancer cells. In this way, the effect of R alkyl chain length in modulating cytotoxicity was evidenced. Complex 2b with the Et moiety resulted to be generally more cytotoxic in the tested series of complexes for used cell lines and in particular for the Hep-G2 hepatocarcinoma cells. This approach opens new perspectives for the structural optimization and development of new antitumor drugs.