Synthesis of Polyamines from Ethylenediamine and Their Platinum(II) Complexes, Potential Antitumor Agents

Abstract

AbstractThis work describes the synthesis and characterization of five new amine ligands and also the preparation and characterization of their respective platinum(II) complexes by reaction with K2PtCl4 in water. These ligands were obtained by treatment of different halides or epoxides with ethylenediamine. Cytotoxic activity and cellular accumulation of three complexes were investigated in a human small‐cell lung carcinoma cell line and its cisplatin resistant subline. The introduction of a spacer (cycle) between the two platinum atoms leads to a significant decrease in cytotoxic activity. At equitoxic doses, the intracellular platinum concentrations found for compounds 12 and 15 were significantly higher than those found for the reference compounds, cisplatin, carboplatin, or compound 9. This fact suggests that the formation of adducts between compounds 12 and 15 and the putative pharmacological target, DNA, is less favored. If these compounds bind more slowly to DNA, interaction with other intracellular ligands such as sulfur‐containing molecules will become relevant and it may be the reason for the elevated intracellular platinum concentrations. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)