Synthesis, characterization and cytotoxicity evaluation of new biimidazole palladium(II) complexes with thioureas

Abstract

The reactions between [PdCl2(tmbiimH2)]·H2O (1) {tmbiimH2 = 2,2’-bis(4,5-dimethylimidazole)} and thiourea (tu), N-methylthiourea (mtu), N-phenylthiourea (ptu), N,N’-dimethylthiourea (dmtu) or N,N’-diphenylthiourea (dptu) in the 1:2 molar ratio resulted in the compounds [PdL2(tmbiimH2)]Cl2·nH2O {L = tu (2), mtu (3), ptu (4), dmtu (5) and dptu (6)}, which were characterized by elemental analyses, infrared (IR), and 1H NMR spectroscopies and conductivity measurements. The IR spectra of 1–6 were consistent with the presence of chelating tmbimH2 ligand. All compounds and cisplatin were tested in vitro by MTT assay for their cytotoxicity against three murine cancer cell lines: mammary adenocarcinoma (LM3), lung adenocarcinoma (LP07) and mouse fibroblast (L929) cells. Relating the series of compounds to their biological activities we found compound 6 as the most promising of them.