New Ruthenium (III) complexes with antitumor activity: design, synthesis and characterization

Valletta E;Trudu F;ISAIA, FRANCESCO;TUVERI, ROSSANA;Melis R;PANI, ALESSANDRA;PIVETTA, TIZIANA

2013-01-01

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Abstract

Cisplatin was introduced in 1978 in clinical practice for the cancer treatment. In spite of the highly successful use of this drug, it shows several side effects and drug resistance. To overcome these limits, many other platinum-containing drugs have been synthesised [1]. However, recently, the research of metal-based anticancer drugs has focused on other transition metal ions, as copper, ruthenium and gold. Some ruthenium compounds cause less side effects with respect to the platinum drug and are selective for cancer cells [2], on this basis, ruthenium complexes might replace the cisplatin as anticancer drug. With the purpose to design and prepare new ruthenium (III) compounds with cytotoxic activities, we prepared new complexes containing 1,10-phenanthroline derivatives and N,N’-substituted-imidazolidine-2-thione as auxiliary ligands (Fig.1). The nitrogen and thionic ligands were chosen because analogous complexes with Cu(II) show a high cytotoxic activity against mouse neuroblastoma and human tumor cell lines [3, 4, 5].The complex formation constants of the synthesised Ru(III) complexes were determined by spectrophotometric and potentiometric titrations in water solution at 25 °C and 37 °C in 0.1 M NaCl as ionic strength. The antiproliferative activity of complexes and ligands was tested in normal (skin fibroblasts, CRL-7065) and cancer derived (prostate carcinoma, DU-145; hepatocellular carcinoma, HEP-G2; squamous cell lung carcinoma, SK-MES-1;acute T-lymphoblastic leukaemia, CCRF-CEM; acute B-lymphoblastic leukaemia, CCRF-SB) human cells. In this work the preliminary results about synthesis, solution equilibria and cytotoxic activities are presented.