Synthesis, spectroscopic characterization, X-ray structure, and in vitro antitumor activities of new triorganotin(IV) complexes with sulfur donor ligand

Abstract

The discovery of the anticancer properties of cisplatin promoted a great deal of interest in the area of metal-based antitumor agents. With this aim, a new series of triorganotin(IV) derivatives: Ph3SnL (1), BZ3SnL (2), where L = morpholine-1-carbodithioate (MCDT) have been synthesized by the reaction of triorganotin(IV) chlorides with the ligand-salt in the appropriate molar ratio. All the complexes have been characterized by FT-IR, 1H, 13C, and 19Sn NMR spectroscopy. In addition, the molecular structure of complex 1 was determined by single crystal X-ray diffraction study. X-ray crystallographic analysis shows that in the compound [Ph3Sn(MCDT)], the Sn ion is in a four-coordinate environment with a dithiocarbamate ligand coordinated to the tin(IV) in a monodentate fashion through the sulfur atom. Furthermore, the cytotoxic activity of the free ligand (MCDT) as well as its triorganotin(IV) complexes were tested against tumor cell lines human cervix carcinoma HeLa, human myelogenous leukemia K562 and normal immunocompetent cells, peripheral blood mononuclear cells PBMC. The cytotoxic results indicate that coupling of MCDT with R3Sn(IV) metal center results in a complex with important biological properties and remarkable cytotoxic activity, since we observe IC50 values better to that of the antitumor drug cisplatin.