Synthesis, Characterization and Anticancer Studies of Rh(I), Rh(III), Pd(II) and Pt(II) Complexes Bearing Dithiooxamide Ligand

Breast cancer is the most common type of cancer in women. In the current study, six transition-metal complexes were reacted with a secondary dithiooxamide (H2-isopropyl2DTO) to obtain the corresponding mononuclear complexes (1-6) and their cytotoxicity was evaluated in two human breast cancer cell lines, i.e. MCF‐7 and MDA-MB-231. The characterization of the complexes, [LnM(H-isopropyl2 DTO κ-S,S M)] (LnM = (C5Me5)RhCl, (1); (COD)Rh, (2); (η3-allyl)Pd, (3); (trinpropyl-phosphine)PdCl, (4); (bpy)Pt, (5) and (pph3)PtCl, (6)), and the ion pair form of 1-4, IP1-IP4, were accomplished through NMR spectroscopy and elemental analysis. The structures of 1 and IP1 were also determined by single crystal XRD technique. In vitro cytotoxicity studies in MCF-7 and MDA-MB-231 (IC50 determination) showed that all complexes are cytotoxic for both cell lines, with the exception of 2. Compound 3 was the most cytotoxic in the conditions tested. In addition, the compounds induce cell death by apoptosis and inhibit the formation of colonies, indicating that these compounds could provide promising new lead derivatives for anticancer drug development.