Synthesis and X-ray structure of the dinuclear platinum(II) complex with saccharin {K[Pt(sac)3(H2O)] · H2O}2: Studies on its antiproliferative activity in aqueous solution

Synthesis and X-ray structure of a dinuclear platinum(II) complex with the ligand saccharin(sac) are described. The structure shows two approximately square-planar platinum centers. Each platinum atom is coordinated to one water molecule and three N-bonded saccharinate ligands. The two centers are linked through two potassium atoms. Each potassium atom interacts with six oxygen atoms from hydration and coordinated water molecules and from carbonyl and sulfonate groups of the ligands. It is suggested that, in aqueous solution, the dimeric structure of the complex is dissociated and the monomeric species K[Pt(sac)3(H2O)] is formed. The complex was dissolved in water and submitted to in vitro cytotoxic analyses using HeLa cells (human cervix cancer). It was shown that the monomeric complex elicited a potent cytotoxic activity when compared to the vehicle-treated cells. The IC50 value for the monomeric complex is 6.8 μM, a little bit higher than that obtained for cisplatin.

Graphical abstractSynthesis and structure of a dinuclear platinum(II) complex with saccharin(sac) are described. {K[Pt(sac)3(H2O)] · H2O}2 crystallizes in the triclinic system, P1¯ (#2). The monomeric complex K[Pt(sac)3(H2O)], formed when the dimeric structure is in aqueous solution, has shown a potent cytotoxic activity. Its IC50 value of 6.8 μM is comparable to that obtained for cisplatin, a classical metal-based antineoplasic drug.Figure optionsDownload full-size imageDownload as PowerPoint slide