Antitumour Activity of a pt(III) Derivative of 2-Mercaptopyrimidine.

The complex [Pt(2)Cl(2)(Spym)(4)], where Spym = 2-mercaptopyrimidine, was synthesized and analyzed spectroscopically. The presence in the (195)Pt NMR spectrum, of only one signal for the Pt(III) indicates the symmetrical arrangement of the ligands and the identical setting of N, S and Cl atoms, PtS(2)ClN(2), for the two Pt atoms being different to other compounds described in the literature. The interaction of this complex with DNA was studied by several techniques, including circular dichroism, melting temperature determination, electron microscopy (EM) and atomic force microscopy (TMAFM). Preliminary results show a high activity against HL-60 and HeLa tumour lines for the Pt-2-mercaptopyrimidine complex in comparison with cisplatin activity. Higher values for IC(50) were obtained, while the values of LD(50) were lower than those for cisplatin.