Platinum(II) complexes with 5,7-disubstituted-1,2,4-triazolo [1,5-a]pyrimidines: spectroscopical characterization and cytotoxic activity in vitro

Abstract

Complexes of the types: cis-[PtI(2)(dptp)(2)] (1), cis-[PtI(2)(NH(3))(dptp)] (2), trans-[PtI(2)(dptp)(dmso)] (3) and trans-[PtI(2)(dbtp)(dmso)] (4), where dptp=5,7-diphenyl-1,2,4-triazolo[1,5-a]pyrimidine (dptp), dbtp=5,7-ditertbutyl-1,2,4-triazolo[1,5-a]pyrimidine have been synthesized and characterized by infrared and multinuclear magnetic resonance spectroscopic techniques ((1)H, (13)C, (15)N, (195)Pt). In (195)Pt NMR, the cis-diiodo complexes were observed between -2601 ppm and -3261 ppm, while the trans coordination compounds were found at higher field (ca. -4389 ppm). In all cases significant (15)N NMR shielding (92-95 ppm) were observed for N(3) atom indicating this nitrogen atom as a coordination site. The cis complexes have been assayed for antitumor activity in vitro against two human cell lines: A549 (non-small cell lung carcinoma) and T47D (breast cancer). The results indicate a moderate antiproliferative activity of (2) against human cancer lines.