In vitro cytotoxicity and antibacterial activity of [Pd(AMTTO)(PPh3)2]: a novel promising palladium(ii) complex

Abstract

The synthesis of a new palladium(II) complex, [Pd(AMTTO)(PPh₃)₂] (1, H₂AMTTO = 4-amino-6-methyl-1,2,4-triazine-3-thione-5-one), is reported. Complex 1 has been characterized by FT-IR, ¹H NMR and ³¹P NMR spectroscopy as well as mass spectrometry. Furthermore, its molecular structure and thermal stability have been investigated via X-ray and thermogravimetric analyses. The crystal structure of 1 revealed that the twofold deprotonated ligand acts as a bidentate chelating one and coordinates to the metal ion through its sulfur and nitrogen atoms in a cis-arrangement. The biological activity including anticancer and antibacterial activity of the ligands and complex 1 was studied. The IC₅₀ value of the latter against MCF-7 was 0.06 mM. This is while carboplatin (as a standard anticancer drug) exhibited no cytotoxicity at the same concentration. Moreover, the synthesized Pd(II) complex displayed potent antimicrobial activity against Gram-positive (ATCC 6538) and Gram-negative (ATCC 25922) bacterial strains.