Pd(I) and Ni(II) complex compounds: [Pd(AMMT)2]Cl2 (1), [Pd(AMMT)4]Cl2 (2) and [Ni(AMMT)2(H2O)](NO3)2 (3) with 4-amino-3-mercapto-5-methyl-1,2,4-triazole (AMMT) have been synthesized. The spectral characteristics of 1, 2 were studied by 1H (13C) NMR and UV-Vis spectroscopy. X-ray diffraction studies established that all complexes contain the AMMT molecule, which are coordinated to the central
metal ion in the
thione tautomeric form. At the ratio M: L = 1:2
ligand is coordinated in bidentate chelate manner by the
nitrogen of amino- and
sulfur of mercapto group (compounds 1, 3). But the molar ratio M: L = 1:4 leads to monodentate coordination of AMMT molecules only by
sulfur of mercaptogroup (complex 2). Vacant coordination sites of the
metal ion are occupied by water molecules (complex 3). The screening of complexes 1-3 and starting compounds [AMMT,
K2PdCl4 (4), Ni(NO3)2 · 6H2O (5)] by their mitochondrial
dehydrogenase activity have been performed by us for the first time, resulting in established that the Pd(II) complexes (1, 2), Pd(II)
salt (4) and AMMT normalize the activity of mitochondrial
dehydrogenases of
cancer HeLa cells, identified by MTT-test. In contrast, the Ni(II) complex (3) and Ni(II)
salt (5) do not stimulate the activity of mitochondrial
dehydrogenases. It has been found, that all investigated compounds do not affect on the cell cycle and the level of apoptotic cells as well as do not show a toxic effect. Thus, these results indicate that AMMT and Pd(II) complexes may be used as modifiers of mitochondrial respiration, which dysfunction is particularly evident in the
tumor cells.