Synthesis, characterization and cytotoxic properties of bismuth(III) chloride complexes with heterocyclic thioamides

Abstract

Bismuth(III) complexes of the formulae [BiCl3(MBZT)2] ·H2O} (1), {[BiCl2(µ2-Cl)(MMI)2]2·(CH3)2CO} (2), {[BiCl3(µ2-S-PYT)(PYT)]2} (3) {([BiCl2(MBZIM)4]+)·2(Cl-)·(H3O+) ·2H2O} (4) and [BiCl3(tHPMT)3] (5) (where MBZT: 2-mercaptobenzothiazole, MMI: 2-mercapto-1-methylimidazole, PYT: 2-mercaptopyridine, MBZIM: 2-mercaptobenzimidazole, tHPMT: 2-mercapto-3,4,5,6-tetrahydro-pyrimidine) are reported. The compounds were characterized by spectroscopic techniques including FT-IR, FT-Raman, UV-Vis, 1H-,13C-NMR spectroscopies, TG-DTA, e.a, molar conductivity and by single-crystal X-ray diffraction analysis. While 1, 4 and 5 are mononuclear compounds, 2 and 3 are dinuclear complexes in which the two Bi3+ ions are bridged through Cl- and SR groups respectively. Interestingly, 3 is the first example of dinuclear Bi3+ complex containing two Bi-(μ-SR)-Bi bridges between the two metal centers formed by covalent bonds. Compounds 1–5 were evaluated for their in vitro cytotoxic activity against human adenocarcinoma cervix (HeLa) and breast (MCF-7) cells. The toxicity of 1–5 was evaluated on normal human fetal lung fibroblast cells (MRC-5). The influence of 1–5, on the catalytic peroxidation of the linoleic acid by the enzyme lipoxygenase (LOX) was determined experimentally.