New antimony(III) halide complexes with dithiocarbamate ligands derived from thiuram degradation: the effect of the molecule's close contacts on in vitro cytotoxic activity

Abstract

Antimony(III) halide complexes of the formulae {[SbBr(Me2DTC)(2)](n)} (1), {[SbI(Me2DTC)(2)](n)} (2) and {[(Me2DTC)(2)Sb(mu(2)-I)Sb(Me2DTC)(2)](+)center dot I-3(-)} (3) (Me2DTC = dimethyldithiocarbomate) were synthesized from SbX3, (X = Br or I) and tetramethylthiuram monosulfide (Me(4)tms) or tetramethylthiuram disulfide (Me(4)tds). The complexes were characterized by melting point (m.p.), elemental analysis (e.a.), Fourier-transform InfraRed (FT-IR), Fourier-transform Raman (FT-Raman), Nuclear Magnetic Resonance (H-1,C-13-NMR) spectroscopy and Thermogravimetric-Differential Thermal Analysis (TG-DTA). Crystal structures of complexes 1-3 were determined with single crystal X-ray diffraction analysis. Complexes 1 and 2 are polymers with distorted square pyramidal (SP) geometry in each monomeric unit, whereas complex 3 is ionic, containing an iodonium linkage SbI+-Sb and an I-3(-) counter anion; to the best of our knowledge, this is the first ionic antimony(III) iodide complex. The in vitro cytotoxic activity of 1-3 against human adenocarcinoma cells: breast (MCF-7) and cervix (HeLa) cells and non-cancerous cells: MRC-5 (normal human fetal lung fibroblast cells) was evaluated with trypan blue (TB) and sulforhodamine B (SRB) assays. Among antimony(III) compounds with sulfur containing ligand, those of dithiocarbamates exhibit significant cytotoxic activity. Hirshfeld surface volumes were analyzed to clarify the nature of the intermolecular interactions by the 2D fingerprint plot. Molecules with lower H-all atoms intermolecular interactions exhibit the higher activity against MCF-7 cells. The in vivo genotoxicity of 1-3 was evaluated by the mean of Allium cepa test. Alterations in the mitotic index values due to the chromosomal aberrations were observed in the case of complexes 2 and 3. Since, no such alteration is caused by 1, it makes this compound candidate for further study as potential drug. (C) 2015 Elsevier B.V. All rights reserved.