Structural motifs and biological studies of new antimony(III) iodide complexes with thiones.
Eight new antimony(III) iodide complexes of the heterocyclic thioamides, 2-mercapto-1-methylimidazole (MMI), 2-mercaptobenzimidazole (MBZIM), 5-ethoxy-2-mercaptobenzimidazole (EtMBZIM), 2-mercaptothiazolidine (MTZD), 3-methyl-2-mercaptobenzothiazole (NMeMBZT), 2-mercapto-3,4,5,6-tetrahydropyrimidine (tHPMT), 2-mercaptopyridine (PYT), and 2-mercaptopyrimidine (PMT) of formulas {[SbI(3)(MMI)(2)].MeOH} (1), [SbI(3)(MBZIM)(2)] (2), {[SbI(2)(mu(2)-I)(EtMBZIM)(2)](2).H(2)O} (3), [SbI(3)(MTZD)] (4), [(NMeMBZT)SbI(2)(mu(2)-I)(2)(mu(2)-S-NMeMBZT)SbI(2) (NMeMBZT)] (5), {[SbI(3)(tHPMT)(3)].MeOH} (6), [SbI(3)(PYT)] (7), and [SbI(3)(PMT)(2)] (8), have been synthesized and characterized by elemental analysis, FT-IR spectroscopy, FT-Raman spectroscopy, and TG-DTA analysis. The crystal structures of 3, 4, 5, 6, and 7 were also determined by X-ray diffraction. The complexes show interesting structural motifs. Complex 6 is a monomer, with octahedral (Oh) geometry around the metal ion formed by three sulfur and three iodide atoms. Complexes 3 and 5 are dimers, with a square pyramidal (SP) geometry in each monomeric unit, while complexes 4 and 7 are polymers with pseudotrigonal bipyramidal (psi-TBP). Two or three sulfur atoms from thioamide ligands and three iodide atoms are bound to Sb atoms forming building blocks for the dimers and polymers. Strong intramolecular interactions between mu(2)-I and/or mu(2)-S and Sb atoms stabilize both structures. In dimer complex 5, two terminal iodide and one terminal sulfur atom are bonded to the Sb ion, while two mu(2)-I and one mu(2)-S bridging atoms bridge the metal ions forming psi-Oh geometry. Computational studies using multivariant linear regression (MLR) and artificial neural networks (ANN) and considering biological results (50% inhibitory concentration, IC(50)) as dependent variables derived a theoretical equation for IC(50) values of the complexes studied. The calculated IC(50) values are compared satisfactorily with the experimental inhibitory activity of the complexes measured. Complexes 3-7 were used to study their influence upon the catalytic peroxidation of linoleic acid by the enzyme Lipoxygenase (LOX). Compounds 1-8 were also tested for in vitro cytotoxicity, and they showed mostly a moderate cytostatic activity against a variety of tumor cell lines but comparable with those found for the antimony(III) chloride and bromide complexes, reported earlier [Ozturk et al. Inorg. Chem. 2007, 46, 2861-2866; Ozturk et al. Inorg. Chem. 2009, 48, 2233-2245].
Ozturk
I
I
Section of Inorganic and Analytical Chemistry, Department of Chemistry, University of Ioannina, 45110 Ioannina, Greece.
Filimonova
S
S
Hadjikakou
S K
SK
Kourkoumelis
N
N
Dokorou
V
V
Manos
M J
MJ
Tasiopoulos
A J
AJ
Barsan
M M
MM
Butler
I S
IS
Milaeva
E R
ER
Balzarini
Jan
J
Hadjiliadis
N
N
D000818:Animals; D000965:Antimony / Q000737:chemistry* / Q000494:pharmacology*; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D018360:Crystallography, X-Ray; D054697:Cytostatic Agents / Q000737:chemistry* / Q000494:pharmacology*; D006801:Humans; D007454:Iodides / Q000737:chemistry* / Q000494:pharmacology*; D008084:Lipoxygenase / Q000378:metabolism; D008958:Models, Molecular; D009369:Neoplasms / Q000188:drug therapy; D013871:Thiones / Q000737:chemistry / Q000494:pharmacology
D054697:Cytostatic Agents; D007454:Iodides; D013871:Thiones; D000965:Antimony; D008084:Lipoxygenase