Structural chemistry of mononuclear, tetranuclear and hexanuclear organotin(IV) carboxylates from the reaction of di-n-butyltin oxide or diphenyltin oxide with rhodanine-N-acetic acid

Novel diphenyltin(IV) complexes with carboxylato N-functionalized 2-quinolone ligands: Synthesis, characterization and in vitro anticancer studies

Three new diphenyltin(IV) complexes, bis(3-(4-methyl-2-oxoquinolinyl-1(2H)-yl)propanoato)diphenyltin(IV) (1), bis(2-(4-methyl-2-oxoquinolin-1(2H)-yl)ethanoato)diphenyltin(IV) (2), and bis(2-(4-hydroxy-2-oxoquinolin-1(2H)-yl)ethanoato)diphenyltin(IV) (3), were synthesized and characterized by elemental microanalysis, FT-IR spectroscopy, and multinuclear (1H, 13C and 119Sn) NMR spectroscopy. Crystal structure of ligand precursor, 2-(4-methyl-2-oxoquinolinyl-1-(2H)-yl)acetic acid (HL2), has been determined by X-ray diffraction studies. Asymmetric bidentate coordination of the carboxylato ligands and skew trapezoidal structures are assumed for the synthesized complexes. In vitro anticancer activity of the synthesized diphenyltin(IV) complexes was evaluated against three human: MCF-7 (breast adenocarcinoma), A375 (melanoma), HCT116 (colorectal carcinoma), and three mouse tumor cell lines: 4T1 (breast carcinoma), B16 (melanoma), CT26 (colon carcinoma) using MTT and CV assays. The IC50 values fall in the range from 0.1 to 3.7 μM. Flow cytometric analysis and fluorescent microscopy suggest that complex 1 induces caspase-dependent apoptosis followed with strong blockade of cell division in HCT116 cells. Since complex 1 showed ROS/RNS scavenging potential mentioned cytotoxicity was not connected with oxidative stress.

Bis(μ2-4-nitrophenolato)bis(4-nitrophenolato)di-μ3-oxido-octaphenyltetratin chloroform sesquisolvate [+ solvate]: a tetranuclear stannoxane

The title tetranuclear stannoxane, [Sn4(C6H5)8(C6H4NO3)4O2]·1.5CHCl3·solvent, crystallized with two independent complex molecules, A and B, in the asymmetric unit together with 1.5 molecules of chloroform. There is also a region of disordered electron density, which was corrected for using the SQUEEZE routine [Spek (2015). Acta Cryst. C71, 9–18]. The oxo-tin core of each complex is in a planar `ladder' arrangement and each Sn atom is fivefold SnO3C2 coordinated, with one tin centre having an almost perfect square-pyramidal coordination geometry, while the other three Sn centres have distorted shapes. In the crystal, the complex molecules are arranged in layers, composed of A or B complexes, lying parallel to the bc plane. The complex molecules are linked by a number of C—H...O hydrogen bonds within the layers and between the layers, forming a supramolecular three-dimensional structure.

Syntheses, structures and anti-tumor activity of four organotin(iv) dicarboxylates based on (1,3,4-thiadiazole-2,5-diyldithio)diacetic acid

Four novel organotin complexes, derived from flexible (1,3,4-thiadiazole-2,5-diyldithio)diacetic acid (H₂tzda), have been synthesized and characterized by elemental analysis, FT-IR, NMR and X-ray crystallography.

New dibutyltin(IV) ladders: Syntheses, structures and, optimization and evaluation of cytotoxic potential employing A375 (melanoma) and HCT116 (colon carcinoma) cell lines in vitro

Synthesis and spectroscopic properties of seven new dibutyltin(IV) compounds of 2-{(E)-4-hydroxy-3-[(E)-4-(aryl)iminomethyl]phenyldiazenyl}benzoic acids (LⁿHH'; n=2-8) with general formula {[Bu₂Sn(LⁿH)]₂O}₂ (1-7) are reported. The compounds were characterized by elemental analysis and by UV-Visible, fluorescence, IR, ¹H, ¹³C and ¹¹⁹Sn NMR spectroscopies. Solid state structures of dibutyltin(IV) compounds 1-3, 6 and 7 were accomplished from single crystal X-ray crystallography which reveal the common ladder-type structure with two endo- and two exo-Sn atoms. The redox properties of LⁿHH' (n=2-4, 7 and 8) and their diorganotin(IV) compounds 1-3, 6 and 7 were also investigated by cyclic voltammetry. In general, the dibutyltin(IV) derivatives exhibited significant in vitro cytotoxic potency towards A375 (melanoma) and HCT116 (colon carcinoma) cell lines as determined by several experiments, like Live and Dead assay, MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) cell viability assay, LDH (lactate dehydrogenase), cleavage of caspases and PARP (poly(ADP-ribose)polymerase), and DNA fragmentation. Dibutyltin(IV) compounds increase cell death without cytolysis and decreases membrane fluidity, without interfering with p53. Among the dibutyltin(IV) compounds, compound 6 was found to be the most potent, with an IC₅₀ value of 78nM. A mechanism of action for tumor cell death is proposed.

Organotin complexes containing carboxylate ligands with maleimide and naphthalimide derived partial structures: TrxR inhibition, cytotoxicity and activity in resistant cancer cells

Di-n-butyltin(IV) carboxylate and tri-n-butyltin(IV) carboxylate derivatives have demonstrated strong cytotoxic effects in different types of tumor cells. Complexes with carboxylate ligands that contain maleimide and naphthalimide derived partial structures were synthesized, characterized and investigated for inhibition of the tumor-relevant enzyme thioredoxin reductase and antiproliferative effects in cancer cells. The complexes were moderate inhibitors of thioredoxin reductase with activities in the micromolar range and triggered strong cytotoxic effects in MCF-7 breast cancer and HT-29 colon carcinoma cells. Interestingly, selected complexes were highly active in vincristine and daunorubicin resistant Nalm-6 cells.

cyclo-Hexa-μ2-diphenylacetato-κ12O:O′-hexa-μ3-oxido-hexakis[phenyltin(IV)]

In the cyclo­hexa­meric centrosymmetric title compound, [Sn₆(C₆H₅)₆(C₁₄H₁₁O₂)₆O₆], each bridging oxide O atom is connected to three Sn atoms and each carboxyl­ate group bridges a pair of Sn atoms so that the three independent Sn atoms all adopt SnCO₅ distorted octa­hedral geometries, resulting in a drum-shaped Sn₆O₆ core.

Syntheses, Crystal Structure and Antibacterial Activities of Mononuclear and Tetranuclear Di-n-butyltin(IV) Complexes Constructed from 2-(4-formyl-2-methoxyphenoxy)Acetic Acid

Two new organotin(IV) carboxylates of composition n-Bu2Sn(O2CCH2OC6H3OCH3 CHO)2 (1) and {[n-Bu2Sn(O2CCH2 OC6H3OCH3CHO)2]2O}2 (2) were obtained by the reaction of n-Bu2SnO and 2-(4-formyl-2-methoxyphenoxy)acetic acid (LH). The compounds 1 and 2 have been characterised by elemental analysis and IR, 1H NMR and X-ray crystallographic diffraction studies. The tin atom in 1 is found to adopt the skew-trapezoidal bipyramidal geometry in the polymeric chains. The compound 2 adopts a dimeric ladder structure and contains a tetranuclear tin framework with six distannoxane rings. The antibacterial activities decrease in the order 2 > 1 > (n-Bu)2SnO > LH.