Organotins: Toxicology and biological effects

Syntheses, structures, and1H,13C{1H} and119Sn{1H} NMR chemical shifts of a family of trimethyltin alkoxide, amide, halide and cyclopentadienyl compounds

The synthesis and full characterization by Nuclear Magnetic Resonance (¹H,¹³C{¹H} and¹¹⁹Sn{¹H}) of eleven Me₃SnX complexes in six common organic solvents is presented.

The pH-dependent adsorption of tributyltin to charcoals and soot

Widespread use of tributyltin (TBT) poses a serious environmental problem. Adsorption by black carbon (BC) may strongly affect its behavior. The adsorption of TBT to well characterized soot and two charcoals with specific surface area in the range of 62-111m(2)g(-1) have been investigated with main focus on pH effects. The charcoals but not soot possess acidic functional groups. TBT adsorption reaches maximum at pH 6-7 for charcoals, and at pH>6 for soot. Soot has between 1.5 and 15 times higher adsorption density (0.09-1.77μmolm(-2)) than charcoals, but charcoals show up to 17 times higher sorption affinities than soot. TBT adsorption is successfully described by a new pH-dependent dual Langmuir model considering electrostatic and hydrophobic adsorption, and pH effects on TBT speciation and BC surface charge. It is inferred that strong sorption of the TBTOH species to BC may affect TBT toxicity.

Triethyltin-induced stress responses and apoptotic cell death in cultured oligodendrocytes

Triethyltin (TET)-induced neurotoxicity in the brain causes the formation of myelin edema and loss. Myelin deficits produced by early postnatal exposure to TET are permanent and cannot be repaired as the brain matures. The underlying causes have not been resolved. To investigate whether TET directly affects oligodendrocytes, the myelin-forming cells of the central nervous system, cultured rat brain oligodendrocytes were prepared and treated with TET. The data show that TET was cytotoxic for oligodendrocytes and led to the onset of programmed cell death, as indicated by DNA fragmentation. Cellular membranous extensions were severely damaged, and the nuclei appeared to be condensed and fragmented. Concomitantly, the small heat shock protein HSP32, also known as heme oxygenase-1 (HO-1), and an indicator of oxidative stress, as well as the activation of extracellular signal-regulated kinases 1 and 2 (ERK1,2), were observed. ERK1,2 have been implicated to participate in the regulation of cell death and survival. Myelin-specific proteins MBP and CNP were not affected. In TET-treated cells mitochondria redistributed from the processes to the cell somata near the nucleus, possibly as a consequence of microtubule disorganization. A disturbance of the mitochondrial membrane potential and mitochondrial fragmentation occurred. Hence, it might be hypothesized that oligodendroglial PCD, rather than axonal degeneration, contributes to myelin damage and deficits observed in rats after treatment with TET in vivo.

Comparison of different liquid chromatography conditions for the separation and analysis of organotin compounds in mussel and oyster tissue by liquid chromatography-inductively coupled plasma mass spectrometry

In this paper, a new high-performance liquid chromatography-inductively coupled plasma mass spectrometry (HPLC-ICP-MS) methodology for the analysis of organotin compounds in complex matrices is described. Earlier studies had failed to show baseline resolution between dibutyltin (DBT) and triphenyltin (TPhT). The data presented in this paper show that, by using a different C-18 stationary phase material (Ace C-18) with decreased particle size, baseline resolution of DBT and TPhT can be achieved, with the resultant separation of a third interfering component. In addition, the Ace C-18 stationary phase yields a significant increase in the number of theoretical plates, and, combined with changes in the mobile phase composition, a reduction in run-time by approximately 25%. It is shown that the minor compounds detected are present in the sample and not artefacts of the analytical procedure. The accuracy and precision of the proposed HPLC-ICP-MS method was demonstrated for the determination of TBT in oyster tissue during the BCR "MULSPOT" international interlaboratory certification project.

The crystal and molecular structure of chlorotriphenyl(isoquinolinium-1-carboxylato)tin(IV)

The synthesis and crystal structure of the 1:1 complex formed between triphenyltin chloride and isoquinoline-1-carboxylic acid ([Ph3SnCl:C10H7NO2]) is described. The tin(IV) atom is found to be five coordinate, being bound to three phenyl groups, the chlorine atom, and an oxygen from isoquinoline-1-carboxylic acid. The geometry around the tin atom is that of a trigonal bipyramid, with the three phenyl groups occupying the equatorial positions, and the apical sites taken by the chlorine atom and a carboxyl oxygen from the isoquinoline-1-carboxylic acid. The crystals are triclinic, space group [Formula: see text] with a = 17.932(12) Å, b = 17.935(15) Å, c = 18.686(12) Å, α = 63.16(5)°, β = 81.70(6)°, γ = 68.45(6)°, V = 4986(6)(10) Å3Z = 8, and Dcalc = 1.486 Mg m−3 The final residual is RF = 0.050, on 8375 reflections with Inet > 2.5σ(Inet). Two of the cell dimensions are equivalent and there are four molecular units in the unit cell, so precautions are described for ensuring that correct space-group determination had been made and that some concealed symmetry in the final structure had not been overlooked. Keywords: triorganotin, complex, isoquinoline-1-carboxylic acid, fungicidal activity.

The synthesis, molecular and crystal structure of the 1:1 adduct of triphenyltin chloride with 2,3-diphenylthiazolidin-4-one

The title compound was synthesized as part of an effort to produce a more effective fungicide to combat Dutch Elm Disease (DED), which is caused by the fungus Ceratocystisulmi. A full X-ray structural analysis of the 1:1 adduct has been carried out and the results are reported along with the Mössbauer data for the compound. The crystals are monoclinic, space group P21/a with a = 19.240(3) Å, b = 9.1463(24) Å, c = 19.3512(24) Å, β = 118.874(8)°, V = 2982.0(10) Å3, z = 4, and Dcalc = 1.427 Mg m−3. The final discrepancy factors are RF = 0.056 and Rw = 0.058 for 1915 significant reflections. The QS and IS values in the Mössbauer spectrum of the complex are 3.08 mm s−1 and 1.28 mm s−1, respectively. The 2,3-diphenylthiazolidin-4-one behaves as a monodentate ligand and coordinates to the tin through the oxygen atom. The complex exhibits a trigonal bipyramidal configuration with the three phenyl groups in equatorial positions and the chloride and ligand oxygen occupying the apical sites. Keywords: triorganotin, fungicide, Dutch Elm Disease, thiazolidin-4-one.

Immunotoxic organotins as possible model compounds in studying apoptosis and thymocyte differentiation

In the mid-seventies it appeared that some organotin compounds selectively caused thymus atrophy. From that time onward efforts were made to reveal molecular and cellular mechanisms involved. In this review recent studies into organotin-sensitive stages and processes of thymocyte maturation are discussed. Together these studies resulted in the recognition of organotin compounds as possible model compounds in studying immature thymocyte differentiation and protein synthesis-independent apoptotic cell death of thymocytes.

The evaluation of data-derived safety factors for bis(tri-n-butyltin)oxide

In this report the evaluation of a safety factor is assessed, according to the decision tree suggested by Renwick (1991a,b), to determine a Tolerable Daily Intake (TDI) value for the environmental contaminant bis(tri-n-butyltin)oxide (TBTO). Based on available literature the nature of the most sensitive parameter of TBTO-toxicity was perceived to be on lymphoid organs and lymphoid function. Subsequently, safety factors were derived in relation to published data on inter-species and inter-individual differences in both kinetics and dynamics of TBTO. Lack of information on human data concerning the nature of toxicity as well as kinetics and dynamics of TBTO finally resulted in a safety factor of 100. A TDI of 5 or 0.25 mg/kg bw per day was assessed based on reductions of lymphoid organ weights (thymus) or lymphoid function (resistance to T. spiralis), respectively. In addition, based on available data in rodents on kinetics and dynamics of TBTO, it is suggested that a combined TDI value for both tri- and dibutyltin compounds might have to be considered.