Tetraalkyltin Compounds Research Articles

Organotin compounds cause structure-dependent induction of progesterone in human choriocarcinoma Jar cells

Organotin compounds, such as tributyltin (TBT) and triphenyltin (TPT), are typical environmental contaminants and suspected endocrine-disrupting chemicals because they cause masculinization in female mollusks. In addition, previous studies have suggested that the endocrine disruption by organotin compounds leads to activation of peroxisome proliferator-activated receptor (PPAR)γ and retinoid X receptor (RXR). However, whether organotin compounds cause crucial toxicities in human development and reproduction is unclear. We here investigated the structure-dependent effect of 12 tin compounds on mRNA transcription of 3β-hydroxysteroid dehydrogenase type I (3β-HSD I) and progesterone production in human choriocarcinoma Jar cells. TBT, TPT, dibutyltin, monophenyltin, tripropyltin, and tricyclohexyltin enhanced progesterone production in a dose-dependent fashion. Although tetraalkyltin compounds such as tetrabutyltin increased progesterone production, the concentrations necessary for activation were 30–100 times greater than those for trialkyltins. All tested active organotins increased 3β-HSD I mRNA transcription. We further investigated the correlation between the agonistic activity of organotin compounds on PPARγ and their ability to promote progesterone production. Except for DBTCl2, the active organotins significantly induced the transactivation function of PPARγ. In addition, PPARγ knockdown significantly suppressed the induction of mRNA transcription of 3β-HSD I by all active organotins except DBTCl2. These results suggest that some organotin compounds promote progesterone biosynthesis in vitro by inducing 3β-HSD I mRNA transcription via the PPARγ signaling pathway. The placenta represents a potential target organ for these compounds, whose endocrine-disrupting effects might cause local changes in progesterone concentration in pregnant women.

Volatilization of Organotin Species from Municipal Waste Deposits: Novel Species Identification and Modeling of Atmospheric Stability

Organotin compounds are used as pesticides and fungicides as well as additives in plastics. This study identifies the de novo generation of novel volatile organotins in municipal waste deposits and their release via landfill gas. Besides tetramethyltin (Me(4)Sn), a strong neurotoxin, and 5 previously reported organotins, 13 novel ethylated, propylated, and butylated tetraalkyltin compounds were identified. A concentration of 2-4 μg of Sn m(-3) landfill gas was estimated for two landfill sites in Scotland. The atmospheric stability of Me(4)Sn and methylated tin hydrides was determined empirically in a static atmosphere in the dark and under UV light to simulate night- and daytime conditions. Theoretical calculations were carried out to help predict the experimentally obtained stabilities and to estimate the relative stabilities of other alkylated species. Assuming first-order kinetics, the atmospheric half-life for Me(3)SnH was found to be 33 ± 16 and 1311 ± 111 h during day- and nighttime conditions, respectively. Polyalkylation and larger alkyl substitutes tend to reduce the atmospheric stability. These results show that substantial concentrations of neurotoxic organotin compounds can be released from landfill sites and are sufficiently stable in the atmosphere to travel over large distances in night- and daytime conditions to populated areas.

Organotin compounds enhance 17β-hydroxysteroid dehydrogenase type I activity in human choriocarcinoma JAr cells: Potential promotion of 17β-estradiol biosynthesis in human placenta

Organotin compounds, such as tributyltin (TBT) and triphenyltin (TPT), are typical environmental contaminants and suspected endocrine-disrupting chemicals because they cause masculinization in female mollusks. However, it remains unclear whether organotin compounds also cause crucial toxicities in human sexual development and reproductive functions. We investigated the effects of 17 tin compounds on the catalytic activity and mRNA expression of 17β-hydroxysteroid dehydrogenase type I (17β-HSD I) in human choriocarcinoma JAr cells. At nontoxic concentrations, both trialkyltins with propyl, butyl or cyclohexyl substituents on the tin atom and triphenyltin (TPT) enhanced 17β-HSD I mRNA transcription and enzyme activity in a dose-dependent fashion. Although tetraalkyltin compounds such as tetrabutyltin and tributylvinyltin also increased the mRNA expression and enzyme activity of 17β-HSD I, the concentrations necessary for activation were >30–100 times greater than those for trialkyltins. Inorganic tin had no effect on the catalytic activity and mRNA expression of 17β-HSD I. Interestingly, diphenyltin and monophenyltin, which are metabolites of TPT, enhanced 17β-HSD I activity with a concomitant increase in mRNA expression, whereas dibutyltin and monobutyltin, which are metabolites of tributyltin, enhanced 17β-HSD I activity without a concomitant increase in mRNA expression. These results suggest that organotin compounds are potent stimulators of 17β-estradiol biosynthesis to enhance 17β-HSD I activity in the human placenta in vitro; the placenta represents a potential target organ for these compounds, whose endocrine-disrupting effects might be the result of local changes in 17β-estradiol concentrations in pregnant women.

Interpretation of butyltin mass spectra using isotope pattern reconstruction for the accurate measurement of isotope ratios from molecular clusters

The fragmentation patterns of butyltin compounds (mono-, di-, and tributyltin) in an electron impact ion source were studied using an isotope pattern reconstruction algorithm with emphasis on isotope ratio measurements from molecular clusters. For this purpose, standards of natural tin isotope abundance and a (119)Sn-enriched mixture of the three compounds were both ethylated and propylated using sodium tetraalkylborates. The corresponding mass spectra of the various tetraalkyltin compounds prepared were obtained by GC/MS after their extraction with hexane. The results showed that pure interference-free molecular clusters were obtained only for certain R(3)Sn(+) ions where no isobaric overlap with R(2)SnH(+) ions occurred (e.g. BuEt(2)Sn(+) overlaps with Bu(2)SnH(+)). These ions are ideal candidates for accurate Sn isotope ratio measurements, while isotope pattern perturbing interferences are observed for other molecular fragments down to Sn(.)(+). Isotope pattern reconstruction algorithm thus can be used as an analytical tool to ensure the absence of molecular interferences--a requirement for accurate isotope ratio measurements from molecular clusters. The relevance of these studies for the determination of butyltin compounds in environmental samples by isotope dilution GC/MS is also discussed.

Studies with Novel Pdr5p Substrates Demonstrate a Strong Size Dependence for Xenobiotic Efflux

The yeast (Saccharomyces cerevisiae) multidrug transporter Pdr5p effluxes a broad range of substrates that are variable in structure and mode of action. Previous work suggested that molecular size and ionization could be important parameters. In this study, we compared the relative sensitivity of isogenic PDR5 and pdr5 strains toward putative substrates that are similar in chemical structure. Three series were used: imidazole-containing compounds, trialkyltin chlorides, and tetraalkyltin compounds. We demonstrate that the Pdr5p transporter is capable of mediating transport of substrates that neither ionize nor have electron pair donors and that are much simpler in structure than those transported by the human MDR1-encoded P-glycoprotein. Furthermore, the size of the substrate is critical and independent of any requirement for hydrophobicity. Substrates have surface volumes greater than 90 A(3) with an optimum response at approximately 200-225 A(3) as determined by molecular modeling. Assays measuring the efflux from cells of [(3)H]chloramphenicol and [(3)H]tritylimidazole were used. A concentration-dependent inhibition of chloramphenicol transport was observed with imidazole derivatives but not with either the organotin compounds or the antitumor agent doxorubicin. In contrast, several of the organotin compounds were potent inhibitors of tritylimidazole efflux, but the Pdr5p substrate tetrapropyltin was ineffective in both assays. This argues for the existence of at least three substrate-binding sites on Pdr5p that differ in behavior from those of the mammalian P-glycoprotein. Evidence also indicates that some substrates are capable of interacting at more than one site. The surprising observation that Pdr5p mediates resistance to tetraalkyltins suggests that one of the sites might use only hydrophobic interactions to bind substrates.

Photoalkylation of 10-alkylacridinium ion via a charge-shift type of photoinduced electron transfer controlled by solvent polarity.

A charge-shift type of photoinduced electron-transfer reactions from various electron donors to the singlet excited state of 10-decylacridinium cation (DeAcrH+) in a nonpolar solvent (benzene) is found to be as efficient as those of 10-methylacridinium cation (MeAcrH+) and DeAcrH+ in a polar solvent (acetonitrile). Irradiation of the absorption bands of MeAcrH+ in acetonitrile solution containing tetraalkyltin compounds (R(4)Sn) results in the efficient and selective reduction of MeAcrH+ to yield the 10-methyl-9-alkyl-9,10-dihydroacridine (AcrHR). The same type of reaction proceeds in benzene when MeAcrH+ is replaced by DeAcrH+ which is soluble in benzene. The photoalkylation of R'AcrH+ (R' = Me and De) also proceeds in acetonitrile and benzene using 4-tert-butyl-1-benzyl-1,4-dihydronicotinamide (Bu(t)BNAH) instead of R(4)Sn, yielding MeAcrHBu(t). The quantum yield determinations, the fluorescence quenching of R'AcrH+ by electron donors, and direct detection of the reaction intermediates by means of laser flash photolysis experiments indicate that the photoalkylation of R'AcrH+ in benzene as well as in acetonitrile proceeds via photoinduced electron transfer from the alkylating agents (R(4)Sn and Bu(t)BNAH) to the singlet excited states of R'AcrH+. The limiting quantum yields are determined by the competition between the back electron-transfer process and the bond-cleavage process in the radical pair produced by the photoinduced electron transfer. The rates of back electron transfer have been shown to be controlled by the solvent polarity which affects the solvent reorganization energy of the back electron transfer. When the free energy change of the back electron transfer (DeltaG(0)(bet)) in a polar solvent is in the Marcus inverted region, the rate of back electron transfer decreases with decreasing the solvent polarity, leading to the larger limiting quantum yield for the photoalkylation reaction. In contrast, the opposite trend is obtained when the DeltaG(0)(bet) value is in the normal region: the limiting quantum yield decreases with decreasing the solvent polarity.

Mass spectrometry studies of organolead compounds

AbstractThe mass spectra of alkyl‐, aryl‐ and chlorinated ‐alkyl, aryl organolead compounds were investigated. Positive and negative ion mass spectra of these compounds were recorded using conventional electron impact conditions. In common with the analogous tetraalkyltin and tetraalkylgermanium compounds, tetrabutyllead produced no negative ion spectra under these conditions. The spectra were also examined by tandem mass spectrometry in order to establish reaction mechanisms for these compounds. Fragmentation patterns of seven organolead compounds, based on precursor–product ion relationships, are proposed. Copyright © 2001 John Wiley & Sons, Ltd.

Organotin(IV) Compounds as Intramolecular Transesterification Catalysts in Thermal Depolymerization of Poly(L-Lactic Acid) Oligomer to form LL-Lactide

ABSTRACT Mono-, di-, and tetraalkyl tin(IV) compounds were evaluated for the intramolecular transesterification reaction of the thermal depolymerization of poly(L-lactic acid) oligomer forming lactide by gas chromatography using a β-cyclodextrin stationary phase capillary column. The most active catalyst was found to be monobutyltin trichloride (BuSnC13) (8), which contains tinhalogen bonds, and the least effective was the coordinatively saturated monoorganotin derivative, monobutyltin tris(2-ethylhexanoate) (7). Cordination of the carbonyl group in the oligomer to the tin catalysts is an important factor influencing its activity.

Electron transfer chemistry of hydride and carbanion donors. Hydride and carbanion transfer via electron transfer

The hydride transfer from 1,5-dihydroriboflavin-2′,3′,4′,5′-tetra-acetate (FlH 2) to various hydride acceptors (tetracyano- p-quinodimethane, tetracyanoethylene, and p-benzoquinone derivatives) in deaerated acetonitrile proceeds via electron transfer from FlH 2 to hydride acceptors followed by proton and electron transfer. The formation of transient radical ion pair has been detected directly in the reactions of 1,5-dihydroriboflavin-2′,3′,4′,5′-tetra-acetate (FlH 2) with some hydride acceptors in deaerated acetonitrile, providing unequivocal evidence for an electron transfer pathway in the overall two-electron redox reactions of FlH 2 with hydride acceptors. The formal carbanion transfer from alkylcobalt(III) complexes to cobalt(III) porphyrin has also been shown to proceed via electron transfer, followed by the cleavage of cobaltcarbon bonds of alkylcobalt(IV) complexes and the subsequent bond formation between alkyl radical and cobalt(II) porphyrin to yield alkylcobalt(III) porphyrins. The rate constants of the overall carbanion transfer from alkylcobalt(III) complexes to cobalt(III) porphyrin agree well with those predicted by the Marcus theory for the rates of outer-sphere electron transfer reactions. In contrast with the case of alkylcobalt(III) complexes, the rate constants of the carbanion transfer from tetraalkyltin compounds (R 4Sn) are 10 2–10 13 times faster than those predicted by the Marcus theory depending on the size of alkyl group of R 4Sn. The polar versus ET pathway is discussed in terms of the difference between outer-sphere versus inner-sphere electron transfer mechanisms based on the Marcus theory.

Determination of organotin compounds in environmental samples by supercritical fluid extraction and gas chromatography with atomic emission detection

AbstractThe extraction of six tetraalkyltin and seven ionic organotin compounds from spiked topsoil samples with supercritical carbon dioxide and carbon dioxide modified with 5 percent methanol was investigated. Analysis of the soil extracts was performed by gas chromatography with atomic emission detection. Retention times, minimum detectable concentrations, and detector linear ranges are included for nine organotin compounds (seven of the nine compounds were derivatized with n‐pentylmagnesium bromide prior to gas chromatographic analysis). A 23 factorial experimental design was used to study the effect of three variables (pressure, temperature, and extraction time) on compound recovery. The results indicate that the tetraalkyltin compounds are extracted from topsoil samples with recoveries ranging from 90 to 110 percent. Recoveries for the ionic organotin compounds ranged from 50 to 75 percent for trimethyltin chloride, triethyltin bromide, and tributyltin iodide; they were below 20 percent for dimethyltin dichloride, dibutyltin dichloride, diphenyltin dichloride, and butyltin trichloride. When sodium diethyldithiocarbamate was added to the soil samples prior to extraction, followed by extraction with carbon dioxide modified with 5 percent methanol, recoveries ranged from 70 to 90 percent for trimethyltin chloride, triethyltin bromide, dimethyltin dichloride, tributyltin iodide, and dibutyltin dichloride; recoveries were approximately 40 percent for butyltin trichloride and diphenyltin dichloride.

Regeneration of rhenium-based catalysts for the metathesis of propene

The regenerability of supported Re 2O 7 metathesis catalysts promoted with tetra-alkyltin compounds has been studied in a micro-catalytic flow reactor using propene metathesis as the model reaction. It appeared that the activity of a deactivated catalyst can be partly restored by an additional treatment with the promoter. The activity of a deactivated catalyst could also be partly restored by regeneration in a stream of oxygen, followed by renewed promoter addition. Each regeneration cycle resulted in some loss of activity. Temperature-programmed reduction and metal-content analysis techniques indicated that this loss of activity was due to SnO 2 which remained behind on the surface of the catalyst and interacted with the rhenium oxide.

Evaluation of inductively coupled plasma mass spectrometry as an elemental detector for supercritical fluid chromatography

Supercritical fluid chromatography coupled with inductively coupled plasma mass spectrometry shows high potential for the determination at ultratrace levels of organometallic compounds of environmental interest. In this study the determination of organotin compounds at ultratrace levels is demonstrated. In this work a supercritical fluid chromatography/inductively coupled plasma mass spectrometry (SFC/ICPMS) interface was developed. Separation of tetraalkyltin compounds shows detection levels in the subpicogram range (0.034 pg for tetrabutyltin; 0.047 pg for tetraphenyltin). The linear ranges are over 3 orders magnitude (1-1000 pg). The reproducibility of sample injections are better than 5% RSD.

Reductive alkylation of cobalt(III) porphyrin by tetraalkyltin compounds and alkylcobalt(III) complexes

Reductive alkylation of cobalt(III) porphyrin by tetraalkyltin compounds and alkylcobalt(III) complexes

Photoinduced radical chain reactions between alkylcobalt(III) complexes and iodine

Cobalt–carbon bonds of various alkylcobalt(III) complexes, cis-[CoR2(bipy)2]ClO4(R = Me, Et, or PhCH2; bipy = 2,2′-bipyridine), trans-[CoMe2(L)](L = 3,9-dimethyl-4,8-diazaundeca-3,8-diene-2,10-dione dioximate), and [CoR(Hdmg)2(py)](R = Me or Et; Hdmg = dimethylglyoximate; py = pyridine), are readily cleaved by iodine in carbon tetrachloride to yield alkyl iodides via photoinduced radical chain reactions with large quantum yields (e.g.Φ= 7.0 × 103) under low-energy irradiation (λ 517 nm). The rate-determining step in the radical chain reactions is suggested to be electron transfer from alkylcobalt(III) complexes to iodine atoms (I˙) which are produced by the photodissociation of I2, based on the formation of by-products that could arise only via electron-transfer processes as well as the kinetic comparison between alkylcobalt(III) complexes and tetra-alkyltin compounds.

Helium microwave-induced plasma mass spectrometry for capillary gas chromatographic detection: speciation of organotin compounds

Helium microwave-induced plasma mass spectrometry has been utilised as an element selective detector for capillary gas chromatography. Several trialkyltin and tetraalkyltin compounds were separated via capillary gas chromatography using a DB-1701 stationary phase. Two different tangential flow torches were evaluated. The major difference between the two torches is the use of a tantalum injector which extends through the microwave cavity and provides a means of introducing the effluent from the capillary column directly into the helium plasma. The optimum signal to noise ratio for the tantalum injector torch was obtained at a microwave power of 70 W with a plasma gas flow-rate of about 3 l min–1. Detection limits obtained with the tantalum injector torch ranged from 0.09 to 0.35 pg of Sn, while those achieved using the standard tangential flow torch ranged from 1 to 4 pg of Sn for the organotin species investigated. The relative standard deviation (RSD) of peak-height reproducibilities ranged from 2.4 to 4.3% for manual injection using the tantalum injector torch for 50 pg of Sn. The manual injection of 1 ng of compound resulted in an RSD of ca. 7% for peak height using the standard tangential flow torch. Linear dynamic ranges were over at least three orders of magnitude.

Long-chain tetraalkyltin compounds as neutral carriers for nitrite-selective PVC membrane electrodes

The nitrite-selective PVC membrane electrodes prepared with lipophilic long-chain tetraalkyltin compounds as neutral carrier show selectivity patterns significantly different from those obtained with classical anion-exchangers. The potentiometric selectivity coefficient for nitrite ion with respect to nitrate ion has been improved by about four orders of magnitude. The linear response range of the electrode based on tetralauryltin (TLT) is from 1 × 10−1M down to 2×10−5M with a detection limit of 5 × 10−6M. The Nernstian response of the electrode in the medium of pH≥7 gradually changes to a doubled super-Nernstian response when the solution turns slightly acidic. The change of the response slope has a closely relation with the stepwise complex-formation equilibrium of the carrier with the anion involved, which was experimentally studied by using ultraviolet spectroscopy. An explanation of the anomalous response behavior as well as the curve form of the potential-pH plot is given.

ChemInform Abstract: Alkylation of Aralkyl Bromides with Tetraalkyl Tin Compounds in Presence of (2,2′‐Bipyridine)fumaronitrile Palladium(O).

AbstractThe activated bromides (I) react with the tetraalkyl tin compounds (II) in the presence of Pd catalysts such as (III) to yield the coupling products (IV).

ChemInform Abstract: Photoelectron‐transfer Reactions of Flavin Analogues with Tetra‐alkyltin Compounds.

AbstractThe fluorescence quenching of the flavin analogues (I) and (II) with the tetraalkyltin compounds (III) in the absence and presence of Mg" ion in acetonitrile is investigated.

Excess thermodynamic properties of tetraalkyltin compounds with Trans-decalin and highly branched alkanes. Effect of steric hindrance

Molar excess thermodynamic quantities hE, [Formula: see text], and vE have been measured at 25 °C over the whole composition range for mixtures of four globular Sn(CnH2n+1)4 (SnR4) (n = 1–4) with t-decalin, and 2,2,4,4,6,8,8-heptamethylnonane (br-C16) as well as hE for the same SnR4 compounds with 2,2,4-trimethylpentane (br-C8). The excess viscosities are measured at −20, 25, and 40 °C for the t-decalin + SnR4 systems. By introducing gE in the solution activation energy, the free energy of mixing can be related to and calculated from the excess viscosities. The steric hindrance contribution, corresponding to an increase of order or diminution of mobility in solution, known to occur either with compounds having highly substituted atoms or with flat-shaped molecules, was investigated. The free volume contribution to the different thermodynamic properties is calculated from the Prigogine–Patterson–Flory theory. The difference between the experimental and calculated excess data is associated with the steric hindrance contribution. Values of hE, [Formula: see text], vE, and sE confirm the existence of a large steric hindrance contribution (hE < −200 J mol−1 and TsE < −400 J mol−1 for two systems). Another contribution, found to occur for the two smaller globular SnR4, may originate in the liberation of movement induced in solution by the second component.

Photoelectron-transfer reactions of flavin analogues with tetra-alkyltin compounds

Download options Please wait... Article information DOI https://doi.org/10.1039/P29860000025 Article type Paper Download Citation J. Chem. Soc., Perkin Trans. 2, 1986, 25-29 BibTex EndNote MEDLINE ProCite ReferenceManager RefWorks RIS Permissions Request permissions Photoelectron-transfer reactions of flavin analogues with tetra-alkyltin compounds S. Fukuzumi, S. Kuroda and T. Tanaka, J. Chem. Soc., Perkin Trans. 2, 1986, 25 DOI: 10.1039/P29860000025 To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page. If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given. If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page. Read more about how to correctly acknowledge RSC content. Search articles by author Shunichi Fukuzumi Sadaki Kuroda Toshio Tanaka