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Environmental contaminant exposures occur due to the widespread use of synthetic chemicals. Tributyltin (TBT), dibutyltin (DBT), and pentachlorophenol (PCP) are each used in a variety of applications, including antifouling paints and stabilizers in certain plastics. Each of these compounds has been found in human blood, as well as other tissues, and they have been shown to stimulate pro-inflammatory cytokine production in human immune cells, Inflammatory cytokines mediate response to injury or infection. However, if their levels are increased in the absence of an appropriate stimulus, chronic inflammation can occur. Chronic inflammation is associated with a number of pathologies including cancer. Stimulation of pro-inflammatory cytokine production by these toxicants is dependent on activation of ERK 1/2 and/or p38 MAPK pathways. MAPK pathways have the capacity to regulate translation by increasing phosphorylation of key translation regulatory proteins. There have been no previous studies examining the effects of TBT, DBT, or PCP on translation. The current study shows that ribosomal protein S6 (S6), eukaryotic initiation factor 4B (eIF4B), and eIF4E are phosphorylated (activated) and/or their total levels are elevated in response to each of these compounds at concentrations found in human blood. Activation/increased levels of translational proteins occurred at concentrations of the compounds that have been shown to elevate pro-inflammatory cytokine production, but where there is no increase in mRNA for those proteins was seen. Compound-stimulated increases in translation appear to be part of the mechanism by which they elevate protein production in immune cells. [ABSTRACT FROM AUTHOR]

Exposure to tin in the general US population is near ubiquitous, as determined using urinary tin levels measured by inductively coupled plasma mass spectrometry (ICP-MS). Urinary tin levels are associated with chronic health outcomes, such as diabetes; however, it is unclear if these associations are due to the presence of inorganic and organic forms of tin in urine. To address this knowledge gap, levels of total tin and several organotin compounds (OTCs) were measured in convenience urine samples from pregnant women and adults from Iowa, United States. Total tin and OTC levels in urine samples were quantified using ICP-MS and gas chromatography with pulsed flame photometric detection (GC-PFPD), respectively. ICP-MS detected tin in almost all urine samples from both study populations. Low levels of dibutyltin were detected in two out of fifty human urine samples. Importantly, storage of urine samples in plastic containers, but not HNO3-pretreated glass vials drastically reduced the recoveries of OTCs, in particular, tributyltin. Although their detection frequency is low, exposures to OTC should be considered when studying associations between human exposures to tin compounds and adverse health outcomes; however, urinary OTC levels measured in banked urine samples may not be suitable as biomarkers of OTC exposure. [ABSTRACT FROM AUTHOR]

Abstract Female marine gastropods develop imposex (growth of penis/vas deferens) when exposed to TBT (tributyltin). Ours, is the first report of an imposex survey associated with TBT in sediment along 920 km of South Africa's Atlantic coastline. We sampled and analysed 1389 individuals of 13 caenogastropod species, and sediment samples from 25 sites, presumed impacted and not impacted by TBT pollution. Imposex was detected in six species not previously reported to suffer from this phenomenon, at eight sites, with up to 100% of females affected. Butyltins were found at quantifiable concentrations at four sites, with TBT and DBT (dibutyltin) concentrations in sediments up to 20 000 μg/kg dry mass (dm) and 3740 μg/kg dm, respectively. These findings are of major concern considering that TBT has been banned globally since 2008 by the International Maritime Organisation (IMO) - more extensive research is required in areas affected by TBT and where aquaculture is present. Highlights • First survey of imposex associated with TBT in sediments from the Atlantic coastline of South Africa • 1389 individuals of 13 caenogastropod species and sediment samples from 25 sites were analysed. • Imposex was detected in six species not previously reported to suffer from this phenomenon. • Measurable concentrations of TBT and DBT were found in sediments from four out of the 25 sites [ABSTRACT FROM AUTHOR]

Organotins present a toxicological risk to biota in the aquatic environment. Understanding the behaviour of these compounds in sediment is challenging, with sophisticated analytical techniques required for their measurement. We investigated the use of silica-bound sorbents for diffusive gradients in thin-films (DGT) adsorption gels to pre-concentrate five organotins (monobutlytin (MBT), dibutyltin (DBT), tributyltin (TBT), diphenyltin (DPhT), triphenyltin (TPhT)) found frequently in coastal sediment. C 8 sorbent showed optimum performance in uptake and recovery of organotins for pH and ionic strength ranges typical of coastal waters. Recoveries from adsorption gels deployed in filtered sea water were MBT = 123 ± 20%, DBT = 75 ± 12%, TBT = 81 ± 16%, DPhT = 72 ± 30%, TPhT = 58 ± 10% respectively. Devices were used to investigate DGT fluxes and pore water concentrations of organotins in coastal sediment collected from a contaminated site. DGT fluxes measured in sediment cores for the five organotins ranged between 4.3 × 10 −8 and 1.6 ×10 −5 ng cm 2 s −1 . The depletion of organotin species within pore waters at the interface with DGT devices was measured over a series of deployment times (2, 7, 14, 21 and 28 days) and provided estimates of the concentration of organotins in pore waters at Langstone Harbour, UK, prior to depletion by the DGT device and information on their spatial heterogeneity. The novel in situ DGT device developed can pre-concentrate organotins from pore waters in coastal sediment core samples and allows their detection at low environmental concentrations using conventional gas chromatographic/mass spectrometric instrumentation. Use of the DGT device overcomes many problems associated with the conventional pore water sampling of organotins. Our preliminary data suggests it has potential in the future to be a useful tool in investigating the environmental fate of these pollutants. The use of the C 8 gel will also allow for the simultaneous sequestration of other semi- and non-polar analytes present in the pore water. [ABSTRACT FROM AUTHOR]

Butyltin contamination was monitored in seven Tunisian harbors using soft tissue of three grazer gastropods (the Mediterranean limpet Patella caerulea , the turbinate monodont Phorcus turbinatus and the false-limpet Siphonaria pectinata), as well as sediments from the rocky substratum. The results revealed that butyltins (BuTs) were still present in the study sites three years after the Tunisian authorities banned their use. Tributyltin (TBT) concentrations in the substratum ranged from 1.5 to 5.7 ngSn/g dw (dry weight), dibutyltin (DBT) from 2.5 to 8.3, and monobutyltin (MBT) from 6.0 to 15.7. Higher concentrations were found in gastropods, ranging from 1.2 to 6.75 ngSn/g dw for TBT, 2.6 to 42.7 ngSn/g for DBT and 2.4 to 78.5 ngSn/g dw for MBT. The species P. caerulea and P. turbinatus accumulated TBT within the same range and at a higher level than S. pectinata , making them more appropriate for monitoring organotin contamination. Furthermore, DBT and MBT accumulated markedly in P. caerulea , up to 5–8 times the concentration recorded in the other two gastropods, suggesting further utility of this species as a good bioaccumulator of BuTs. Among the seven harbors studied, Zarzouna was the most contaminated whereas Zarat was the least polluted. The contamination is directly related to vessel traffic and shipyard activity at the studied harbors. The temporal comparison with previous studies shows that BuTs contamination is decreasing and that Tunisia's prohibition of TBT is effective in terms of environmental recovery. • Butyltins concentrations varied according to boating traffic and gastropod species. • Grazer gastropods accumulate more butyltins than imposex-exhibited species. • Pre/post ban comparisons showed decreases in butyltin contamination. • AFS convention ratification was effective in environmental recovery. [ABSTRACT FROM AUTHOR]

This study reports on the first assessment of the treatment of sediment contaminated by organotin compounds using homogenous and heterogeneous photocatalysis. Photo-Fenton and photocatalysis of low level (µg/L) organotins in water were carried out. A quasi-complete degradation of tributyltin (TBT) in water (99.8%) was reached after 30 and 7 min for photocatalytic and photo-Fenton treatment, respectively. For the first time decontamination of highly polluted marine sediments by photo-oxidation proves that the use of UV and the production of hydroxyl radicals are an efficient way to treat organotins adsorbed onto marine sediment despite the complexity of the matrix. [ABSTRACT FROM AUTHOR]

Up to now, the ability of target cells to activate protein kinase C (PKC) and protein kinase D (PKD) (which is often a downstream target of PKC) has not been examined in natural killer (NK) lymphocytes. Here we examined whether exposure of human NK cells to lysis sensitive tumor cells activated PKC and PKD. The results of these studies show for the first time that activation of PKC and PKD occurs in response to target cell binding to NK cells. Exposure of NK cells to K562 tumor cells for 10 and 30 min increased phosphorylation/activation of both PKC and PKD by roughly 2-fold. Butyltins (tributyltin (TBT), dibutyltin (DBT)) and brominated compounds (tetrabromobisphenol A (TBBPA)) are environmental contaminants that are found in human blood. Exposures of NK cells to TBT, DBT, or TBBPA decrease NK cell lytic function in part by activating the mitogen-activated protein kinases (MAPKs) that are part of the NK lytic pathway. We established that PKC and PKD are part of the lytic pathway upstream of MAPKs and thus we investigated whether DBT, TBT, and TBBPA exposures activated PKC and PKD. TBT-activated PKC by 2–3-folds at 10 min at concentrations ranging from 50 to 300 nM while DBT caused a 1.3-fold activation at 2.5 µM at 10 min. Both TBT and DBT caused an approximately 2-fold increase in phosphorylation/activation of PKC. Exposures to TBBPA caused no statistically significant changes in either PKC or PKD activation. [ABSTRACT FROM AUTHOR]

A tributyltin chloride (TBTCl) resistant bacterial strain was isolated from the Zuari estuary, in Goa, India, and identified as Klebsiella pneumoniae based on biochemical characteristics and 16S rRNA sequence analysis, and designated as strain SD9. It could utilize TBTCl as a sole carbon source in mineral salt medium and tolerated up to 2.5 mM TBTCl with maximum growth at 2 mM. Nuclear magnetic resonance spectroscopic analysis of column purified TBTCl degradation products clearly demonstrated the presence of dibutyltin dichloride (DBTCl 2 ) and monobutyltin trichloride (MBTCl 3 ). Mass spectrometry further confirmed degradation of toxic TBTCl into its less toxic derivatives, viz., DBTCl 2 and MBTCl 3 . This strain also showed enhanced siderophore production in the presence of TBTCl, which was demonstrated by chrome azurol S agar assay as an increase in diameter of the orange halo around the bacterial colony in the presence of 2 mM TBTCl; this seems to be a mechanism to counteract TBTCl toxicity. Furthermore, scanning electron microscopy revealed significant morphological alterations as shrinkage in cell size along with roughness of cell surface when bacterial cells were exposed to 2 mM TBTCl. These interesting characteristics of this estuarine bacterium make it a potential tool for bioremediation of TBTCl-contaminated sites since it possesses biotransformation capability to convert TBTCl into DBTCl 2 and MBTCl 3 . [ABSTRACT FROM AUTHOR]

A simple method based on high-performance liquid chromatography–tandem mass spectrometry (LC–MS/MS) was developed for the simultaneous determination of organotins—tri-n-butyltin chloride (TBT), triphenyltin chloride (TPT), dibutyltin dichloride (DBT), and diphenyltin dichloride (DPT)—in plastic food packaging. Samples were prepared by ultrasonic extraction with dichloromethane, followed by dissolution in acetonitrile containing 0.1% formic acid, and purification by an MCX column. The extracts were analyzed by LC–MS/MS in multiple reaction monitoring and positive modes with a C18 column; elution was carried out with a gradient of 0.1% formic acid and methanol containing 0.1% formic acid. The limits of detection for TBT, TPT, DBT, and DPT were 0.1, 0.6, 0.8, and 0.3 μg kg −1 , respectively. The recovery of organotins in spiked samples ranged from 68% to 113% (relative standard deviation: 0.4–4.2%). The proposed method was successfully employed to identify the target analytes in plastic packaging used for milk and cake. [ABSTRACT FROM AUTHOR]

Reaction between 2,2′-bipyridine-3,3′,6,6′-tetracarboxylic acid (bptcH 4 ) ( 1 ) and [Sn 2 Bu 6 O] in mild conditions proceeds with Sn-Bu bond cleavage giving polynuclear compounds. Complexes [(H 2 O)SnBu 2 (bptc)Sn 2 Bu 6 ]·H 2 O ( 2 ), [(CH 3 OH)SnBu 2 (bptc)Sn 2 Bu 6 ]·H 2 O ( 2a ), [(DMF)SnBu 2 (bptc)Sn 2 Bu 6 ] ( 2b ) and [(DMF)SnBu 2 (bptc)Sn 2 Bu 6 ]·0.5DMF·0.5H 2 O ( 3 ) were characterized using IR, NMR and ESI-MS spectroscopies. The X-ray structures of 1 ·H 2 O and ( 3 ) have been determined. Compound ( 3 ) is an exceptional polymer with seven-coordinate and five-coordinate Sn atoms. The Sn atoms are connected via screw-shaped C 10 H 4 N 2 (COO) 4 bridges giving 3D helical network. The NMR and ESI-MS spectra reveal, that complexes in solutions dissociate giving mainly dinuclear complexes. Complex 2 interacts with adenosine 5′-monophosphate (AMP) via phosphate group. Compounds ( 2 ), ( 2a ) and ( 2b ) are very effective cytostatic agents against C-32, SNB-19, SH-4 and Colo-829 tumor cells. [ABSTRACT FROM AUTHOR]

A novel approach has been developed for the separation of organotin species with capillary electrophoresis hyphenated to time-of-flight mass spectrometry. It has been applied to the development of a method for the determination and speciation of organotin compounds namely, dibutyltin (DBT), tributyltin (TBT), diphenyltin (DPT) and triphenyltin (TPT) in water samples. Experiments were made with a special laboratory constructed CE instrument. A non-aqueous buffer system compatible with TOF-MS has been developed using ammonium acetate–acetic acid (50mM and 1M) in acetonitrile: methanol (80:20). The total analysis time is less than 3min for these compounds under the conditions developed. The method has been applied successfully to the determination of these compounds in river water samples. Detection limits of the CE-TOF-MS method were between 1 and 8×10−7 M, and between 2 and 11×10−9 M (0.46 to 3.2µgL−1) when used in conjunction with solid phase extraction. The short analysis time as well as good sensitivity and selectivity make it a useful approach for the fast screening of organotin compounds. [ABSTRACT FROM AUTHOR]

The biomagnification of tributyltin (TBT), dibutyltin (DBT), monobutyltin (MBT), and total butyltins (ΣBT) was analyzed in the Northern Adriatic food-web (Mediterranean) considering trophodynamic interactions among species and carbon sources in the food-web. Although it is acknowledged that these contaminants bioaccumulate in marine organisms, it is still controversial whether they biomagnify along food-webs. A wide range of species was considered, from plankton feeders to top predators, whose trophic level (TL) was assessed measuring the biological enrichment of nitrogen stable isotopes (δ15N). Carbon isotopic signature (δ13C) was used to trace carbon sources in the food-web (terrestrial vs marine). At least one butyltin species was detected in the majority of samples, and TBT was the predominant contaminant. A significant positive relationship was found between TL and butyltin concentrations, implying food-web biomagnification. Coherently, the Trophic Magnification Factor resulted higher than 1, ranging between 3.88 for ΣBT and 4.62 for DBT. A negative but not significant correlation was instead found between δ13C and butyltin concentrations, indicating a slight decreasing gradient of contaminants concentrations in species according to the coastal influence as carbon source in their diet. However, trophodynamic mechanisms are likely more important factors in determining butyltin distribution in the Northern Adriatic food-web. [ABSTRACT FROM AUTHOR]

Abstract: The acute toxicity of organic tin compounds (OTCs) has been studied in detail. However, due to their complex nature, very little is known about species-specific methods of accumulation and consequences for food-webs. Chironomids, on which e.g. Daubenton''s bats feed, may act as vectors for the transport of organic tin compounds from aquatic to terrestrial ecosystems. Bats are prone to environmental toxins because of their longevity and their ecological role as top predators. Organic tin compounds are associated with increased formation of reactive oxygen species and associated oxidative damage as well as suppression of immune function. The present paper investigates whether the OTC, tributyltin (TBT) and its metabolite, dibutyltin (DBT), accumulate in natural populations of Daubenton''s bats and whether TBT-associated effects are seen in general body condition, redox balance, redox enzyme activities, associated oxidative damage of red blood cells and complement function. We discovered the concentration of bat fur DBT correlated with local marine sediment TBT concentrations. However, we did not find a correlation between the explanatory factors, bat fur DBT and marine sediment TBT concentrations, and several physiological and physical response variables apart from complement activity. Higher DBT concentrations resulted in weaker complement activity and thus a weaker immune response. Although the observed physiological effects in the present study were not strongly correlated to butyltin concentrations in fur or sediment, the result is unique for natural populations so far and raises interesting questions for future ecotoxicological studies. [Copyright &y& Elsevier]

Abstract: Butyltin complexes with biologically important hydroxyacids, citric HOOCCH2C(OH)(COOH)CH2COOH (C6H8O7) acid and (2R,3R)-(+)-tartaric HOOCCH(OH)CH(OH)COOH (C4H6O6) acid: [Sn(C4H9)2(C6H6O7)] (1), [Sn(C4H9)3(C6H7O7)] (2), (phenH)2[Sn(C4H9)3(C6H5O7)] (3), [Sn(C4H9)2(C4H4O6)] (4), [Sn(C4H9)3(C4H5O6)] (5), (phenH)[Sn(C4H9)3(C4H4O6)] (6) and [{Sn(C4H9)3}2(C4H4O6)] (7) have been synthesized and characterized by ESI–MS, IR and 1H, 13C and 119Sn NMR spectra. Their structures and properties in solid state and solutions were proposed on the basis of the spectroscopic data and density functional theory (DFT) calculations at B3LYP/3-21G** level. Complexes in solutions in polar solvents are five-coordinate as evidenced by 13C and 119Sn NMR spectra. Geometries of the five-coordinate complexes were optimized with B3LYP/3-21G** calculations. The 13C, 31P and 119Sn NMR spectra prove that complexes effectively interact with AMP, ATP and DAMP nucleotides forming Sn–OP bonds and N⋯H–O (nucleotide–carboxylate ligand) hydrogen bonds. In the case of dibutyltin complexes (1 and 4) nucleotides may also be coordinated as a chelating ligands via phosphate group and N7 atom of adenine residue. [Copyright &y& Elsevier]

Abstract: Butyltin complexes with 5-sulfosalicylic acid (H3ssal) [Sn(C4H9)3{O3SC6H3(OH)COOH}] (1), [Sn2(C4H9)6(OOCC6H3OHSO3)] (2) and [Sn3(C4H9)6(OOCC6H3(OH)SO3)2O] (3) have been synthesized and characterized by ESI-MS, IR and 1H, 13C and 119Sn NMR spectra. Their structures and properties in solid state and solutions were proposed on the basis of the spectroscopic data and density functional theory (DFT) calculations at B3LYP/3-21G∗∗ level. The complex 1 in solid state is a chain compound with bridging ligand O3SC6H3(OH)COOH− coordinated to two adjacent SnBu3 units via SO3 and COOH groups and complex 2 is a dinuclear compound with O3SC6H3(OH)COO2− bridging ligand bound to the SnBu3 moieties through SO3 and COO groups. The spectroscopic data indicate that 3 is probably a trinuclear complex containing bridging oxido and Hssal ligands containing two five-coordinate and one six-coordinate tin atoms. The complexes effectively interact with ATP and DAMP nucleotides forming Sn–OP bonds and O′–H′…O and N…H–O (nucleotide–Hssal) hydrogen bonds. All compounds are very effective cytotoxic agents against tumor cells. The cytotoxic activity changes in the order 2 > 1 > 3. Their activity toward non-tumor NHDF cells is much lower. They show also antibacterial and antifungal activity. [Copyright &y& Elsevier]

The use of tributyltin (TBT) has been banned in Korea since 2003. In this study, changes in butyltin compound concentration from 1992 to 2009 were examined by area. The number of ships, which greatly influences butyltin compound contamination, continuously increased, but butyltin compound concentration decreased. Results indicated that the regulation of TBT is effective in Korea. The increase in the concentration was caused by military and coast-guard ships, ballast water, and the illegal use of materials. According to port distribution characteristics along the Korean coasts, the level of butyltin compound contamination was high along the west and south coasts in 1992, whereas it was high along the south and east coasts since 2006. We found that overall butyltin compound concentrations decreased in Korea, but concentrations remained high in some regions. [ABSTRACT FROM AUTHOR]

Abstract: Three butyltin complexes with 2-sulfobenzoic acid [Sn(C4H9)2{O3SC6H4COO-2}(H2O)]·(C2H5OH) (1), [Sn(C4H9)3{O3SC6H4COOH-2}] (2) and [Sn2(C4H9)6{μ-O3SC6H4COO-2}] (3) have been synthesized and characterized by IR and 1H, 13C and 119Sn NMR spectra. They show interesting properties in solid state and solutions because there are many modes of coordination of the Sbz ligand. The structure of complex 1 has been determined by X-ray crystallography. It is a chain compound with 2-sulfonatobenzoate coordinated to Sn atoms as a bridging and chelate ligand via O atoms of COO and SO3 groups. In solutions the chains dissociate giving mainly mononuclear complexes. The NMR spectra and calculation at the DFT B3LYP/3-21G** level indicate that in solutions of compounds 1, 2 and 3 in polar solvents, many complexes showing dynamic properties are formed. Density functional theory (DFT) calculations showed that many five- and six-coordinate isomers and conformers can exist in equilibrium. All compounds effectively interact with AMP and ATP. The NMR spectra showed that nucleotides are coordinated to Sn atoms via PO4 groups. The complexes are very active cytostatic agents against tumor strains. They are more effective than cisplatin. It is interesting that activity of 3 against non-tumor cell NHDF is lower than against tumor cells. Antibacterial activity of 1 and 2 has been investigated. Compound 2 is a very effective agent against Gram-positive bacteria. Antibacterial activity of 1 is lower than that of 2. Activity of 1 both against Gram-positive and Gram-negative bacteria is similar. [Copyright &y& Elsevier]

Abstract: Evaluation of the assimilation pathway and depuration time of a given pollutant by aquatic species is important to understand the dynamics of this substance in the biota, and to search for potential ecological indicators. In the present study, the uptake pathway and depuration time and rate of the pollutant tributyltin (TBT) were investigated in the omnivorous hermit crab (Clibanarius vittatus). The assimilation and uptake pathway were investigated using hermit crabs collected in an area free of TBT. The crabs were held in the laboratory for 45 days, under one of four treatments: procedural control (PC) – water and food without TBT; T1 – water with and food without TBT; T2 – water without and food with TBT; and T3 – water and food with TBT. To determine the depuration time, the crabs were collected in a contaminated area, maintained in the laboratory with clean water, and removed every 15 days for 120 days. The concentrations of TBT and DBT (dibutyltin) were determined by chromatographic analysis. The TBT was taken up by the crabs mainly via food, and the presence of DBT in crab tissues was hypothesized to result from internal TBT degradation. TBT (as well as DBT) was depurated rapidly by C. vittatus. After approximately 30 days, the initial concentration of 111±36ngSng−1 w.w. decreased to 3±3ngSng−1 w.w., and after 75 days the TBT concentration was below the detection limit. The same pattern was recorded for DBT, which showed a higher depuration rate than TBT. The rapid TBT and DBT depuration is useful information, since C. vittatus and possibly other hermit crabs may be used as indicators of recent or recycled environmental contamination. [Copyright &y& Elsevier]

Abstract: An environmentally friendly method for the determination of seven organotin compounds in honey and wine samples, using headspace solid-phase microextraction (HS-SPME) and gas chromatography (GC), was developed. The analytes were derivatized in situ with sodium tetraethylborate, and the derivatization and preconcentration steps were optimized. A 100μm polydimethylsiloxane fiber was the most suitable for preconcentrating the derivatized analytes from the headspace of an aqueous solution containing the sample. When microwave-induced plasma atomic emission (MIP-AED) and mass spectrometry (MS) detection were compared, higher sensitivity was attained for all compounds with MS, although MIP-AED showed more specific chromatograms. Using MS, detection limits ranged roughly from 0.3 to 4.3pg(Sn)/g, depending on the compound for honey samples, and from 0.1 to 2pg(Sn)/mL for wine samples. The optimized method was successfully applied to different samples, and the compounds studied were detected in some wines at 0.05–5ng(Sn)/mL levels. [Copyright &y& Elsevier]

Butyltins (BTs), such as tributyltin (TBT) and dibutyltin (DBT), are toxic to aquatic organisms, but the presence of the strong adsorbent, black carbon (BC), can markedly influence BT toxicity and uptake in organisms. In the present study, the acute toxicity and uptake of TBT and DBT in the crustacean, Daphnia magna, were investigated with and without addition of nano-charcoal at different pHs and water hardnesses. The results showed that the toxicity of TBT and DBT increased by lowering the pH from 8 to 6. This reflects a relatively higher toxicity of cationic BT species than of the neutral species. At pH 6, by enhancing the water hardness of the media from 0.6 to 2.5 mM, the toxicity of TBT and DBT consistently decreased due to competitive binding of bivalent cations (Mg2+, Ca2+) to biotic ligands of D. magna. Furthermore, the toxicity of TBT to D. magna significantly decreased in the presence of nano-charcoal compared with experiments without nano-charcoal at pH 6 and 8, while no significant decrease in toxicity of DBT was observed in the presence of nano-charcoal. This can be attributed to the insignificant decrease of free DBT concentration in the presence of nano-charcoal compared with that for TBT. Conversely, it was observed that more TBT and DBT were taken up in D. magna in the presence of nano-charcoal due to the uptake of TBT or DBT associated with nano-charcoal by Daphnia in gut systems, as seen by light microscopy. This indicated that only free nonadsorbed BTs were toxic to D. magna, at least during short periods of exposure. Environ. Toxicol. Chem. 2011;30:2553-2561. © 2011 SETAC [ABSTRACT FROM AUTHOR]

A laboratory-established capillary gas chromatography (GC)-atomic fluorescence spectrometry (AFS) hyphenated system was applied to butyltin speciation in water samples. Monobutyltin (MBT), dibutyltin (DBT), and tributyltin (TBT) were extracted and preconcentrated with headspace solid-phase microextraction (SPME) technique after derivatization using KBH4, and then determined by GC-AFS directly. The experimental conditions-including the flow rates of carrier gas, argon and hydrogen-and the lamp current-were optimized in detail. Under the optimum conditions, the detection limits for MBT, DBT, and TBT, calculated as three times the baseline noise, were 10, 0.2, and 0.1 ng mL-1 Sn, respectively. Good linear relationships were obtained when the concentrations of MBT, DBT, and TBT increased to 3000, 100, and 200 ng mL-1 Sn. The relative standard deviations (RSDs) of five replicates were 5.2%, 7.4%, and 7.1% for MBT, DBT, and TBT, respectively. The recoveries of MBT, DBT, and TBT in three different types of water samples (seawater, tap water, and wastewater) were between 72.1% and 97.9%, indicating that the proposed method was accurate and feasible for speciation analysis of butyltin compounds in water samples. [ABSTRACT FROM AUTHOR]

Abstract: Tri-n-butyltin (TBT) has long been considered as the most toxic among organotins, especially to membrane systems. The partially dealkylated derivative di-n-butyltin (DBT) has up to now received poor attention and, whenever considered, shown to be less toxic than TBT except on the immune system. The present kinetic approach evidences that both TBT and DBT in vitro inhibit the Mg-ATPase in mussel digestive gland mitochondria by a different mechanism. DBT even displays a higher efficiency than TBT (IC50 =0.32μM for TBT vs. 0.19μM for DBT) in inhibiting the enzyme hydrolytic activity. Differently from TBT which at high concentrations (>1μM) apparently decreases the oligomycin-sensitivity of the Mg-ATPase, DBT at any concentration tested does not affect the oligomycin sensitivity. TBT probably binds to F0, either in the form of free enzyme or of enzyme–substrate complex (Ki =K′i), acting as non-competitive inhibitor with respect to the ATP substrate. Conversely DBT, which acts as uncompetitive inhibitor of ATP and as competitive inhibitor of Mg2+ cofactor, may bind strongly to F1 subunit, thus preventing ATP hydrolysis. The Mg-ATPase inhibition by both organotins warns against a potential threat to crucial cell energy metabolism processes even after years from contamination and partial TBT debutylation. [ABSTRACT FROM AUTHOR]

Natural killer (NK) cells are a major immune defense mechanism against cancer development and viral infection. The butyltins (BTs), tributyltin (TBT) and dibutyltin (DBT), have been widely used in industrial and other applications and significantly contaminate the environment. Both TBT and DBT have been detected in human blood. These compounds inhibit the lytic and binding function of human NK cells and thus could increase the incidence of cancer and viral infections. Butyltin (BT)-induced loss of NK function is accompanied by activation of mitogen activated protein kinases (MAPKs) and decreases in expression of cell-surface and cytolytic proteins. MAPKs activate components of the transcription regulator AP-1 and activate the transcription regulator Elk-1. Based on the fact that BTs activate MAPKs and alter protein expression, the current study examined the effect of BT exposures on the levels and phosphorylation states of the components of AP-1 and the phosphorylation state of Elk-1. Exposure to 300 nM TBT for 10 min increased the phosphorylation of c-Jun in NK cells. One hour exposures to 300 nM and 200 nM TBT increased the phosphorylation and overall level of c-Jun. During a 300 nM treatment with TBT for 1 h the binding activity of AP-1 was significantly decreased. There were no significant alterations of AP-1 components or of Elk-1 with DBT exposures. Thus, it appears that TBT-induced alterations on phosphorylation, total levels, and binding activity of c-Jun might contribute to, but are not fully responsible for, TBT-induced alterations of NK protein expression. [ABSTRACT FROM AUTHOR]

Most analytical methods for butyltins are based on high resolution techniques with complicated sample preparation. For this study, a simple application of an analytical method was developed using High Performance Liquid Chromatography (HPLC) with UV detection. The developed method was studied to determine tributyltin (TBT), dibutyltin (DBT) and monobutyltin (MBT) in sediment and water samples. The separation was performed in isocratic mode on an ultra cyanopropyl column with a mobile phase of hexane containing 5% THF and 0.03% acetic acid. This method was confirmed using standard GC/MS techniques and verified by statistical paired t-test method. Under the experimental conditions used, the limit of detection (LOD) of TBT and DBT were 0.70 and 0.50 μg/mL, respectively. The optimised extraction method for butyltins in water and sediment samples involved using hexane containing 0.05-0.5% tropolone and 0.2% sodium chloride in water at pH 1.7. The quantitative extraction of butyltin compounds in a certified reference material (BCR-646) and naturally contaminated samples was achieved with recoveries ranging from 95 to 108% and at %RSD 0.02-1.00%. This HPLC method and optimum extraction conditions were used to determine the contamination level of butyltins in environmental samples collected from the Forth and Clyde canal, Scotland, UK. The values obtained severely exceeded the Environmental Quality Standard (EQS) values. Although high resolution methods are utilised extensively for this type of research, the developed method is cheaper in both terms of equipment and running costs, faster in analysis time and has comparable detection limits to the alternative methods. This is advantageous not just as a confirmatory technique but also to enable further research in this field. [ABSTRACT FROM AUTHOR]

Murray cod (Maccullochella peelii peelii) is an iconic native Australian freshwater fish and an ideal species for ecotoxicological testing of environmental pollutants. The species is indigenous to the Murray-Darling basin, which is the largest river system in Australia but also the ultimate sink for many environmental pollutants. The organotins tributyltin (TBT) and dibutyltin (DBT) are common pollutants of both freshwater and marine environments and are also known for their immunotoxicity in both mammals and aquatic organisms. In this study, TBT and DBT were used as exemplar immunotoxins to assess the efficiency of immune function assays (i.e., mitogen-stimulated lymphoproliferation, phagocytosis in head kidney tissue, and serum lysozyme activity) and to compare the sensitivity of Murray cod to other fish species. The organotins were lethal to Murray cod at concentrations previously reported as sublethal in rainbow trout (i.e., intraperitoneal [i.p.] lethal dose to 75% of the Murray cod [LD75] = 2.5 mg/kg DBT and i.p. lethal dose to 100% of the Murray cod [LD100] = 12.5 mg/kg TBT and DBT). In vivo TBT exposure at 0.1 and 0.5 mg/kg stimulated the phagocytic function of Murray cod (F = 6.89, df = 18, p = 0.004), while the highest concentration of 2.5 mg/kg TBT decreased lymphocyte numbers (F = 7.92, df = 18, p = 0.02) and mitogenesis (F = 3.66, df = 18, p = 0.035). Dibutyltin was the more potent immunosuppressant in Murray cod, causing significant reductions in phagocytic activity (F = 5.34, df = 16, p = 0.013) and lymphocyte numbers (F = 10.63, df = 16, p = 0.001). [ABSTRACT FROM AUTHOR]

Different anode materials were tested to evaluate their suitability to eliminate organotin compounds electrochemically from shipyard process waters. The capacity of two types of anode materials was investigated: niobium coated with boron-doped diamond (BDD) and titanium coated with iridium dioxide, (Ti/IrO2). The aim of this work was to characterize the performance of the process using both anode materials at different current densities, and also to evaluate the generation of by-products. A further objective of this work was to evaluate if operating at low potentials with BDD anodes (to avoid the generation of elemental oxygen) the consumption of energy for degradation of pollutants could be minimized. The processes were tested on synthetic and real shipyard water containing approximately 25,000ngL−1 of tributyltin (TBT) (as Sn) and 5000ngL−1 dibutyltin. The range of current densities was between 6 and 70mAcm−2. The results showed that electrochemical treatment is suitable to eliminate organotins down to very low concentrations following a stepwise debutylation mechanism. Both anode materials exhibited a similar performance with energy consumption in the range of 7–10kWhm−3 in order to decrease organotins down to 100ngL−1 (as Sn). For the water composition tested, BDD did not outperform Ti/IrO2 as initially expected, most probably because organotins were not only oxidized by lso by active chlorine compounds generated by the oxidation of chloride present in the wastewater (1.6gL−1, Cl−) with both anode materials. It was also found that the residual oxidants remaining in the treated effluent had to be eliminated if the water is to be discharged safely in the aquatic environment. [Copyright &y& Elsevier]

A treatment process for marine sediment heavily contaminated with tributyltin (TBT) was designed that included dehydrating, sunlight drying and dumping processes. The time course in butyltin (BTs) compounds, TBT, dibutyltin (DBT) and monobutyltin concentrations were investigated in the sediment treated under various conditions (light (UV, sunlight and light exclusion), moisture (air-drying and water saturation) and wetting and drying cycles). Significant changes in all the BT compound concentrations with time were not found regardless of the sediment conditions for light and moisture. The results indicated the high stabilities of TBT and DBT in the sediments versus light and moisture condition changes, probably taking place in the treatment process. It is also estimated that the BTs in the sediment are resistant to photo-degradation and biochemical degradation and their half lives are relatively long. In contrast, the decreases in the TBT and DBT were observed during the wetting and drying cycle treatment for the water saturated sediment both during exposure to sunlight and under a dark condition. This result suggested the hypothesis that the TBT degradation could be accelerated by the high microbial activity induced by the moisture changing treatments. [Copyright &y& Elsevier]

Abstract: A simple, fast, and accurate method for the simultaneous determination of methylmercury (MeHg+), monobutyltin (MBT), dibutyltin (DBT) and tributyltin (TBT) in seafood is proposed. The method makes use of relatively cheap instrumentation and allows simultaneous analysis of those four species in a routine basis. The sample is treated with methanolic potassium hydroxide in an ultrasound bath, derivatised with sodium tetraethylborate (NaBEt4), preconcentrated into n-hexane and analysed by gas chromatography with atomic emission detection (GC–MIP/AES). The soft extraction conditions provided by ultrasound energy prevent chemical decomposition of the analytes and allow fast and efficient recovery of the species considered. Both the extraction and the derivatisation/preconcentration steps were optimised. Detection limits of 34, 3, 6 and 8ngg−1 (dry mass) were obtained for MeHg+, MBT, DBT and TBT, respectively, using the best experimental conditions found. The uncertainty of the analysis ranged from 11% (MeHg+) to 15% (MBT). The accuracy of the method was checked by the analysis of several certified reference materials, e.g., BCR 477 (mussel tissue, MBT, DBT and TBT), DOLT-2 (dogfish liver, MeHg+), BCR 463 (tuna fish, MeHg+) and NIST 2976 (mussel tissue, MeHg+) with satisfactory results. Several oyster samples collected in the estuary of the Oka River (Urdaibai, Unesco Reserve of the Biosphere, Basque Country) during four sampling campaigns in 2003–2004 were processed following the proposed procedure. Concentrations ranging from 65 to 149ngg−1 (MeHg+),

Abstract: A liquid chromatographic method is described for the simultaneous determination of tributyltin (TBT) and the hydroxylated intermediate 4-hydroxybutyldibutyltin (OHBuDBT). Separation was achieved in reverse phase mode on a cyanopropyl-bonded silica column under a gradient elution. Various organic solvents and additives were tested and the optimum composition of the mobile phase contained methanol, water, formic acid and tropolone as a complexing agent. Butyltin compounds were detected with an ion trap mass spectrometer interfaced to a liquid chromatograph with an atmospheric pressure chemical ionization source (LC–APCI-MS). Identification and fragmentation pattern of OHBuDBT chloride in full scan MS and MS/MS are reported for the first time using LC–APCI-MS. Gas chromatography–mass spectrometry (GC–MS) spectrum of the same compound is also reported for the first time for comparison purpose. This method allowed limits of detection (LOD) of 35 and 26ngmL−1 for TBT and OHBuDBT, respectively, based on successive injections of 10μL of blank seawater extract. A liquid–liquid extraction procedure using n-hexane–ethyl acetate was developed for the simultaneous analysis of TBT and OHBuDBT chlorides in natural seawater and allowed average recoveries from 72 to 96% for the two compounds at three different spiking levels. [Copyright &y& Elsevier]

The objective of this study was to estimate the intake of organic tin compounds from foodstuffs in a Finnish market basket. The study was conducted by collecting 13 market baskets from supermarkets and market places in the city of Kuopio, eastern Finland. Altogether 115 different food items were bought. In each basket, foodstuffs were mixed in proportion to their consumption and analysed by GC/MS for seven organic tin compounds (mono-, di-, and tributyltin, mono-, di-, and triphenyltin, and dioctyltin). Organotin compounds were detected in only four baskets, with the fish basket containing the largest number of different organotins. The European Food Safety Authority has established a tolerable daily intake of 250  ng  kg -1 body weight for the sum of dibutyltin, tributyltin, triphenyltin and dioctyltin. According to this study, the daily intake of these compounds was 2.47  ng  kg -1 body weight, of which 81% originated from the fish basket. This exposure is only 1% of the tolerable daily intake and poses negligible risk to the average consumer. However, for consumers eating large quantities of fish from contaminated areas, the intake may be much higher. [ABSTRACT FROM AUTHOR]

Abstract: Here we provided evidence, for the first time, on the placental transfer of butyltin species in Dall’s porpoise (Phocoenoides dalli). The maternal to fetal transfer of butyltins including monobutyltin (MBT), dibutyltin (DBT) and tributyltin (TBT) was investigated in a mother–fetus pair collected off the Sanriku coast of Japan. The maternal individual was found contaminated as its liver accumulated the highest concentrations of all MBT, DBT and TBT. This study revealed that the transfer rate was about 0.3% for total butyltins to a fetus of about 6 months old. Unlike in the mother, the fetal liver does not appear to be a preferential organ for accumulation of all the butyltins. In a approximately 100kg-weight mother Dall’s porpoise and its fetus of 2.21kg-weight about 1269μg (TBT, 578μg; DBT, 480μg; MBT, 211μg) and 4.2μg of total butyltins (TBT, 1.1μg; DBT, 2.1μg; MBT, 0.96μg) were found, respectively. [Copyright &y& Elsevier]

Abstract: Concentrations and body burdens of 14 trace elements (Hg, Cr, Mn, Co, Cu, Zn, Sr, Ag, Cd, V, Se, Pb, Mo, and Fe) and butyltins (BTs) (tributyltin TBT, dibutyltin DBT, and monobutyltin MBT) were determined in various tissues of a mature male Dall’s porpoise (Phocoenoides dalli) collected off the Sanriku coast of Japan. Selective accumulation in this porpoise was observed for Hg, Mn, Cu, Ag, Mo, Fe, and total BTs (TBT, DBT, and MBT) in the liver, Cd in the kidney, Zn, Sr, V, Pb, and Co in the bone, and Se in the skin. In contrast, Cr concentrations in all tissues were similar. This distribution pattern in this mature porpoise was in general agreement with the accumulation characteristics of trace elements and butyltins reported for other marine mammals. The whole body of the porpoise contained approximately 62g Fe, 8.8g Zn, 4.0g Sr, 0.6g Se, 0.41g Cu, 0.19g Hg, 0.17g Cd, 0.16g Mn, 0.05g Cr, 0.009g Ag, 0.008g Mo, 0.005g Pb, 0.004g Co, and 0.7mg of BTs (0.4mg TBT, 0.2mg DBT, and 0.1mg MBT). Metabolism of TBT to its breakdown products of this porpoise seems to be limited, since TBT still accounted for about half of the total burden of BTs. As in the cases of Hg, Mn, Cu, Se, and Fe, the muscle was the most important reservoir (43%) for the whole body burden of total BTs, 80% of which was TBT, and thus muscle played a crucial role in the higher body composition of TBT in this Dall’s porpoise. [Copyright &y& Elsevier]

Abstract: In the present contribution, a new automated on-line hydride generation methodology was developed for dibutyltin and tributyltin speciation at the trace level, using a programmable temperature-vaporizing inlet followed by capillary gas chromatography coupled to mass spectrometry in the selected ion-monitoring mode acquisition (PTV-GC/MS(SIM)). The methodology involves a sequence defined by two running methods, the first one configured for hydride generation with sodium tetrahydroborate as derivatising agent and the second configured for speciation purposes, using a conventional autosampler and data acquisition controlled by the instrument''s software. From the method-development experiments, it had been established that injector configuration has a great effect on the speciation of the actual methodology, particularly, the initial inlet temperature (−20°C; He: 150ml/min), injection volume (2μl) and solvent characteristics using the solvent venting mode. Under optimized conditions, a remarkable instrumental performance including very good precision (RSD<4%), excellent linear dynamic range (up to 50μg/ml) and limits of detection of 0.12μg/ml and 9ng/ml, were obtained for dibutyltin and tributyltin, respectively. The feasibility of the present methodology was validated through assays upon in-house spiked water (2ng/ml) and a certified reference sediment matrix (Community Bureau of Reference, CRM 462, Nr. 330 dibutyltin: 68±12ng/g; tributyltin: 54±15ng/g on dry mass basis), using liquid–liquid extraction (LLE) and solid-phase extraction (SPE) sample enrichment and multiple injections (2×5μl) for sensitivity enhancement. The methodology evidenced high reproducibility, is easy to work-up, sensitive and showed to be a suitable alternative to replace the currently dedicated analytical systems for organotin speciation in environmental matrices at the trace level. [Copyright &y& Elsevier]

Organotins, important environmental pollutants widely used in agricultural and industrial applications, accumulate in the food chain and induce imposex in several marine species as well as neurotoxic and immunotoxic effects in higher animals. Reduced birth weight and thymus involution, observed upon exposure to organotins, can also be caused by excessive glucocorticoid levels. We now demonstrate that organotins efficiently inhibit 11β-hydroxysteroid dehydrogenase type 2 (11β-HSD2), converting active 11β-hydroxyglucocorticoids into inactive 11-ketoglucocorticoids, but not 11β-HSD1, which catalyzes the reverse reaction. Di- and tributyltin as well as di- and triphenyltin inhibited recombinant and endogenous 11β-HSD2 in lysates and intact cells with IC50 values between 500 nM and 3 µM. Dithiothreitol protected 11β-HSD2 from organotin-dependent inhibition, indicating that organotins act by binding to one or more cysteines. Mutational analysis and 3-D structural modeling revealed several important interactions of cysteines in 11β-HSD2. Cys90, Cys228, and Cys264 were essential for enzymatic stability and catalytic activity, suggesting that disruption of such interactions by organotins leads to inhibition of 11β-HSD2. Enhanced glucocorticoid concentrations due to disruption of 11β-HSD2 function may contribute to the observed organotin-dependent toxicity in some glucocorticoid-sensitive tissues such as thymus and placenta. [ABSTRACT FROM AUTHOR]

A copper(II) complex with o ‐phthalate acid [Cu( o ‐phth)(H 2 O)] n (1) and a cobalt(II) complex with 3‐nitro‐phthalic acid and 4,4′‐bipyridine [Co(3‐nitro‐phth) (4,4′‐bipy) 2 (H 2 O) 3 ] n (2) have been synthesized. These two novel complexes were characterized by IR, X‐ray crystallography diffraction. Complex 1 belongs to monoclinic crystal with C2 (1)/c space group, the complex 2 triclinic crystal with P‐1. Also, electrochemical properties of these complexes and thermal decomposition process of complex 1 were investigated. [ABSTRACT FROM AUTHOR]

Three new organotin derivatives of polyoxometalates have been obtained by reaction between the trilacunary precursors [PW 9 O 34 ] 9- and [AsW 9 O 34 ] 9- and organotin trichlorides RSnCl 3 (R=Me, Bu) in aqueous solution. The compounds were characterized using elemental and thermogravimetrical analysis, UV, IR, Raman and multinuclear ( 1 H, 13 C, 31 P) NMR spectroscopy, ESI‐MS and cyclic voltammetry. Ion‐exchange, and ESI‐MS experiments provided evidence for covalent, inner‐sphere bonding of organotin groups to the trilacunary [XW 9 O 34 ] 9- heteropolyanions. Cyclic voltammograms of all three organotin complexes exhibited two pairs of reduction/oxidation waves with negative half‐wave potential (E 1/2 ) values. These waves were attributed to redox processes corresponding to the polyoxotungstate framework. [ABSTRACT FROM AUTHOR]

Organotin as monobutyltin (MBT), dibutyltin (DBT) and tributyltin (TBT) compounds are used as fungicides and anti-fouling compounds; small amounts are added to the new European Euro bills. Little is known about the toxicological profile of these compounds uptake and metabolism. We, therefore, studied the cytotoxicity of these agents in different cell lines, i.e., liver HepG2, renal LLC-MK2 and ocular CEC cells. As a measure of cell growth and death, the neutral red assay and the release of LDH into the medium were used. IC50 values for growth inhibition by TBT were calculated as 160 nM in LLC-MK2, 150 nM in HepG2 and 180 nM in CEC cells; for DBT the corresponding values were higher, i.e., 500 nM DBT for LLC-MK2 cells, 300 nM for HepG2 cells and 220 nM for CE cells. ED50 values for LDH release indicating disturbances of the outer cell membrane was > 250 nM for TBT and > 350 nM for DBT in all cells. MBT was not toxic in concentrations up to 500 nM. Electron microscopic studies of cells treated with 300 nM tributyltin indicated severe mitochondrial damage with much less effect seen in other cell structures. We conclude that no differences exist between different cell lines that may serve as examples of tissues relevant for organotin exposure (eye), metabolism (liver) and specific metalloid damage (kidney). Growth inhibition was affected at organotin concentrations between 150 and 500 nM. This concentration is approximately 70–200 fold higher than values estimated in environmental samples. [ABSTRACT FROM AUTHOR]

Abstract: The in-situ solid/pore-water partitioning of tributyltin (TBT), dibutyltin (DBT) and monobutyltin (MBT) was determined for an estuarine sediment profile collected from a commercial marina. Total butyltin levels exceeded sediment quality guideline values, and were 220–8750μg/kg for TBT, 150–5450μg/kg for DBT and 130–4250μg/kg for MBT. Pore-water butyltin concentrations ranged from 0.05 to 2.35μg/l for TBT, 0.07–3.25μg/l for DBT, and 0.05–0.53μg/l for MBT. The partitioning of butyltin compounds between the sediment solid-phase and pore-water was described by an organic carbon normalised distribution ratio (D OC). The observed D OC values were similar for TBT, DBT and MBT, and were 105–106 l/kg. Values for the Butyltin Degradation Index (BDI) were larger than 1 at depths greater than 10cm below the sediment/water-column interface. This indicates that substantial TBT degradation has occurred in the sediments, and suggests that natural attenuation may be a viable sediment remediation strategy. [Copyright &y& Elsevier]

An in vitro gastrointestinal digestion approach in combination with species-specific isotope dilution analysis has been employed for the first time to study the transformation reactions as well as the solubilisation of butyltin species throughout a simulated human digestion. Different sample preparation procedures were assayed in order to avoid problems derived from lack of isotope equilibration between the endogenous and the isotopically-enriched added species. A “triple spike” approach, which can be used to calculate the corrected concentrations of mono-, di-, and tributyltin (MBT, DBT and TBT, respectively), as well as six interconversions, was employed throughout this work. In order to calculate and compare the species degradation factors, a triple spike solution containing each butyltin species enriched in a different isotope was added to the simulated gastric and intestinal fluids before the digestion procedures in the presence and in the absence of a solid biological matrix (commercial mussel tissue). Additionally, by analysing the soluble and insoluble fractions resulting from the simulated digestion of a commercial mussel tissue (gastric and gastric plus intestinal digestion), total mass balances for each butyltin compound could be derived. For this purpose, the isotopically-enriched species were added after the enzymatic digestions in order to avoid problems derived from lack of isotope equilibration. The mass balances provided information not only about the solubilisation but also about the degradation of the butyltin species during the digestion procedures. Good agreement between the degradation factors calculated under all experiments performed in this work and between those reported in previous works were obtained. The most serious degradation observed was that of DBT to produce MBT, whereas slight degradations of TBT and MBT were detected. Moreover, a worrying 61% of the original total butyltin content present in a commercial mussel tissue was found to be solubilised after complete simulated gastrointestinal digestion, with minimal degradation of TBT. [ABSTRACT FROM AUTHOR]

A procedure for the simultaneous determination of six organotin compounds, including methyl-, butyl- and phenyltins, in waters and marine sediments is developed. The analytes were leached from the solid samples into an acetic acid:methanol mixture by using an ultrasonic probe. The organotins were derivatized with sodium tetraethylborate (NaBEt4) in the aqueous phase, stripped by a flow of helium, pre-concentrated in a trap and thermally desorbed. This was followed by capillary gas chromatography with microwave-induced plasma atomic emission spectrometry as the detection system (GC–AED). Each chromatographic run took 22min, including the purge time. Calibration curves were obtained by plotting peak area versus concentration and the correlation coefficients for linear calibration were at least 0.9991. Detection limits ranged from 11 to 50ngSnl-1 for tributyltin and tetramethyltin, respectively. The seawater samples analyzed contained variable concentrations of mono-, di- and tributyl- and monophenyltin, ranging from 0.05 to 0.48μgSnl-1, depending on the compound. Some of the sediments analyzed contained concentrations of dibutyl- and tributyltin of between 6.0 and 13.0ngSng-1. Analysis of the certified reference material PACS-2, as well as of spiked water and sediment samples showed the accuracy of the method. The proposed method is selective and reproducible, and is considered suitable for monitoring organotin compounds in water and sediment samples. [Copyright &y& Elsevier]

Organotin compounds, triphenyltin (TPT), tributyltin, dibutyltin, and monobutyltin (MBT), showed potent inhibitory effects on both l-arginine oxidation to nitric oxide and l-citrulline, and cytochrome c reduction catalyzed by recombinant rat neuronal nitric oxide synthase (nNOS). The two inhibitory effects were almost parallel. MBT and TPT showed the highest inhibitory effects, followed by tributyltin and dibutyltin; TPT and MBT showed inhibition constant (IC50) values of around 10μM. Cytochrome c reduction activity was markedly decreased by removal of calmodulin (CaM) from the complete mixture, and the decrease was similar to the extent of inhibition by TPT and MBT. The inhibitory effect of MBT on the cytochrome c reducing activity was rapidly attenuated upon dilution of the inhibitor, and addition of a high concentration of CaM reactivated the cytochrome c reduction activity inhibited by MBT. However, other cofactors such as FAD, FMN or tetrahydrobiopterin had no such ability. The inhibitory effect of organotin compounds (100μM) on l-arginine oxidation of nNOS almost vanished when the amount of CaM was sufficiently increased (150–300μM). It was confirmed by CaM–agarose column chromatography that the dissociation of nNOS–CaM complex was induced by organotin compounds. These results indicate that organotin compounds disturb the interaction between CaM and nNOS, thereby inhibiting electron transfer from the reductase domain to cytochrome c and the oxygenase domain. [Copyright &y& Elsevier]

Four new compounds of organic mono carboxylic acid, 3-maleimidopropionic acid; with Bu2Sn(IV)2+, Ph3Sn(IV)+ and Cychex3Sn(IV)+ having ligand to metal ratio 1:2 and 1:1 were prepared. The spectrophotometric techniques used for structure determination like 1H-, 13C- and 119Sn-NMR, FT IR and 119mSn Mössbauer have demonstrated that the organotin(IV) moieties establish chemical bonding with the ligand through carboxylic oxygen atom. The percent CHN analyses and MS data also corroborates the spectroscopic results. During in vitro LD50, anti-fungal, anti-bacterial and anti-yeast bioassays promising results were exhibited. In vitro anti-tumour activity assays against five human tumor cell lines, MCF-7 Breast cancer-EVSA-T Breast cancer-WiDr Colon cancer-IGROV Ovarian cancer-M226 Non small cell lung cancer and anti-inflammatory screenings furnished the significant toxicities of the title complexes. In addition the triorganotin(IV) complexes were comparatively less toxic than the diorganotin(IV) complexes. [ABSTRACT FROM AUTHOR]

The main objective of the work was the setup of the Caco-2 human intestinal cell-line model for the study of the intestinal permeation of monobutyltin (MBT), dibutyltin (DBT) and tributyltin (TBT). The study was focused in gathering information on (a) the relative permeability of butyltins, (b) their possible permeation routes (paracellular/transcellular) and (c) the eventual interactions between the different butyltins when occurring as a mixture. The presence of basolateral serum protein greatly influenced the permeability, causing a large net clearance, but the apparent permeability (Papp) values were comparable to that of phenolred, suggesting a low in vivo permeability of the butyltins. The found permeability pattern correlates well with the general in vivo toxicity pattern (trialkyltin > dialkyltin ≫ monoalkyltin). The accumulation pattern (DBT > TBT > MBT) was different from that of permeability and may be an important element regarding the elucidation of some specific strong toxic effects caused by the dialkyltins in several species. The transport of MBT and DBT was found to be dependent on the paracellular route status. An interaction between the butyltin compounds in a mixture was found for the accumulation results (the accumulation was significantly higher for the three compounds when in a mixture). A set of useful information about the butyltin accumulation and transport by the epithelial Caco-2 cell line was, thus, achieved, constituting a starting point for future research on the permeability of butyltins from contaminated food and beverages. [Copyright &y& Elsevier]

A GC–ICP–MS method based on extraction and alkylation of butyltins with sodium tetraethylborate was used to quantitatively assess the fate of these analytes in solutions and sediments following exposure to γ-irradiation. The effects of a 2.5 Mrad sterilization dose on three butyltin species in both methanolic calibration solutions and in sediment matrices were investigated. Although significant losses of tributyltin (TBT, 90%), dibutyltin (DBT, 100%) and monobutyltin (MBT, 80%) were detected in standard solutions prepared in methanol following γ-irradiation, no species inter-conversion occurred. Some degradation of TBT (38%) and DBT (32%) but no significant change in MBT content was found using a spiked sediment CRM HISS-1. Conversion DBT to MBT in spiked HISS-1 was deduced. Much smaller degradation of TBT (16% loss) and 10% loss of DBT by conversion to MBT (14% gain) was registered using a sediment blend of PACS-2 and HISS-1 (SOPH). Despite some initial losses of TBT and DBT due to irradiation, better than 2% RSD in both TBT and DBT concentrations measured in twelve different bottles of blended sediment SOPH were obtained, indicating the material may be considered homogeneous for these analytes. Results from a long-term five-year stability study of PACS-2 show that all three butyltins are stable during storage at 4 °C followed with 2.5 Mrad minimum dose of γ-irradiation sterilization treatment. [ABSTRACT FROM AUTHOR]

Butyltins are widely used biocides and accumulate in the food chain. Tributyltin is an imposex-inducing endocrine disrupter in animals. Imposex is characterized by the development of additional male sex organs on females. In a previous study, we identified tributyltin as an inhibitor of human cytochrom P450 aromatase activity. The present work focuses on the impact of butyltins on human androgen metabolism. Activation of androgens is mediated by two human 5α-reductase isoenzymes. 5α-Reductase type 1 was completely inhibited by tributyltin chloride (IC50=19.9 μM) and dibutyltin dichloride (IC50=32.9 μM), whereas 5α-reductase type 2 was only inhibited by tributyltin chloride (IC50=10.8 μM). Both isoenzymes were not affected by tetrabutyltin or monobutyltin indicating that at least two butyl groups bound to the positively charged Sn are required for the interaction of butyltins with the enzymes. Tributyltin inhibited 5α-reductase type 1 competitively whereas an irreversible inhibition was evident for the type 2 isoenzyme. In contrast to the distinct effects on 5α-reductases, reductive brain 17β-hydroxysteroid dehydrogenase activity was not inhibited by any butyltin. Insufficient activation of androgens is responsible for developmental disorders of the male reproductive system such as hypospadias. At pharmacologic levels butyltins might contribute to the onset of developmental disorders of the male reproductive system. At present, however, it is unknown whether these levels are reached after acute or chronic exposure to butyltins. [Copyright &y& Elsevier]

Tributyltin (TBT), dibutyltin (DBT), and monobutyltin (MBT) compounds were quantitatively determined in surface-sediment samples collected from 23 sites in the commercial harbor of Alexandria City, Egypt. Butyltin concentrations in sediments varied widely depending on the sample location, ranging from less than 0.1 to 186 ng g-1 of Sn for MBT, less than 0.1 to 379 ng g-1 of Sn for DBT, and 1 to 2,067 ng g-1 of Sn for TBT. Elevated TBT concentrations, ranging from 727 to 2,067 ng g-1 of Sn were observed in harbors, marinas, and near ship-repair facilities, indicating that the butyltin-containing, antifouling paints of boats and vessels are the major source of butyltin contamination. The TBT concentration decreased rapidly away from potential source areas of boat docking and repair facilities. The high relative concentrations of TBT in the sediments indicated that degradation processes in the sediments are minor, probably due to the anoxic sedimentary conditions at the sampling sites and/or relatively fresh input of TBT to these sites. [ABSTRACT FROM AUTHOR]

Studies tributyltin (TBT) and its degradation products, mono-(MBT) and dibutyltin (DBT) in liver, kidney and brain tissues of adult southern sea otters (enhydra lutris nereis) found dead along the coast of California. Domination of the composition of butyltin compounds in sea otter tissues; Methodology used in the study; Findings of the study.

Dibutyltin applied cutaneously at 67 nmole/cm² produced minor histologic changes in rat dorsal skin while the same specific dose of tributyltin produced cellular necrosis. Dibutyltin at. 335 nmole/cm² also produced cellular necrosis but the development of the lesion was delayed compared with that produced by tributyltin. Dibutyltin at 67 nmole/cm² produced only minor vascular changes in rat dorsal skin as measured by increases in vascular permeability (dye leakage), tissue water content, and degree of erythema. In contrast, the same specific dose of tributyltin and 5 times this dose of dibutyltin both produced marked increases in vascular permeability, tissue water content, and erythema, the maximum increases of which were similar for both compounds although the times for attainment of the maxima differed. When the maximum increases of the individual vascular changes were used to assess the irritancy of dibutyltin and tributyltin. the same ranking order was obtained from each parameter and this order agreed with that obtained from the histologic assessment of tissue damage. The increase in water content of skin is a representative and quantitative measure of the vascular changes produced by cutaneous application of dibutyltin and tributyltin. Skin water content measurements should, therefore, be a useful parameter in future studies of the relationship between the vascular changes produced by irritants and the corresponding cellular injury, especially if it is applicable to other irritants. It is, however. necessary to billow the time course of the response in order to determine the maximum increase in water content. [ABSTRACT FROM AUTHOR]

[³H]thymidine is incorporated into DNA from epidermal and dermal slices of untreated dorsal skin at similar rates. Treatment of dorsal skin with dibutyltin (67 nmoles/sq cm) stimulated the incorporation of the nucleoside into DNA from both preparations (relative to zero time controls) but the greater increase incurred into DNA from epidermal slices. Single cutaneous applications of different applied doses of dibutyltin, tributyltin, and 1-chloro-2:4-dinitrobenzene altered the incorporation of [³H]thymidine into DNA of epidermal slices from the treated skin in a complex manner. Doses which produced minimal damage (as assessed histologically) stimulated the incorporation above zero time controls while doses producing moderate damage inhibited at early times and stimulated later. Doses which produced marked damage, not surprisingly, resulted in a marked and prolonged inhibition of incorporation. The increased incorporation of [³H]thymidine does not correlate with the degree of cellular damage as presently assessed histologically but does indicate the sensitivity and thus potential usefulness of biochemical parameters since considerable stimulation of thymidine incorporation was observed at times when minimal morphological changes were observed. [ABSTRACT FROM AUTHOR]

Melanoma is the most aggressive and deadly form of skin cancer, which is largely due to its propensity to metastasize. Therefore, with the aim to inhibit the growth and the metastatic dissemination of melanoma cells and to provide a novel treatment option, we studied the effects of the melanoma treatment with two organotin(IV) complexes of the meso-tetra(4-sulfonato-phenyl)porphine, namely (Bu2Sn)2TPPS and (Bu3Sn)4TPPS. In particular, we showed that nanomolar concentrations of (Bu2Sn)2TPPS and (Bu3Sn)4TPPS are sufficient to inhibit melanoma cell growth, to increase the expression of the full-length poly (ADP-ribose) polymerase (PARP-1), to induce the cell cycle arrest respectively at G2/M and G0/G1 through the inhibition of the Cyclin D1 expression and to inhibit cell colony formation. Nanomolar concentrations of (Bu2Sn)2TPPS and (Bu3Sn)4TPPS are also sufficient to inhibit the melanoma cell migration and the expression of some adhesion receptors. Moreover, we report that (Bu2Sn)2TPPS and (Bu3Sn)4TPPS act downstream of BRAF, mainly bypassing its functions, but targeting the STAT3 signalling protein. Finally, these results suggest that (Bu2Sn)2TPPS and (Bu3Sn)4TPPS may be effective therapeutic strategies for their role in the inhibition of melanoma growth and migration. [ABSTRACT FROM AUTHOR]