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PubMed2002

Asia-Pacific mussel watch: monitoring of butyltin contamination in coastal waters of Asian developing countries.

Butyltin compounds (BTs) including mono-, di-, and tributyltin and total tin (sigmaSn), were determined in green mussels (Perna viridis) from various Asian developing countries, such as Cambodia, China (Hong Kong and southern China), Malaysia, India, Indonesia, the Philippines, and Vietnam, to elucidate the contamination status, distribution, and possible sources and to assess the risks on aquatic organisms and humans. Butyltin compounds were detected in green mussels collected from all the sampling location investigated, suggesting widespread contamination of BTs along the coastal waters of Asian developing countries. Among butyltin derivatives, tributyltin (TBT) was the predominant compound, indicating its ongoing usage and recent exposures in Asian coastal waters. Higher concentrations of BTs were found in mussels collected at locations with intensive maritime activities, implying that the usage of TBT as a biocide in antifouling paints was a major source of BTs. In addition, relatively high concentrations of BTs were observed in mussels from aquaculture areas in Hong Kong and Malaysia, as it has been reported in Thailand. With the recent improvement in economic status in Asia, it is probable that an increase in TBT usage will occur in aquaculture. Although contamination levels were generally low in mussel samples from most of the Asian developing countries, some of those from polluted areas in Hong Kong, India, Malaysia, the Philippines, and Thailand revealed levels comparable to those in developed nations. Furthermore, the concentrations of TBT in some mussels from polluted areas exceeded the threshold for toxic effects on organisms and estimated tolerable average residue levels as seafoods for human consumption. A significant correlation was observed between the concentrations of sigmaBTs and sigmaSn in mussels, and sigmaBTs were made up mostly 100% of sigmaSn in mussels taken from locations having intensive maritime/human activities. This suggests that anthropogenic BTs represent the major source of tin accumulation in mussels. To our knowledge, this is a first comprehensive report on butyltin pollution monitoring in developing countries in the Asia-Pacific region.

Animals↗
PubMed2006

Antioxidative effect of quercetin and its equimolar mixtures with phenyltin compounds on liposome membranes.

Our earlier studies have shown that the compounds diphenyltin dichloride (DPhT) and triphenyltin chloride (TPhT) in the presence of UVC radiation enhanced the degree of phosphatidylcholine liposome membrane oxidation (J. Agric. Food Chem. 2005, 53, 76-83). The prooxidative behavior of the compounds has now been confirmed with the electron paramagnetic resonance method, which proved the possibility that the studied compounds can exist in free radical forms. The present work investigates the possibility of the protective action of quercetin on phosphatidylcholine liposome membranes exposed to the prooxidative action of DPhT and TPhT induced by UV radiation (lambda = 253.7 nm). The concentrations of quercetin and its equimolar mixtures with DPhT and TPhT were determined (and compared with well-known antioxidants as standards-trolox and butylated hydroxytoluene, also in the presence of phenyltins) as those that induce 50% inhibition in oxidation of liposomes radiated with UV. They are 5.1 +/- 0.10, 2.9 +/- 0.12, and 1.9 +/- 0.08 microM (differences between the values are statistically significant), constituting the following sequence of antioxidative activity: quercetin:TPhT > quercetin:DPhT > quercetin. This relation is confirmed by the results on the antiradical ability of quercetin and its mixtures with DPhT and TPhT toward the free radical 1,1-diphenyl-2-pricrylhydrazil. Similar sequences obtained in both studies suggest a possible mechanism of the antiradical action of the mixtures as free radical scavengers. We suggested that (i) quercetin's ability, documented by spectrophotometric, infrared attenuated total reflectance spectroscopy, (1)H NMR, and molecular modeling methods, to form complexes with phenyltins indicates a possible way of protection against the peroxidation caused by the free radical forms of phenyltins and (ii) the differentiation in the action of the quercetin/TPhT and quercetin/DPhT associates (statisticaly significant) may result from a different localization in the liposome membrane, which is indicated by the results of the fluorimetric studies.

Antioxidants↗
PubMed1991

Inhibitory effects of phenyltin compounds on stimulus-induced changes in cytosolic free calcium and plasma membrane potential of human neutrophils.

To clarify the inhibitory mechanisms by triphenyltin chloride (TPTCl) on superoxide anion formation in neutrophils, the effects of phenyltin compounds [TPTCl, diphenyltin dichloride (DPTCl2) and phenyltin trichloride (MPTCl3) on the increase of cytosolic free calcium and the changes in membrane potential in neutrophils stimulated by n-formyl-methionyl-leucyl-phenylalanine (FMLP) were examined. TPTCl and DPTCl2 concentration dependently inhibited the increase of fluorescence intensity of the dye 3,3'-dipropyl-thiodicarbocyanine iodide [diS-C3-(5)] (membrane potential probe) in neutrophils induced by 0.1 microM FMLP in the presence or absence of extracellular calcium (1.26 mM). TPTCl had a greater inhibitory effect on FMLP-mediated membrane potential change than that of DPTCl2. In the presence of extracellular calcium, TPTCl and DPTCl2 increased intracellular free calcium [( Ca2+]i) of unstimulated fura-2-loaded neutrophils at concentrations from 1.0 to 10 microM TPTCl and from 2.5 to 10 microM DPTCl2. TPTCl and DPTCl2 also increased slightly, in the absence of extracellular calcium, [Ca2+]i without stimulation of FMLP in neutrophils. However, TPTCl and DPTCl2 significantly inhibited the rise of [Ca2+]i in neutrophils stimulated by FMLP at concentrations from 2.5 microM to 10 microM TPTCl and at a concentration of 10 microM DPTCl2 in the absence of extracellular calcium. TPTCl and DPTCl2 significantly inhibited the superoxide anion production by FMLP at concentrations over 2.5 microM in the presence of extracellular calcium. In the absence of extracellular calcium, TPTCl and DPTCl2 also inhibited the superoxide anion production by FMLP at concentrations over 1.5 microM TPTCl and over 5.0 microM DPTCl2.(ABSTRACT TRUNCATED AT 250 WORDS)

Benzothiazoles↗
PubMed2006

Sources and fate of butyltins in the St. Lawrence Estuary ecosystem.

Butyltins (BTs) were determined in sediment, zooplankton, benthic fish and invertebrates in the St. Lawrence Estuary and its mixing zone with the Gulf of St. Lawrence (Canada) in an attempt to assess sources and fate of these compounds in a large ecosystem before the enforcement of the world-wide ban of TBT-based antifouling paints. All BTs (MBT, DBT and TBT) were found along the studied area (450 km) where the traffic of large vessels occurs around the year. Concentrations of total butyltins (BTs) in surface sediment were below 6 ng Sn g(-1) d.w. Total BTs concentrations found in zooplankton samples at the mouth of the Saguenay Fjord were the highest (793 ng Sn g(-1) d.w.), indicating the influence of the Fjord on the St. Lawrence contamination. Although a relatively low contamination level was measured in sediment, total BTs concentrations ranged from 9 to 489 ng Sn g(-1) d.w. for benthic organisms. Biota-sediment accumulation factors (BSAFs), calculated on the basis of the organic carbon content in the sediment (concentrations normalized to 1% Corg), ranged from 0.9 to 98.3, and are an indicator of an important source of BTs from the Saguenay Fjord particulate matter. This may be explained by the fact that when TBT is released in a large and deep well stratified coastal environment, it could bind to the suspended particulate matter and then be taken in charge by water column organisms and may be mostly metabolised before it reaches bottom sediment. Sediment is not considered as the main contributor to the contamination of fish and invertebrates. It is expected that any reduction of direct inputs of TBT from ship hulls in a near future should result in a rapid reduction of butyltins in the St. Lawrence ecosystem.

Animals↗
PubMed2006

Biochemical, ultrastructural and molecular characterization of the triphenyltin acetate (TPTA)-induced apoptosis in primary cultures of mouse thymocytes.

Triphenyltin acetate (TPTA), a triorganotin compound used in agriculture as a biocide, is immunotoxic in vivo and in vitro. The present study was undertaken to ascertain whether apoptosis might play a role in the TPTA toxicity in vitro. Mouse thymocyte primary cultures were exposed to 0, 4 and 8 micromol/L TPTA; methyl prednisolone (1 micromol/L) was used as a positive control. Cell aliquots were harvested after 0, 1, 2, 4, and 8 h and the presence of early or late apoptotic phenomena was checked by (a) morphological investigations; (b) spectrophotometric quantification of fragmented DNA and agarose gel electrophoresis; (c) cell flow cytofluorometry, using an annexin V-FITC kit; and (d) detection of in situ apoptosis by a colorimetric detection kit (Titer-Tacs). TPTA cytotoxicity was also evaluated using the trypan blue dye exclusion test. Morphological investigation indicated apoptosis and/or necrosis. After 8 h of incubation, cells exposed to 4 micromol/L TPTA showed an increase in DNA fragmentation (on electrophoresis), which was confirmed by spectrophotometry (p < 0.05). Flow cytofluorometry pointed out an early (p < 0.05) increase of annexin V-positive (apoptotic) cells in TPTA-exposed flasks, whereas at least partly contradictory, results were obtained with the Titer-Tacs kit. Overall, these results provide evidence that TPTA, at low concentrations (4 micromol/L) induces early and late apoptotic phenomena, whereas cells exposed to the highest concentrations (8 micromol/L) are likely to undergo necrosis rather than apoptosis.

Animals↗
PubMed2003

Expression of functionally relevant cell surface markers in dibutyltin-exposed human natural killer cells.

Butyltin (BT) compounds are known for their worldwide contamination. Dibutyltin (DBT) is used as a stabilizer in plastic products, and as a deworming agent in poultry. Poultry products have been shown to contain measurable levels of DBT. Drinking water has also been reported to contain BTs due to leaching from PVC pipes. We, and others, have found measurable levels of DBT in human blood. BTs appear to increase the risk of cancer and other viral infections in exposed individuals. In previous studies we have shown that the tumor killing function of natural killer (NK) lymphocytes was greatly diminished after as little as a 1 h exposure to DBT and the inhibition continued even after removal of the compound. We also showed that there was a significant decrease in NK cell lysis of K562 target cells after an exposure to 1.5 microM DBT for 24 h. This 24 h exposure also decreased the ability of NK cells to bind to tumor cells. Loss of binding function was not seen when NK cells were exposed to 5-10 microM DBT for 1 h. However, NK cells exposed to 5 microM DBT for 1 h and then incubated in DBT-free media for 24, 48, or 96 h, showed a significant loss of tumor-binding function within 24 h. The effects of DBT exposure on seven cell surface molecules that are involved in NK-cell interactions with target cells were investigated. The results indicated that the exposure of NK cells to 1.5 microM DBT for 24 h decreased the expression of CD2, CD11a, CD16, CD11c. There was no decrease in expression of any of the markers studied when NK cells were exposed to 5 microM DBT for 1 h, consistent with the fact that a 1-h exposure had no effect on the ability of NK cells to bind tumor cells. However, when NK cells were exposed to 5 microM DBT for 1 h followed by 24, 48 or 96 h incubations in DBT-free media there was decreased expression of several of the cells surface molecules with the most dramatic decreases being in CD16 and CD56.

Antigens, CD↗
PubMed1997

Impaired cytosolic Ca2+ response to glucose and gastric inhibitory polypeptide in pancreatic beta-cells from triphenyltin-induced diabetic hamster.

Oral administration of a single dose of triphenyltin compounds induces diabetes with decreased insulin secretion in rabbits and hamsters after 2-3 days without any morphological changes in pancreatic islets. In the present study, to test the possibility that the impaired insulin secretion induced by triphenyltin compounds could result from an impaired Ca2+ response in pancreatic beta-cells, we investigated the effect of triphenyltin-chloride (TPTCl) administration on the changes in the cytoplasmic Ca2+ concentration ([Ca2+]i) induced by secretagogues, such as glucose, high K+, gastric inhibitory polypeptide (GIP), and acetylcholine (ACh) in hamster pancreatic beta-cells. TPTCl administration caused partial suppression in 10 mM K+-induced rise in [Ca2+]i without suppressing the increase in [Ca2+]i evoked by 20-50 mM K+. Administration of TPTCl strongly inhibited the rises in [Ca2+]i induced by 27.8 mM glucose, 100 microM ACh in the presence of 5.5 mM glucose, and by 100 nM GIP in the presence of 5.5 mM glucose. In the ACh-induced response, TPTCl administration strongly suppressed the late sustained phase, while weakly suppressing the initial rise in [Ca2+]i. TPTCl administration significantly suppressed the rise of cAMP content in islet cells induced by 100 nM GIP with 1 mM 3-isobutyl-1-methylxanthine in the presence of 5.5 mM glucose (P < 0.01, N = 5-11). TPTCl administration also impaired the insulin secretion in islet cells induced by 27.8 mM glucose, 100 nM GIP in the presence of 5.5 mM glucose, and 100 microM ACh in the presence of 5.5 mM glucose (P < 0.05, N = 9-16). We conclude that the pathology of triphenyltin-induced diabetes in hamsters involves a defect in cellular Ca2+ response due to a reduced Ca2+-influx through voltage-gated Ca2+ channels.

Acetylcholine↗
PubMed2006

Some chemical contaminant of surface sediments at the Baltic Sea coastal region with special emphasis on androgenic and anti-androgenic compounds.

Androgenic and anti-androgenic compounds including p,p'-DDE, Diuron, Linuron, Fenarimol, Vinclozolin, 1-(3,4-dichlorophenyl) urea (DCPU), 1-(3,4-dichlorophenyl)-3-methylurea, (DCPMU), tributyltin (TBT) and triphenyltin (TPT) and their metabolites (DBT, MBT, DPT, MPT) as well as metallic elements (Ni, Cu, Zn, As, Cd, Pb, Co, Tl, Cr, Fe, Mn, Al, K, Mg, Na, Ca, Ba, Ti, Sn), PAHs (16 indicator compounds), DDTs and PCBs have been quantified in top layer (0-10 cm) of up to 37 surface sediment samples collected from several sites in costal zone of the Gulf of Gdańsk, an inland freshwater area of Brdyujście in Poland and the tidal flats of the Norderney Island, Wadden Sea in 2002-2003. These sites differed in the degree of anthropogenic activities, including chemical pollution and related impact on biota. Especially in sediments near shipyards, ship repair facilities, harbours, other industrial activities or close to municipal sewage treatment plant outlets butyltins, PAHs and some metallic elements were found at high concentrations. Diuron, Linuron and DCPMU were detected at a few sites, Fenarimol only once, while Vinclozolin and DCPU were not detected. DDT concentrations in the sediments from the Gdańsk and Gdynia region of the Gulf show a stepwise decrease following the ban for production and use, while diffusion of PCBs at some industrial sites seems to continue. Elevated PAH concentrations in sediments seem to be mainly due to pyrogenic and less to mixed pyrogenic and petrogenic sources, while for a few sites rather petrogenic sources dominated. The reference sites in the Norderney Island, Wadden Sea showed similar or slightly higher loads of DDTs, BTs, PAHs, PCBs and metallic elements when compared to sediments from the least contaminated sites in the coastal Gulf of Gdańsk area, while phenyltins were not detected at both spatially distant European areas.

Androgen Antagonists↗
PubMed2004

p53-dependent apoptotic mechanism of a new designer bimetallic compound tri-phenyl tin benzimidazolethiol copper chloride (TPT-CuCl2): in vivo studies in Wistar rats as well as in vitro studies in human cervical cancer cells.

We have studied the effect of tri-phenyl tin benzimadazolethiolcopper chloride (TPT-CuCl(2)), a novel bimetallic compound, on the regulation of apoptosis in HeLa cells, MCF-7 cells, and in vivo Wistar rat model. TPT-CuCl(2) induces significant apoptosis in HeLa cell line characterized by DNA fragmentation and chromosome condensation. Comet assay revealed that TPT-CuCl(2) targets and causes severe damage to the DNA. Treatment of HeLa cells with TPT-CuCl(2) rescues the accumulation of p53 from the suppression of human papilloma virus E6, resulting in a dramatic up-regulation of Bax and Bak and down-regulation of the antiapoptotic factor Survivin. Apoptotic induction by TPT-CuCl(2) was shown to mediate in a p53-depedent manner; loss of p53 impairs the release of cytochrome c and Smac/DIABLO from mitochondria to cytosol. Moreover, we have shown that TPT-CuCl(2) induced-apoptosis was through an intrinsic mitochondrial pathway, which was inhibited by viral oncoprotein E1B19K. Caspase-3 was found to be indispensable in TPT-CuCl(2)-triggered apoptosis signaling pathway, because caspase-3 deficient cell line MCF-7 was resistant to TPT-CuCl(2). Furthermore, in vivo studies using C6 glioblastoma xenograft rat model revealed that TPT-CuCl(2) exhibits significant antiproliferative activity against tumor development with minimal cytotoxicity toward normal physiological function of the experimental rats. These findings imply the attractiveness of TPT-CuCl(2) as a drug candidate for further development.

Animals↗
PubMed2004

Global pollution monitoring of butyltin compounds using skipjack tuna as a bioindicator.

Butyltin compounds (BTs) including mono- (MBT), di- (DBT), tri-butyltin (TBT) and total tin (sigmaSn), were determined in the liver of skipjack tuna (Katsuwonus pelamis) collected from Asian offshore waters (off-Japan, the Japan Sea, off-Taiwan, the East China Sea, the South China Sea, off-Philippines, off-Indonesia, the Bay of Bengal), off-Seychelles, off-Brazil and open seas (the North Pacific). BTs were detected in all the skipjack tuna collected, suggesting widespread contamination of BTs even in offshore waters and open seas on a global scale. Considering specific accumulation, Sex-, body length- differences and migration of skipjack tuna did not seem to affect BT concentrations, indicating rapid reflection of the pollution levels in seawater where and when they were collected. Skipjack tuna is a suitable bioindicator for monitoring the global distribution of BTs in offshore waters and open seas. High concentrations of BTs were observed in skipjack tuna from offshore waters around Japan, a highly developed and industrialized region (up to 400 ng/g wet weight). Moreover skipjack tuna collected from offshore waters around Asian developing countries also revealed the levels comparable to those in Japan (up to 270 ng/g wet weight) which may be due to the recent improvement in economic status in Asian developing countries. High percentages (almost 90%) of BTs in total tin (sigmaSn: sum of inorganic tin+organic tin) were found in the liver of skipjack tuna from offshore waters around Asian developing countries. This finding suggests that the anthropogenic BTs represent the major source of Sn accumulation in skipjack tuna from these regions.

Animals↗
PubMedDate not supplied

Biomarkers in Ruditapes decussatus: a potential bioindicator species.

The clam Ruditapes decussatus is distributed worldwide and due to its ecological and economical interest has been proposed as a bioindicator in areas where mussels are not available. The accumulation of several anthropogenic compounds in their tissues suggests that they possess mechanisms that allow them to cope with the toxic effects of these contaminants. Besides pollutant uptake, the use of biomarkers is pointed out in this paper since it is a promising approach to monitor the effect of these contaminants in the marine environment. Biomarkers complement the information of the direct chemical characterization of different types of contaminants. Therefore, the aim of this paper is to review the role of several biomarkers: (metallothioneins (MT), superoxide dismutase (SOD), catalase (CAT), glutathione peroxidases (GPx) (total and selenium-dependent), lipid peroxidation (measured as MDA, one of the final products of lipid peroxidation), glutathione S-transferase (GST) and acetylcholinesterase (AChE), measured in different tissues of the clam R. decussatus, in laboratory conditions and under various environmental stresses, in two ecosystems (Ria Formosa lagoon- Portugal) and Bizerta lagoon (Tunisia) in a perspective of a multibiomarker approach to assess environmental changes. Experiment and field studies are in good agreement since MT levels, especially in the gills, the first target tissue of these contaminants, can be used as biomarker of exposure to Cd. GPx and MDA may also be determined in this respect. AChE activity is inhibited by pesticide and, to a less extent, by metal exposure in the gills and whole soft body of clams. However, the induction of GST isoforms experimentally demonstrated is not observed in the field because only global GST activity was determined. The whole set of results opens new research perspectives for the use of this species to assess the effect of mixtures of pollutants in the aquatic environment.

Acetylcholinesterase↗
PubMed1988

A 119Sn Mössbauer spectroscopic study on the interaction of dimethyltin (IV) derivatives with rat hemoglobin, and of related model systems in aqueous solution.

In the context of a study of the molecular basis of the antileukemia (murine) activity of diorganotin (IV) compounds, the interaction with rat hemoglobin (selected as a model protein) of the representative terms dimethyltin dichloride, dimethyltin glycylglycinate (Me2SnGlyGly), and dimethyltin L-cysteinate (Me2Sn-Cys) has been investigated by 119Sn Mössbauer spectroscopy. In order to possibly determine the reaction pathway, aqueous model systems in Hepes buffer at pH 7.4 were also considered. The structural characteristics of reactants and products were advanced on the basis of semiempirical calculations of Mössbauer nuclear quadrupole splitting parameters, delta E, by the point-charge model approach. In aqueous Hepes at pH 7.4, evidence was obtained for the formation of the five-coordinated species, trigonal bipyramidal type (tbp), Me2Sn(OH)2.Hepes(II), Me2Sn(OH)(GlyGly).Hepes(III), and Me2Sn(OH)Cys(IV) (see Fig. 1). Equatorial groups or atoms would be the Me radicals, as well as OH, N(peptide), and S(thiol), respectively. Hepes would coordinate to tin in axial position through the tertiary amino nitrogen, while cysteine would behave as a bidentate chelating agent, with an axially located amino group. Species (II), (III), and (IV) react with cysteine in aqueous Hepes at pH 7.4, yielding Me2Sn(OH)Cys(IV), as well as Me2SnCys2(V), where tin would be embedded into a tbp structure due to one cysteine probably chelating (equatorial S thiol and axial amino nitrogen), and one monodentate through S thiol. Species (II), (III), and (IV) react analogously with rat hemoglobin, primarily through the S thiol of a cysteine side chain, yielding pellets where the environment of tin could be tetrahedral, such as in Me2Sn(OH)(S thiol), (VI), and tetrahedral (IX) or tbp (V) in Me2Sn(Cys)(S thiol), where Cys would act either as chelating or monodentate. Further reaction of (VI) and (IX) could involve imidazole nitrogen atoms, N het, of histidine side chains, forming tetrahedral Me2Sn(S thiol)(N het), (VIII), or tbp Me2Sn(OH)(S thiol)(N het), (VII), and Me2Sn(Cys)(S thiol)(N het), (V) (see Figs. 1 and 5).

Animals↗
PubMed1985

On the mechanism of dialkyltin-induced thymus involution.

In relation to the thymolytic activity of dialkyltin compounds, the effects of di-n-butyltin (DBTC) and di-n-octyltin dichloride (DOTC) on the ultrastructure of the rat thymus, the proliferation of bone marrow stem cells and their interference with growth hormone production are analyzed. Ultrastructurally, depletion of small lymphocytes in the thymic cortex, without signs of lymphocyte destruction or macrophage activation, was the most prominent feature of DOTC treatment. The thymus cortex was maximally depleted 96 h after a single i.p. injection of 1 mg DOTC/kg body weight. 120 h after DOTC treatment a repopulation of the cortex with small lymphocytes was noted together with the presence of many pale large nuclei of large lymphocytes, suggestive of active blast transformation. These thymus effects are probably not caused by a diminished input of bone marrow stem cells into the thymus, since neither the spontaneous blastogenesis nor the colony formation of bone marrow cells isolated from DBTC-treated animals were affected. An indirect mechanism of thymus involution induced by interference with the hormonal system is also very unlikely. A stress-related increase of glucocorticosteroids by dialkyltins has already been excluded (Seinen and Willems, 1976). An interference of dialkyltins with growth hormone production, as indicated in this study, did not occur. Application of growth hormone in amounts that reversed the hypophysectomy-induced thymus atrophy did not modify the thymus involution induced by DOTC treatment of rats. However, an interference with the production of thymic humoral factors cannot be excluded yet, although it is not supported by morphological changes in thymic reticular cells. Only an increased vacuolization of reticular epithelial cells is seen when the thymus is markedly involuted, but this is considered to be a consequence rather than a cause of thymus atrophy. Most probably the dialkyltin-induced thymus involution is caused by an antiproliferative activity, which is strongly supported by an inhibition of thymidine incorporation of thymocytes isolated from DBTC-treated rats.

Animals↗
PubMed1998

[Health and environmental risk assessment of organotin pollution in Japan].

In the course of developing the Concise International Chemical Assessment Document (CICAD) on triphenyltin compounds for the IPCS, the author assessed health and environmental risks paused by major organotin species, i.e., triphenyltin compounds and tributyltin compounds. Organotin has been used widely as biocide in such applications as antifouling paints of boats and for other purposes, until its use was restricted in 1980's after discovery of severe damages on aquatic ecosystem caused by this agent. Among many other deleterious effects of organotin to aquatic species, imposex is one of the most conspicuous effects which is the development of male reproductive organs by female gastropods at concentrations as low as a few ng/l. Although environmental concentrations of organotin have declined as a result of tight regulations, periodical monitoring in these years shows their levels in the water still range several ng/l in Tokyo bay area which are hazardous to certain aquatic lives. Human intake of organotin in foods has been estimated through market basket surveys in Japan which showed intake of triphenyltin or tributyltin compound in 1997 as 2.29 micrograms/day (as tributyltin chloride) and 2.69 micrograms/day (as triphenyltin chloride), respectively. The intake value for tributyltin chloride corresponds to 5.2% of the provisional acceptable daily intake (ADI) estimated for bis(tributyltin) oxide (TBTO) in Japan, and 28.0% of the guidance value suggested in the CICAD draft for TBTO, respectively. The intake value for triphenyltin chloride corresponds to 10.8% of the ADI estimated by the FAO/WHO Joint Meeting on Pesticide Residues. Potential critical effects on human health observed in animal tests are the effects on immune systems and reproduction. Based on this investigation, needs for future research on mechanism of toxicity and further control of risks are discussed.

Animals↗
PubMed1997

Determination of the pesticide fenbutatin oxide in tomatoes, cucumbers and bananas by high performance liquid chromatographic/atmospheric pressure chemical ionization-mass spectrometry.

A rapid method, using high-performance liquid chromatography (HPLC)/ atmospheric pressure chemical ionization-mass spectrometry, has been developed for the determination of fenbutatin oxide in tomatoes, cucumbers and bananas. Samples were homogenized with sodium carbonate and ethyl acetate, filtered through sodium sulphate, concentrated and solvent exchanged into acetonitrile prior to analysis. HPLC was performed on a Hypercarb column with 10:90 acetic acid (5% v/v glacial acetic acid in water)/acetonitrile at a flow rate of 1 mL/min. Positive ionization selected-ion monitoring was performed on the 7 isotopic cluster ions from the tris(2-methyl-2-phenylpropyl) tin fragment. A comparison of solvent-based and extract-based standards showed that tomato and cucumber matrices had a slight enhancement effect on the signal intensity, whereas the banana matrix exerted a signal suppression effect. Calibration was linear over the range 0.25-5.0 ng/microL. The mean spike recoveries (extracts spiked at 0.5 mg/kg) were 88% for tomatoes and 80% for both cucumbers and bananas with relative standard deviations of 6%, 7% and 8% respectively. Limits of detection were commodity dependent and ranged from 0.06-0.12 ng/microL (equivalent to 0.01-0.02 mg/kg in the crop). Ionization was stable for long analytical time periods.

Chromatography, High Pressure Liquid↗
PubMed2003

Structural study of 2,6-bis[(dimethylaminomethyl)phenyl]butyl stannanes: nonconventional behaviour of triorganotin(IV) halides.

The four organotin (IV) compounds ([2,6-bis(dimethylaminomethyl)phenyl](n-butyl)R(1)R(2)stannane, with R(1)=R(2)=nBu (1), R(1)=nBu, R(2)=Cl (2), R(1)=nBu, R(2)=Br (3) and R(1)=R(2)=Br (4)), have been prepared and their structures have been investigated in various solvents and at various temperatures (NMR). The structures of these compounds in solution are solvent- and temperature-dependent. The solid state structures of 2 and 3 were studied using CP/MAS NMR spectroscopy and Xray diffraction techniques. The tetraorganotin compound 1 exhibits tetrahedral geometry with very weak Sn-N coordination. The dynamic process of Sn-N bond(s) association/dissociation was observed using low-temperature NMR measurements. The tin central atom in 2 and 3 is [4+2]-coordinated in toluene solutions and the NMR low-temperature measurements reveal the same dynamic behavior as for 1 in this solution, with retention of the covalent halogen-tin bond. However, this bond is dissociated in methanol solutions, yielding ionic species, where the tin atom is only [3+2]-coordinated, and the halogen atom lies outside of the primary coordination sphere of the tin atom. In addition, while the same ionic structure as in methanol was found in the whole measured temperature range in the chloroform solution of 3, the structure of 2 varies in this solvent. In this compound, the covalent Sn-Cl bond (similar structure as in toluene solution), which is retained at room temperature in chloroform solution, is continuously dissociated with a decrease in temperature, leading to ionic bonding (a similar structure as in methanol solution). All the above-mentioned processes are reversible in all the solvents and at all temperatures. In the solid state, the covalent Sn-Cl bond is observed for 2, while an ionic bond was found in 3.

Journal Article↗