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With the global ban on tributyltin (TBT), the pollution of triphenyltin (TPhT) is an emerging issue in some aquatic ecosystems. In this study, we investigated the concentrations of typical butyltin and phenyltin compounds in the surface water and sediments in the lower Yangtze River, analyzed their occurrence and sources, and assessed their ecological risks. The findings indicate that butyltin and phenyltin compounds are widespread. The total concentration of organotin compounds in surface water was as high as 42.41 ng Sn/L, with an average of 25.71 ng Sn/L, and the total concentration of organotins in sediments reached up to 111.5 ng Sn/g dw, averaging 61.1 ng Sn/g dw. Since the implementation of the AFS Convention, the concentration of organotins in surface water has been significantly reduced. However, the ecological risk of TBT is still high, and the risk of TPhT is also noteworthy. The findings also suggest that the primary source of butyltins in the lower Yangtze River is historical input residues. In contrast, the main source of PhTs is the recent input of agricultural runoff. Therefore, organotin contamination in the lower Yangtze River has changed, but its governance still presents challenges. [ABSTRACT FROM AUTHOR]

A motivating class of compounds with interest in the research field of biological active metallopharmaceuticals for cancer treatment is based on organometallic complexes of Sn(IV), exhibiting advantages such as improved cellular uptake and body excretion, lower toxicity, and fewer side effects compared to platinum-based drugs. In this study, the mononuclear organotin coordination complex [(CH3)2SnCl2(mebta)2] was synthesized and characterized using vibrational spectroscopy (IR, Raman), 1H NMR, 13C{1H} NMR, and X-ray crystallography. Its antiproliferative properties were thoroughly assessed across an aggressive triple-negative human breast cancer cell line. Notably, comparative studies with precursor materials verified that the observed biological activity is intrinsic to the complex itself. This study highlights the compound's ability to induce cell fate by disrupting essential cellular functions, such as proliferation. By exploring the antiproliferative effects of organotin(IV) derivatives, we introduce a novel class of Sn complexes with 1-methylbenzotriazole (mebta), demonstrating significant potential as promising antitumor agents in the field of organotin compounds. [ABSTRACT FROM AUTHOR]

Triphenyltin (TPT) is a commonly encountered organotin compound known for its endocrine-disrupting properties; it frequently interacts with antibiotics in aquatic environments. In this study, common carp (Cyprinus carpio) (17.43 ± 4.34 g, 11.84 ± 0.88 cm) were chosen as the experimental organisms. According to the environmental concentration in the heavily polluted area, the control group and the experimental groups were exposed for 21 days to the following treatments: 1 μg/L TPT, 1 mg/L NOR, and a combination of 1 μg/L TPT plus 1 mg/L NOR. The investigation examined the individual and combined toxicities of TPT and norfloxacin (NOR) on the gill, liver, and gut tissues of common carp in highly polluted areas. The findings revealed tissue-specific variations in 1L-1β enzyme activity; specifically, 1L-1β enzyme activity exhibited a significant reduction in liver tissue under both NOR exposure and combined exposure, indicating that high concentrations of NOR had the most pronounced impact on the immune system of liver tissue. Furthermore, the gene expression levels of IL-1β, Lysozyme-C, NKA, and CPT1 in the liver, intestinal, and gill tissues showed differences after exposure. In addition, TPT exerted the most significant effect on intestinal tissue, followed by the liver and gill tissues. Interestingly, when TPT and NOR were exposed together, the toxic effects on all tissues were reduced, suggesting the existence of antagonistic effects. [ABSTRACT FROM AUTHOR]

Fluorescent organotin compounds are useful in sensing, optoelectronic devices, and in vitro bioimaging. Although in vitro fluorescence bioimaging shows low resolution at room temperature, a better resolution is possible at cryotemperatures. Therefore, the search for new cryoluminescent materials with potential application in high-resolution fluorescence bioimaging remains a great challenge. Herein, we report the cryoluminescence properties of two fluorescent bis-organotin compounds, namely, BisNTHySnBu2 (5) and BisNTHySnPh2 (6), synthesized via microwave irradiation. All compounds were fully characterized using 1H, 13C, and 119Sn NMR spectroscopy, Raman spectroscopy, IR spectroscopy, and HR-MS. The 119Sn δ and 3J(1H,119Sn) of 5 and 6 indicate that two Sn-ligands are chemically and electronically equivalent, as confirmed by cyclic voltammetry. The crystal structure of 6 showed pentacoordinate tin atoms with skeleton ligands. The study of self-assembled monolayers of both Sn-complexes via STM microscopy revealed a similar supramolecular packing in lamella-like patterns, adopting a face-on arrangement, where molecules stay flat lying on HOPG in accordance with the height profile of closely packed monolayers on graphite of about 0.33 nm thickness. However, only the Sn complex 6, which bears phenyls, covers large surface areas. The photophysical properties of bis-organotin compounds were also investigated in solution (room and low temperatures) and in the solid state. Good luminescence properties in solutions with fluorescence quantum yields (Φ) of approximately 35% and 50% were found. Despite this, Φ is quenched in the solid state because of aggregation, as supported by solvent/non solvent fluorescence studies, which is in agreement with STM and AFM investigation. [ABSTRACT FROM AUTHOR]

Based on two years of monitoring of modern bottom sediments of two sections of the Kaliningrad shelf of the Baltic Sea – “Curonian Spit” and “Northern Sambian” – an assessment of the sources of pollution with organotin compounds (OTs) and heavy metals was carried out. The content of individual organotin compounds and OTCs spectra obtained by gas chromatography with mass spectrometry of relatively coarse-grained bottom sediments indicate the presence of organotins in significant quantities – the total OTs content (ΣOTs) is from 0.6 to 8.3 ng/g. However, the content of tributyltin (TBT), the main component of anti-fouling systems for marine vessels and the most dangerous endocrine-disrupting compound among the hazardous substances for marine ecosystems, is at a low level (0-2.3 ng/g) in all studied samples and has not increased over the two-year observation period (biodegradation index 1.7-12.4). At the same time, the presence of abnormally high concentrations of mono-, triphenyl- and tricyclohexyltin in the sediments of the ”Northern Sambian” site (up to 30, 7 and 6.4 ng/g, respectively) indicates an additional source of pollution of coastal waters and shelf sediments (for example, plastic litter and agricultural runoff). The absence of significant shipping in the study areas ensures a consistently low level of pollution with tributyltin and its derivatives (less than 0.3 and 2.3 ng/g of TBT in 2017 and less than 0.1 and 1.3 ng/g in 2018 for the sites “Curonian Spit” and “Northern Sambian”, respectively), which indicates the activity of the processes of TBT transformation and self-cleaning of sandy sediments. However, the identified trends and their predictive accuracy require long-term observation and monitoring of the sediment environment using data on the deep-water part of the shelf, enriched in clay and humus components.

A series of organotin heterocycles of general formula [{Me2C(C6H3CH2)2O}SnR2] [R = methyl (Me, 4), n‐butyl (n‐Bu, 5), benzyl (Bn, 6) and phenyl (Ph, 7)] was easily synthesized by a Barbier‐type reaction assisted by the sonochemical activation of metallic magnesium. The 119Sn{1H} NMR data for all four compounds confirm the presence of a central Sn atom in a four‐coordinated environment in solution. Single‐crystal X‐ray diffraction studies for 17,17‐dimethyl‐7,7‐diphenyl‐15‐oxa‐7‐stannatetracyclo[11.3.1.05,16.09,14]heptadeca‐1,3,5(16),9(14),10,12‐hexaene, [Sn(C6H5)2(C17H16O)], 7, at 100 and 295 K confirmed the formation of a mononuclear eight‐membered heterocycle, with a conformation depicted as boat–chair, resulting in a weak Sn...O interaction. The Sn and O atoms are surrounded by hydrophobic C—H bonds. A Hirshfeld surface analysis of 7 showed that the eight‐membered heterocycles are linked by weak C—H...π, π–π and H...H noncovalent interactions. The pairwise interaction energies showed that the cohesion between the heterocycles are mainly due to dispersion forces. [ABSTRACT FROM AUTHOR]

Qalaee is Unani name of tin (stannum), which is a metallic element, belongs to group 14 of periodic table. Atomic number of tin is 50 and its atomic mass is 119. Qalaee (Tin) consist two types of compounds, inorganic tin compounds and organic tin compounds. Several toxic and adverse effect studies of Qalaee (stannum) have been reported such as, Respiratory Effects, Gastrointestinal Effects, Haematological Effects, Renal Effects, Dermal Effects, Ocular Effects, Immunological and Lymph reticular Effects, Neurological Effects, Cardiovascular Effects, Body weight effect and reproductive effects. Some studies on different pharmacological activities of tin also reported like, antibacterial activity, anticancer activity and anti-parasitic activity. In traditional system of medicine Qalaee is used in the form of Kusta or Bhasm for various disorders such as spermatorrhoea, excessive nocturnal emission, premature ejaculation and Syphilis etc. Its important Unani formulation is Kusta qalaee. [ABSTRACT FROM AUTHOR]

Organotin compounds (OTs) belong to persistent organic pollutants (POPs) group and are capable of persisting up to 40 years due to their chemical nature. Tributyltin (TBT) is an anti‐fouling agent and can easily leach out into water threatening the aquatic life. Molluscs are sensitive towards the presence of toxins in their surrounding environment and respond accordingly to overcome stress conditions. Lamellidens marginalis, a freshwater bivalve is popular for its food value and pink pearls. The present study focuses on the effect of Tributyltin chloride (TBTCl), a form of TBT, on Lamellidens marginalis under laboratory conditions. The 96 h median lethal concentration (LC50) was calculated to be 1 mg L−1. Bivalves were segregated into three sub‐groups that is, group I; control, group II; experimental (treated with 0.2 mg L−1 TBTCl that is, 1/5th of LC50 value), group III; experimental (treated with 0.2 mg L−1 TBTCl + 0.003% w/v spirulina). A static non‐renewal toxicity assay was performed for 96 h. Estimation of total protein, acid phosphatase (ACP), alkaline phosphatase (ALP), aspartate aminotransferase (AST), alanine aminotransferase (ALT) and glycogen was carried out. An overall decrease in the total protein, ACP, ALP, glycogen, and ALT was observed in both the experimental groups (Groups II and III) in comparison to the control group whereas, the concentration of AST was found to increase in hepatopancreas. Integrated biomarker response index (IBR) value was calculated to be 12.60 for control and 10.56 and 11.29 for groups II and III, respectively in hepatopancreas. Similarly, in gill tissue the values were 3.69, 1.37, and 3.43, respectively. After treatment with nutritional supplement spirulina, a higher BRI (biomarker response index) value of 3.3 for group III was observed, suggesting the therapeutic role of spirulina in test organisms. BRI value derived for group II was 2.7 indicating more severity of TBTCl compared to group III in the absence of spirulina. [ABSTRACT FROM AUTHOR]

Objective: Trimethyltin (TMT) chloride is an organotin compound used in industry. It has been linked to generating reactive oxygen species (ROS), inflammatory processes, and neuronal death. Carvacrol is a monoterpene phenol found in the Lamiaceae plant family, modulating inflammatory conditions and necroptosis in neural tissue. This study aimed to investigate the neuroprotective effects of carvacrol in a rat model of hippocampal neuronal injury induced by TMT. Materials and Methods: In this experimental study, sixty male Wistar rats were randomly divided into five groups (n=12): group 1 receiving saline, group 2 received dimethyl sulfoxide (DMSO) as a vehicle for 21 days, group 3 receiving a single dose of TMT (8 mg/kg) and groups 4 and 5 receiving carvacrol 40 and 70 mg/kg daily for 21 days after a single dose of TMT. All injections were intraperitoneal (I.P.). Caspase-3, Bax, Bcl-2, and Bdnf gene expression and the number of pyknotic neurons in the hippocampus were quantified. Spatial memory was assessed with a radial arm maze. Results: Statistical analysis of histological data revealed the carvacrol significantly attenuated cognitive dysfunction and the number of pyknotic neurons in the hippocampal CA1 region of rats treated with TMT. Based on real-time polymerase chain reaction (PCR), carvacrol modulated the expression of genes involved in apoptosis (Bax and Caspase-3) and upregulated anti-apoptotic (Bcl-2) and brain derived neurotrophic factor (Bdnf) genes in the hippocampal tissue. Conclusion: These findings revealed neuroprotective effects of carvacrol which might be mediated by apoptotic and anti-apopetotic factors. [ABSTRACT FROM AUTHOR]

Two series of dinuclear organotin macroheterocycles of general formula [R2Sn{Ch(C6H4CH2)2}2SnR2] [Ch = O with R = n-Bu (2a), Bn (3a), Ph (4a) and Ch = S with R = n-Bu (2b), Bn (3b), Ph (4b)] were easily synthetized by a Barbier-type reaction assisted by sonochemical activation of metallic magnesium. The 119Sn{1H} NMR data for all compounds and the X-ray single-crystal diffraction studies for 2a and 4a confirmed the presence of a central Sn atom in a four-coordinate environment. The molecular structures of 2a and 4a showed puckered 16-membered macroheterocycles. The tin and oxygen atoms are in the interior of the cavity of the macrocycle, surrounded by hydrophobic C–H bonds. A Hirshfeld surface analyses of 2a and 4a showed that the macrocycles are linked by weak C–H···π, C···C, and H···H non-covalent interactions. The pairwise interaction energies showed that the cohesion between the macrocycles are mainly due to dispersion forces. [ABSTRACT FROM AUTHOR]

Marinas are semi-enclosed environments characterised by reduced hydrodynamic energy, high sedimentation rates, and reduced oxygen levels. The ongoing development of activities and infrastructure construction are leading to deterioration in the quality of coastal aquatic environments, creating environmental risks. Trace metal elements (TMEs) and organotins are significant contaminants, prompting this study to evaluate the added value of spatiotemporal monitoring compared to one-time sediment assessments. Two Mediterranean harbours, Port Camargue (PC) and Port Carnon (C), differing in morphology and size, were monitored for a year with regular water sampling, focusing on TMEs and organotins. Sediment contamination, notably in the technical zone, revealed concentrations of Cu (309 and 1210 mg kg−1 for C and PC, respectively), Zn (242 and 425 mg kg−1 for C and PC, respectively), and tributyltin (TBT) (198 and 4678 µg (Sn) kg−1 for C and PC, respectively) surpassing the effect range medium (ERM), while other marina stations generally stayed below this threshold. Spatiotemporal water monitoring highlighted concentrations above environmental quality standards (EQS) at all stations of the larger marina. This exceedance was systematic for Cu and Zn in all samples, ranging respectively between 2.54 and 37.56 µg (Sn) L−1 and 0.63 and 33.48 µg (Sn) L−1. A notable temporal dynamic for TBT and Cu was also observed. Conversely, the open marina, connected to the open sea, rarely exhibited concentrations above EQS in water, despite sediment concentrations occasionally exceeding ERM values. This underscores that risk assessment in these ecosystems cannot rely solely on sediment characterisation. [ABSTRACT FROM AUTHOR]

With the global ban on tributyltin (TBT), the pollution of triphenyltin (TPhT) is an emerging issue in some aquatic ecosystems. In this study, we investigated the concentrations of typical butyltin and phenyltin compounds in the surface water and sediments in the lower Yangtze River, analyzed their occurrence and sources, and assessed their ecological risks. The findings indicate that butyltin and phenyltin compounds are widespread. The total concentration of organotin compounds in surface water was as high as 42.41 ng Sn/L, with an average of 25.71 ng Sn/L, and the total concentration of organotins in sediments reached up to 111.5 ng Sn/g dw, averaging 61.1 ng Sn/g dw. Since the implementation of the AFS Convention, the concentration of organotins in surface water has been significantly reduced. However, the ecological risk of TBT is still high, and the risk of TPhT is also noteworthy. The findings also suggest that the primary source of butyltins in the lower Yangtze River is historical input residues. In contrast, the main source of PhTs is the recent input of agricultural runoff. Therefore, organotin contamination in the lower Yangtze River has changed, but its governance still presents challenges.

Concentrations and distribution for 16 organotin compounds were studied in all kinds of foods, including seafood, agricultural products, and wine. Meanwhile, the degradation of the TBT or TPhT was also evaluated. Concentrations of total organotins in seafood, agricultural products, and wine were 1047.2, 469.4, and 13.5 μg Sn/kg. Meanwhile, the most frequently detected organotin in three kinds of samples were TPhT, MPhT, and MPhT, respectively. The results demonstrated that phenyltin may probably become an emerging organotin pollutant. Regarding seafood, organotin concentrations of fish and mollusks were much higher than those of crustaceans. At the same time, a significant positive correlation was observed between the concentrations of TBT and MBT (p < 0.05), and between DBT and MBT(p < 0.0001). Moreover, TPhT was significantly and positively associated with DPhT (p < 0.0001), suggesting that TPhT was the precursor of DPhT. Apart from the likely illegal use of OTs as biocides in antifouling paints for ships, anthropogenic activity like agricultural activity or industrial activity also caused organotin contamination. Further research and more effective measures should be formulated to protect the food safety. Meanwhile, monitoring of the organotin contamination should not only in Qinhuangdao, but also expand to the cities along Bohai Bay. [ABSTRACT FROM AUTHOR]

Organotin compounds (OTs) accumulate in fish easily, however, research on their influencing factors is still limited. This study collected 25 species of fish with different diets, habitats, and age from the Three Gorges Reservoir (TGR), the largest deep-water river channel-type reservoir in China, and analyzed the accumulation characteristics of OTs in these fish. The results showed that tributyltin (TBT) and triphenyltin (TPhT) were the dominant OTs in fish from the TGR. The correlation between OTs concentration and age, body length, and body weight varied with fish species. The concentrations of TBT and TPhT in carnivorous fish (mean, 25.78 and 11.69 ng Sn/g dw, respectively) were higher than those in other diet fish (P<0.01), but there was no significant difference in fish at different habitat water layers (P>0.05). In addition, the degradation rates of TBT and TPhT in different fish species were all below 50%. In summary, the accumulation of TBT and TPhT in fish is mainly influenced by diet, and both TBT and TPhT were difficult to degrade in fish. These results reveal the pollution characteristics of OTs in fish from the TGR, and can improve our understanding of the factors influencing TBT and TPhT accumulation in freshwater fish. [ABSTRACT FROM AUTHOR]

In organic synthesis, the Stille reaction is one of the most general, effective, and selective Pd-catalyzed cross-coupling reactions for the formation of C-C bonds. It is based on organotin compounds using catalytic amounts of Pd complexes under mild reaction conditions normally. The stability toward moisture and air of organotin mediators provides superiority to the Stille reaction over other Pd-catalyzed cross-coupling transformations. The Stille reaction is effective in preparing promising organic molecules and is generally superior for synthesizing complex molecules including natural products. Currently, metal nanoparticles are more fascinating tools for catalysis due to their high surface-area-to-volume ratio. Besides, magnetic nanoparticles have been the focus of more attraction during the last two decades as they can be easily separated from the reaction mixture. Hence, this review aims to focus on the applications of nanoparticles as an efficient catalyst in Stille coupling elegantly for the first time. [ABSTRACT FROM AUTHOR]

To elucidate the usefulness of commercial Bu2SnO as catalyst for syntheses of linear and/or cyclic polylactides l‐Lactide was polymerized in bulk with variation of the LA/Cat ratio, temperature and time. Based on a ring‐expansion polymerization (REP) mechanism cyclic polylactides (PLAs) with weight average molecular weights in the range of 200,000–300,000 are obtained at the highest temperature (180 °C). Polymerizations at 150 °C yielded crystalline, mainly cyclic polylactides which, after annealing, showed high melting temperatures (up to 197.5 °C) and high crystallinities (>80%). Polymerization at 120 °C confirmed the trend towards more linear chains with lower temperatures but yielded extended‐ring crystals showing a "saw‐tooth pattern" in the mass spectra. Oct2SnO gave similar results as Bu2SnO. Bu2SnS proved a sluggish polymerization catalyst, but a good transesterification catalyst in solid PLA. [ABSTRACT FROM AUTHOR]

Extreme ultraviolet (EUV)-induced radiation exposure chemistry in organotin-oxo systems, represented by the archetypal [(R-Sn)12O14(OH)6](A)2 cage, has been investigated with density functional theory. Upholding existing experimental evidence of Sn-C cleavage-dominant chemistry, computations have revealed that either electron attachment or ionization can single-handedly trigger tin-carbon bond cleavage, partially explaining the current EUV sensitivity advantage of metal oxide systems. We have revealed that tin atoms at different parts of the molecule react differently to ionization and electron attachment and have identified such selectivity as a result of local coordination chemistry instead of the macro geometry of the molecule. An ionization-deprotonation pathway has also been identified to explain the observed evolution of an anion conjugate acid upon exposure and anion mass dependence in resist sensitivity.

Endocrine‐disrupting chemicals (EDCs) often affect homeostatic regulation in living organisms by directly acting on nuclear receptors (NRs). Retinoid X receptors (RXRs), the most highly conserved members of the NR superfamily during evolution, function as partners to form heterodimers with other NRs, such as retinoic acid, thyroid hormone, and vitamin D3 receptors. RXRs also homodimerize and induce the expression of target genes upon binding with their natural ligand, 9‐cis‐retinoic acid (9cRA), and typical EDCs organotin compounds, such as tributyltin and triphenyltin. In the present study, we established a new yeast reporter gene assay (RGA) to detect the ligands of freshwater cladoceran Daphnia magna ultraspiracle (Dapma‐USP), a homolog of vertebrate RXRs. D. magna has been used as a representative crustacean species for aquatic EDC assessments in the Organization for Economic Corporation and Development test guidelines. Dapma‐USP was expressed along with the Drosophila melanogaster steroid receptor coactivator Taiman in yeast cells carrying the lacZ reporter plasmid. The RGA for detecting agonist activity of organotins and o‐butylphenol was improved by use of mutant yeast strains lacking genes encoding cell wall mannoproteins and/or plasma membrane drug efflux pumps as hosts. We also showed that a number of other human RXR ligands, phenol and bisphenol A derivatives, and terpenoid compounds such as 9c‐RA exhibited antagonist activity on Dapma‐USP. Our newly established yeast‐based RGA system is valuable as the first screening tool to detect ligand substances for Dapma‐USP and for evaluating the evolutionary divergence of the ligand responses of RXR homologs between humans and D. magna. The freshwater cladoceran Daphnia magna has been used as a representative crustacean species for aquatic assessments of endocrine‐disrupting chemicals (EDCs) in the Organization for Economic Corporation and Development test guidelines. The typical EDCs, organotin compounds, which include tributyltin and triphenyltin, exhibit ligand activities for nuclear receptor retinoid X receptors (RXRs). In the present study, a new reporter gene assay to detect ligands of D. magna ultraspiracle, a homolog of vertebrate RXRs, was established in the yeast Saccharomyces cerevisiae. [ABSTRACT FROM AUTHOR]

In this study, determination of the inorganic and organic forms of tin in waters of different salinities is considered. The possibility of the separation of speciations of tin using liquid–liquid extraction (LLE); precipitation with fluorides, iodides, ammonia, and iron (III) chloride; and sorption of organotin compounds (OTCs) was studied. The LLE and analyte precipitation methods proved to be ineffective. Inorganic and organic forms of tin were separated by the sorption of OTCs using silica gel sorbent Diapak C18. Under optimized conditions, a technique for the separate determination of the forms of tin in natural waters was developed. The technique combines hydride generation and microwave mineralization of solutions followed by ICP spectrometry. The inorganic forms of tin were determined after their solid-phase separation from organotin compounds. The lower limits of analyte quantification were 0.03 μg/L (ICP-MS) and 0.05 μg/L (ICP-OES), which provide separate determinations of inorganic and organic forms of tin in waters with different salinities. The content of OTCs in water was determined by subtracting the inorganic concentration from the total concentration of tin. The technique will allow a comprehensive assessment of the toxicological impact of tin speciations on the aquatic ecosystem. [ABSTRACT FROM AUTHOR]

New complexes I–IV of di-tert-butyltin with ligands based on heterocyclic thioamides (2-mercaptobenzoxazole, 2-mercaptobenzothiazole, 2-mercaptobenzimidazole) and 2,6-di-tert-butyl-4-mercaptophenol are synthesized and studied by X-ray diffraction (XRD). The XRD results for single crystals of I, II, and IV are presented (CIF files CCDC nos. 2251495, 2251493, and 2251494, respectively). Specific features of the synthesized crystal structures are discussed. Complexes I and II contain the expected Sn–C and Sn–S bonds and an additional coordination with the nitrogen atom in the heterocycles, which indicates the octahedral environment of the Sn(IV) atom (coordination number 6). The coordination polyhedron in complex IV can be described as a distorted tetrahedron (coordination number 4). The proposed compounds are studied as antiproliferative agents. Their antiproliferative activity is determined using the human cancer cell lines (PC3, MCF-7, НСT116, A549, and normal cells WI38). A dependence of the activity on the ligand structure is found. A comparative evaluation of the activity shows that the introduction of the antioxidant 2,6-di-tert-butyl-4-mercaptophenol fragment into complex IV substantially decreases the cytotoxicity. [ABSTRACT FROM AUTHOR]

Although restricting environmental quality values for organotin compounds (OTs) are set by Directive 2013/39/EU of the European Parliament, marine environment remains being affected due to maritime circulation at global scale. Fish and seafood accumulate OTs, making fish and seafood consumption the main source of OTs in humans. Because of the fish and seafood matrices complexity and the required low limits of detection, a robust and fast procedure for the quantification of OTs in fish and seafood, using ultrasound-assisted extraction and gas chromatography–tandem mass spectrometry, was validated and applied. Detection (2.7 µg Sn kg−1) and quantification (8.0 µg Sn kg−1) limits, repeatability and intermediate precision (<10%), accuracy by analysing ERM®-CE477 Mussel Tissue and analytical recoveries (65–122%) were assessed. Multivariate analysis shown that the matrix effect for some OTs displayed good negative correlation with the fat and protein content. Health risk assessment of OTs intake revealed no serious risk for human consumption. [ABSTRACT FROM AUTHOR]

This paper considers the features of determining the total tin content in waters with different salinity. Direct ICP-spectrometric analysis of sea waters with a salinity of more than 6‰ significantly reduced the analytical signal of tin by 70% (ICP-MS) and 30% (ICP-OES). The matrix effect of macrocomponents was eliminated by generating hydrides using 0.50 M sodium borohydride and 0.10 M hydrochloric acid. The effect of transition metals on the formation of tin hydrides was eliminated by applying L-cysteine at a concentration of 0.75 g/L. The total analyte concentrations, considering the content of organotin compounds, were determined after microwave digestion of sample with oxidizing mixtures based on nitric acid. The generation of hydrides with the ICP-spectrometric determination of tin leveled the influence of the sea water matrix and reduced its detection limit from 0.50 up to 0.05 µg/L for all digestion schemes. The developed analysis scheme made it possible to determine the total content of inorganic and organic forms of tin in sea waters. The total content of tin was determined in the waters of the Azov and Black seas at the levels of 0.17 and 0.24 µg/L, respectively. [ABSTRACT FROM AUTHOR]

Organotin (IV) dithiocarbamate has recently received attention as a therapeutic agent among organotin (IV) compounds. The individual properties of the organotin (IV) and dithiocarbamate moieties in the hybrid complex form a synergy of action that stimulates increased biological activity. Organotin (IV) components have been shown to play a crucial role in cytotoxicity. The biological effects of organotin compounds are believed to be influenced by the number of Sn-C bonds and the number and nature of alkyl or aryl substituents within the organotin structure. Ligands target and react with molecules while preventing unwanted changes in the biomolecules. Organotin (IV) dithiocarbamate compounds have also been shown to have a broad range of cellular, biochemical, and molecular effects, with their toxicity largely determined by their structure. Continuing the investigation of the cytotoxicity of organotin (IV) dithiocarbamates, this mini-review delves into the appropriate method for synthesis and discusses the elemental and spectroscopic analyses and potential cytotoxic effects of these compounds from articles published since 2010. [ABSTRACT FROM AUTHOR]

The widely used organotin compounds are notorious for their acute toxicity. Experiments revealed that organotin might cause reproductive toxicity by reversibly inhibiting animal aromatase functioning. However, the inhibition mechanism is obscure, especially at the molecular level. Compared to experimental methods, theoretical approaches via computational simulations can help to gain a microscopic view of the mechanism. Here, in an initial attempt to uncover the mechanism, we combined molecular docking and classical molecular dynamics to investigate the binding between organotins and aromatase. The energetics analysis indicated that the van der Waals interaction is the primary driving force of binding the organic tail of organotin and the aromatase center. The hydrogen bond linkage trajectory analysis revealed that water plays a significant role in linking the ligand–water–protein triangle network. As an initial step in studying the mechanism of organotin inhibiting aromatase, this work provides an in-depth understanding of the binding mechanism of organotin. Further, our study will help to develop effective and environmentally friendly methods to treat animals that have already been contaminated by organotin, as well as sustainable solutions for organotin degradation. [ABSTRACT FROM AUTHOR]

Metal-derived platinum complexes are widely used to treat solid tumors. However, systemic toxicity and tumor resistance to these drugs encourage further research into similarly effective compounds. Among others, organotin compounds have been shown to inhibit cell growth and induce cell death and autophagy. Nevertheless, the impact of the ligand structure and mechanisms involved in the toxicity of organotin compounds have not been clarified. In the present study, the biological activities of commercially available bis(tributyltin) oxide and tributyltin chloride, in comparison to those of specially synthesized tributyltin trifluoroacetate (TBT-OCOCF3) and of cisplatin, were assessed using cells with different levels of tumorigenicity. The results show that tributyltins were more cytotoxic than cisplatin in all the tested cell lines. NMR revealed that this was not related to the interaction with DNA but to the inhibition of glucose uptake into the cells. Moreover, highly tumorigenic cells were less susceptible than nontumorigenic cells to the nonunique pattern of death induced by TBT-OCOCF3. Nevertheless, tumorigenic cells became sensitive when cotreated with wortmannin and TBT-OCOCF3, although no concomitant induction of autophagy by the compound was detected. Thus, TBT-OCOCF3 might be the prototype of a family of potential anticancer agents. [ABSTRACT FROM AUTHOR]

A series of novel organotin(IV) complexes on the base of 2-(N-3′,5′-di-tert-butyl-4′-hydroxyphenyl)-iminomethylphenol (L) of formulae Me2SnBr2(L)2 (1), Bu2SnCl2(L)2(2), Ph2SnCl2(L) (3), Ph2SnCl2(L)2 (4) Ph3SnBr(L)2 (5) were synthesized and characterized by 1H, 13C, 119Sn NMR, IR, ESI-MS and elemental analysis. The crystal structures of initial L and complex 2 were determined by XRD method. It was found that L crystallizes in the orthorhombic syngony. The distorted octahedron geometry around Sn center is observed in the structure of complex 2. Intra- and inter-molecular hydrogen bonds were found in both structures. The antioxidant activity of new complexes as reducing agents, radical scavengers and lipoxygenase inhibitors was estimated spectrophotometrically in CUPRAC and DPPH tests (compounds 1 and 5 were found to be the most active in both methods), and in the process of enzymatic oxidation in vitro of linoleic acid under the action of lipoxygenase LOX 1-B (EC50 > 33.3 μM for complex 2). Furthermore, compounds 1–5 have been investigated for their antiproliferative activity in vitro towards HCT-116, MCF-7 and A-549 and non-malignant WI-38 human cell lines. Complexes 2 and 5 demonstrated the highest activity. The plausible mechanisms of the antiproliferative activity of compounds, including the influence on the polymerization of Tb+MAP, are discussed. Some of the synthesized compounds have also actively induced apoptosis and blocked proliferation in the cell cycle G2/M phase. [ABSTRACT FROM AUTHOR]

The expanded use of copper(I)-based antifouling paints (AF) has increased copper leaching into coastal environments, requiring attention and legislative restrictions for potential long-term effects on benthic populations. The ecological succession of macrofouling communities was analysed on wooden and stainless steel panels coated with four copper(I)-based AF (Paints A–D) immersed for 10 months in the Lagoon of Venice. With the exception of Paint B, which contained only copper(I) compounds and was based on hard-matrix technology, the other paints were based on self-polishing matrices and various booster biocides. The booster content was a mix of TBT compounds for Paint A, dichlofluanid for Paint C, Irgarol 1051, and chlorothalonil for Paint D. The macrofouling communities appeared dissimilar to those on the reference uncoated panels as regard the species richness, the coverage areas, and the biocoenosis structure. Generally, green algae, bryozoans, and barnacles were the most tolerant taxa and a negative species selection occurred for sponges, serpulids, and ascidians. Paints A and D showed the highest performance, and Paint D also prevented molluscs on wood panels. Paints B and C rapidly decreased their efficiency, the first probably due to the insoluble matrix with the highest biocidal leaching rate, and the second due to the presence of a booster with low toxicity. Paint B also inhibited red algae and molluscs, but Paint C did not reveal significant differences in types of species settlements with reference panels. [ABSTRACT FROM AUTHOR]

The local structure of four amorphous organotin sulfide compounds is investigated by X‐ray absorption spectroscopy. These compounds exhibit a nonlinear optical (NLO) response upon irradiation with a continuous‐wave near‐infrared laser. Their basic structural motif is a hetero‐adamantane cluster with different organic substituent, but depending on the morphology of the compound and the choice of the organic substituent, the nature of the NLO response changes to either a second harmonic generation or the generation of a supercontinuum, potentially appearing as white light. The structural results provide an experimental evidence that the nature of the NLO properties is tied to distortions occurring at the cluster core, with almost ideal clusters in compounds that show second harmonic generation, and strongly distorted clusters in the case of compounds that generate a supercontinuum. These distortions may enable a closer proximity of the cluster cores, altering the intermolecular order, and thereby influencing the NLO response. [ABSTRACT FROM AUTHOR]

We measured the concentrations of antifouling biocides in sediment, mangrove leaves and seagrasses from Merambong and Tinggi Island, Johor, Malaysia to evaluate their contamination levels. Although the concentrations of tributyltin (TBT) in mangrove leaves in Merambong in 2013 were significantly lower than those in 2012, the Sea-Nine 211 concentration in 2013 was significantly higher than that in 2012, suggesting that the use of antifouling biocides changed from TBT to Sea-Nine 211. The concentration of each BT (butyltin) and PT (phenyltin) in the mangrove area was significantly higher than the corresponding concentration in the seagrass area in Merambong, but the concentrations of Sea-Nine 211, diuron, chlorothalonil, Irgarol 1051 and M1 in seagrasses were significantly higher than those in mangrove leaves. There were differences in the accumulation profiles of OTs (organotins) and alternative biocides between the seagrass shoots and roots. The concentration of OTs in the seagrass roots was almost the same or higher than those in the shoots, whereas those of alternative biocides shows the opposite pattern to the OTs. Significant high relationships were observed between stable carbon isotope (δ 13C) and OTs, Sea-Nine 211 and Irgarols in mangrove leaves. The concentrations of these compounds increased along with the δ 13C values of the mangroves. These results suggest that mangroves take up the bicarbonate ions and nutrients in sediment and/or seawater through their roots, along with OTs, Sea-Nine 211 and Irgarols which were accumulated in sediment. [ABSTRACT FROM AUTHOR]

Organotin compounds (OTCs) are a commercially important group of organometallic compounds of tin used globally as polyvinyl chloride stabilizers and marine antifouling biocides. Worldwide use of OTCs has resulted in their ubiquitous presence in ecosystems across all the continents. OTCs have metabolic and endocrine disrupting effects in marine and terrestrial organisms. Thus, harmful OTCs (tributyltin) have been banned by the International Convention on the Control of Harmful Antifouling Systems since 2008. However, continued manufacturing by non-member countries poses a substantial risk for animal and human health. In this study, structural binding of common commercial OTCs, tributyltin (TBT), dibutyltin (DBT), monobutyltin (MBT), triphenyltin (TPT), diphenyltin (DPT), monophenyltin (MPT), and azocyclotin (ACT) against sex-steroid nuclear receptors, androgen receptor (AR), and estrogen receptors (ERα, ERβ) was performed using molecular docking and MD simulation. TBT, DBT, DPT, and MPT bound deep within the binding sites of AR, ERα, and Erβ, showing good dock score, binding energy and dissociation constants that were comparable to bound native ligands, testosterone and estradiol. The stability of docking complex was shown by MD simulation of organotin/receptor complex with RMSD, RMSF, Rg, and SASA plots showing stable interaction, low deviation, and compactness of the complex. A high commonality (50–100%) of interacting residues of ERα and ERβ for the docked ligands and bound native ligand (estradiol) indicated that the organotin compounds bound in the same binding site of the receptor as the native ligand. The results suggested that organotins may interfere with the natural steroid/receptor binding and perturb steroid signaling. [ABSTRACT FROM AUTHOR]

Organotin compounds are widely employed as pesticides and fungicides in agriculture and as stabilizers for the industrial manufacture of polyvinyl chloride and other polymers. Accordingly, these endocrine disruptors can be found in a variety of foods and beverages. In the present study, we describe the optimization of a hollow-fiber liquid-phase micro-extraction approach for the simultaneous derivatization, extraction, and pre-concentration of butyltin species from commercial fruit juices with the aim of investigating their migration from the packaging. The best extraction efficiencies were achieved by using hexane as the acceptor solvent and a polypropylene fiber length of 2 cm, whereas the agitation speed, extraction temperature, and total extraction time were set at 1100 rpm, 25 ºC, and 10 min, respectively. Using these optimal conditions, the method was satisfactorily validated in terms of linearity (5–1000 µg L−1), limits of detection (0.8–1.8 µg L−1), recovery (80.5–92.1%), intraday precision (10.2–13.1%), inter-day precision (11.0–15.5%), matrix effect (83.2–91.8%), accuracy (85.2–95.2%), specificity, and carryover. The application of this technique to commercial samples obtained from a local market demonstrated that levels of organotin species in packed fruit juices are negligible, in agreement with the limits established by the European Food Safety Authority (0.14 mg of total organotin compounds per kg of food). [ABSTRACT FROM AUTHOR]

The application of organotin-based antifouling compounds in the harbour during repairing and painting of ships in Nigeria harbour is a common practice in the maintenance wing of the dockyard. These antifouling chemicals are extremely toxic to aquatic life. As a result of dearth of data on the levels of organotin compounds in the West African coast including Lagos harbour, a study was undertaken to profile organotin compounds, in Lagos Dockyard harbour, Nigeria. The sediment and water samples were collected for two years (2016–2018) covering both the dry and wet seasons. A cold extraction technique by ultrasonication was used for sediments collected and a liquid-liquid separation technique was applied to water samples and later cleaned up by the use of silica gel-based packed column. The six organotin compounds considered in this work are Monobutyltin (MBT), Dibutyltin (DBT), Tributyltin (TBT), Monophenyltin (MPhT), Diphenyltin (DPhT), Triphenyltin (TPhT) were analysed by using an optimised high-performance liquid chromatography (HPLC). The result of the analysis on the sediment showed that the concentration of the organotin compounds (OTCs) ranges from 0.008 ± 0.00 to 272.710 ± 100.2 (ng/g) in MBT, 0.001 ± 0.00 to 69.780 ± 42.01 (ng/g) in DBT, 0.002 ± 0.00 to 7.110 ± 0.45 (ng/g) in TBT, 0.046 ± 0.01 to 76.210 ± 4.00 (ng/g) in MPhT, 0.070 ± 0.01 to 11.520 ± 0.62 (ng/g) in DPhT and 0.006 ± 0.00 to 2.330 ± 0.04 (ng/g) in TPhT. Higher values of OTCs were recorded during the wet season than the dry season and this was attributed to the dredging of harbour and remobilisation of organotin compounds from sediments into the water compartment. Principal Component Analysis (PCAs), Cluster Analysis (CA) and correlation analysis provided evidence for the interaction among these contaminants and possible sources of the contaminants. More so, the study showed that the degradation of these organotin compounds into their metabolites was governed by the influence of specific microorganisms. Therefore, regular monitoring of harbour was recommended for public safety. [ABSTRACT FROM AUTHOR]

Organotin compounds are causing deterioration effect on non-targeted aquatic species in the environment, such as shell anomalies in oysters and imposex in gastropods, even at concentrations as low nanograms per litre. Specific analytical methods have been developed for different environmental matrices. Analysis of organotin compounds in sediment because of hydrophobic properties and tend to adsorb onto particulate matter is valuable for assessing the environmental distribution and fate. Therefore, in this study, a rapid, reliable, sensitive and effective method developed for quantification and identification of antifouling organotin butyl- and phenyltin compounds in sediment samples by using Gas chromatography with Tandem MS detector (GC-MSMS and GC-QTOF). The method is based on the single extraction step followed by GC-MSMS and GC-QTOF detection. The sample extraction steps were decreased for low labour laboratory costs and time-consuming. Not only the extraction procedure but instrumental method parameters were carefully optimised in order to increase sensitivity and precision. The QTOF system with the help of mass accuracy and mass resolution showed a good sensitivity and precision to analyse sediment samples. The isotopic disturbance and utilisation isotopic space for confirmation of organotin compounds have been scrutinised in GC-QTOF. GC Triple Quadrupole (GC-MSMS) system also utilised as a secondary confirmation method for organotin compound analysis. Additionally, the sensitivity of both MS detectors under the matrix effect was investigated. The recoveries of extraction were in the range of 82–106%. The acquired results have shown that the concentration range in 10–250 ppb (ng/ml) level was denoted good linearity (r2 = 0.9725–0.9983). Moreover, limits of detection (LOD) for both butyl and phenyl fractions of organotin compounds were ranged between 0.23 and 22.11 pg/ml. Consequently, the developed method successfully was applied to certificated reference material (BCR – 462) and the targeted organotin compounds in a real marine/harbour sediment sample. [ABSTRACT FROM AUTHOR]

Organotin compounds are organometallic compounds composed of one or more tin-carbon (Sn-C) bonds. Organotin compounds have been shown to have anticancer, antibacterial, and antitumor activities. Based on the several activities of the organotin group, it is hoped that the Dibutyltin (IV) Bis-N-Benzylmethyl Dithiocarbamate compound has the potential to be developed as a new drug candidate. To be a candidate for a new drug, the study was aimed to test and determine the safety level of the compound. Study to determine the LD50 value and category of toxicity of the Dibutyltin (IV) Bis-N-Benzylmethyl Dithiocarbamate compound in white mice (Mus musculus). This research is a laboratory experimental study using 40 white mice, consisting of 20 male mice and 20 female mice. The dose of the test substance was 240, 480, and 960mg/Kg body weight. Observations of mice were carried out for 24 hours by observing the number of dead animals and seeing toxic symptoms, body weight, and ROW (Relative Organ Weight) then the data were analyzed statistically. The results showed that the dose of 960 mg caused the most death with LD50 values of 776.2mg and 794 .3mg of toxic symptoms, weight loss in mice, and an effect on ROW. This compound can cause death in male and female mice, with the LD50 value of male mice being 776.2mg/kg body weight and female mice at 794.3mg/ kg body weight, and this compound is categorized as slightly toxic. [ABSTRACT FROM AUTHOR]

The effect of antitumor and antimetastatic agent, triphenyltin (3,5-di-tert-butyl-4-hydroxyphenyl)thiolate (Me-5), on the in vitro activity of inducible nitric oxide synthase (iNOS) as a relevant biological target was studied. The compound Me-5 (the half-maximal inhibitory concentration IC50 = 0.47 µmol L−1) induced a significant inhibition of NO formation by macrophages, exceeding that of dexamethasone used as the reference compound (IC50 = 1.55 µmol L−1). Estimation of the morphology of macrophages after incubation with Me-5 in 10 µmol L−1 concentration revealed signs of the pronounced cytotoxicity: destruction of cell membranes, reduction of cell volume, chromatin condensation, and nuclear shrinkage. It was found that the organotin compound substantially inhibits the anti-inflammatory response and viability of macrophages, especially the functions of lysosomes. Molecular docking of Me-5 into the iNOS structure was carried out. According to calculations, the molecule is located at the entrance of the active site cavity, above the plane of the heme moiety, and hinders the substrate penetration into the active site, which may attest to a plausible mechanism of antitumor and antimetastatic action of Me-5. [ABSTRACT FROM AUTHOR]

DCOIT (4,5-dichloro-2-n-octyl-4-isothiazolin-3-one) is the main ingredient in SeaNine-211, a new antifouling agent that replaces organotin compounds to prevent the growth of fouling organisms on board. Biocides from antifoulants can cause problems for marine ecosystems by destroying non-target algal species. This study evaluated the potential adverse effects DCOIT using the Marine Chlorella sp. The concentration of DCOIT were set according to the semi-inhibitory concentrations for acute exposure experiments, and relevant oxidative stress indicators were measured to assess the acute toxic effects. The results showed that the inhibition concentrations (IC50) of DCOIT against Marine Chlorella sp was 2.522 mg/L. The genes related to photosynthesis and antioxidant capacity showed the effect of promoting low concentration and inhibiting high concentration. In addition, based on the ultrastructural observation and the expression analysis of photosynthesis related genes, it was found that DCOIT had a significant effect on plant photosynthesis. [ABSTRACT FROM AUTHOR]

Tributyltin (TBT) is an organotin compound that has several adverse health effects, including the development of obesity. Although obesity is strongly associated with adipose redox imbalance, there is a lack of information on whether TBT promotes a pro-oxidative environment in WAT. Thus, adult male Wistar rats were randomly exposed to either vehicle (ethanol 0.4%) or TBT (1000 ng/kg) for 30 days. Body and fat pad masses, visceral fat morphology, lipid peroxidation, protein carbonylation, redox status markers, and catalase activity were evaluated. TBT promoted increased adiposity and visceral fat, with hypertrophic adipocytes, but did not alter body mass and subcutaneous fat. ROS production and lipid peroxidation were elevated in TBT group, as well as catalase protein expression and activity, although protein oxidation and glutathione peroxidase protein expression remained unchanged. In conclusion, this is the first study to demonstrate that subacute TBT administration leads to visceral adipose redox imbalance, with increased oxidative stress. This enlights the understanding of the metabolic toxic outcomes of continuous exposure to TBT in mammals. • TBT promotes white adipose tissue dysfunction. • TBT increases adipose oxidative stress. • TBT upregulates the adipose antioxidant defense. [ABSTRACT FROM AUTHOR]

• A high-yield general synthetic route was chosen for (Aryl)RSnCl 2. • The crystal structure of some compounds was determined. • A new polymorph of p -methylphenyl tin dichloride has been discovered. In an effort to develop new organotin compound, a series of organotin compounds containing mixed aryl-alkyl substituents have been synthesized. All prepared organotin (IV) compounds were characterized by IR, 1H, 13C, 119Sn NMR spectra, and the elemental analysis. In addition, the solid-state structures of 4–1a, 4–2a, 4–2b, 4–2c, 5–1b, 5–2a, 5–2b, and 5–1a' were determined by the X-ray diffraction analysis. The Hirshfeld surface analysis shows that the complexes 5–1b and 5–2b have a similar contribution of different contacts to the Hirshfeld surfaces. A high-yield general synthetic route was chosen for (Aryl)RSnCl 2 , it involves the formation of mixed aryl-alkyl tetraorganotin compounds (Aryl)RSnCl 2 from the reaction of (Aryl) 3 SnCl and the appropriate alkyl Grignard reagent, followed by cleavage of two aryl group with hydrogen chloride, the crystal structure of some compound was determined. [Display omitted] [ABSTRACT FROM AUTHOR]

The presence of the organotin compound tributyltin (TBT) in aquatic ecosystems has been a serious environmental problem for decades. Although a number of studies described the negative impact of TBT on mollusks at different levels, investigations connected to its potential effects during embryogenesis have been neglected. For a better understanding of the impact of TBT on mollusks, in the present study, embryos of previously TBT-treated or not treated specimens of the great pond snail (Lymnaea stagnalis) were exposed to 100 ng L−1 TBT from egg-laying (single-cell stage) until hatching. According to our results, TBT significantly delayed hatching and caused shell malformation. TBT transiently decreased the locomotion (gliding) and also reduced the feeding activity, demonstrating for the first time that this compound can alter the behavioral patterns of molluscan embryos. The heart rate was also significantly reduced, providing further support that cardiac activity is an excellent indicator of metal pollution in molluscan species. At the histochemical level, tin was demonstrated for the first time in TBT-treated hatchlings with intensive reaction in the central nervous system, kidney, and hepatopancreas. Overall, the most notable effects were observed in treated embryos derived from TBT treated snails. Our findings indicate that TBT has detrimental effects on the development and physiological functions of Lymnaea embryos even at a sub-lethal concentration, potentially influencing their survival and fitness. Highlighting our observations, we have demonstrated previously unknown physiological changes (altered heart rate, locomotion, and feeding activity) caused by TBT, as well as visualized tin at the histochemical level in a molluscan species for the first time following TBT exposure. Further studies are in progress to reveal the cellular and molecular mechanisms underlying the physiological and behavioral changes described in the present study. [Display omitted] • The effect of 100 ng L−1 TBT on Lymnaea embryos was investigated. • TBT significantly delayed hatching and caused shell malformation. • Decrease in heart rate, gliding, and feeding were observed. • Tin accumulated in the nervous system, kidney, and hepatopancreas of hatchlings. [ABSTRACT FROM AUTHOR]

In this study, determination of the inorganic and organic forms of tin in waters of different salinities is considered. The possibility of the separation of speciations of tin using liquid–liquid extraction (LLE); precipitation with fluorides, iodides, ammonia, and iron (III) chloride; and sorption of organotin compounds (OTCs) was studied. The LLE and analyte precipitation methods proved to be ineffective. Inorganic and organic forms of tin were separated by the sorption of OTCs using silica gel sorbent Diapak C18. Under optimized conditions, a technique for the separate determination of the forms of tin in natural waters was developed. The technique combines hydride generation and microwave mineralization of solutions followed by ICP spectrometry. The inorganic forms of tin were determined after their solid-phase separation from organotin compounds. The lower limits of analyte quantification were 0.03 μg/L (ICP-MS) and 0.05 μg/L (ICP-OES), which provide separate determinations of inorganic and organic forms of tin in waters with different salinities. The content of OTCs in water was determined by subtracting the inorganic concentration from the total concentration of tin. The technique will allow a comprehensive assessment of the toxicological impact of tin speciations on the aquatic ecosystem.

BackgroundThe organotin dibutyltin (DBT) is used in the manufacture of polyvinyl chloride (PVC) plastics, in construction materials, and in medical devices. Previous animal studies showed detrimental effects of DBT during in utero development at relatively high doses, but little was known about the effects of DBT exposure at environmentally relevant doses on endpoints such as obesity and metabolic disease.ObjectivesWe tested the potential obesogenic effects of DBT using in vitro and in vivo models.MethodsWe evaluated the effects of DBT on nuclear receptor activation and adipogenic potential using human and mouse multipotent mesenchymal stromal stem cells (MSCs). We also evaluated the effects of perinatal exposure to environmentally relevant doses of DBT in C57BL/6J mice.ResultsDBT activated human and mouse PPARγ and RXRα in transient transfection assays, increased expression of adipogenic genes, promoted adipogenic differentiation and increased lipid accumulation in mouse and human MSCs, in vitro. DBT-induced adipogenic differentiation was abolished by the PPARγ antagonist T0070907, indicating that DBT was acting primarily through PPARγ. Perinatal exposure to low doses of DBT led to increased fat storage, decreased glucose tolerance, and increased circulating leptin levels in male, but not female, mice.ConclusionsDBT acted as an obesogen by inducing lipid accumulation in human and mouse MSCs through a PPARγ-dependent pathway. In vivo exposure to biologically relevant doses of DBT during perinatal development led to increased fat storage, elevated leptin levels in plasma, and glucose intolerance in mice. Based on these findings, we posit that monitoring of DBT levels in human samples may aid in understanding and potentially preventing the rising rates of metabolic disorders in human populations. https://doi.org/10.1289/EHP3030.

Organotin compounds are widely used in the plastic industry. We demonstrate the role of brain magnetic resonance imaging in a patient with leukoencephalopathy. A 38-year-old man who worked with trimethyltin and dimethyltin in a polyvinyl chloride factory reported a two-week progression of impaired memory, loss of balance, apathy, tinnitus, scaly darkened skin, and psychomotor slowing that rendered him unable to continue his daily activities. Magnetic resonance imaging revealed diffuse bilateral white matter lesions. Tin concentrations in both blood (344 μ/L) and urine (3,050 μg/L) were elevated. Removal from exposure and treatment with succimer were associated with clinical, laboratory, and imaging improvements. The high lipid content of myelin is a likely target for lipid-soluble alkyl tin compounds. This patient demonstrates the clinical and magnetic resonance imaging findings of organotin toxicity. The contribution of chelation to the patient's recovery is uncertain and warrants further study. [ABSTRACT FROM AUTHOR]

The preparation methods of methyltin were reviewed. Combined with the research status of methyltin compounds at home and abroad, the application of methyltin in chemical synthesis, surface metal-organic chemistry, tin film preparation, heat stabilizer, and other fields was introduced. Some limitations of methyltin compounds were pointed out, and the future development of methyltin compounds was prospected. [ABSTRACT FROM AUTHOR]

The local structure of four amorphous organotin sulfide compounds exhibiting nonlinear optical (NLO) properties is investigated by low‐energy X‐ray absorption spectroscopy (XANES and EXAFS). The basic structural motif of a heteroadamantane cluster with different organic substituents is confirmed by the experiments and by comparison with computer simulations of the near‐edge structure. Essential information is obtained on a special role of the nonaromatic but electron‐rich cyclopentadienyl substituents, which are able to affect the structure of the heteroadamantane cluster core. The EXAFS fits also indicate a structural distinction between two groups within these compounds, which exhibit fundamentally different NLO responses: compounds that show a second harmonic generation can be described well using the single‐molecule approach, whereas the compounds exhibiting the generation of a supercontinuum manifest additional structural contributions. [ABSTRACT FROM AUTHOR]

In this work, we report polyvinyl toluene (PVT)-based plastic scintillators highly loaded with five different kinds of organotin compounds. The newly developed Sn-loaded plastic scintillators demonstrate the capability of gamma spectroscopy detection with fast decay characteristics. The maximum of organotin loading ratio of 33 wt% (10.8 wt% Sn) was achieved in tributyl(1-ethoxyvinyl) tin. PVT plastic scintillators containing 20 wt% tributyl(1-ethoxyvinyl) tin have optimal performance, providing gamma-ray spectroscopy with a light yield of 7100 photons/MeV and an energy resolution of 11.7% at 662 keV. [ABSTRACT FROM AUTHOR]

The concentrations of organotin (OT) compounds, butyltin (BT) and phenyltin (PT), in aquatic organisms from Merambong and Tinggi Island, Malaysia, which differ in industrial and economic activities, were measured. Tributyltin (TBT) compounds among BTs ranged from 2.9–28 and <0.1–21 ng g−1 ww in aquatic organisms from Merambong and Tinggi Island, respectively. Triphenyltin (TPT) compounds among PTs ranged from <0.1–25 ng g−1 ww and <0.1–61 ng g−1 ww in aquatic organisms from Merambong and Tinggi Island, respectively. A survey of OT concentrations among the species of OT compounds revealed that the concentrations of BTs and PTs in crabs and clams were high while those in fish were low. Correlation analysis with stable nitrogen isotopes suggest that OT compounds did not accumulate in aquatic organisms through the food web. The measurement of OT compounds in tissues and organs of fish revealed that BT concentrations in liver were higher than those in muscle and that BTs were detected in eggs of fish. [ABSTRACT FROM AUTHOR]

Organotin compounds (OTCs) are a category of persistent toxic substances with endocrine disrupting effects and may pose a risk to aquatic organisms and human health via water. This study collected 78 surface water samples from the drinking water source in the upper Yangtze River Estuary from July 2018 to November 2019. Out of the nine OTC targets, tributyltin (TBT), dimethyltin (DMT), trimethyltin (TMT), dibutyltin (DBT), and monobutyltin (MBT) were detected from more than 50% of the water samples, with cumulative concentrations of OTCs ranging from 42.5 ± 54.0 to 421 ± 176 ng Sn L−1. The composition and concentrations of OTCs in the stormy months were different from those in other months. The concentrations of OTCs with the ebbing tide exceeded those in the flooding tide and increased when the flooding tide transitioned to the ebbing tide. A pulsed trend in concentrations of OTCs in river water was evident due to the impact of rainfall runoff and tidal currents. Identified sources of OTCs included ship antifouling paints, agricultural pesticides, and plastic waste. TBT in water sources poses a low risk to human health and a risk to the ecosystem, particularly during the stormy months.

This paper considers the features of determining the total tin content in waters with different salinity. Direct ICP-spectrometric analysis of sea waters with a salinity of more than 6‰ significantly reduced the analytical signal of tin by 70% (ICP-MS) and 30% (ICP-OES). The matrix effect of macrocomponents was eliminated by generating hydrides using 0.50 M sodium borohydride and 0.10 M hydrochloric acid. The effect of transition metals on the formation of tin hydrides was eliminated by applying L-cysteine at a concentration of 0.75 g/L. The total analyte concentrations, considering the content of organotin compounds, were determined after microwave digestion of sample with oxidizing mixtures based on nitric acid. The generation of hydrides with the ICP-spectrometric determination of tin leveled the influence of the sea water matrix and reduced its detection limit from 0.50 up to 0.05 µg/L for all digestion schemes. The developed analysis scheme made it possible to determine the total content of inorganic and organic forms of tin in sea waters. The total content of tin was determined in the waters of the Azov and Black seas at the levels of 0.17 and 0.24 µg/L, respectively.

Organotin compounds (OTCs) are among the most hazardous substances found in the marine environment and can be determined by either the ISO 23161 method based on extraction with non-polar organic solvents and gas chromatography analysis or by the recently developed QuEChERS method coupled to liquid chromatography-mass spectrometry (LC-MS/MS). To date, the QuEChERS LC/MS and ISO 23161 methods have not been compared in terms of their fit-for-purpose and reliability in the determination of OTCs in bottom sediments. In the case of ISO 23161, due to a large number of interferences gas chromatography-mass spectrometry was not suitable for the determination of OTCs contrary to more selective determination by gas chromatography with an atomic emission detector. Moreover, it has been found that the derivatization of OTCs to volatile compounds, which required prior gas chromatography determination, was strongly affected by the sediments' matrices. As a result, a large amount of reagent was needed for the complete derivatization of the compounds. Contrary to ISO 23161, the QuEChERS LC-MS/MS method did not require the derivatization of OTC and is less prone to interferences. Highly volatile and toxic solvents were not used in the QuEChERS LC-MS/MS method. This makes the method more environmentally friendly according to the principles of green analytical chemistry. QuEChERS LC-MS/MS is suitable for fast and reliable environmental monitoring of OTCs in bottom sediments from the Odra River estuary. However, determination of di- and monobutyltin by the QuEChERS LC-MS/MS method was not possible due to the constraints of the chromatographic system. Hence, further development of this method is needed for monitoring di- and monobutyltin in bottom sediments. [ABSTRACT FROM AUTHOR]