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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]

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]

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]

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 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]

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]

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]

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]

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]

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]

Trans-anethole is an aromatic compound that has been studied for its anti-inflammation, anticonvulsant, antinociceptive, and anticancer effects. A recent report found that trans-anethole exerted neuroprotective effects on the brain via multiple pathways. Since noxious stimuli may both induce neuronal cell injury and affect synaptic functions (e.g., synaptic transmission or plasticity), it is important to understand whether the neuroprotective effect of trans-anethole extends to synaptic plasticity. Here, the effects of trimethyltin (TMT), which is a neurotoxic organotin compound, was investigated using the field recording method on hippocampal slice of mice. The influence of trans-anethole on long-term potentiation (LTP) was also studied for both NMDA receptor-dependent and NMDA receptor–independent cases. The action of trans-anethole on TMT-induced LTP impairment was examined, too. These results revealed that trans-anethole enhances NMDA receptor-dependent and -independent LTP and alleviates TMT-induced LTP impairment. These results suggest that trans-anethole modulates hippocampal LTP induction, prompting us to speculate that it may be helpful for improving cognitive impairment arising from neurodegenerative diseases, including Alzheimer's disease. [ABSTRACT FROM AUTHOR]

The central element of the "metastatic organotropism" is a shift of the pro/antioxidant balance in cells and activation of oxidative stress and protective antioxidant systems. We studied the effects of bis(3,5-di-tert-butyl-4-hydroxyphenylthiolate)dimethylol (Me-3) in the maximum effective and toxic total doses on the level of markers of oxidative stress and antioxidant protection in the liver of mice with melanoma B16 before the appearance of macroscopic metastases. In 48 h after tumor inoculation, Me-3 was administered intraperitoneally once a day for 5 days in total doses of 375 and 500 mg/kg according to the classical method. Administration of the hybrid organotin compound Me-3 produced different effects on the pro/antioxidant state of the microenvironment of liver tissue as the target of melanoma B16 metastasis. The results suggest that inversion of the anti/prooxidant profile of Me-3 is determined by its dose. [ABSTRACT FROM AUTHOR]

A quantum chemical study of tin–substituent bonds in tricoordinated tin compounds is conducted using the PC GAMESS-Firefly package. The structures of the studied molecules are optimized by the DFT method (B3PW91 functional; aug-cc-pVTZ-pp effective core potential basis set for tin; 6-311++(2d,p) basis set for other atoms). The wave functions and the NBOs of tin–substituent bonds are calculated with HF method using the x2c-TZVPall all-electron relativistic basis set for tin and the 6-311G(2d,2p) basis set for other atoms. Topological characteristics of tin–substituent bonds are calculated with the AIM method. It is shown that these bonds can be referred to as "intermediate type" bonds characterized by small contributions of Sn AOs to the bond MOs, large difference between the charges of tin atoms and the substituent, and low populations of bond MOs. The energies of Sn–R bonds are estimated. [ABSTRACT FROM AUTHOR]

Organotin compounds (OTs) are well studied in various environmental compartments, with a critical focus on the water column as their primary entry point into aquatic ecosystems. In this context, a method for the analysis of organotin (OTs) in water using silicone rubber-based passive sampling was optimized, validated, and field-tested. Validation covered crucial parameters, including the limit of detection (LOD), limit of quantification (LOQ), accuracy, precision, linearity, and matrix effect. The method was shown to be robust (R2 ≥ 0.99), with recoveries between 70.2 and 114.6%, and precise (CV < 12.8%) (N = 3). LOD Cw and LOQ Cw were ≤15 and ≤ 48 pg Sn L−1, respectively, for TBT and TPhT. The matrix effect showed to be low (>-20% ME < 20%) for all OTs but TPhT (69.4%). The silicone rubber–water partition coefficients (Log K sr,w) were estimated at 3.37 for MBT, 3.77 for DBT, 4.17 for TBT, 3.49 for MPhT, 3.83 for DPhT, and 4.22 for TPhT. During the field study carried out between October 2021 and February 2022 at the entrance of the Port of Santos navigation channel (Southeastern Brazil), sampling rates ranged between 4.1 and 4.6 L d−1, and the equilibrium was achieved for MBT, DBT, MPhT, and DPhT after ∼45 days of deployment. The freely dissolved concentrations varied between 134 and 165 pg Sn L−1 for TBT, 388 and 610 pg Sn L−1 for DBT, and 1114 and 1509 pg Sn L−1 for MBT, while MPhT, DPhT, and TPhT were below the limit of detection. Results pointed out that J-FLEX® rubber-based passive sampling is a suitable and reliable alternative method for the continuous monitoring of OTs in the water column. [Display omitted] • J-FLEX® silicone-based passive sampling device has been implemented for the analysis of OTs. • Sampler-water partition coefficients were determined for 6 OTs. • Matrix effect may be a matter of concern and must be appraised. • Freely dissolved OTs were detected at pg Sn L−1 levels in an estuarine water column, meeting guidelines requirements. • J-FLEX® rubber has proven to be a reliable tool for continuous monitoring of OTs in the water column. [ABSTRACT FROM AUTHOR]

• Complexation chromatography for speciation of organotin compounds. • Ternary eluent and flow-rate gradient method. • Ligand addition to mobile phase for on-column complex formation. • Robust ICP-MS conditions for liquid chromatography gradient method. Organotin compounds (OTCs) are widely regulated but rank among the most used organometallic compounds in various industrial sectors. They are significantly more toxic than inorganic tin compounds. At workplaces, OTCs can be released as vapors or dust particles and can be absorbed by inhalation or skin contact. Occupational exposure thus represents a great risk for the absorption of OTCs for employees. Methods for OTCs speciation in workplace air monitoring currently do not exist. This study describes the development of a separation method for eleven in Germany regulated OTCs via HPLC-ICP-MS. The method allows a near baseline separation of MMT, MBT, MOT, MPhT, DMT, DBT, DPhT, TMT, TBT, TPhT and TTMT within 22 min on a C18 column and a ternary solvent and flow rate gradient using methanol, acetonitrile, and ultrapure water + 6% (v/v) acetic acid + 0.17% (m/v) α-tropolone. Ten analytes show linearity in the working range of 10 - 100 µg OTCs/L with R² > 0.999. Due to its high volatility the analyte TTMT showed a quadratic relationship between concentration and signal intensity with R² = 0.9998. The determination of the instrumental limits resulted in detection limits between 0.14 and 0.57 µg Sn/L and limits of quantification between 0.49 and 1.97 µg Sn/L. Over the course of this study thermal instability and cross reactivity of OTC in solution became apparent. Formation of two reaction products in mixed OTCs solutions have been observed. These effects will further be examined within development of appropriate sampling and sample preparation for workplace air to provide a suitable method for the determination of OTCs at workplaces according to normative references. [ABSTRACT FROM AUTHOR]

• 8-Hydroxyquinoline-based tin(IV) complexes have been synthesized and characterized. • Photophysical studies have been carried out in solvents of varying polarity. • All complexes show high fluorescence quantum yield apart from displaying longer lifetimes. • DFT calculations support the observed electronic and structural properties. Four different 8-hydroxyquinoline derivative-based tin(IV) complexes [(n Bu) 2 Sn(Cl-Q-CHO) 2 ] (1), [{(n Bu) 4 Sn 2 (Q-COO) 2 } 2 ] (2), [Ph 2 Sn(Cl)(Q-CHO)] (3) and [Ph 2 Sn(Cl)(Q-CH{OMe} 2)] (4) (Cl-Q-CHO = 5‑chloro-8-hydroxyquinolin-7-carbaldehyde; Q-COO− = 8-hydroxyquinolin-2-carboxylate; Q-CHO = 8-hydroxyquinolin-2-carbaldehyde and Q-CH{OMe} 2 = 2-(dimethoxy methyl)quinolin-8-ol) have been synthesized and characterized by elemental analysis, spectroscopy (FT-IR, Mass, UV–Vis, photoluminescence, 1H, 13C and 119Sn NMR) and thermogravimetric analysis. Complexes 1 and 4 have also been characterized by single-crystal diffraction studies and the bulk purity established by powder X-ray diffraction studies. Photophysical studies were conducted in a variety of solvents to demonstrate the effect on excitation and emission on the polarity of the solvent. All the new complexes show higher luminescence in a polar solvent resulting in the stabilization of the excited states. Complex 1 shows a high quantum yield of 97% in chloroform. Further, the photophysical results were substantiated through DFT calculations. [Display omitted] [ABSTRACT FROM AUTHOR]

Triphenyltin (TPT) is a class of organotin compounds that are extensively used in industry and agriculture. They have endocrine-disrupting effects and cause severe environmental contamination. Pollutants may accumulate in the kidneys and cause pathological complications. However, the mechanism of TPT's toxicological effects on the kidney remains unclear. This study aimed to investigate the toxic effects and mechanism of action of TPT exposure on renal impairment in rats. Male SD rats were divided into four groups: the Ctrl group (control group), TPT-L group (0.5 mg/kg/d), TPT-M group (1 mg/kg/d), and TPT-H group (2 mg/kg/d). After 28 days of exposure to TPT, we observed the morphology and structure of kidney tissue using HE, PASM, and Masson staining. We also detected serum biochemical indexes, performed transcriptome sequencing of rat kidney tissue using RNA-seq. Furthermore, protein expression levels were measured through immunohistochemistry and gene expression levels were determined using RT-qPCR. The study results indicated a decrease in kidney weight and relative kidney weight after 28 days of exposure to TPT. Additionally, TPT caused damage to kidney structure and function, as evidenced by HE staining, PASM staining, and serum biochemical tests. Transcriptomics identified 352 DEGs, and enrichment analyses revealed that TPT exposure primarily impacted the renin-angiotensin system (RAS). The expression levels of water channel proteins were reduced, and the expression levels of RAS and lipid metabolism-related genes (Mme, Ace, Fasn, Cyp4a8, Cpt1b and Ppard) were significantly decreased in the TPT-treated group. In summary, exposure to TPT may impair renal structure and function in rats by affecting RAS, AQPs, and lipid metabolism. [Display omitted] • TPT exposure caused reduced kidney weight and kidney weight ratio in rats. • Serum biochemical parameters showed that TPT exposure impaired renal function. • Transcriptomics analysis showed that 309 genes were down-regulated and 43 genes were up-regulated. • TPT exposure may cause renal injury by affecting RAS, AQPs and lipid metabolism. [ABSTRACT FROM AUTHOR]

We performed a comparative analysis of the pharmacological activity of the hybrid organotin compound bis(3,5-di-tert-butyl-4-hydroxyphenylthiolate)dimethylol (Me-3) administered in different modes to mice with transplanted melanoma B16 to identify the most effective dosage regimen. Three modes of administration were used: preventive (before transplantation of tumor cells), classical according to Z. P. Sof'ina (48 h after transplantation of tumor cells), and delayed (7 days after transplantation of tumor cells, after formation of nodules of the primary tumor node). Compound Me-3 was administered at a total dose of 375 mg/kg intraperitoneally once a day for 5 days. The classical mode of administration was identified as the most effective, which indicates the preventive antimetastatic activity of Me-3 on the model of the transplanted mouse tumor melanoma B16. [ABSTRACT FROM AUTHOR]

Triphenyltin chloride (TPhT) is an organotin compound that causes intensive toxicological risk to the environment and humans. A detection method with high sensitivity and stability is therefore desired to better detect TPhT. In this study, a novel SERS substrate was prepared by sputtering an ultra-thin Au layer on a honeycomb-like silver nanoarray fabricated via the nanosphere lithography method. The ultra-thin Au layer was formed by sputtering the intermittent Au nanoparticles on the silver nanoarray, resulting in bimetallic coupling with dramatically increased hotspots and extremely high SERS enhancement with an analytical enhancement factor (AEF) of 6.08 × 109 using Rhodamine 6G (R6G) as the probe molecule. Based on density functional theory (DFT) simulations, the Raman characteristic peaks of TPhT at 999 cm−1 and 655 cm−1 were selected for TPhT detection. The AEF of the SERS substrate HC5-AgAu was calculated to be 3.38 × 106 with the detection concentration of TPhT down to 10−10 M. The as-prepared honeycomb-like silver–gold bimetallic SERS substrate demonstrated great stability and sensitivity for TPhT detection, which might also be applied in monitoring many other environmental pollutants. [ABSTRACT FROM AUTHOR]

Eugène Anatole Demarçay (1852-1904), a French chemist who discovered the element europium and identified the presence of radium in a radioactive mixture provided by Marie and Pierre Curie; synthesized a variety of organic compounds of titanium and of tin, among them, those resulting from the reaction of titanium chloride with a variety of esters of organic monoacids. He proved that the essence of chamomile was a mixture of several esters, mainly butyl and amyl valerate and angelate, and not a mixture of aldehydes. He studied the compounds of nitrogen and sulfur, among them the nitrogen sulfide chlorosulfates, and described their properties. Developed an apparatus for determining the spectrum of rare earths and radioactive elements based on the spark produced by an induction coil provided with a short and thick platinum wire, and used it to propose a method for their separation by fractionation. He also determined the presence of molybdenum and vanadium in vegetables, etc. [ABSTRACT FROM AUTHOR]

A simple, sensitive and high-throughput method has been developed for the determination of triethyl tin (TET), tributyl tin (TBT) and triphenyl tin (TPhT) in environmental water samples using dispersive liquid-liquid microextraction (DLLME) and ultra-performance liquid chromatography coupled with tandem mass spectrometry (UPLC-MS/MS). The effects of several parameters, including the type and volume of extraction solvent, type and volume of disperser solvent, and influence of salt and extraction time, were investigated. Under the optimized conditions, 25.0 µL of chlorobenzene were used as the extractant solvent. The enrichment factors were 168, 187, 175 for triethyl tin, tributyl tin, and triphenyl tin, respectively. Good linear relationships for the three organotin compounds were obtained across the range from 0.05 to 5.0 µg/L, and the limits of detection were from 0.003 to 0.010 µg/L based on a signal-to-noise ratio of three. The method was successfully applied to the analysis of seawater, river water and lake water samples with spiked recoveries from 81.4 to 109%, with the relative standard deviations from 4.2 to 8.4% (n = 6) obtained. [ABSTRACT FROM AUTHOR]

Six dinuclear organotin building blocks of general composition RR′R′′SnCH2Si(CH3)2−biphenyl−Si(CH3)2CH2SnR′′R′R, in which the tin atoms are separated by a p,p′‐biphenylene bridge and carry different substituents [BD1 with R, R′=CH2Si(CH3)3, R′′=Ph; BD2 with R, R′=CH2Si(CH3)3, R′′=Cl; BD3, with R, R′=CH2Si(CH3)3, R′′=I; BD4 with R=CH2Si(CH3)2(C5H4FeCp), R′, R′′=Ph; BD5 with R=CH2Si(CH3)2(C5H4FeCp), R′=Ph, R"=Cl; BD6 with R=CH2Si(CH3)2(C5H4FeCp), R′=Ph, R′′=I], were synthesized and characterized by spectroscopic and spectrometric methods. Furthermore, the crystal and molecular structures of BD2 were determined by single‐crystal X‐ray diffraction (SCXRD) analysis, revealing the formation of molecular strands through intermolecular Cl→Sn contacts. The 1D coordination polymer [BD2]n comprises macrocyclic rings of composition [BD2]2 that motivated the generation of a related molecular macrocyclic structure by reaction of BD2 with silver (I) oxide in a 2 : 2 stoichiometry. The [2+2] macrocyclization yielded the 30‐membered tetra‐nuclear ring structure M1, viz., {[R2SnCH2Si(CH3)2−biphenyl−(CH3)2SiCH2SnR2](μ‐O)}2, in which two BD2 dinuclear building blocks are linked through two covalent Sn−O−Sn moieties. Examination by DFT calculations at the B3LYP/def2svp and B3LYP/6‐31G*(C,H,O,Si)/LanL2DZ(Sn) levels of theory gave energy minima for molecular conformers of M1 carrying the Sn−O−Sn and p,p′‐biphenylene bridges in syn‐ or anti‐orientation. [ABSTRACT FROM AUTHOR]

Organotin compounds are important catalysts for the synthesis of polyurethanes consisting of aliphatic isocyanates and polyols. Due to their toxicity, however, it has been a long-standing goal to develop more environmentally benign catalysts. Bismuth octoates and neodecanoates are such well-known alternatives, but their catalytic activity is insufficient for many applications. Herein we show that the catalytic activity of bismuth carboxylates can be enhanced significantly by the addition of lithium carboxylates. Structural and spectroscopic results reveal the spontaneous formation of heterobimetallic complexes consisting of two bismuth and four lithium carboxylates that show dynamic behaviour in solution. The mechanism of the bismuth-catalyzed urethane reaction was elucidated in detail using quantum chemical calculations, paving the way for a rational catalyst design. [ABSTRACT FROM AUTHOR]

A sensitive, confirmatory ultra-high performance liquid chromatography–tandem mass spectrometry based on modified QuEChERS was developed and validated to detect five organotin compounds (tributyltin chloride (TBT), triphenyltin chloride (TPT), trimethyltin chloride (TMT), azocyclotin and cyhexatin) in classical tropical fruits (mango, pineapple and banana). Fruits samples were ultrasonically extracted with methanol and subsequently purified by graphitized carbon black adsorbents. Five organotins were separated on a C18 column with the mobile phase of a mixture of methanol and 0.1% (v/v) aqueous formic acid, and detected by MS/MS under multiple reaction monitoring mode. The developed method was validated in terms of linearity, limit of detection (LOD), recovery and precision. Results were linear in their corresponding concentration ranges, with coefficients of determination (r) bigger than 0.999. The average LODs (S/N = 3) of the method for TBT, TPT, TMT, azocyclotin and cyhexatin were 1.3, 3.5, 3.2, 5.1 and 1.7 μg/kg, respectively. The average recoveries (n = 5) at three spiked levels (0.01, 0.1 and 0.2 mg/kg) ranged from 69 to 103% with relative standard deviations of 2.1–11.9%. The method is simple, effective, accurate and non-derivatized, and meets the routine monitoring requirements for trace organotins in tropical fruits. [ABSTRACT FROM AUTHOR]

Pecan scab, caused by Venturia effusa, is the most economically damaging disease of pecan in the southeastern United States, and annual epidemics are most effectively managed through multiple fungicide applications. The fungicide applications can be the single greatest operating cost for commercial growers and the return on that investment is impacted by fungicide resistance. V. effusa produces multiple generations of conidia per season, exhibits substantial genetic diversity, overwinters as stromata in the tree, and is under immense selection from the applied fungicides, all of which lead to a high risk for developing fungicide resistance. Since the mid-1970s, resistance or reduced sensitivity has been observed in isolates of V effusa to the methyl benzimidazole carbamates, demethylation inhibitors, quinone outside inhibitors, organotin compounds, and the guanidines. Over the last 10 years, several studies have been conducted that have improved both scab management and fungicide resistance management in V. effusa. The aim of this review is to summarize recent developments in our understanding of fungicide resistance in V. effusa in the context of scab management in southeastern pecan orchards. The history, modes of action, general use of the labeled fungicides, and mechanisms and stability of fungicide resistance in V. effusa are discussed; conclusions and future research priorities are also presented. [ABSTRACT FROM AUTHOR]

The tin–substituent bonds in Sn(II) organic compounds are studied by quantum chemical methods using the PC GAMESS-Firefly program package. The geometry optimization for the studied molecules is carried out by the DFT method (B3PW91functional, using the aug-cc-pVTZ-pp basis set with an effective core potential for tin and the 6-311++(2d,p) basis set for other atoms. The wave functions and the NBOs of tin–substituent bonds were calculated by the HF method using the x2c-TZVPall-electron relativistic basis set for the tin atom and the 6-311G(2d,p) basis set for other atoms. The values of topological characteristics of tin–substituent bonds are obtained by the AIM method. These bonds can be classified as "intermediate bonds" characterized by small contributions of Sn AOs in the MOs of the bonds, large differences between the charges on tin atoms, and low occupancies of the MOs of the bonds. The energies of Sn–R bonds are estimated. [ABSTRACT FROM AUTHOR]

• A chromone-based diorganotin(IV) crystalline solid (DOC) is synthesized. • Single crystal X-ray diffraction and spectroscopic characterization of DOC. • Investigation of adsorption of organic dyes on DOC in an aqueous system. • Investigation of kinetics, thermodynamics and modelling of the adsorption process. A glucosyl appended chromone-based diorganotin(IV) crystalline solid (DOC) is obtained from β-D-allopyranoside substituted 3-hydroxy-benzo-γ-pyrone. The combination of organotin(IV) unit, glucosyl substituent and chromone skeleton introduced some special features to the solid including controlled solubility, water stability, and plenty of interactive sites. The step-wise formation of products is supported by FT-IR spectroscopy, multinuclear NMR spectroscopy, CHN elemental analyses, mass spectrometry, scanning electron microscopy, thermal gravimetric analysis, and single-crystal X-ray diffraction analyses. The DOC molecules led to herringbone architecture via O–H···O, C–H·····Sn, C–H···O, C–H·····π, and π⋯π interactions, where each DOC molecule possessed "skew-trapezoidal bipyramidal" geometry. Furthermore, the DOC has been found efficient adsorbent for organic dyes with a partition coefficient of 793.3 mg g−1 μM−1 for Brilliant blue. The theoretical studies justified the highest adsorption of Brilliant blue due to the small value of the HOMO-LUMO energy gap (Δ E = 0.34 eV), the high value of electrophilicity index (ω = 40.64), and the low value of chemical hardness (η = 0.17 eV). The Langmuir model and pseudo-second-order model well-described the adsorption parameters like adsorption behaviour, diffusion, and removal rates of dyes. Based on the results, the DOC is expected as a viable option for the uptake of organic dyes from an aqueous solution. Mononuclear water stable glucosyl appended diorganotin(IV) chelate, structural features, controlled solubility, thermal stability, and plenty of interactive sites for holding Brilliant Blue [Display omitted] [ABSTRACT FROM AUTHOR]

• Synthesis of bis (2-ethylhexyl terephthalate) from waste PET. • Application of organotin catalysts in PET chemical recycling. • Application of waste PET in plasticizer synthesis. • Monobutyltin tris(2-ethylhexanoate) an efficient depolymerization catalyst. The production scale and usage of plastics have generated significant amounts of waste especially in regards of PET which is one of the widely produced polymer worldwide, whose accumulation in the environment has become an issue despite attempts to increase its recycling rate. Herein, we applied a new group of catalysts based on organotin compounds for the depolymerization of PET waste. The obtained results showed the formation of dioctyl terephthalate (DOTP), which is a commonly produced plasticizer. For this purpose, a number of organotin catalysts, including tin (II) oxalate, tin (II) bis (2-ethylhexanoate), monobutyltin tris (2-ethylhexanoate), dibutyltin oxide, and dioctyltin oxide (V) were tested. Additionally, common transesterification catalysts, such as zinc acetate and potassium hydroxide, were applied and proved less effective than the tested organotin compounds. Our results showed that among tested compounds monobutyltin tris (2-ethylhexanoate) was the most effective catalyst. Taking into account its good properties an application sample of plasticizer was synthesized on a large scale using monobutyltin tris (2-ethylhexanoate). Furthermore, the physio-chemical and plasticizing properties were determined for two types of plasticizer samples (purified and unpurified). These properties were compared with commercial DOTP, where both plasticizers had similar plasticizing properties towards PVC [ABSTRACT FROM AUTHOR]

In addition to a variety of conventional non-covalent intermolecular interactions such as C–H⋯π (arene), C–H⋯Cl and π(arene)⋯π(chelate-ring) contacts, the molecular packing in the crystal of an organotin dithiocarbamate compound, [SnCl(4-ClC6H4)2{S2CN(i-Pr)2}], exhibits evidence for a C–Cl⋯π(chelate-ring) interaction. These interactions occur via a side-on approach of the chloride atom to the chelate-ring and therefore are characterised as C–Cl(lone-pair)⋯π(chelate-ring) interactions, are shown to be attractive by NCI plots and QTAIM analysis, and are apparent in the calculated Hirshfeld surfaces. Theory suggests the energy of association provided by the C–Cl⋯π(chelate-ring) interactions to be about 3–4 kcal mol−1, a value greater than for analogous C–Cl⋯π(arene) and C–H⋯π(arene) interactions. A survey of the literature for related structures suggests that these interactions are not common. The newly described C–Cl(lone-pair)⋯π(chelate-ring) interactions add to the variety of intermolecular interactions able to be formed by chelate-rings in the supramolecular chemistry of metal complexes. [ABSTRACT FROM AUTHOR]

Herein, we report the syntheses of the water‐soluble organotin compounds [{Me2(H)N(CH2)3}2SnX2]Y2 (1, X = Cl, Y = ClO4; 2, X = F, Y = ClO4) and {Me2(H)N(CH2)3}2SnX4 (3, X = Cl; 4, X = F). The compounds were characterized by elemental analysis, electrospray mass spectrometry, 1H, 13C, 19F, and 119Sn NMR spectroscopy, and in the case of compounds 1, 3 and 4, by single‐crystal X‐ray diffraction analysis. The reaction of compound 2 with fluoride anions in water was investigated by NMR spectroscopy. DFT calculations accompany the experimental work. [ABSTRACT FROM AUTHOR]

New paramagnetic tin(IV) derivatives containing the radical-anion of 2,4,6,8-tetra-tert-butylphenoxazin-1-one redox-active ligand (phenox-imQ) are synthesized and studied by EPR spectroscopy. Complexes I–V are paramagnetic in the crystalline state and in solution. The geometry of the obtained paramagnetic species and spin density distribution in them are studied by the Density functional theory. Diamagnetic complex VI is synthesized from the phenox-imQ dianion, and its one-electron oxidation is studied. The molecular structure of complex VI · ТHF is determined by X-ray diffraction analysis (CIF file CCDC no. 2000962 (VI · ТHF)). [ABSTRACT FROM AUTHOR]

[Display omitted] Crystalline triphenyltin cumyl and tert-butyl peroxides (Ph 3 SnOOCMe 2 Ph and Ph 3 SnOOBut, respectively) and triphenyllead cumyl peroxide (Ph 3 PbOOCMe 2 Ph) were synthesized and characterized by single crystal and powder X-ray diffraction, NMR, FTIR and Raman spectroscopies, TG and DSC analysis. The formation of triphenyltin tert-butyl peroxide in benzene in the presence of a base was proved by 119Sn, 13C and 1H NMR spectroscopy. To the best of our knowledge, the obtained complexes are the first structurally characterized coordination compounds of tin and lead with organic peroxides. [ABSTRACT FROM AUTHOR]

Complement component 8 ? (C8?) is a subunit of complement protein 8 (C8), which itself is a subunit of the complement cytolytic membrane attack complex. However, C8? is also suggested to be a carrier protein for the general clearance of endogenous and exogenous compounds because it belongs to the lipocalin family of small secreted proteins that have the common ability to bind small hydrophobic ligands. Although retinoic acid, a metabolite of vitamin A, has been suggested as a potential ligand of C8?, it remains unclear which other substances are able to bind to C8? as ligands. Here, we evaluated the binding affinity of several organotin compounds that are ligands of a receptor of retinoic acid, retinoid X receptor, by using radioligand binding assays. The amount of [14C]triphenyltin (TPT), a tri-substituted organotin, that bound to purified recombinant C8? was increased with increasing protein concentration, whereas that of [3H]all-trans retinoic acid and [3H]9-cis retinoic acid was unchanged. Scatchard analysis revealed that [14C]TPT bound to C8? with an equilibrium dissociation constant (Kd) of 56.2 ± 16.2 nM. Non-radiolabeled tributyltin (TBT), another tri-substituted organotin, blocked the binding of [14C]TPT to C8? in a competitive manner, but non-radiolabeled mono- or di-substituted organotin compounds did not. Together, our present observations indicate that TBT and TPT, but not retinoic acid or mono- or di-substituted organotin compounds, are potent ligands of C8?, suggesting that C8? may be involved in the toxicities of these organotin compounds. [ABSTRACT FROM AUTHOR]

Cancer is one of the most common causes of death in modern medicine. Molecular design of novel substances with pharmacological activity is one of the goals of medicinal inorganic chemistry. Platinum complexes are widely used in the treatment of cancer, despite high efficacy their use is limited by side effects, as well as primary or acquired resistance. In this regard, the search for novel metal-containing antitumor compounds is underway. Organotins and gold compounds are promising pharmacological agents with anti-cancer properties. The introduction of protective antioxidant fragments into inorganic compounds molecules is a way to reduce the side effects of anti-cancer drugs on healthy cells. 2,6-dialkylphenols belonging to vitamin E (α-tocopherol) mimetics are widely used as antioxidants and stabilizers. The properties of Ph3SnCl (Sn-I), Ph3PAuCl (Au-I) and complexes Ph3SnSR (Sn-II) and Ph3PAuSR (Au-II) based on 2,6-di-tert-butyl-4-mercaptophenol (RSH) as radical scavengers and reducing agents were studied in model reactions. For Sn-II and Au-II the comparative study of cytotoxic action was made and the IC50 values on different cancer cell lines were found to be depended on the nature of metal. In general, Sn(IV) complexes possessed higher cytotoxicity than Au(I) complexes. In order to clarify the mechanism of cytotoxic mode of action the effect of compounds on Fe3+-induced lipid peroxidation, mitochondrial potential and mitochondrial permeability, cell cycle and induction of apoptosis was studied. Organotin compounds can bind tubulin SH-groups and inhibit its polymerization by a dose-dependent mechanism, whereas gold compounds inhibit Thioredoxin reductase (TrxR). In vivo experiments on acute toxicity of Sn-II and Au-II proved their moderate toxic action that opens prospects for the further study as antitumor agents. [ABSTRACT FROM AUTHOR]

The purpose of this study is to investigate the current status of contamination due to the heavy metal and organic substances (PAHs, HC >12, organotin compounds, PCB, DDD, DDE, DDT) pollution of the sediments from the coastal area of the Bagnoli brownfield (Naples, Italy) and draw some hypotheses on the origin and trends of industrial and also geogenic contamination. Surface sediments and cores were collected and analysed. The results showed remarkable concentrations of heavy metals, PAHs, and other substances that are significantly higher than the national guideline values of sea sediment quality. Correlation analyses and spatial distribution analyses showed that generally the inorganic and organic pollutants have similar patterns, confirming the common origin from the industrial activity, but also that some of the studied metals have some natural contribution originated from the geologic setting of the area. The distribution of most of the heavy metals (especially Cd, Hg, Pb, Cu, Zn, partially Cr and Ni) and PAHs are similar, and the highest concentrations were recognised between and just off the piers, but a diffuse contamination is widespread up to the external areas of the site perimeter, rising concern on the diffusion of contaminants to the whole Gulf of Pozzuoli. [ABSTRACT FROM AUTHOR]

Autophagy is a degradative process playing an important role in removing misfolded or aggregated proteins, clearing damaged organelles, such as mitochondria and endoplasmic reticulum, as well as eliminating intracellular pathogens. The autophagic process is important for balancing sources of energy at critical developmental stages and in response to nutrient stress. Recently, autophagy has been involved in the pathophysiology of neurodegenerative diseases although its beneficial (pro-survival) or detrimental (pro-death) role remains controversial. In the present review, we discuss the role of autophagy following intoxication with trimethyltin (TMT), an organotin compound that induces severe hippocampal neurodegeneration associated with astrocyte and microglia activation. TMT is considered a useful tool to study the molecular mechanisms occurring in human neurodegenerative diseases such as Alzheimer's disease and temporal lobe epilepsy. This is also relevant in the field of environmental safety, since organotin compounds are used as heat stabilizers in polyvinyl chloride polymers, industrial and agricultural biocides, and as industrial chemical catalysts. [ABSTRACT FROM AUTHOR]

One hundred and twenty-two red wines were analysed for their total tin, total mercury and speciation concentrations. Total Sn and Hg concentrations were in average 4.4 ± 7.2 µg/L and 0.22 ± 0.12 µg/L, respectively. Two GC-ICP-MS methods were developed and validated for speciation purposes: one to measure organotin compounds (OTCs) with internal standard correction; the other, to evaluate methylmercury (MeHg+) by isotopic dilution. Methyltins (mainly dimethyltin, but also monomethyltin) were the most abundant OTCs recovered. Methylation seems to occur biotically during the wine making process and not during the bottling time. Therefore, it also seems to be roughly dependent on the geographical origin of the wine. For higher OTCs, monobutyltin was the most regularly found, but dibutyltin and monooctyltin were also detected sometimes. MeHg+ was not recovered in any of the samples investigated, probably due to the low level of Hg. These results suggest that, in terms of these parameters, normal consumption of wine is not a hazard for human health. [ABSTRACT FROM AUTHOR]

The determination of trace-amount organotins in plastic food packaging materials is of great significance in food safety. However, due to the complexity of organotins and sample treatment processes, it is still a challenging task. Here, we report a method for the sensitive and simultaneous determination of organotins in plastic food packaging materials and edible oils, by utilizing sheathless capillary electrophoresis-electrospray ionization-mass spectrometry. The method of sample pretreatment with ultrasonic extraction and solid phase extraction is used to eliminate interference. The results showed low limits of detection (LODs) of 2 pg mL−1–50 pg mL−1 and excellent inter/intra-day repeatability. Good average recoveries in the range of 80.27% to 108.52% were obtained at three spiked concentrations, with a relative standard deviation less than 8.71%. The successful simultaneous determination of the target analytes will pave the way for further assessment of contamination and migration behaviour of organotins from packaging materials to food, which is of great significance for evaluating and controlling food safety. [ABSTRACT FROM AUTHOR]

The crystal and mol­ecular structures of the title organotin di­thio­carbamate compounds, [Sn(C6H5)3(C7H10NS2)] (I) and [Sn(C6H5)2(C7H10NS2)2] (II), present very distinct tin atom coordination geometries. In (I), the di­thio­carbamate ligand is asymmetrically coordinating with the resulting C3S2 donor set defining a coordination geometry inter­mediate between square-pyramidal and trigonal-bipyramidal. In (II), two independent mol­ecules comprise the asymmetric unit, which differ in the conformations of the allyl substituents and in the relative orientations of the tin-bound phenyl rings. The di­thio­carbamate ligands in (II) coordinate in an asymmetric mode but the Sn-S bonds are more symmetric than observed in (I). The resulting C2S4 donor set approximates an octa­hedral coordination geometry with a cis-disposition of the ipso-carbon atoms and with the more tightly bound sulfur atoms approximately trans. The only directional inter­molecular contacts in the crystals of (I) and (II) are of the type phenyl-C-H...π(phen­yl) and vinyl­idene-C-H...π(phen­yl), respectively, with each leading to a supra­molecular chain propagating along the a-axis direction. The calculated Hirshfeld surfaces emphasize the importance of H...H contacts in the crystal of (I), i.e. contributing 62.2% to the overall surface. The only other two significant contacts also involve hydrogen, i.e. C...H/H...C (28.4%) and S...H/H...S (8.6%). Similar observations pertain to the individual mol­ecules of (II), which are clearly distinguishable in their surface contacts, with H...H being clearly dominant (59.9 and 64.9%, respectively) along with C...H/H...C (24.3 and 20.1%) and S...H/H...S (14.4 and 13.6%) contacts. The calculations of energies of inter­action suggest dispersive forces make a significant contribution to the stabilization of the crystals. The exception is for the C-H...π contacts in (II) where, in addition to the dispersive contribution, significant contributions are made by the electrostatic forces. [ABSTRACT FROM AUTHOR]