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A new heterobimetallic Ru(II)-Cu(II) donor-acceptor complex is synthesized and characterized. A suitable choice of metal centers and coordination ligands, can fine-tune heterobimetallic donor-acceptor complexes to produce sensitive chemodosimetric responses to specific analytes.

An experiment was conducted to describe the synthesis of a triple-stranded ruthenium helicate from [Ru(py-pzH)3]-(ClO4)2. The absorption band of the acetonitrile solution of [Ru(py-pzH)3]-(Clo4)2 was observed to be at 400 nanometer. A C3 rotation axis was also seen in the triple-stranded ruthenium helicate. The stability of ruthenium helicate in solution was indicated by the simplicity and consistency of its nuclear magnetic resonance spectrum.

Increased use of antidepressants has led to an increase in their detection in final treated wastewater effluents and receiving streams. Antidepressants are intended to modify human behavior by altering brain chemistry, and because of the high functional conservation of antidepressant target receptors in vertebrates, aquatic organisms may be at risk. The antidepressant bupropion is designed to alter brain norepinephrine and dopamine concentrations in humans. The objective of the present study was to understand if alteration of dopaminergic neurotransmitter concentrations in the hybrid striped bass ( Morone saxatilis × Morone chrysops) brain by bupropion would alter this predator's ability to capture prey. The authors exposed hybrid striped bass to bupropion in a static system for 6 d, followed by a 6-d recovery period. During the present study's 12-d experiment, each hybrid striped bass was fed 4 unexposed fathead minnows every 3 d, and the time it took the hybrid striped bass to consume each of those 4 fathead minnows was quantified. After each feeding event, hybrid striped bass brains were harvested and analyzed for changes in several brain neurotransmitter concentrations, including serotonin, norepinephrine, dopamine, and many of their metabolites. Although bupropion altered the concentration of dopamine and many of the dopaminergic neurotransmitter metabolite concentrations in the brains on day 3 of the exposure, it did not alter the time to capture prey. This suggests that alteration of dopaminergic neurotransmitter concentrations in the hybrid striped bass brain does not alter a predator's ability to capture prey. Environ Toxicol Chem 2016;35:2058-2065. © 2016 SETAC [ABSTRACT FROM AUTHOR]

Polybrominated diphenyl ethers (PBDEs) have been widely studied in sediments from the North American Great Lakes; however, no studies have been conducted of occurrences of methoxylated (MeO-) PBDEs in abiotic compartments in this region. In the present study, 23 tri- to hepta-PBDEs and 12 MeO-PBDEs were analyzed in dated sediment cores collected from two inland lakes (White Lake and Muskegon Lake) in Michigan, USA. Concentrations of ΣPBDEs ranged from 3.9 × 10 to 2.4 × 10 and from 9.8 × 10 to 3.9 × 10 ng/g dry weight in White Lake and Muskegon Lake, respectively. The historical trends of tri- to hepta-PBDEs in the two lakes were different, possibly because of different input and remediation histories. The tri- to hepta-PBDE profiles were similar in the two lakes, with BDE-47 as the predominant congener, followed by BDE-99 and BDE-183. A different temporal trend for BDE-183 was found compared with other PBDEs, which is consistent with debromination of high-brominated PBDEs during sedimentation and aging. Methoxylated-PBDEs were detected only in Muskegon Lake (3.6 × 10 to 1.2 × 10 ng/g dry wt). Methoxylated PBDEs showed different temporal trends compared with tri- to hepta-PBDEs. The differences in patterns of concentrations of MeO-PBDEs in the two lakes might be due to different aquatic communities in each lake. The occurrences of MeO-PBDEs could be the major source of hydroxylated-polybrominated diphenyl ethers (OH-PBDEs) observed in organisms collected in these freshwater systems. Environ. Toxicol. Chem. 2011; 30:1236-1242. © 2011 SETAC [ABSTRACT FROM AUTHOR]

Abstract: Since 1990s, various booster biocides have been increasingly used as substitutes of organotins. However, knowledge about their toxicities on tropical/sub-tropical marine species is significantly lacking. This study comprehensively investigated the acute toxicities of copper, tributyltin (TBT), and five commonly used booster biocides including Irgarol, diuron, zinc pyrithione (ZnPT), copper pyrithione (CuPT) and chlorothalonil on the growth or survival of 12 marine species in which eight of them are native species of subtropical Hong Kong. We found that Irgarol was more toxic than TBT on the growth of autotrophic species. The toxicity of CuPT was comparable to that of TBT on almost all test species, while it showed higher toxicity than TBT on medaka fish larvae. As the usage of these biocides is expected to further increase worldwide, accurate assessments of their ecological risks are required for better informed decision on their management. This study provided useful datasets for such purposes. [Copyright &y& Elsevier]

Abstract: A new Fe3O4/poly(divinylbenzene-co-methacrylic acid) core-shell magnetite microspheric material have been successfully developed as magnetic-mediated solid-phase extraction micro-particle sorbent in dispersion mode (MM-SPE-MP) for the determination of selected estrogenic endocrine disrupting chemicals (EDCs), namely: estrone (E1), 17β-estradiol (E2), estriol (E3), 17α-ethynylestradiol (EE2) and bisphenol-A (BPA), in natural water, via quantification by HPLC tandem mass spectrometry. The magnetite Fe3O4 core of this MM-SPE-MP sorbent was fabricated by a solvothermal approach and the thin layer of amphipolar poly(divinylbenzene-co-methacrylic acid) (pDVB-MAA) coating was established via suspension polymerization. The resultant core-shell MM-SPE-MP sorbent material was characterized by electron microscopy, X-ray diffraction and Fourier-transformed infrared spectroscopy. Particle size distribution of the core-shell microspheres was within the range 300–700nm in diameter and the thickness of the pDVB-MAA coating was ca. 10nm. This magnetite microspheric material can be easily dispersed in aqueous samples and retrieved by the application of external magnetic field via a small piece of permanent magnet. The MM-SPE-MP process for the selected estrogenic EDCs involved the dispersion of the core-shell microspheric sorbent in water samples with sonication, followed by magnetic aided retrieval of the sorbent and solvent (methanol) desorption of extracted EDCs for LC–MS/MS analysis. Partition equilibrium for all the selected EDCs onto this MM-SPE-MP sorbent was achieved within 15min. Recoveries of the EDCs were in ranges of 56–111%. Analytes with smaller K OW value showed relatively lower recovery (and relatively longer equilibration time for partitioning). Method detection limits achieved were found to be 1–36pgml−1 (n =3), while the repeatability was 6–34% (p <0.05, n =3). This work demonstrates the usefulness of MM-SPE-MP in the rapid and highly sensitive monitoring of trace organic contaminants in natural waters. [Copyright &y& Elsevier]

A new ruthenium(II) photosensitizer, [RuII(py-pzH)3]2+ (where py-pzH=3-(2′-pyridyl)pyrazole), has been synthesized. The complex displayed outstanding excited state redox properties (estimated RuIII/RuII*&ap;−1.24 V vs. NHE) and was expected to sensitize the injection of electrons into the conduction band of anatase TiO2 upon visible irradiation. The photosensitizer was anchored onto the surface of anatase TiO2 particles via in situ silylation. The silyl-linkage displayed excellent stability in both aqueous media, over a wide pH range, and in common organic solvents. The resultant material, TiO2—[RuII(py-pz-Si≡)3], was found to be able to mediate degradation of CCl4 in neutral aqueous medium under broad band visible irradiation (λ>450 nm). The relation between the rate of degradation and concentration of substrate was explored and the mechanism of the photodegradation of the perhalogenated organic was discussed. [Copyright &y& Elsevier]

Reports the synthesis and characterization of a neutral trinuclear heterobimetallic cyano-bridged Ru(II)/Pt(II) complex, cisRu(phen)[sub 2][CN-Pt(DMSO)Cl[sub 2]][sub 2] (phen = 1,10-phenanthroline), as achemodosimetric ensemble for sulfhydryl-containing amino acids and peptides. Substrate binding process; Luminescent responses of complex 1 toward amino acids and peptides.

Abstract: Polybrominated diphenyl ethers (PBDEs) are additive flame retardants that have been found in the environment as well as human tissues. Environmental concentrations of these compounds have been increasing in many parts of the world in recent years. Due to their structural similarity, PBDEs are believed to have similar toxicity to PCBs, but their toxicological properties are still being determined. In this study, the steroidogenic effects of hydroxylated, methoxylated and/or chlorinated derivatives of PBDEs were assessed at both the gene and enzyme/hormone levels in the H295R human adrenocortical carcinoma cell line. The expression levels of 10 steroidogenic genes were measured using quantitative real-time PCR (Q-RT-PCR). Aromatase activity in the cells and sex steroid (testosterone (T) and 17β-estradiol (E2)) concentrations in the culture medium were also measured. CYP11B2, which regulates the synthesis of aldosterone, was the most sensitive gene and was induced by most of the compounds tested in this study. CYP19 gene expression, aromatase activity, and E2 production were also affected by several metabolites, but no consistent relationship was observed between these endpoints. Several PBDE metabolites showed some potential ability to interfere with steroidogenesis, including 5-Cl-6-OH-BDE-47, a biologically relevant BDE-47 metabolite, which significantly decreased aromatase activity and E2 production at a concentration of 10μM. The results of this study indicate that PBDE metabolites affect steroidogenesis in vitro and that they may have the potential to affect steroidogenesis and reproduction in whole organisms. [Copyright &y& Elsevier]

Abstract: The feasibility of using sol–gel amorphous titania (TiO2) as a solid-phase sorbent for the pre-concentration of domoic acid (DA), a potent amnesic shellfish poisoning (ASP) toxin, directly from seawater was explored. The sol–gel titania material is able to adsorb DA from seawater, via the formation of ester-linkage between the carboxylic moieties of DA and the Ti–OH groups on the sorbent surface, at low pH and desorb it at high pH. The chemisorption process is not significantly interfered by the seawater matrix. The optimum pH values for the adsorption and desorption of DA were found to be pH 4 and 11, respectively. The optimal sorbent loading for the batch-type solid-phase extraction of DA was 0.67mg-TiO2 ng-DA−1 and adsorption equilibrium was achieved in 2h at room temperature. The desorbed DA in 500μL of 0.1M alkaline borate buffer can be directly derviatized by 4-fluoro-7-nitro-2,1,3-benzoxadiazole (NBD-F) in aqueous media for fluorimetric HPLC quantification. Analyte recovery, repeatability and detection limit of this titania SPE-fluorimetric HPLC determination are 89%, 6.2% and 120pg-DAmL−1 (n =7, P <0.05), respectively, for a sample volume of 30mL. This titania SPE technique should also be applicable to the pre-concentration of other polar carboxylate- and phosphonate-containing biomolecules and pharmaceuticals in complex and interfering environmental sample matrices. [Copyright &y& Elsevier]

Abstract: Some endocrine disrupting chemicals (EDCs) in the environment have been shown to exert their biological effects through interference with steroidogenesis. In this study, the potential effects of four selected polychlorinated biphenyl (PCB) congeners (PCB101, PCB110, PCB126 and PCB149) as well as several of their environmentally-relevant methylsulfonyl-(MeSO2–) PCB metabolites (3′-MeSO2–CB101, 4′-MeSO2–CB101, 4′-MeSO2–CB110, 3′-MeSO2–CB149 and 4′-MeSO2–CB149) on adrenocortical steroidogenesis were evaluated by in vitro bioassay based on the human adrenocortical carcinoma H295R cell line. The PCBs included in the study represented different structures and potential mechanisms of action. Cells were exposed for 48h to 10μM of each PCB congener in the presence or absence of 20% (w/w) of their corresponding MeSO2–PCB metabolite(s). After the chemical treatments, changes in mRNA expression of 11 steroidogenic genes (CYP11A, CYP11B1, CYP11B2, CYP17, CYP19, CYP21, 3β-HSD1, 3β-HSD2, 17β-HSD1, StAR and HMGR) were quantified using molecular beacon-based real-time RT-PCR. Genes coding for enzymes involved in the later or final steps of steroid production (CYP11B1, CYP11B2, CYP19, 3β-HSD1, 3β-HSD2 and 17β-HSD1) were up-regulated to various extents by most PCBs. The greatest transcriptional activations (2.8–29.9-fold) were elicited by PCB110 on CYP11B1, CYP11B2, 3β-HSD2 and CYP19, and PCB149 on CYP11B1, 3β-HSD1 and 17β-HSD1. Increased expression of these steroidogenic genes might ultimately lead to a change in hormonal balance through excessive production of steroid hormones including aldosterone, cortisol and estradiol. In addition, co-treatment with 3′- and 4′-MeSO2–PCB149 resulted in a significant decrease in PCB149-induced 3β-HSD1 and 17β-HSD1 expression. This result indicates that some PCB congeners and their MeSO2-metabolites may affect steroidogenesis via different mechanisms. Overall, these findings suggest that PCBs and PCB metabolites can affect regulation of adrenocortical steroidogenesis. [Copyright &y& Elsevier]