Combined biological and chemical assessment of estrogenic activities in wastewater treatment plant effluents

Five wastewater treatment plant effluents were analyzed for known endocrine disrupters and estrogenicity. Estrogenicity was determined by using the yeast estrogen screen (YES) and by measuring the blood plasma vitellogenin (VTG) concentrations in exposed male rainbow trout (Oncorhynchus mykiss). While all wastewater treatment plant effluents contained measurable concentrations of estrogens and gave a positive response with the YES, only at two sites did the male fish have significantly increased VTG blood plasma concentrations after the exposure, compared to pre-exposure concentrations. Estrone (E1) concentrations ranged up to 51 ng L^–1, estradiol (E2) up to 6 ng L^–1, and ethinylestradiol (EE2) up to 2 ng L^–1 in the 90 samples analyzed. Alkylphenols, alkylphenolmonoethoxylates and alkylphenoldiethoxylates, even though found at µg L^–1 concentrations in effluents from wastewater treatment plants with a significant industrial content, did not contribute much to the overall estrogenicity of the samples taken due to their low relative potency. Expected estrogenicities were calculated from the chemical data for each sample by using the principle of concentration additivity and relative potencies of the various chemicals as determined with the yeast estrogen screen. Measured and calculated estradiol equivalents gave the same order of magnitude and correlated rather well (R ²=0.6).An erratum to this article can be found at     

Experimental parameters affecting sensitivity and specificity of a yeast assay for estrogenic compounds: results of an interlaboratory validation exercise

In vitro assays are considered as the first step in a tiered approach to compound screening for hormonal activity. Although many new assays have been developed in recent years, little attention has been paid towards assay validation. Our objective was to identify critical experimental parameters in a yeast estrogen screen (YES) that affect its sensitivity and specificity. We investigated the role of incubation time, solvent type, yeast inoculum growth stage and concentration on the outcome of the YES. Compounds tested included new and established agonists, antagonists and negative controls, and results were evaluated according to prefixed statistical criteria. In addition, we assessed the assay’s performance in a blind interlaboratory validation exercise (IVE). An incubation time of five days was necessary to positively identify the estrogenic properties of all agonists tested, when dissolved in DMSO. Longer incubation times were required when using an ethanol protocol. Similar estrogenic activity was reported for benzyl butyl phthalate, bisphenol-A, methoxychlor, permethrin and genistein in the IVE. One out of the three laboratories did not classify α,β-endosulfan, dissolved in DMSO, as an estrogen. The same was true for 4,4′-DDE and lindane, dissolved in ethanol, a result that might be attributable to an inappropriate yeast start concentration and/or growth stage. These validation experiments show that under appropriate experimental conditions the YES yields sensitive, specific and reliable results. Therefore it fulfills the requirements as a first step screening assay to evaluate the capacity of chemicals to interact with the estrogen receptor.     

双(三烃基锡)二元羧酸酯的合成、结构和农药活性普筛

合成了一系列双(三烃基锡)二元羧酸酯类化合物,表征了这些化合物的结构,并进行了农药活性普筛。结果表明,三环己基锡系列大多具有很好的杀螨和杀虫活性,三苯基锡系列则在除草和植物生物刺激方面有一定效果。同时,还发现农药活性同二元羧酸酯的骨架有关,邻苯二甲酸和丁烯二酸衍生物的效果优于脂肪二酸衍生物。     

Effects of tin(IV) chloride and of organotin compounds on aquatic micro-organisms

The growth response of the alga Chlorella kessleri and the euglenoid Euglena gracilis has been studied as a model system to determine the effects of a tin salt (SnCl₄·5H₂O) and of some organotin (OT) derivatives, namely tetrabutyltin (TeBT), tributyltin (TBT) and tributyltin oxide (TBTO). Abiotic degradation was studied as well. Cells were exposed to a toxicity series (0–50 μg/mL⁻¹) for the four chemicals in seven-day bioassays. Both microorganisms are tolerant of the inorganic salt, but growth inhibition was significant for all OT compounds, and especially large for TBT and TBTO. Although C. kessleri and E. gracilis are known to be tolerant towards metals and organic chemicals, the present results show that both are sensitive to organotin compounds: the inhibition of the growth was greater for C. kessleri. © 1998 John Wiley & Sons, Ltd.     

Performance of (consensus) kNN QSAR for predicting estrogenic activity in a large diverse set of organic compounds

A novel method (in the context of quantitative structure–activity relationship (QSAR)) based on the k nearest neighbour (kNN) principle, has recently been introduced for the derivation of predictive structure–activity relationships. Its performance has been tested for estimating the estrogen binding affinity of a diverse set of 142 organic molecules. Highly predictive models have been obtained. Moreover, it has been demonstrated that consensus-type kNN QSAR models, derived from the arithmetic mean of individual QSAR models were statistically robust and provided more accurate predictions than the great majority of the individual QSAR models. Finally, the consensus QSAR method was tested with 3D QSAR and log?P data from a widely used steroid benchmark data set.     

Prescriptions and Ingredients for Controlled CC Bond Formation with Organometallic Reagents. New synthetic methods (5)

Merits and drawbacks of known carbon-carbon linking procedures are outlined. Two novel methods are discussed in some detail: the copper-catalyzed alkylation of Grignard reagents and reactions with allylpotassium compounds. Both methods provide a very efficient access to saturated, unsaturated, as well as functionally substituted hydrocarbons and moreover permit an astonishing degree of regio- and stereoselective control of olefin synthesis.     

Synthesis,DNA-binding,and cytotoxic studies on three copper(II) complexes of unsymmetrical synthetic analogues of curcumin

Copper(II) chelates of three unsymmetrical synthetic analogs of curcumin, namely (2E)-2-(4-hydroxy-3-methoxybenzylidene)-5-((E)-3-(4-hydroxy-3-methoxyphenyl)acryloyl)cyclopentanone(1), (2E)-2-(3,4-dihydroxybenzylidene)-5-((E)-3-(3,4-dihydroxyphenyl)acryloyl)cyclopentanone(2), and (2E)-2-(3,4-dimethoxybenzylidene)-5-((E)-3-(3,4-dimethoxyphenyl)acryloyl)cyclopeantanone(3) have been synthesized and characterized by physicochemical and spectroscopic methods. The ligands were in their enolic form and metal complexes have 1 : 2 metal:ligand stoichiometry. The DNA-binding properties of the ligands and their metal complexes were studied by absorption titrations, fluorescence quenching experiments, and viscosity measurements with calf-thymus DNA. The interactions of copper(II) complexes were higher than that of free ligands. The observed intrinsic binding constants reveal moderate interaction of copper(II) complexes with calf-thymus DNA. The binding involves intercalative mode through non-covalent interactions and produced conformational changes in the structure of DNA. The compounds were investigated for their possible cytotoxic and antitumor activities. All the compounds were cytotoxic towards Dalton’s lymphoma ascites cells. It was found that copper chelates are remarkably active compared to free curcumin analogs. Concentrations needed for 50% cell death were 10–22 μg mL^?1 for copper complexes and 27–52 μg mL^?1 for curcumin analogs. Copper complex of 2 with two hydroxyl groups in the phenyl ring was most active towards Dalton’s lymphoma ascites cells (increase in life span 77.91%). Copper(II) complex of 3, which possesses methoxy groups in the phenyl ring system, showed the lowest activity towards increase in lifespan of tumor-bearing mice (increase in lifespan 60.14%). Copper chelates of all curcuminoid analogs showed a significant reduction in solid tumor volume in mice.     

Antioxidant activities and bioactive compounds of five Jalopeno peppers (Capsicum annuum) cultivars

The present study was designed to evaluate the contents of different antioxidants compounds and their antioxidant activities in Jalopeno peppers (Capsicum annuum) cultivars (El Dorido, Grande, Tula, Sayula and El Rey) extracts. Free radical scavenging activity of Grande was recorded as high as 87% followed by El Dorido (83%). Results of reducing power (Fe³⁺ to Fe²⁺) showed that Grande (0.85%) and El Dorido (0.81%) fruit extract absorbance value were close to synthetic antioxidant BHT (0. 97%) obtained at100 μg/mL. The results showed that total phenolic content of El Dorido and Grande were significantly higher compared to other Jalapeno pepper. Results indicated strong and positive correlation between antioxidant activity and carotenoids content (r = 0.75), vitamin C (r = 0.78) and total capsaicinoids (r = 0.84), respectively. The results of the antioxidant activity assays showed that the El Dorido and Grande had strongest antioxidant activity compared to other peppers cultivars in this study.     

Sn(I) halides: Novel binary compounds of tin and their application in synthetic chemistry

Metalloid cluster compounds are ideal model compounds for the area between the molecular and solid state, i.e. the nanometer regime. For the synthesis of metalloid cluster compounds, the disproportionation reaction of a metastable subhalide is a fruitful synthetic route. In the case of tin, monohalides are needed for this synthetic route as tin(II) halides are too stable to be used. Due to thermodynamic data, gaseous SnBr should be formed at 1370 °C, and by applying a co-condensation technique it can be trapped at −196 °C and prepared in synthetic scale. Herein first analyses of SnBr are presented, showing that SnBr is more reactive than the corresponding GeBr, already disproportionating quantitatively to elemental tin and SnBr₂ on heating to room temperature. By applying nitrogen-based donor molecules like NnBu₃ or pyridine, the reactivity can be moderated and the solubility is enhanced leading e.g. to an SnBr emulsion, which can be used for the synthesis of metalloid cluster compounds of tin.     

New concept for a toxicity assay based on multiple indexes from the wave shape of damped metabolic oscillation induced in living yeast cells (part I): characterization of the phenomenon

The damped glycolytic oscillation phenomenon occurring in starved cells of the yeast Saccharomyces cerevisiae (NBRC 0565) was characterization for application to a toxicity bioassay. S. cerevisiae was grown under semi-anaerobic conditions. The transient oscillations were observed photometrically as the time course of the fluorescent intensity of reduced pyridine nucleotide resulting from instantaneous addition of glucose to a cell suspension. In this study, simple and reproducible conditions inducing damped oscillations were obtained by modifying a literature method. For estimation of the wave shapes of the damped oscillations we used six indexes. To investigate the total reproducibility as the averaged relative standard deviation (RSD_av) for the six indexes obtained from the wave shapes, the damped oscillations were induced under the optimum conditions and the RSD_av values were calculated as 14% in a buffer cell suspension (n = 62) and 22% in a water cell suspension (n = 78). Finally, the effects of glucose concentration on the six indexes were examined, and all the indexes changed when the glucose concentration was changed. Excellent correlations were obtained between the index of oscillation-state time and the concentration of glucose in a buffer cell suspension (r = 0.9985, 0.5–250 mmol L⁻¹, 10 points) and in a water cell suspension (r = 0.9989, 2.5 μmol L⁻¹–250 mmol L⁻¹, 12 points), respectively. Figure Characterization of damped glycolytic oscillation, (a) typical shape, and (b) its estimation Electronic supplementary material The online version of this article (doi:)contains supplementary material, which is available to authorized users.     

New concept for a toxicity assay based on multiple indexes from the wave shape of damped metabolic oscillation induced in living yeast cells (part II): application to analytical toxicology

An ideal toxicity assay should utilize multiple indexes obtained from transient changes of metabolic activities. Here, we demonstrate the possibility for a novel toxicity bioassay using the damped glycolytic oscillation phenomenon occurring in starved yeast cells. In a previous study, the phenomenon was characterized in detail. Under optimum conditions to induce the phenomenon, the wave shapes of the damped glycolytic oscillations were changed by the instantaneous addition of both glucose and chemicals and by changing the chemical concentration. We estimated the changes in the oscillation wave shapes as six indexes, i.e., the number of wave cycles, maximum amplitude, oscillation frequency, attenuation coefficient, initial peak height, and non-steady-state time. These index changes were obtained from several kinds of chemicals. The chemicals, especially those for acids (0.01–100 mM HCl and 0.01–50 mM citric acid), bases (0.001–50 mM KOH), heavy metal ions (1–1,000 mg L⁻¹; Cu²⁺, Pb²⁺, Cd²⁺, Hg²⁺), respiratory inhibitors (3–500 mg L⁻¹ NaN₃), dissolved oxygen removers (10–300 mg L⁻¹ NaSO₃), surfactants (10–200 mg L⁻¹ benzalkonium chloride), and aldehyde (10–1,000 mg L⁻¹ acetaldehyde), showed characteristic patterns depending on each chemical and its concentration. These significant results demonstrate the possibilities of new methods for both toxicity qualification and quantification. Figure Influences of surfactant on the oscillation wave shape Electronic Supplementary Material The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Solid-state NMR and EXAFS spectroscopic characterization of polycrystalline copper(I) O,O'-dialkyldithiophosphate cluster compounds: Formation of copper(I) O,O'-diisobutyldithiophosphate compounds on the surface of synthetic chalcocite

A number of polycrystalline copper(I) O,O'-dialkyldithiophosphate cluster compounds with Cu4, Cu6, and Cu8 cores were synthesized and characterized by using extended X-ray absorption fine-structure (EXAFS) spectroscopy. The structural relationship of these compounds is discussed. The polycrystalline copper(I) O,O'-diisobutyldithiophosphate cluster compounds, [Cu8{S2P(OiBu)2}6(S)] and [Cu6{S2P(OiBu)2}6], were also characterized by using 31P CP/MAS NMR (CP = cross polarization, MAS = magic-angle spinning) and static 65Cu NMR spectroscopies (at different magnetic fields) and powder X-ray diffraction (XRD) analysis. Comparative analyses of the 31P chemical-shift tensor, and the 65Cu chemical shift and quadrupolar-splitting parameters, estimated from the experimental NMR spectra of the polycrystalline copper(I) cluster compounds, are presented. The adsorption mechanism of the potassium O,O'-diisobutyldithiophosphate collector, K[S2P(OiBu)2], at the surface of synthetic chalcocite (Cu2S) was studied by means of solid-state 31P CP/MAS NMR spectroscopy and scanning electron microscopy (SEM). 31P NMR resonance lines from collector-treated chalcocite surfaces were assigned to a mixture of [Cu8{S2P(OiBu)2}6(S)] and [Cu6{S2P(OiBu)2}6] compounds.     

Surface-assisted laser desorption/ionization mass spectrometry (SALDI-MS) of low molecular weight organic compounds and synthetic polymers using zinc oxide (ZnO) nanoparticles

We have developed surface-assisted laser desorption/ionization mass spectrometry using zinc oxide (ZnO) nanoparticles with anisotropic shapes (ZnO-SALDI-MS). The mass spectra showed low background noises in the low m/z, i.e. less than 500 u region. Thus, we succeeded in SALDI ionization on low molecular weight organic compounds, such as verapamil hydrochloride, testosterone, and polypropylene glycol (PPG) (average molecular weight 400) without using a liquid matrix or buffers such as citric acids. In addition, we found that ZnO-SALDI has advantages in post-source decay (PSD) analysis and produced a simple mass spectrum for phospholipids. The ZnO-SALDI spectra for synthetic polymers of polyethylene glycol (PEG), polystyrene (PS) and polymethylmethacrylate (PMMA) showed the sensitivity and molecular weight distribution to be comparable to matrix-assisted laser desorption/ionization (MALDI) spectra with a 2,5-dihydroxybenzoic acid (DHB) matrix. ZnO-SALDI shows good performance for synthetic polymers as well as low molecular weight organic compounds.     

Certification of a new selenized yeast reference material (SELM-1) for methionine, selenomethinone and total selenium content and its use in an intercomparison exercise for quantifying these analytes

A new selenized yeast reference material (SELM-1) produced by the Institute for National Measurement Standards, National Research Council of Canada (INMS, NRC) certified for total selenium (2,059±64 mg kg⁻¹), methionine (Met, 5,758±277 mg kg⁻¹) and selenomethionine (SeMet, 3,431±157 mg kg⁻¹) content is described. The ±value represents an expanded uncertainty with a coverage factor of 2. SeMet and Met amount contents were established following a methanesulfonic acid digestion of the yeast using GC-MS and LC-MS quantitation. Isotope dilution (ID) calibration was used for both compounds, using ¹³C-labelled SeMet and Met. Total Se was determined after complete microwave acid digestion based on ID ICP-MS using a ⁸²Se spike or ICP-OES spectrometry using external calibration. An international intercomparison exercise was piloted by NRC to assess the state-of-the-art of measurement of selenomethione in SELM-1. Determination of total Se and methionine was also attempted. Seven laboratories submitted results (2 National Metrology Institutes (NMIs) and 5 university/government laboratories). For SeMet, ten independent mean values were generated. Various acid digestion and enzymatic procedures followed by LC ICP-MS, LC AFS or GC-MS quantitation were used. Four values were based on species-specific ID calibration, one on non-species-specific ID with the remainder using standard addition (SA) or external calibration (EC). For total selenium, laboratories employed various acid digestion procedures followed by ICP-MS, AFS or GC-MS quantitation. Four laboratories employed ID calibration, the remaining used SA or EC. A total of seven independent results were submitted. Results for methionine were reported by only three laboratories, all of which used various acid digestion protocols combined with determination by GC-MS and LC UV. The majority of participants submitted values within the certified range for SeMet and total Se, whereas the intercomparison was judged unsuccessful for Met because only two external laboratories provided values, both of which were outside the certified range.     

Application of double-spike isotope dilution for the accurate determination of Cr(III), Cr(VI) and total Cr in yeast

A method is presented for the simultaneous determination of Cr(III) and Cr(VI) in yeast using species-specific double-spike isotope dilution (SSDSID) with anion-exchange liquid chromatography (LC) separation and sector field inductively coupled plasma mass spectrometric (SF-ICP-MS) detection. Total Cr is quantitated using ID SF-ICP-MS. Samples were digested on a hot plate at 95±2 °C for 6 h in an alkaline solution of 0.5 M NaOH and 0.28 M Na₂CO₃ for the determination of Cr(III) and Cr(VI), whereas microwave-assisted decomposition with HNO₃ and H₂O₂ was used for the determination of total Cr. Concentrations of 2,014±16, 1,952±103 and 76±48 mg kg⁻¹ (one standard deviation, n=4, 3, 3), respectively were obtained for total Cr, Cr(III) and Cr(VI) in the yeast sample. Significant oxidation of Cr(III) to Cr(VI) (24.2±7.6% Cr(III) oxidized, n=3) and reduction of Cr(VI) to Cr(III) (37.6±6.5% Cr(VI) reduced, n=3 ) occurred during alkaline extraction and subsequent chromatographic separation at pH 7. Despite this significant bidirectional redox transformation, quantitative recoveries for both Cr(III) and Cr(VI) were achieved using the SSDSID method. In addition, mass balance between total Cr and the sum of Cr(III) and Cr(VI) concentrations was achieved. Method detection limits of 0.3, 2 and 30 mg kg⁻¹ were obtained for total Cr, Cr(VI) and Cr(III), respectively, based on a 0.2-g sub-sample.     

Synthesis,characterization, crystal structure and biological activities of supramolecular compounds of Mn(II) and Zn(II) with dipicolinic acid and 8-hydroxyquinoline

Two compounds, (8-H₂Q)₂[Mn(dipic)₂] · 6H₂O (1) and (8-H₂Q)₂[Zn(dipic)₂] · 6H₂O (2) (8-HQ = 8-hydroxyquinoline (oxine), H₂dipic = dipicolinic acid), have been prepared and characterized by elemental, spectroscopic (IR and UV–Vis), and thermal analyses, magnetic measurements and single crystal X-ray diffraction techniques. Compounds 1 and 2 consist of two 8-hydroxyquinolinium cations, one bis(dipicolinato)M(II) anion (M = Mn(II) and Zn(II)) and six uncoordinated water molecules. Both 1 and 2 crystallize in the monoclinic space group C2/c. In the complex anion, each dipic ligand is tridentate through N of pyridine and oxygens of the carboxylate groups. Crystal packing of 1 and 2 is a composite of intermolecular hydrogen bonding interactions. The in vitro antibacterial and antifungal activities of 1 and 2 were evaluated by the agar well diffusion method by MIC (Minimal Inhibition Concentration), looking for compounds which display high-inhibitory effect against gram positive bacteria and fungi. No growth inhibition was observed against tested gram negative bacteria.     

Correlation of colour and crystal structure for silver(I) compounds

A geometrical analysis on 22 crystal structures of Ag(I) compounds with hard bases demonstrates that the observed colour-changes from colourless to red depend on the number of Ag(I) atoms coordinating the donor atoms of the base.

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Korrelation zwischen Farbe und Kristallstruktur in Silber(I)-VerbindungenKurze Mitteilung

Zusammenfassung Eine geometrische Analyse an 22 Kristallstrukturen von Ag(I)-Verbindungen mit harten Basen zeigt, daß sich die Farbe der Verbindungen mit steigender Anzahl von Silberatomen um die Donorzentren vertieft.

     

Profiling of organosulphur compounds using HPLC-PDA and GC/MS system and antioxidant activities in hooker chive (Allium hookeri)

This study investigates the comprehensive organosulphur compounds and evaluation of antioxidant activities in Allium hookeri, called hooker chive. The non-volatile and volatile organosulphur compounds were determined by high-performance liquid chromatography-photodiode array detector (HPLC-PDA) and gas chromatography-mass spectrometry (GC-MS), respectively. Among 11 non-volatileorganosulphur compounds, methiin and cycloalliin were major compounds. A total of 42 volatile compounds were identified and allyl methyl sulphides and dimethyl sulphides were primarily volatiles. The total phenols ranged from 19.32 to 71.19 mg gallic acid equivalents (GAE)/g. The antioxidant capacities expressed IC₅₀ values ranged from 9.59 to 38.54 mg/mL for DPPH radical scavenging activity and from 0.39 to 2.36 for ferric reducing antioxidant power assay. The results were proposed as useful tools for evaluating the nutraceutical of hooker chive.