127 results on '"Jörg W. Metzger"'
Search Results
2. Design and cost analysis of batch adsorber systems for removal of dyes from contaminated groundwater using natural low-cost adsorbents
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Jörg W. Metzger, Elham Khalilzadeh Shirazi, Amir Hessam Hassani, and Klaus Fischer
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Chemistry ,General Chemical Engineering ,Dolomite ,Cationic polymerization ,Langmuir adsorption model ,02 engineering and technology ,General Chemistry ,010501 environmental sciences ,engineering.material ,021001 nanoscience & nanotechnology ,01 natural sciences ,symbols.namesake ,Adsorption ,Chemical engineering ,Bentonite ,Materials Chemistry ,engineering ,medicine ,symbols ,0210 nano-technology ,Vermicompost ,Groundwater ,0105 earth and related environmental sciences ,Activated carbon ,medicine.drug - Abstract
Batch adsorbers were designed for the adsorption of the fabric dyes Basic Violet 16 (BV16) and Reactive Red 195 (RR195) on locally available low-cost natural adsorbents of Persian bentonite, vermicompost and Persian charred dolomite. The adsorption isotherm data were in agreement with the Langmuir isotherm model (R2 > 99%). Results showed that with increasing the adsorption capacity of bentonite for BV16 from 434.78 to 833.33 mg/g due to the presence of the anionic dye, the amount of the adsorbent decreases by 50%. The adsorption capacity of vermicompost for the cationic dye was obtained 16 mg/g in single dye solution and of charred dolomite for the anionic dye was almost 7 mg/g in both dye systems. Based on the extended Langmuir model, the maximum adsorption capacity of natural bentonite for BV16 and of charred dolomite for RR195 were concluded 821.63 mg/g and 7.03 mg/g, respectively, which the capacities are almost the same in single and binary systems. The adsorption capacity and removal efficiency of Persian bentonite from contaminated water are comparable with that of activated carbon. Compared to activated carbon bentonite and the other natural adsorbents used in this study are less expensive and do not require a separate activation or pre-treatment step. Cost for 90% removal of dye from 100 m3 groundwater using 1 kg the studied adsorbents of vermicompost, charred dolomite and bentonite was calculated 0.06, 0.05 and 0.04 euro, respectively, in both single and binary systems.
- Published
- 2020
3. Simultaneous removal of a cationic and an anionic textile dye from water by a mixed sorbent of vermicompost and Persian charred dolomite
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Elham Khalilzadeh Shirazi, Amir Hessam Hassani, Jörg W. Metzger, and Klaus Fischer
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Anions ,Environmental Engineering ,Sorbent ,Health, Toxicology and Mutagenesis ,Static Electricity ,0208 environmental biotechnology ,Dolomite ,02 engineering and technology ,010501 environmental sciences ,01 natural sciences ,Calcium Carbonate ,Water Purification ,symbols.namesake ,Adsorption ,Cations ,Environmental Chemistry ,Magnesium ,Surface charge ,Coloring Agents ,0105 earth and related environmental sciences ,Chemistry ,Composting ,Textiles ,Public Health, Environmental and Occupational Health ,Cationic polymerization ,Water ,Langmuir adsorption model ,Sorption ,General Medicine ,General Chemistry ,Pollution ,020801 environmental engineering ,symbols ,Water treatment ,Water Pollutants, Chemical ,Nuclear chemistry - Abstract
The potential of a mixed sorbent consisting of vermicompost and Persian charred dolomite for simultaneous adsorption of Basic Violet 16 (BV16) and Reactive Red 195 (RR195) was investigated. First-order derivative spectrophotometry was used for simultaneous analysis of the two dyes. In single dye experiments, the maximum adsorption capacity of vermicompost for BV16 was found to be 16 mg g−1 and the adsorption capacity of charred dolomite for RR195 was 7.3 mg g−1. Anionic RR195 was not noticeably adsorbed by vermicompost (negative surface charge) and cationic BV16 not by charred dolomite (positive surface charge) but adsorbed by the oppositely charged adsorbents which indicates a selective electrostatic adsorption mechanism. In binary dye solution, BV16 adsorption onto charred dolomite was increased in the presence of RR195 (synergistic effect), yet RR195 adsorption on charred dolomite was not influenced by BV16. An antagonistic effect of RR195 was concluded for BV16 adsorption onto vermicompost. The adsorption equilibrium data for both adsorbents fitted more acceptable to the Langmuir isotherm model than to the Freundlich model in single and binary solutions, but other than the adsorption of BV16 on vermicompost in binary solution which followed the Freundlich model. More than 50% of the removal efficiencies determined for both dyes onto the mixed sorbents were >70% which highlights that the mixed sorbent investigated is highly efficacious for the simultaneous removal of cationic and anionic dyes from contaminated groundwater. Eight cycles reusing vermicompost with 1 N NaOH for regeneration demonstrates the practicability and economic advantage of this natural biosorbent.
- Published
- 2019
4. Internationale Aus- und Weiterbildung
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Martin Kranert and Jörg W. Metzger
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Pollution ,Water Science and Technology - Published
- 2016
5. A Methodology for Sewage Network Maintenance Toward the Fulfillment of Sustainable Development Goals
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Karen Juliana do Amaral, Regina Maria Matos Jorge, Luciano Rodrigues Penido, Rafael Cabral Gonçalves, Jefferson Skroch, and Jörg W. Metzger
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Sustainable development ,geography ,geography.geographical_feature_category ,Sanitation ,business.industry ,Environmental resource management ,Drainage basin ,Sewage ,Structural basin ,Urban area ,Metropolitan area ,Water resources ,Environmental science ,business - Abstract
Domestic effluents collected from urban areas are transported along extensive sewer networks that are assumed to operate as watertight systems. Such operability is ensured by maintenance routines, both preventive and corrective, that are capable of detecting weak points where loss of effluents might occur and affect bodies of water. Since urban rivers are the destination of such organic loads, they may be used as indicators of potential weak points along the sewage network. The implementation of initiatives whose goal is to avoid such input of pollutant loads is in line with at least three of the 17 Sustainable Development Goals from the 2030 Agenda. The assumption that rivers may be used as indicators forms the basis of the Urban River Revitalization Program (PRRU) carried out since 2011 by the Water Resources Management division of the Sanitation Company of Parana—Sanepar. Since its inception, over 3410 weak points have already been located and repaired within the Metropolitan Region of Curitiba, which covers about 98 river basins including the Belem River, one of the most important, located completely inside the urban area. In its northern basin 309 weak spots have been corrected, resulting in improved appearance and odor, as well as higher levels of dissolved oxygen.
- Published
- 2019
6. Removal of textile dyes from single and binary component systems by Persian bentonite and a mixed adsorbent of bentonite/charred dolomite
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Elham Khalilzadeh Shirazi, Klaus Fischer, Jörg W. Metzger, and Amir Hessam Hassani
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Textile ,Chemistry ,business.industry ,Dolomite ,Cationic polymerization ,Langmuir adsorption model ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,symbols.namesake ,Colloid and Surface Chemistry ,Adsorption ,Chemical engineering ,Bentonite ,symbols ,Freundlich equation ,0210 nano-technology ,business ,Groundwater - Abstract
A research was undertaken into the adsorption of Basic Violet 16 (BV16) and Reactive Red 195 (RR195) in single or binary dye solutions on natural bentonite (NB), and a commercially available bentonite ('standard bentonite'; SB) in a batch mode. Groundwater samples were treated with single and mixed adsorbents consisting of natural bentonite/charred dolomite and standard bentonite/charred dolomite. The respective maximum adsorption capacities of 434.78 mg g−1 and 833.33 mg g−1 for natural bentonite and 500 mg g−1 and 1111.11 mg g−1 for standard bentonite were obtained to remove BV16. Thus, the adsorption capacity for BV16 doubled in the presence of the anionic dye demonstrating synergistic effects. Moreover, the amount of RR195 adsorbed on bentonite remarkably increased in the presence of the cationic dye BV16. The adsorption equilibrium data for both types of bentonites fitted the Langmuir isotherm model more adequately than the Freundlich isotherm model in single- and binary-component experiments. The pseudo-second-order kinetic model described in depth the adsorption of BV16 and RR195 on both types of bentonites in single and binary dye solutions. In multi-adsorbent systems, results showed that the adsorption behavior of bentonite toward BV16 and charred dolomite toward RR195 was selective, indicating the electrostatic adsorption mechanism. For both dyes most removal efficiencies (> 50 %) achieved with the mixed adsorbent were >70 %. The reusability of bentonite using 1 N NaOH for 5 cycles is indicative of the economic benefits which could be achieved from natural bentonite.
- Published
- 2020
7. Aplicação de ferramentas de avaliação de risco à saúde humana em águas subterrâneas contaminadas com organoclorados
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Jörg W. Metzger, Marielle Feilstrecker, and Mariana Barbosa Druszcz
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Flexibility (engineering) ,Human health ,Risk analysis (engineering) ,Computer science ,media_common.quotation_subject ,Conceptual model ,Context (language use) ,General Medicine ,Data entry ,Risk assessment ,media_common - Abstract
Human health risk assessment is an important step in the management of contaminated areas (brownfields) and aims to reduce remediation costs. Currently, there is no mandatory tool to be used for determining the risks caused by exposure to contaminants and target concentrations for the intervention phase. In this context, the aim of this study was to determine if there is an objective difference in the outcome of a risk assessment study by applying one tool over another. The CETESB Spreadsheets and the software RISC5 were evaluated. In order to increase knowledge about each system, in addition, this study also sought to identify possible specificities in the use of each instrument throughout the development of the risk assessment. The methodology involved simulations of a risk assessment with the application of real data from a land where the aquifer is contaminated with organochlorine compounds. This study concluded that the most current versions of the tools provide a different range of exposure scenarios, mathematical models, toxicological information and even have different levels of flexibility for custom data entry. Finally, it was found that according to the conceptual model of the area and substances of interest that are objects of a human health risk assessment study, the choice of a particular tool can influence the final outcome of the evaluation, including the following stages of the management of brownfields.
- Published
- 2020
8. Anthropogenic Trace Compounds (ATCs) in aquatic habitats — Research needs on sources, fate, detection and toxicity to ensure timely elimination strategies and risk management
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Thomas-Benjamin Seiler, Karl H. Engesser, Holger Class, Steffen Helbich, Wolfgang Nowak, Sabine Ulrike Gerbersdorf, Claudia Lange, Heidrun Steinmetz, Silke Wieprecht, Carla Cimatoribus, Jörg W. Metzger, Martin Kranert, Kristin Steger, and Henner Hollert
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Status quo ,media_common.quotation_subject ,Harmonization ,Risk Assessment ,Environmental Science(all) ,Environmental monitoring ,Water Pollution, Chemical ,Humans ,Environmental planning ,Ecosystem ,lcsh:Environmental sciences ,Risk management ,General Environmental Science ,media_common ,TRACE (psycholinguistics) ,lcsh:GE1-350 ,Effect-related bioassays ,business.industry ,Chemical detection methods ,Environmental engineering ,Water ,Environmental risk assessment ,Trace Elements ,Variety (cybernetics) ,Analytics ,Elimination strategies ,Environmental science ,Micropollutants ,Biofilm-influenced sediment dynamics ,business ,Risk assessment ,Water Pollutants, Chemical ,Environmental Monitoring - Abstract
Anthropogenic Trace Compounds (ATCs) that continuously grow in numbers and concentrations are an emerging issue for water quality in both natural and technical environments. The complex web of exposure pathways as well as the variety in the chemical structure and potency of ATCs represents immense challenges for future research and policy initiatives. This review summarizes current trends and identifies knowledge gaps in innovative, effective monitoring and management strategies while addressing the research questions concerning ATC occurrence, fate, detection and toxicity.We highlight the progressing sensitivity of chemical analytics and the challenges in harmonization of sampling protocols and methods, as well as the need for ATC indicator substances to enable cross-national valid monitoring routine. Secondly, the status quo in ecotoxicology is described to advocate for a better implementation of long-term tests, to address toxicity on community and environmental as well as on human-health levels, and to adapt various test levels and endpoints. Moreover, we discuss potential sources of ATCs and the current removal efficiency of wastewater treatment plants (WWTPs) to indicate the most effective places and elimination strategies. Knowledge gaps in transport and/or detainment of ATCs through their passage in surface waters and groundwaters are further emphasized in relation to their physico-chemical properties, abiotic conditions and biological interactions in order to highlight fundamental research needs. Finally, we demonstrate the importance and remaining challenges of an appropriate ATC risk assessment since this will greatly assist in identifying the most urgent calls for action, in selecting the most promising measures, and in evaluating the success of implemented management strategies. Keywords: Micropollutants, Water, Chemical detection methods, Effect-related bioassays, Elimination strategies, Biofilm-influenced sediment dynamics, Environmental risk assessment
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- 2015
9. Organophosphonates: A review on environmental relevance, biodegradability and removal in wastewater treatment plants
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Eduard Rott, Heidrun Steinmetz, and Jörg W. Metzger
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Environmental Engineering ,0208 environmental biotechnology ,Organophosphonates ,Context (language use) ,02 engineering and technology ,010501 environmental sciences ,Wastewater ,01 natural sciences ,Waste Disposal, Fluid ,chemistry.chemical_compound ,Environmental Chemistry ,Aminomethylphosphonic acid ,Waste Management and Disposal ,0105 earth and related environmental sciences ,EDTMP ,Pollution ,Phosphonate ,DTPMP ,020801 environmental engineering ,Enhanced biological phosphorus removal ,Biodegradation, Environmental ,chemistry ,Environmental chemistry ,Water Pollutants, Chemical - Abstract
The worldwide increasing consumption of the phosphonates 2-phosphonobutane-1,2,4-tricarboxylic acid [PBTC], 1-hydroxyethane 1,1-diphosphonic acid [HEDP], nitrilotris(methylene phosphonic acid) [NTMP], ethylenediamine tetra(methylene phosphonic acid) [EDTMP] and diethylenetriamine penta(methylene phosphonic acid) [DTPMP] over the past decades put phosphonates into focus of environmental scientists and agencies, as they are increasingly discussed in the context of various environmental problems. The hitherto difficult analysis of phosphonates contributed to the fact that very little is known about their concentrations and behavior in the environment. This work critically reviews the existing literature up to the year 2016 on the potential environmental relevance of phosphonates, their biotic and abiotic degradability, and their removal in wastewater treatment plants (WWTPs). Accordingly, despite their stability against biological degradation, phosphonates can be removed with relatively high efficiency (>80%) in WWTPs operated with chemical phosphate precipitation. In the literature, however, to our knowledge, there is no information as to whether an enhanced biological phosphorus removal alone is sufficient for such high removal rates and whether the achievable phosphonate concentrations in effluents are sufficiently low to prevent eutrophication. It is currently expected that phosphonates, although being complexing agents, do not remobilize heavy metals from sediments in a significant amount since the phosphonate concentrations required for this (>50μg/L) are considerably higher than the concentrations determined in surface waters. Various publications also point out that phosphonates are harmless to a variety of aquatic organisms. Moreover, degradation products thereof such as N-(phosphonomethyl)glycine and aminomethylphosphonic acid are regarded as being particularly critical. Despite their high stability against biological degradation, phosphonates contribute to eutrophication due to abiotic degradation (mainly photolysis). Furthermore, the literature reports on the fact that phosphonates in high concentrations interfere with phosphate precipitation in WWTPs. Thus, it is recommended to remove phosphonates, in particular from industrial wastewaters, before discharging them into water bodies or WWTPs.
- Published
- 2017
10. A Glance at the World
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Klaus Kümmerer, Samuel Sasu, Jörg W. Metzger, and Martin Kranert
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InformationSystems_GENERAL ,Chemistry ,Waste management ,MathematicsofComputing_GENERAL ,Pharmaceutical waste ,Environmental science ,waste management ,Ghana ,Sustainability Science ,Waste Management and Disposal ,GeneralLiterature_MISCELLANEOUS - Abstract
Editorial
- Published
- 2011
11. Reply to 'Comment on ‘Long-term leaching of photovoltaic modules’ '
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Michael Koch, Renate Zapf-Gottwick, Jessica Nover, Jörg W. Metzger, Carolin Feifel, and Jürgen H. Werner
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Physics and Astronomy (miscellaneous) ,020209 energy ,Photovoltaic system ,General Engineering ,Environmental engineering ,General Physics and Astronomy ,02 engineering and technology ,010501 environmental sciences ,01 natural sciences ,Term (time) ,0202 electrical engineering, electronic engineering, information engineering ,Environmental science ,Leaching (metallurgy) ,0105 earth and related environmental sciences - Published
- 2017
12. Effect-related monitoring: estrogen-like substances in groundwater
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Frieder Kern, Bertram Kuch, Karl Theo von der Trenck, and Jörg W. Metzger
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Pollution ,Environmental remediation ,Health, Toxicology and Mutagenesis ,media_common.quotation_subject ,Fresh Water ,Fractionation ,Endocrine Disruptors ,Gas Chromatography-Mass Spectrometry ,Cell Line, Tumor ,Groundwater pollution ,Humans ,Environmental Chemistry ,Bioassay ,Polycyclic Aromatic Hydrocarbons ,media_common ,Chemistry ,Estrogens ,General Medicine ,Contamination ,Polychlorinated Biphenyls ,Environmental chemistry ,Biological Assay ,Gas chromatography ,Gas chromatography–mass spectrometry ,Water Pollutants, Chemical ,Environmental Monitoring - Abstract
Concentration monitoring as a basis for risk assessment is a valid approach only if there is an unambiguous relation between concentration and effect. In many cases, no such unambiguous relation exists, since various substances can exert the same effect with differing potencies. If some or all of these substances contributing to a biological effect are unknown, effect-related monitoring becomes indispensable. Endocrine-disrupting substances in water bodies, including the groundwater, are a prominent example of such a case. The aim of the investigations described here was to detect hormonally active substances in the groundwater downstream of obsolete landfills by using the E-screen assay and to possibly assign the biological effect to individual chemical compounds by means of instrumental analyses carried out in parallel. Grab samples of the groundwater were collected downstream from abandoned landfills and prepared by liquid/liquid extraction. The total estrogenic activity in these samples was determined in vitro by applying the E-screen assay. The human breast cancer cells (MCF-7) used in the E-screen proliferate in response to the presence of estrogenically active compounds. Expressed in concentration units of the reference substance 17β-estradiol (E2), the test system allows the quantification of estrogenicity with a limit of detection (LOD) in the range of 0.1 ng/L. Aliquots of the samples were screened using gas chromatography/mass spectrometry (GC/MS) in order to quantify known estrogenically active substances and to identify unknown compounds. Estrogen-positive samples were extracted at different pH values, split into acidic, neutral, and basic fractions and analyzed by GC/MS, searching for individual components that display estrogenic activity. Estrogenic activity exceeding the LOD and the provisional benchmark of 0.5 ng E2/L was found at three out of seven abandoned waste disposal sites tested. The low concentrations of known xenoestrogens such as bisphenol-A, nonylphenols, or phthalic acid esters determined by GC/MS, however, were not sufficient to explain the detected activity. Neither natural nor synthetic hormones have caused the activity because these chemical structures are readily degradable and cannot persist in abandoned landfills for decades. The highest activity in the E-screen assay was found in the acidic fractions. Hydroxy-polychlorinated biphenyls (PCBs), hydroxylated polycyclic aromatic hydrocarbons (PAHs) and hetero-PAHs, as well as alkylphenols could be identified as further compounds with possible hormonal activity. Estrogenically active substances may occur in the groundwater below obsolete landfills, especially those that contain PCBs or waste from gasworks. These substances are not part of analytical programs routinely applied to contaminated sites and may therefore escape detection and assessment. Analyses using the E-screen assay and GC/MS in parallel have shown that the total estrogenic activity found in groundwater samples is to be ascribed to a multitude of individual compounds, some of which cannot be quantified due to lack of standard substances or assessed due to lack of a standardized procedure for determination of their estrogenic potency. By comparison with provisional guide values for estradiol (0.5 ng/L) and ethynylestradiol (0.3 ng/L), the damaging potential of the total estrogenic activity in groundwater samples can in fact be assessed, but specific remediation measures are impossible unless the hormonal activity can be attributed to individual chemical substances. On the one hand, further analyses of samples taken from possible pollution sources should be conducted in order to characterize the extent of groundwater pollution with xenoestrogens. On the other hand, the most potent individual compounds should be identified according to their estrogenic potency. To this end, bioassay-directed fractionation and structure elucidation should be carried out with concentrated samples.
- Published
- 2009
13. Synthesis of Nα-Fmoc protected derivatives of S-(2,3-dihydroxypropyl)-cysteine and their application in peptide synthesis
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Karl-Heinz Wiesmüller, Jörg W. Metzger, and Günther Jung
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Fluorenes ,Oligopeptide ,Magnetic Resonance Spectroscopy ,Molecular Structure ,biology ,Lipoproteins ,Molecular Sequence Data ,Diastereomer ,Biochemistry ,Combinatorial chemistry ,Mass Spectrometry ,chemistry.chemical_compound ,Bacterial Proteins ,chemistry ,Peptide synthesis ,biology.protein ,Amino Acid Sequence ,Cysteine ,Bacterial antigen ,Diglyceride ,Amino Acids ,Antibody ,Peptides ,Conjugate - Abstract
Acylated derivatives of S-(2,3-dihydroxypropyl)-cysteine (S-glycerylcysteine) form the N-terminus of structural and functional proteins of bacterial origin. Synthetic lipopeptides containing tripalmitoyl-S-glycerylcysteine are derived from bacterial lipoprotein and constitute potent immunoadjuvants activating both B-lymphocytes and macrophages. There is increasingly interest in conjugates consisting of tripalmitoyl-S-glycerylcysteine linked to appropriate viral and bacterial antigens, because of their capability of inducing antigen specific antibodies and T-helper and T-killer cell specific immune responses. A new convenient synthetic pathway for the preparation of these tripalmitoyl-S-glycerylcysteinyl peptides is described. The use of N alpha-Fmoc-protected S-(2,3-dihydroxypropyl)-cysteine and its O,O'-bis acylated derivatives for the synthesis of triacyl-S-glycerylcysteinyl, O,O'-bis-acyl-S-glycerylcysteinyl and S-glycerylcysteinyl peptides of high diastereomeric purity by solid phase peptide synthesis or synthesis in solution is demonstrated.
- Published
- 2009
14. Synthesis of novel immunologically active tripalmitoyl-S-glycerylcysteinyl lipopeptides as useful intermediates for immunogen preparations
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Karl-Heinz Wiesmüller, Jörg W. Metzger, Wolfgang G. Bessler, Renate Schaude, and Günther Jung
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chemistry.chemical_classification ,Immunogen ,Stereochemistry ,Lipoproteins ,Molecular Sequence Data ,Lipopeptide ,Peptide ,In Vitro Techniques ,Macrophage Activation ,Lymphocyte Activation ,Biochemistry ,Mice ,Structure-Activity Relationship ,chemistry.chemical_compound ,Adjuvants, Immunologic ,chemistry ,Antigen ,Peptide synthesis ,Animals ,Structure–activity relationship ,Amino Acid Sequence ,Cysteine ,Peptide sequence ,Hapten - Abstract
The synthesis and characterization of lipopeptides consisting of the lipoamino acid N-palmitoyl-S-[2,3-bis(palmitoyloxy)-(2RS)-propyl]-[R]-cysteine (Pam3Cys-OH) and different peptide segments and/or spacer molecules is described. Pam3Cys-peptides, which are derived from the immunologically active N-terminus of bacterial lipoprotein, were obtained either by solution or solid phase peptide synthesis. In particular, the amphiphilic and water-soluble lipohexapeptides Pam3Cys-Ser-(Lys)4 and Pam3Cys-Ser-(Glu)4 proved to be potent macrophage and B-cell activators and non-toxic, non-pyrogenic immune adjuvants in combination with or covalently linked to antigens and haptens.
- Published
- 2009
15. Biodegradation of the Antituberculosis Drug Isoniazid in the Aquatic Environment
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Klaus Kümmerer, Jörg W. Metzger, Samuel Sasu, and Martin Kranert
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Biochemical oxygen demand ,Antituberculosis drug ,Chromatography ,Biological degradation ,Chemistry ,Isoniazid ,Surface water ,Biodegradation ,Pollution ,High-performance liquid chromatography ,Microbiology ,Sewage treatment plant ,Aquatic environment ,medicine ,Pharmaceutical waste ,Environmental Chemistry ,Pharmaceuticals ,Water Science and Technology ,medicine.drug - Abstract
As part of our study on pharmaceutical waste management in Ghana, we investigated the biodegradability of the most widely used antituberculosis drug isoniazid in the aquatic environment. The experiment was conducted using three tests from the Organization for Economic Co-operation and Development guidelines (close bottle test (CBT) 301D, low bacterial density i.e. -1, manometric respiratory test (MRT) 301F, i.e. -1 and the Zahn-Wellens test (ZWT) 302B, i.e. -1) employing different concentrations. At the end of the study, the results showed that isoniazid at concentrations of 4.29mgL -1 for the CBT and 25.7mgL -1 for the MRT were found not to be readily biodegradable in accordance with the test guidelines. In the ZWT, at a concentration of 142.92mgL -1 which allows evaluation of aerobic degradation at high bacterial density, the results provided evidence for biological degradation of isoniazid. Finally, the test samples after 28days analyzed by high performance liquid chromatography coupled to ultraviolet detector showed a complete primary elimination of the test substance in MRT and ZWT. The difference of the results obtained by HPLC and oxygen consumption in the MRT indicated the formation of stable transformation products, i.e. incomplete biodegradation, whilst there was no biodegradation at all in CBT. The study was conducted to investigate the biodegradability of the mostly widely use antituberculosis drug isoniazid. The test samples analyzed after 28days by HPLC-UV showed a complete primary elimination of the test substance in MRT and ZWT.
- Published
- 2015
16. Brominated–chlorinated diphenyl ethers formed by thermolysis of polybrominated diphenyl ethers at low temperatures
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Jörg W. Metzger and Silke Rupp
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Hot Temperature ,Environmental Engineering ,Health, Toxicology and Mutagenesis ,Polybrominated Biphenyls ,chemistry.chemical_element ,Ether ,Gas Chromatography-Mass Spectrometry ,chemistry.chemical_compound ,Blood serum ,Polybrominated diphenyl ethers ,Hexabromobenzene ,Chlorine ,Environmental Chemistry ,Organic chemistry ,Flame Retardants ,Chemistry ,Phenyl Ethers ,Thermal decomposition ,Diphenyl ether ,Temperature ,Public Health, Environmental and Occupational Health ,General Medicine ,General Chemistry ,Pollution ,Environmental chemistry ,Chlorine Compounds ,Plastics ,Bromobenzenes ,Ethers ,Fire retardant - Abstract
Polybrominated diphenyl ethers (PBDEs) are a group of brominated flame retardants (BFRs) used mainly as additives in different kinds of plastic material. Various PBDEs are found in all environmental compartments as well as in tissue and blood serum of animals and humans due to their persistence and tendency to bioaccumulate. Emission of PBDEs into the environment can occur during recycling of PBDE-containing plastic material or during their uncontrolled or insufficient combustion as e.g. in accidental fires or landfill fires. Under these circumstances, PBDEs can also function as precursor molecules for the formation of polybrominated dibenzodioxins (PBDDs) and dibenzofurans (PBDFs). In this study, we qualitatively investigated the reaction of two PBDE congeners, 2,2',4,4'-tetrabromo diphenyl ether (BDE 47) and 2,2',4,4',5,5'-hexabromo diphenyl ether (BDE 153), as well as hexabromobenzene (HBB), a flame retardant used in the past, when exposed to temperatures between 250 degrees C and 500 degrees C. The formed reaction products were analysed by high resolution gas chromatography-low resolution mass spectrometry (HRGC-LRMS). Among others brominated-chlorinated diphenyl ethers were formed by chlorodebromination of the PBDEs. In addition, thermolysis of BDE 47 and BDE 153 in the presence of tetrachloromethane as model substance for an organic chlorine source was studied. Thermal treatment of HBB resulted in the formation of brominated-chlorinated benzenes.
- Published
- 2005
17. Determination of estrogenic activity by LYES-assay (yeast estrogen screen-assay assisted by enzymatic digestion with lyticase)
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T. Schultis and Jörg W. Metzger
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Environmental Engineering ,medicine.drug_class ,Health, Toxicology and Mutagenesis ,Diethylstilbestrol ,Estrogen receptor ,Estrone ,Sensitivity and Specificity ,chemistry.chemical_compound ,Multienzyme Complexes ,Yeasts ,medicine ,Environmental Chemistry ,Receptor ,chemistry.chemical_classification ,Chromatography ,Chemistry ,Glucan Endo-1,3-beta-D-Glucosidase ,Public Health, Environmental and Occupational Health ,Estrogens ,General Medicine ,General Chemistry ,Pollution ,Yeast ,Enzyme ,Evaluation Studies as Topic ,Estrogen ,Biological Assay ,Digestion ,Peptide Hydrolases ,medicine.drug - Abstract
In order to enhance the sensitivity and the speed of the yeast estrogen screen (YES)-assay, which has been established in many laboratories for the determination of estrogenic activity of compounds and environmental samples, the LYES-assay, a modified version of the YES-assay including a digestion step with the enzyme lyticase, was developed. With the LYES-assay the estrogenic activities of natural (17beta-estradiol E2 and estrone), synthetic (17alpha-ethinylestradiol EE2) and pharmaceutical estrogens (diethylstilbestrol DES) as well as xenoestrogens (4-nonylphenol NP and five parabens) were determined and compared with the results obtained by other in vitro-assays namely the conventional YES-assay, the E-Screen-assay (MCF-7 breast tumor cell proliferation) and a receptor binding-assay (RB) with human estrogen receptors hER-alpha and hER-beta. In the case of E2 the LYES-assay had a significantly lower limit of quantification (LOQ) than the conventional YES-assay and even two orders of magnitude lower than the RB-assay. Compared to the E-Screen-assay the LOQ of the LYES-assay was almost one order of magnitude higher. The time required to perform the LYES-assay was as little as seven hours compared to three to five days for the conventional YES-assay. Thus, the LYES-assay is a very good alternative to existing estrogenic in vitro-assays, since it has a good sensitivity, is cheap and much faster than the other assays.
- Published
- 2004
18. On Sensitivity, Specificity, and the Influence of Various Parameters on Ethyl Glucuronide Levels in Urine???Results From the WHO/ISBRA Study
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Wolfgang Weinmann, Marc Graf, Gerhard A. Wiesbeck, Friedrich M. Wurst, and Jörg W. Metzger
- Subjects
Adult ,Male ,Adolescent ,Alcohol Drinking ,Body water ,Medicine (miscellaneous) ,Physiology ,Glucuronates ,Urine ,World Health Organization ,Toxicology ,Sensitivity and Specificity ,Statistics, Nonparametric ,chemistry.chemical_compound ,Ethyl glucuronide ,Sobriety ,Humans ,Medicine ,Aged ,Receiver operating characteristic ,business.industry ,Alcohol dependence ,Area under the curve ,Middle Aged ,Alcoholism ,Psychiatry and Mental health ,chemistry ,Regression Analysis ,Female ,business ,Body mass index - Abstract
Background: Ethyl glucuronide (EtG), a direct ethanol metabolite, seems to meet the need for a sensitive and specific marker for monitoring recent alcohol consumption in different settings. Our aim was to study sensitivity, specificity, and the influence of various parameters on EtG levels in urine. Patients and Methods: Urine samples for a total of 453 patients (373 male, 80 female) were statistically analyzed. The mean age was 37.1 years (median 36, SD 12.59), body mass index was 24.7, total ethanol consumed last month was 1817.66 g (each median), and 80 patients reported cannabis use within the last 30 days. Determination of EtG was performed with a liquid chromatography-tandem mass spectrometry method with deuterium-labeled EtG as internal standard. Results: For EtG in urine, a good correlation was found with other state markers and days of sobriety. In a regression analysis, age, gender, marijuana use, kidney disease, and total grams of ethanol consumed last month were the variables that significantly influenced EtG levels in contrast to race, smoking, body mass index, cirrhosis of liver, age began drinking regularly, packs of cigarettes smoked last month, and total body water. Furthermore, in a receiver operating characteristic curve analysis to distinguish between nondrinkers and individuals sober >4 days versus individuals drinking in the recent 4 days, area under the curve was 0.834. At a cutoff of 0.145 mg/liter, sensitivity was 83.5% and specificity 68.3%. A receiver operating characteristic curve was calculated for lifetime alcohol abuse or dependence against those who had never been abusers or dependent. In this case, subjects were either never dependent or lifetime dependent, but those currently dependent were excluded. The resulting area under the curve was 0.694. At a cutoff of 0.145 mg/liter, sensitivity was 73.8% and specificity 60.3%. For those with a self-reported sobriety of less than 24 hr, the area under the curve was 0.899, sensitivity was 90.8%, and specificity was 76.5% at a cutoff of 0.435 mg/liter when we calculated nondrinkers and light drinkers against heavy drinkers and drinkers needing treatment. Cannabis-using patients showed significant differences with regard to almost all state markers when compared with nonconsuming subjects. Conclusions: Age, gender, marijuana use, kidney disease, and total grams of ethanol consumed last month should be taken into consideration when interpreting results of EtG in urine. Sensitivity and specificity seem promising. Cannabis use can be regarded as an indicator for other serious mental problems in alcohol-using subjects.
- Published
- 2004
19. Interaction of xenin with the neurotensin receptor of guinea pig enteral smooth muscles
- Author
-
Gerd Hamscher, Jörg W. Metzger, Gerhard E. Feurle, and Alexandra Grudinski
- Subjects
medicine.medical_specialty ,Physiology ,Molecular Sequence Data ,Guinea Pigs ,Peptide ,In Vitro Techniques ,Biology ,Xenin ,Binding, Competitive ,Biochemistry ,Gastrointestinal Hormones ,Guinea pig ,Jejunum ,Cellular and Molecular Neuroscience ,chemistry.chemical_compound ,Endocrinology ,Internal medicine ,medicine ,Animals ,Receptors, Neurotensin ,Peptide bond ,Amino Acid Sequence ,Neurotensin receptor ,Intestinal Mucosa ,Receptor ,Neurotensin ,chemistry.chemical_classification ,Muscle, Smooth ,Intestines ,Kinetics ,medicine.anatomical_structure ,chemistry ,Peptides ,Muscle Contraction - Abstract
Xenin, a 25 aminoacid peptide, interacts with the neurotensin receptor subtype 1 of intestinal muscles of the guinea pig. Replacement of the C-terminal Lys -Arg peptide bond in xenin 6 by a reduced pseudo-peptide bond augmented binding affinity to isolated jejunal and colonic muscle membranes by factors of 7.7 and 21.0 respectively; the potency to contract the jejunum and to relax the colon was increased by factors of 3.2 and 1.3. The C-terminus Trp-Ile-Leu (WIL) of xenin, in contrast to the C-terminus Tyr-Ile-Leu (YIL) of neurotensin, bound competitively to the muscle membranes. WIL blocked the contractile action of xenin in the jejunum and was synergistic with the relaxing action in the colon. The Lys -Arg motif and Trp in the C-terminus of xenin are essential structures in the action of xenin on the enteral smooth muscle receptors.
- Published
- 2002
20. Nano-HPLC-mass spectrometry and MEKC for the analysis of oligosaccharides from human milk
- Author
-
Beate Behnke, Dietmar G. Schmid, Jörg W. Metzger, and Reinhard Kuhn
- Subjects
Pharmacology ,Chromatography ,Milk, Human ,Electrospray ionization ,Clinical Biochemistry ,Oligosaccharides ,Aminobenzoates ,General Medicine ,Mass spectrometry ,Biochemistry ,Analytical Chemistry ,chemistry.chemical_compound ,chemistry ,Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization ,Drug Discovery ,Nano ,Aminobenzoic acid ,Molecule ,Sodium dodecyl sulfate ,Derivatization ,Molecular Biology ,Chromatography, High Pressure Liquid ,Chromatography, Micellar Electrokinetic Capillary - Abstract
The separation of oligosaccharides derivatized with various esters of aminobenzoic acid by means of reversed-phase nano-HPLC (nHPLC) with on-line ESI mass spectrometry and off-line MALDI-TOF mass spectrometry as well as MEKC is described. For this purpose methyl, ethyl and butyl aminobenzoates and heptyloxyaniline were used as derivatization agents for homologous maltodextrins and oligosaccharides from human milk. Four different C 1 8 stationary phases were tested for this purpose because the type of stationary phase was shown to have a dramatic effect on the performance of the separation. Optimal results were obtained using n-butyl aminobenzoate as label and an encapsulated ODS stationary phase. The on-line coupling of nHPLC to ESI MS allowed to separate and identify various oligosaccharides from human milk. This technique enabled the exact attribution of the molecular structure to a signal in the chromatogram. In a second approach oligosaccharides were separated by nHPLC and subsequently fractionated. The fractions were analyzed by MALDI-TOF mass spectrometry. The results obtained by this approach confirmed the ESI MS data. An analogous separation profile was obtained by using sodium dodecyl sulfate in MEKC, which proves that the retention mechanisms of both techniques are identical.
- Published
- 2002
21. Substances with estrogenic activity in effluents of sewage treatment plants in southwestern Germany. 1. Chemical analysis
- Author
-
Ulrike Bolz, Jörg W. Metzger, Volker Hanf, Winfried Schuller, Peter Spengler, and Wolfgang Körner
- Subjects
business.industry ,Health, Toxicology and Mutagenesis ,Sewage ,Estrone ,chemistry.chemical_compound ,chemistry ,Endocrine disruptor ,Activated charcoal ,Environmental chemistry ,Environmental Chemistry ,Sewage treatment ,business ,Xenobiotic ,Effluent ,hormones, hormone substitutes, and hormone antagonists ,Waste disposal - Abstract
The proliferation test with human estrogen receptor-positive MCF-7 breast cancer cells (E-Screen assay) was applied for quantitative determination of total estrogenic activity in 24-h composite effluent samples from 16 municipal and two industrial sewage treatment plants (STPs) in the state of Baden-Wurttemberg, southwestern Germany. The estrogenic efficacy relative to the positive control, 17beta-estradiol, was between 26 and 74% (median, 48%) for the 16 municipal STPs. Estradiol equivalent concentrations (EEQs) were between 0.2 and 7.8 ng/L (median, 1.6 ng/L) and, thereby, were lower than those found in a pilot study, which revealed EEQs of greater than 10 ng/L in the effluents of two other STPs. The EEQs in 14 of the 16 effluent samples were very similar (0.9-3.3 ng/L), indicating a rather constant input of estrogenic substances via STPs into rivers. Additional activated charcoal filtration turned out to be very efficient in further eliminating estrogenic activity from effluents. The EEQs of the E-Screen assay and those calculated from the results of extensive chemical analysis using the estradiol equivalency factors determined for 13 natural and synthetic estrogenic substances were comparable for most of the effluent samples. 17beta-Estradiol, 17alpha-ethinylestradiol, and, to a lesser extent, estrone contributed to 90% or more of the EEQ value.
- Published
- 2001
22. Nano-HPLC of Oligosaccharides - Method Development and Optimization
- Author
-
Beate Behnke, Reinhard Kuhn, Jörg W. Metzger, Dietmar G. Schmid, and Christoph Kempter
- Subjects
Van Deemter equation ,chemistry.chemical_classification ,Chromatography ,technology, industry, and agriculture ,Analytical chemistry ,Reversed-phase chromatography ,Oligosaccharide ,Mass spectrometry ,High-performance liquid chromatography ,Analytical Chemistry ,chemistry.chemical_compound ,chemistry ,Mass spectrum ,Aminobenzoic acid ,Derivatization - Abstract
The separation of homologous maltodextrins using methyl-, ethyl- and n-butyl esters of aminobenzoic acid and n-heptyloxyaniline by means of reversed phase nano-HPLC is presented. Fused silica capillaries packed with four different stationary phases were tested, the separation of the derivatized sugars was optimized and the separation properties of these columns were tested on the basis of the van Deemter plots. UV/VIS detection was used (285 nm for the aminobenzoic esters and 275 nm for the aniline derivatives) in combination with on-line ESI triple quadrupole mass spectrometry and off-line MALDI-TOF mass spectrometry. The choice of the stationary phase had a tremendous influence on the separation. Optimal results were obtained with an encapsulated ODS stationary phase and n-butyl aminebenzoate as label for the oligosaccharides. Malto-oligosaccharides with a degree of polymerization of up to of 25 could be resolved to baseline. On-line coupling with ESI-MS yielded additional information as a result of induced fragmentation and increased sensitivity by monitoring precursor ion. Off-line mass detection with MALDI-TOF was performed on the separated derivatized saccharides collected from nano-HPLC runs. The MALDI-TOF mass spectra confirm the ESI-MS data.
- Published
- 2001
23. Definition of assigned values for proficiency tests in water analysis
- Author
-
Jörg W. Metzger and Michael Koch
- Subjects
Analyte ,Engineering ,Operations research ,Assurance qualite ,business.industry ,General Chemical Engineering ,Value (computer science) ,General Chemistry ,Proficiency test ,Matrix (chemical analysis) ,Statistics ,Proficiency testing ,Safety, Risk, Reliability and Quality ,business ,Instrumentation ,Quality assurance - Abstract
The definition of an assigned value is usually achieved by calculating mean values from the data (with different methods) or by designating reference laboratories. Neither method is completely satisfactory. In this paper a new method is presented for the definition of the assigned value for spiked samples with an unknown content of the analyte in the matrix. The method consists of two parts. The first is the estimation of the assigned values from the spiked amounts and the content in the matrix, based on the results of reference laboratories. The other is the designation of these reference laboratories by comparing their results with the assigned values. Because each of these parts requires the other, an iterative procedure is necessary. As an example, the results of a proficiency test for the analysis of copper in wastewater are used to compare the calculated values with those from other methods, e.g., the Huber estimation.
- Published
- 2001
24. Occurrence and fate of synthetic musk fragrances in a small German river
- Author
-
Jörg W. Metzger, Claudia Lange, and Bertram Kuch
- Subjects
Environmental Engineering ,Tetrahydronaphthalenes ,Trout ,Health, Toxicology and Mutagenesis ,Population ,chemistry.chemical_compound ,Lactones ,Rivers ,Germany ,Environmental Chemistry ,Animals ,Benzopyrans ,Galaxolide ,education ,Waste Management and Disposal ,Effluent ,education.field_of_study ,biology ,biology.organism_classification ,Pollution ,Perfume ,Wastewater ,chemistry ,Synthetic musk ,Environmental chemistry ,Bioaccumulation ,Environmental science ,Surface water ,Water Pollutants, Chemical ,Environmental Monitoring - Abstract
The polycyclic musks tonalide ® (acetyl hexamethyltetraline = 1-(3,5,5,6,8,8-hexamethyl-6,7-dihydronaphthalen-2-yl)ethanone, AHTN), galaxolide ® (1,3,4,6,7,8-hexahydro-4,6,6,7,8,8-hexamethylcyclopenta( g )-2-benzopyrane, HHCB) and the degradation product HHCB-lactone were determined in water samples and brown trouts ( Salmo trutta fario ) of the river Ammer, a small catchment in the state of Baden-Wurttemberg, south-west Germany. The Ammer receives the effluent discharge of two municipal wastewater treatment plants (WWTPs) with 90,000 population equivalents. The wastewater contributes 14% of the total discharge of the river (average 1.0 m 3 /s). Water samples were collected monthly at 12 sampling points from June 2010 to May 2011. Downstream the WWTPs the median concentrations of HHCB, AHTN and HHCB-lactone were 0.26 μg/L, 0.06 μg/L and 1.0 μg/L, respectively. The effluent of the WWTPs was identified as main source of the synthetic musks in the surface water. The ratio of HHCB-lactone/HHCB showed significant seasonal variations indicating the influence of the water temperature on the degradation of HHCB in the surface water. A total of 251 trout was caught in two campaigns in October 2010 at 12 sampling points. The median concentrations of HHCB and AHTN in the trouts downstream the WWTPs significantly increased to 10.8 μg/g lipid weight (LW) and 3.7 μg/g LW, respectively.
- Published
- 2013
25. Molecular Evidence for Genus Level Diversity of Bacteria Capable of Catalyzing Anaerobic Ammonium Oxidation
- Author
-
Markus Schmid, Jörg W. Metzger, Mike S. M. Jetten, Stefan Juretschko, Michael Wagner, Karl-Heinz Schleifer, Michael Klein, Ulf Twachtmann, and Marc Strous
- Subjects
DNA, Bacterial ,Molecular Sequence Data ,Biology ,DNA, Ribosomal ,Polymerase Chain Reaction ,Applied Microbiology and Biotechnology ,Microbiology ,Planctomycetales ,chemistry.chemical_compound ,Bioreactors ,RNA, Ribosomal, 16S ,Ammonium ,Anaerobiosis ,Nitrosomonas ,In Situ Hybridization, Fluorescence ,Phylogeny ,Ecology, Evolution, Behavior and Systematics ,Bacteria ,Sewage ,Biofilm ,Sequence Analysis, DNA ,biology.organism_classification ,Quaternary Ammonium Compounds ,Anammoxosome ,Brocadia anammoxidans ,chemistry ,Anammox ,Biofilms ,Scalindua ,Proteobacteria ,Oxidoreductases ,Oxidation-Reduction ,Filtration - Abstract
Recently, a bacterium capable to oxidize ammonium anaerobically at a high rate was identified as novel member of the Planctomycetales (Strous, M., Fuersi, J. A., Kramer, E. H. M., Logemann, S., Muyzer, G., van de Pas-Schoonen, K. T., Webb, R. I., Kufnen, J. G., and Jetten, M. S. M.: Nature 400, 446-449, 1999). Here we investigated the microbial community structure of a trickling filter biofilm with a high anaerobic ammonium oxidation activity. Fluorescence in situ hybridization (FISH) with a set of nine probes designed for specific identification of the recently described anaerobic ammonium oxidizer demonstrated that only one probe hybridized to bacteria within the biofilm. For phylogenetic characterization of putative biofilm anaerobic ammonium oxidizers a full-cycle 16S rDNA approach was performed by using a Planctomycetales-specific forward primer for PCR amplification. Of the twenty-five 16S rDNA fragments (1364 bp in length) amplified from the biofilm, nine were affiliated to the Planctomycetales. Comparative analysis showed that these sequences were more than 98.9% similar to each other but only distantly related to the previously recognized anaerobic ammonium oxidizer (below 91% similarity) and all other organisms represented in public 16S rRNA databases (similarities of below 79%). The retrieved sequences and the previously recognized anaerobic ammonium oxidizer represent two well-separated groups of a deep-branching lineage within the Planctomycetales. Quantitative FISH analysis with a newly designed specific probe showed that the novel bacterium, provisionally classified as "Candidatus Kuenenia stuttgartiensis" constituted the dominant fraction of the biofilm bacteria. In situ probing revealed that ammonia-oxidizing bacteria of the beta-subclass of Proteobacteria were also present, albeit in significant smaller amounts, within the anoxic biofilm. Comparative sequence analysis of a stretch of the gene encoding ammonia-monooxygenase (amoA) demonstrated the occurrence of the DNA of at least three different populations of beta-subclass ammonia oxidizers within the biofilm.
- Published
- 2000
26. Tryptic digest mapping by gradient capillary electrochromatography
- Author
-
Jörg W. Metzger and Beate Behnke
- Subjects
Packed bed ,Capillary electrochromatography ,Chromatography ,Resolution (mass spectrometry) ,Chemistry ,Capillary action ,Clinical Biochemistry ,Analytical chemistry ,Biochemistry ,High-performance liquid chromatography ,Analytical Chemistry ,Electrochromatography ,Liquid bubble ,Joule heating - Abstract
A high performance liquid chromatography (HPLC) system complemented with T-split, capillary detection cell and a high voltage power supply was used for peptide mapping by gradient electrochromatography and nanoliquid chromatography (nano-LC). With capillary columns of 100 microm ID, 6 cm packed with octadecylated 1.5 microm silica particles, the typical analysis time was approximately 10-15 min. The resolution of a tryptic digest of cytochrome c obtained by electrochromatography at 100 kV/m was superior compared to the analysis by nano-LC. Bubble formation caused by Joule heating at currents up to 100 microA was successfully suppressed by using a resistor capillary of 25 microm ID connected to the outlet of the packed column.
- Published
- 1999
27. Isolation, Characterization, and Heterologous Expression of the Novel Lantibiotic Epicidin 280 and Analysis of Its Biosynthetic Gene Cluster
- Author
-
Ulrike Pag, Jörg W. Metzger, Christoph Heidrich, Gabriele Bierbaum, Günther Jung, Hans-Georg Sahl, Ralph W. Jack, and Michaele Josten
- Subjects
Operon ,Molecular Sequence Data ,Microbial Sensitivity Tests ,Applied Microbiology and Biotechnology ,Open Reading Frames ,Bacteriocins ,Gene cluster ,Staphylococcus epidermidis ,Amino Acid Sequence ,Cloning, Molecular ,Gene ,Peptide sequence ,Chromatography, High Pressure Liquid ,Staphylococcus carnosus ,Sequence Homology, Amino Acid ,Ecology ,biology ,Lantibiotics ,biology.organism_classification ,Molecular biology ,Recombinant Proteins ,Anti-Bacterial Agents ,Open reading frame ,Biochemistry ,Genes, Bacterial ,Multigene Family ,Food Microbiology ,Heterologous expression ,Oxidoreductases ,Peptides ,Food Science ,Biotechnology - Abstract
Epicidin 280 is a novel type A lantibiotic produced by Staphylococcus epidermidis BN 280. During C 18 reverse-phase high-performance liquid chromatography two epicidin 280 peaks were obtained; the two compounds had molecular masses of 3,133 ± 1.5 and 3,136 ± 1.5 Da, comparable antibiotic activities, and identical amino acid compositions. Amino acid sequence analysis revealed that epicidin 280 exhibits 75% similarity to Pep5. The strains that produce epicidin 280 and Pep5 exhibit cross-immunity, indicating that the immunity peptides cross-function in antagonization of both lantibiotics. The complete epicidin 280 gene cluster was cloned and was found to comprise at least five open reading frames ( eciI , eciA , eciP , eciB , and eciC , in that order). The proteins encoded by these open reading frames exhibit significant sequence similarity to the biosynthetic proteins of the Pep5 operon of Staphylococcus epidermidis 5. A gene for an ABC transporter, which is present in the Pep5 gene cluster but is necessary only for high yields (G. Bierbaum, M. Reis, C. Szekat, and H.-G. Sahl, Appl. Environ. Microbiol. 60:4332–4338, 1994), was not detected. Instead, upstream of the immunity gene eciI we found an open reading frame, eciO , which could code for a novel lantibiotic modification enzyme involved in reduction of an N-terminally located oxopropionyl residue. Epicidin 280 produced by the heterologous host Staphylococcus carnosus TM 300 after introduction of eciIAPBC (i.e., no eciO was present) behaved homogeneously during reverse-phase chromatography.
- Published
- 1998
28. Release of nitrous oxide (N2O) from denitrifying activated sludge caused by H2S-containing wastewater: quantification and application of a new mathematical model
- Author
-
Manfred Rizzi, Karlheinz Krauth, Jörg W. Metzger, Ruxandra Rehner, and Barbara Schönharting
- Subjects
Environmental Engineering ,Water Science and Technology - Abstract
A new mathematical model is presented which describes the denitrification process by dynamic material balance equations. In this approach the kinetic rate expressions of the single denitrification steps and the observed strong inhibition of nitrate on nitrite and nitrous oxide reduction are based exclusively on fundamental enzyme kinetics. This allows a prediction of the denitrification process in a wide range of wastewater-relevant nitrate concentrations. The model was successfully applied to the description of the kinetic behavior of a standardized denitrifying activated sludge system. Furthermore the experimentally investigated influence of hydrogen sulfide was quantified by extending the model with a non-competitive inhibition mechanism involving all steps of the denitrification process. The inhibitory effect was related to the free membrane-permeable hydrogen sulfide concentration. This means that the extent of its inhibition depends additionally on the pH-value. Even very low hydrogen sulfide concentrations lead to a strong inhibition of nitrous oxide reduction and therefore to a high release of nitrous oxide from wastewater treatment plants.
- Published
- 1998
29. Spirofungin, a New Antifungal Antibiotic from Streptomyces violaceusniger Tue 4113
- Author
-
Alexandra Höltzel, Hans-Peter Fiedler, Jörg W. Metzger, Christoph Kempter, Thomas Fritz, Ingrid Groth, and Günther Jung
- Subjects
Pharmacology ,Antifungal ,Antifungal Agents ,Molecular Structure ,biology ,Chemistry ,Streptomycetaceae ,Antifungal antibiotic ,medicine.drug_class ,Microbial Sensitivity Tests ,Secondary metabolite ,biology.organism_classification ,Streptomyces ,Microbiology ,Streptomyces violaceusniger ,Yeasts ,Fermentation ,Drug Discovery ,medicine ,Spiro Compounds ,Actinomycetales ,Chromatography, High Pressure Liquid ,Bacteria ,medicine.drug - Abstract
A new secondary metabolite was detected in the culture filtrate and extracts of Streptomyces violaceusniger Tü 4113 by HPLC-diode-array and HPLC-electrospray-mass-spectrometry screening. The compound named spirofungin has a polyketide-spiroketal structure and shows various antifungal activities, particularly against yeasts.
- Published
- 1998
30. MS-Pep: a computer program for the interpretation of mass spectra of peptide libraries
- Author
-
K. H. Wiesmüller, Jente Brünjes, Jörg W. Metzger, Günther Jung, and Stefan Kienle
- Subjects
chemistry.chemical_classification ,Electrospray ,Chromatography ,Qualitative analysis ,Mass distribution ,Computer program ,Chemistry ,Peptide spectral library ,Mass spectrum ,Peptide ,Mass spectrometry ,Biochemistry ,Combinatorial chemistry - Abstract
Electrospray mass spectrometry (ESI-MS) is an established method for the qualitative analysis of synthetic peptide libraries and combinatorial mixtures or collections of small organic compounds. However, the calculation of the mass distribution of even small peptide mixtures is a time-consuming and error-proned task. Therefore, the computer program MS-Pep has been developed, which calculates the masses of expected peptides, byproducts and the mass distributions of peptide libraries.
- Published
- 1997
31. Isolation and Analysis of Moenomycin and Its Biosynthetic Intermediates from Streptomyces ghanaensis (ATCC 14672) Wildtype and Selected Mutants
- Author
-
Wolfgang Wohlleben, Jörg W. Metzger, Bhavani Subramaniam-Niehaus, and Thomas Schneider
- Subjects
Molecular Structure ,Ultraviolet Rays ,Chemistry ,Stereochemistry ,Molecular Sequence Data ,Mutant ,Mutagenesis ,Wild type ,Biological activity ,Streptomyces ghanaensis ,High-performance liquid chromatography ,Streptomyces ,General Biochemistry, Genetics and Molecular Biology ,Anti-Bacterial Agents ,chemistry.chemical_compound ,Bambermycins ,Carbohydrate Sequence ,Biosynthesis ,Solid phase extraction ,Chromatography, High Pressure Liquid - Abstract
Streptomyces ghanaensis (ATCC 14672) produces the phosphoglycolipid antibiotic moenomycin consisting of several components. A solid phase extraction procedure was developed which allowed a rapid isolation of both moenomycin and its biosynthetic intermediates from culture filtrates. Semi-preparative high performance liquid chromatography followed by high performance liquid chromatographv-mass spectrometry provided structural data on the different moenomycin components. In order to obtain initial information on the biosynthetic pathway, moenomycin non-producing mutants were isolated. They were shown to release intermediates with shorter lipid chains suggesting that the lipid chain synthesis probably takes place at a later stage of the moenomycin biosynthesis. Based on the biological activity and the analytical data, we assume that a modification and in particular a shorter lipid portion drastically influences the inhibitory activity of this antibiotic.
- Published
- 1997
32. CDA: Calcium-Dependent Peptide Antibiotics fromStreptomyces coelicolor A3(2) Containing Unusual Residues
- Author
-
Günther Jung, Dietmar Kaiser, Heinrich Decker, Jörg W. Metzger, Hans Zähner, Tilmann Walk, Volker Gnau, Sabine Haag, Graeme J. Nicholson, Christoph Kempter, and Karl Heinz Gierling
- Subjects
chemistry.chemical_classification ,biology ,medicine.drug_class ,Streptomyces coelicolor ,Antibiotics ,Peptide ,General Medicine ,General Chemistry ,biology.organism_classification ,Calcium dependent ,Catalysis ,chemistry ,Biochemistry ,medicine - Published
- 1997
33. Calcium-abhängige Peptidantibiotika mit ungewöhnlichen Bausteinen ausStreptomyces coelicolor A3(2)
- Author
-
Graeme J. Nicholson, Karl Heinz Gierling, Heinrich Decker, Jörg W. Metzger, Tilmann Walk, Volker Gnau, Christoph Kempter, S. Haag, Hans Zähner, Günther Jung, and Dietmar Kaiser
- Subjects
Chemistry ,General Medicine - Published
- 1997
34. [Untitled]
- Author
-
Wolfgang J. Haap, Jörg W. Metzger, Günther Jung, and Christoph Kempter
- Subjects
Chromatography ,Protein mass spectrometry ,Tandem ,Chemistry ,Component (thermodynamics) ,Aryl ,Organic Chemistry ,Selected reaction monitoring ,Analytical chemistry ,Ether ,General Medicine ,Composition (combinatorics) ,Catalysis ,Sample preparation in mass spectrometry ,Inorganic Chemistry ,chemistry.chemical_compound ,Drug Discovery ,Physical and Theoretical Chemistry ,Molecular Biology ,Information Systems - Abstract
Electrospray mass spectrometry (ESI-MS), tandem massspectrometry and on-line RP-HPLC-ESI-MS were used toevaluate the composition and purity of three differentaryl ether mixtures consisting of 10 and 45 arylethers synthesized on solid support by Williamsonetherification. The libraries feature two potentialpharmacophores connected with three different spacersand serve as models for a detailed component analysis.Individual members of the library and by-products wereidentified rapidly and conveniently by product ionscans. Compound collections obtained by two differentsynthetic methods, the split/combine approach and thepremix method, showed different mass distributions inthe ESI-MS spectra. Some components were not detectedin direct ESI-MS measurements, but were found by MS/MSexperiments. Precursor ion and constant neutral lossscans allowed the identification of components withcommon structural features.
- Published
- 1997
35. Estrogenic activity of constituents of underarm deodorants determined by E-Screen assay
- Author
-
Claudia Lange, Jörg W. Metzger, and Bertram Kuch
- Subjects
Preservative ,Environmental Engineering ,Health, Toxicology and Mutagenesis ,medicine.medical_treatment ,Parabens ,Pharmacology ,Gas Chromatography-Mass Spectrometry ,Cell Line, Tumor ,Germany ,medicine ,Environmental Chemistry ,Humans ,Food science ,Deodorants ,Estradiol ,Chemistry ,Public Health, Environmental and Occupational Health ,Biological activity ,Estrogens ,General Medicine ,General Chemistry ,E-SCREEN ,Pollution ,Aquatic environment ,Deodorant ,Estrogenic Effects ,Female ,Cancer cell lines ,Human breast - Abstract
The purpose of this study was to ascertain whether different kinds of underarm deodorants commercially available in Germany might contain substances with estrogenic potential which after use enter the aquatic environment via wastewater. Twenty five deodorants produced by ten different manufacturers in the form of sprays, roll-ons and sticks were investigated using an in vitro -test system (E-Screen assay) for the determination of estrogenic activity based on the human breast cancer cell line MCF-7. Seven out of ten spray deodorant samples showed a quantifiable estrogenic activity. In the case of the sticks and roll-ons it was only one out of six and one out of nine, respectively. The 17β-estradiol equivalent concentrations (EEQs) of the samples ranged from 0.1 ng g − 1 to 9 ng g − 1 deodorant. Spray deodorant samples showed the highest activities in the E-Screen assay compared to the stick and roll-on deodorants. In order to identify substances possibly contributing to the observed biological activity the samples were additionally analyzed by GC/MS. The obtained results of this non-target screening led to the selection of 62 single substances present in the deodorants which for their part were analyzed by E-Screen assay. Eight of these single substances, all of them fragrances, showed estrogenic effects with estradiol equivalence factors (EEFs) similar to parabens, a group of 4-hydroxybenzoic acid esters commonly used as preservatives in personal care products, which are known to have a slight estrogenic effect. Thus, these fragrances are obviously responsible to a substantial degree for the observed estrogenic activity of the deodorants.
- Published
- 2013
36. SchussenAktivplus: reduction of micropollutants and of potentially pathogenic bacteria for further water quality improvement of the river Schussen, a tributary of Lake Constance, Germany
- Author
-
Sabrina Giebner, Michael Weyhmüller, Hans Güde, Claudia Lange, Bertram Kuch, Markus Spieth, Klaus Amler, Herbert Löffler, Raphaela Osterauer, Jörg Oehlmann, Katharina Peschke, Magali Rault, Sven Kneipp, Ludek Blaha, Marco Scheurer, Merav Seifan, Stefanie Krais, Michael Muller, Anja Henneberg, Jürgen Raizner, Doreen Richter, Ralph-Michael Jung, Harald Hetzenauer, Jutta Schneider-Rapp, Heinz-R. Köhler, Stefanie Hess, Rita Triebskorn, Frank Sacher, Peter Rey, Jörg W. Metzger, Hans-Joachim Vogel, Josef Winter, Karl Wurm, Claudia Gallert, Diana Maier, and Klaus Jedele
- Subjects
Hydrology ,021110 strategic, defence & security studies ,geography ,geography.geographical_feature_category ,Ecology ,Stormwater ,0211 other engineering and technologies ,02 engineering and technology ,010501 environmental sciences ,01 natural sciences ,Pollution ,6. Clean water ,13. Climate action ,ddc:570 ,Tributary ,Environmental science ,Sewage treatment ,Catchment area ,Water quality ,0105 earth and related environmental sciences - Abstract
The project focuses on the efficiency of combined technologies to reduce the release of micropollutants and bacteria into surface waters via sewage treatment plants of different size and via stormwater overflow basins of different types. As a model river in a highly populated catchment area, the river Schussen and, as a control, the river Argen, two tributaries of Lake Constance, Southern Germany, are under investigation in this project. The efficiency of the different cleaning technologies is monitored by a wide range of exposure and effect analyses including chemical and microbiological techniques as well as effect studies ranging from molecules to communities.
- Published
- 2013
37. Isolation, identification and stability of 8-desacetylmatricine, a new degradation product of matricine
- Author
-
Jörg W. Metzger, Andrea Ness, and Peter C. Schmidt
- Subjects
Chamazulene carboxylic acid ,Aqueous solution ,Chromatography ,Chemistry ,Chamazulene ,Decomposition ,law.invention ,Steam distillation ,chemistry.chemical_compound ,law ,Matricaria recutita ,Product (mathematics) ,Molecular Medicine ,Degradation (geology) ,General Pharmacology, Toxicology and Pharmaceutics - Abstract
Matricine, a genuine compound of chamomile, is unstable under acid conditions. Upon steam distillation it is readily converted into chamazulene carboxylic acid and further on into chamazulene. In the present work stability tests were performed in the pH-range between 4 and 10. The decomposition of matricine in aqueous pH adjusted and in buffered solutions was monitored using an isocratic HPLC-method. In buffered solutions of pH 4 to 6 stored at room temperature for several days chamazulene carboxylic acid was found to be the first intermediate degradation product. In alkaline solutions of pH 8 to 10 however, 8-desacetyl-matricine was observed as a new degradation product. This compound was identified by UV, IR, MS and 1H-NMR. A log κ/pH-profile of matricine was established showing a stability optimum at pH 8.
- Published
- 1996
38. Thioenols from Peptidyl Cysteines: Oxidative Decarboxylation of a13C-Labeled Substrate
- Author
-
Thomas Kupke, Jörg W. Metzger, Günther Jung, Dietmar Kaiser, and Christoph Kempter
- Subjects
Chemistry ,Polymer chemistry ,Substrate (chemistry) ,Organic chemistry ,General Medicine ,General Chemistry ,Catalysis ,Oxidative decarboxylation - Published
- 1996
39. Thioenole aus Peptidyl-Cysteinen: oxidative Decarboxylierung eines13C-markierten Substrats
- Author
-
Thomas Kupke, Christoph Kempter, Günther Jung, Dietmar Kaiser, and Jörg W. Metzger
- Subjects
Chemistry ,General Medicine - Published
- 1996
40. Betacyanins from plants and cell cultures of Phytolacca americana
- Author
-
Richard W. Joy, Jörg W. Metzger, Atsushi Komamine, Manfred Nimtz, Victor Wray, Dieter Strack, and Willibald Schliemann
- Subjects
Indoles ,Magnetic Resonance Spectroscopy ,Molecular Sequence Data ,Plant Science ,Horticulture ,Biology ,Biochemistry ,Mass Spectrometry ,chemistry.chemical_compound ,Pigment ,Betalain ,Botany ,Phytolacca americana ,Betacyanins ,Glycosides ,Molecular Biology ,Cells, Cultured ,Chromatography, High Pressure Liquid ,Betanin ,Molecular Structure ,food and beverages ,Ripening ,Pigments, Biological ,General Medicine ,Plants ,biology.organism_classification ,Phytolaccaceae ,Carbohydrate Sequence ,chemistry ,Cell culture ,visual_art ,visual_art.visual_art_medium - Abstract
Betacyanins from cell cultures of Phytolacca americana were characterized and compared with those of the stems and ripening fruits of the plant. Whereas in fruits prebetanin (betanin 6'-O-sulphate) and its isoform predominate, in the stem and cell cultures feruloylated derivatives occur as the major components. These were rigorously identified by various spectroscopic techniques (DAD-HPLC, NMR, LC-MS and electrospray MS-MS) and carbohydrate analyses as betanidin 5-O-[(5"-O-E-feruloyl)-2'-O-beta-D-apiofuranosyl] -beta-D-glucopyranoside, a new betacyanin of higher plants, and betanidin 5-O-(6'-O-E-feruloyl)-beta-D-glucopyranoside (lampranthin II), together with their isoforms.
- Published
- 1996
41. Kanchanamycins, New Polyol Macrolide Antibiotics Produced by Streptomyces olivaceus Tue 4018. II. Structure Elucidation
- Author
-
Holger Stephan, Christoph Kempter, Günther Jung, Olivier Potterat, Jörg W. Metzger, Hans-Peter Fiedler, and Christoph Pfefferle
- Subjects
Pharmacology ,chemistry.chemical_classification ,Magnetic Resonance Spectroscopy ,biology ,Streptomycetaceae ,Stereochemistry ,Nuclear magnetic resonance spectroscopy ,biology.organism_classification ,Streptomyces ,Anti-Bacterial Agents ,Lactones ,chemistry.chemical_compound ,Heteronuclear molecule ,chemistry ,Polyol ,Drug Discovery ,Hemiacetal ,Macrolides ,Heteronuclear single quantum coherence spectroscopy ,Lactone ,Antibacterial agent - Abstract
Kanchanamycins are a new group of polyol macrolide antibiotics isolated from Streptomyces olivaceus Tü 4018. They all share a common bicyclic carbon skeleton formed by a 36-membered lactone ring and a 6-membered hemiacetal ring. A feature unusual for that class of macrolides is the terminal urea moiety observed in kanchanamycin A. The structures of the kanchanamycins were determined by electrospray MS and modern 2D NMR techniques. Due to substantial overlap of the signals intensive use of inverse detected heteronuclear correlation experiments (HSQC, HMBC, 2D-HSQC-TOCSY) was made.
- Published
- 1996
42. β-Glucosylarginine: a new glucose-protein bond in a self-glucosylating protein from sweet corn
- Author
-
Jörg W. Metzger, William J. Whelan, Wieslawa M. Lomako, Helmut E. Meyer, David G. Singh, Maria Serwe, and Joseph Lomako
- Subjects
Glycosylation ,Glycogenin ,Arginine ,Molecular Sequence Data ,Biophysics ,Zea mays ,Biochemistry ,Mass Spectrometry ,Homology (biology) ,Autocatalysis ,chemistry.chemical_compound ,Glucosides ,Structural Biology ,Amylogenin ,Autoglucosylation ,Enzyme Stability ,Carbohydrate Conformation ,Genetics ,Trypsin ,Amino Acid Sequence ,Amino Acids ,Intramolecular Transferases ,Molecular Biology ,Peptide sequence ,Glycoproteins ,Plant Proteins ,Sequence Homology, Amino Acid ,Molecular mass ,Glycogen ,Chemistry ,food and beverages ,Cell Biology ,Chromatography, Agarose ,Glucose ,Self-glucosylating protein ,β-Glucosylarginine ,Peptides ,Sequence Analysis ,Glucose & Protein - Abstract
In the search for a protein primer for starch synthesis, an autocatalytic self-glucosylating protein has been isolated from sweet corn. Several tryptic peptides were obtained from the [14C]glucosylated protein and were sequenced, corresponding to over 40% of the estimated total sequence (molecular mass 42 kDa). There is no homology with the amino acid sequence of the autocatalytic glycogen primer, glycogenin, nor in respect of the nature of the union between the autocatalytically added glucose and the protein, which, in the case of the corn protein, now named amylogenin, is a novel glucose-protein bond, a single β-glucose residue joined to an arginine residue.
- Published
- 1995
43. Sequence Analysis by NMR Spectroscopy of the Peptide Lantibiotic Epilancin K7 from Staphylococcus epidermidis K7
- Author
-
Angelika Frey, Ruud N.H. Konings, Lennard M. Horstink, Cornelis W. Hilbers, Mart Van De Kamp, Jörg W. Metzger, Henno W. van den Hooven, Frank J. M. Van De Ven, and Hans-Georg Sahl
- Subjects
Alanine ,Magnetic Resonance Spectroscopy ,Molecular Structure ,Edman degradation ,Stereochemistry ,Sequence analysis ,Molecular Sequence Data ,Protein primary structure ,Nuclear magnetic resonance spectroscopy ,Biochemistry ,Anti-Bacterial Agents ,chemistry.chemical_compound ,Bacteriocins ,chemistry ,Staphylococcus epidermidis ,Organic chemistry ,Amino Acid Sequence ,Peptides ,Peptide sequence ,Two-dimensional nuclear magnetic resonance spectroscopy ,Lanthionine - Abstract
The amino acid sequence of the novel lantibiotic epilancin K7 from Staphylococcus epidermidis K7 was determined by NMR spectroscopy. NMR spectroscopy was used because sequencing by conventional Edman degradation techniques was prohibited by internal sequence blocks owing to the presence of modified residues. Epilancin K7 consists of 31 residues, including two alpha,beta-didehydroalanine (one-letter code U) and two alpha,beta-didehydrobutyrine (O) residues, one lanthionine (A-S-A), two beta-methyllanthionines (A*-S-A), and six lysines. Epilancin K7 has a molecular mass of 3032 +/- 1.5 Da. The amino acid sequence of epilancin K7 was derived from both through-space dipolar proton-proton interactions and through-bond scalar proton-carbon interactions as detected by two-dimensional 1H-NOESY, 1H-ROESY and three-dimensional 1H-TOCSY-NOESY, and by two-dimensional 1H,13C-heteronuclear multiple-bond correlation spectroscopy, respectively. The sequence is as follows: [sequence: see text] The N-terminal residue X partly resembles an alanine but its exact nature is unclear. The organization of the sulfide-bridge-containing (beta-methyl-)lanthionines was revealed by 1H-NMR and 1H,13C-NMR spectroscopy. Epilancin K7 has a linear structure and a high positive net charge, and therefore is classified as a type-A lantibiotic. NMR analysis of a degraded though still active form of epilancin K7 showed that two N-terminal residues of epilancin K7 were missing, owing to decomposition at the alpha,beta-didehydro alanine at position 3; it was called the epilancin K7-(3-31)-peptide (peptide fragment of epilancin K7 consisting of positions 3-31). The usefulness of three-dimensional 1H-TOCSY-NOESY, and two-dimensional 1H,13C-heteronuclear multiple-bond correlation spectroscopy at natural abundance for the study of (modified) polypeptides is demonstrated.
- Published
- 1995
44. Biosynthetic Capacities of Actinomycetes. 4. Echinoserine, a New Member of the Quinoxaline Group, Produced by Streptomyces tendae
- Author
-
Günther Jung, Sabine Blum, Graeme J. Nicholson, Jörg W. Metzger, Hans-Peter Fiedler, Ingrid Groth, Holger Stephan, and Christoph Kempter
- Subjects
Pharmacology ,Antibiotics, Antineoplastic ,biology ,Stereochemistry ,Structural similarity ,Streptomycetaceae ,Chemical structure ,Echinomycin ,Microbial Sensitivity Tests ,Tandem mass spectrometry ,biology.organism_classification ,Streptomyces ,chemistry.chemical_compound ,Quinoxaline ,chemistry ,Fermentation ,Drug Discovery ,Actinomycetales ,Chromatography, High Pressure Liquid - Abstract
A new member of the quinoxaline group antibiotics has been detected by HPLC-diode-array screening. The main compound produced by Streptomyces tendae strain Tü 4031 showed a high degree of similarity in the UV-visible spectral region with echinomycin and their structural similarity was confirmed by structure elucidation using electron tandem mass spectrometry and 2D nuclear magnetic resonance. The new compound, named echinoserine, is a non-cyclic form of echinomycin, but it is not a biosynthetic precursor. Echinoserine is less antibiotically active than echinomycin.
- Published
- 1995
45. Electrospray Mass Spectrometry and Multiple Sequence Analysis of Synthetic Peptide Libraries
- Author
-
Günther Jung, Stefan Stevanovic, Jörg W. Metzger, Jente Brünjes, and Karl-Heinz Wiesmüller
- Subjects
chemistry.chemical_classification ,Chromatography ,Edman degradation ,Protein mass spectrometry ,Sequence analysis ,Electrospray mass spectrometry ,Chemistry ,Peptide ,Tandem mass spectrometry ,Combinatorial chemistry ,General Biochemistry, Genetics and Molecular Biology ,Sample preparation in mass spectrometry ,Isobaric labeling ,Molecular Biology - Abstract
The determination of the composition and purity of synthetic combinatorial libraries of free peptides requires analytical techniques that are especially suited for the challenging task of mixture analysis. Qualitative and semi-quantitive information on the composition of complex mixtures can be obtained by electrospray mass spectrometry with a maximum of reliability, accuracy, and fastness. Especially in combination with tandem mass spectrometry, contaminations with by-products (e.g., peptides with uncleaved side-chain protecting groups) can be easily revealed. Multiple sequence analysis based on Edman degradation allows a quantitative determination of the composition of libraries as well as the determination of coupling efficiencies during the synthesis of a library.
- Published
- 1994
46. Betacyanins from bracts of Bougainvillea glabra
- Author
-
Manfred Nimtzt, Jörg W. Metzger, Sabine Richter, Susanne Heuer, Victor Wray, and Dieter Strack
- Subjects
Dihydropyridines ,Indoles ,Magnetic Resonance Spectroscopy ,Flavonols ,Molecular Sequence Data ,Betalains ,Plant Science ,Horticulture ,Biochemistry ,Gas Chromatography-Mass Spectrometry ,Mass Spectrometry ,chemistry.chemical_compound ,Betalain ,Botany ,Caffeic acid ,Betacyanins ,Glycosides ,Molecular Biology ,Chromatography, High Pressure Liquid ,Flavonoids ,chemistry.chemical_classification ,Bract ,biology ,General Medicine ,Plants ,biology.organism_classification ,Carbohydrate Sequence ,chemistry ,Quercetin ,Bougainvillea glabra ,Kaempferol - Abstract
Betacyanins from the bracts of Bougainvillea glabra were isolated and characterized by a combination of spectroscopic techniques (DAD-HPLC, NMR, LC-MS, GC-MS, electrospray MS, tandem MS) as gomphrenin I (betanidin 6-O-beta-glucoside) and various derivatives of bougainvillein-v (betanidin 6-O-beta-sophoroside), i.e. mono- and diglucosylsophorosides which are acylated with 4-coumaric and caffeic acid (mono- and diesters). Besides the betacyanins, B. glabra bracts accumulated large amounts of flavonols (kaempferol and quercetin conjugates) reaching ratios of flavonol to betacyanin of 1:1.
- Published
- 1994
47. Effects of supplied cinnamic acids and biosynthetic intermediates on the anthocyanins accumulated by wild carrot suspension cultures
- Author
-
David C. Baker, A. Rose, Jörg W. Metzger, Werner E. Gläßgen, Donald K. Dougall, S. C. Johnson, and Hanns Ulrich Seitz
- Subjects
chemistry.chemical_classification ,Cyanidin ,Flavonoid ,Plant physiology ,Horticulture ,Biology ,biology.organism_classification ,Cinnamic acid ,Tissue culture ,chemistry.chemical_compound ,Biochemistry ,chemistry ,Anthocyanin ,Caffeic acid ,Daucus carota - Abstract
Anthocyanins isolated and characterized from the wild carrot suspension cultures used here were 3-O-β-D-glucopyranosyl-(1→6)-[β-D-xylopyranosyl-(1→2)-]β-D
- Published
- 1994
48. Metabolic Products of Microorganisms. Part 269. 5-Phenylpentadienoic-acid derivatives fromStreptomycessp
- Author
-
Stefan M.V. Freund, Jörg W. Metzger, Olivier Potterat, and Hans Zähner
- Subjects
chemistry.chemical_classification ,Electrospray ,biology ,Streptomycetaceae ,Stereochemistry ,Chemistry ,Microorganism ,Organic Chemistry ,biology.organism_classification ,Biochemistry ,Streptomyces ,High-performance liquid chromatography ,Catalysis ,Inorganic Chemistry ,Dicarboxylic acid ,Drug Discovery ,Actinomycetales ,Physical and Theoretical Chemistry ,Bacteria - Abstract
Two new phenylpentadienamides isolated from the culture filtrate of Streptomyces sp. were assigned the structures 5-(4-aminophenyl)penta-2,4-dienamide (2) and N2-[5-(4-aminophenyl)penta-2,4-dienoyl]-L-glutamine (3). In addition, 5-(4-aminophenyl)penta-2,4-dienoic acid (1) has been isolated, and its spectroscopic characteristics are reported for the first time. Compounds 1–3 exist in both the (2E,4E)- and (2E,4Z)-configurations. Electrospray and tandem MS, and HPLC/MS proved to be particularly suitable for the characterization of these metabolites.
- Published
- 1994
49. Lipopeptide-Polyoxyethylene Conjugates as Mitogens and Adjuvants
- Author
-
Karl-Heinz Wiesmüller, Bernhard Kleine, Jörg W. Metzger, Werner Beck, Wolfgang G. Bessler, Günter Jung, Matthias Edinger, Ravshan Ataulakhanov, and Wolfgang Rapp
- Subjects
Male ,Lipoproteins ,medicine.medical_treatment ,Immunology ,B-Lymphocyte Subsets ,Enzyme-Linked Immunosorbent Assay ,Biology ,medicine.disease_cause ,Polyethylene Glycols ,Mice ,chemistry.chemical_compound ,Adjuvants, Immunologic ,In vivo ,Albumins ,medicine ,Animals ,Humans ,Immunology and Allergy ,Antigens ,Escherichia coli ,Cells, Cultured ,Mice, Inbred BALB C ,Lipopeptide ,Biological activity ,Hematology ,biology.organism_classification ,Melitten ,Enterobacteriaceae ,In vitro ,chemistry ,Biochemistry ,biology.protein ,Female ,Mitogens ,Antibody ,Adjuvant ,Spleen - Abstract
Two lipopeptide analogues of the Escherichia coli lipoprotein rendered water-soluble by polyoxyethylene were tested for mitogenicity in vitro in murine and human B lymphocytes and for adjuvant activity in vivo in mice. These highly amphiphilic lipopeptides retained the biological activity other lipopeptides usually exerted which supports the hypothesis of specific interactions of lipopeptides with membranes of reactive cells. The activation of human B lymphocytes by these lipopeptides was much less pronounced compared to that of murine cells. However, given in combination with anti-CD40 antibodies plus interleukin-4, human B lymphocytes could synergistically be stimulated to proliferate. As an adjuvant, the polyoxyethylene linked lipopeptides were almost as potent as Freund's adjuvants and other basic lipopeptides. Being water-soluble, these novel analogues are easy to apply and they are suitable for field studies as adjuvants when sonication can not usually be provided.
- Published
- 1994
50. Identification of the reaction products of rosmarinic acid synthase from cell cultures ofColeus blumei by ion spray mass spectrometry and tandem mass spectrometry
- Author
-
Jörg W. Metzger and Maike Petersen
- Subjects
chemistry.chemical_classification ,Chromatography ,Rosmarinic acid ,Plant Science ,General Medicine ,Mass spectrometry ,Tandem mass spectrometry ,Biochemistry ,High-performance liquid chromatography ,Analytical Chemistry ,Catalysis ,chemistry.chemical_compound ,Enzyme ,Complementary and alternative medicine ,Biosynthesis ,chemistry ,Drug Discovery ,Molecular Medicine ,Moiety ,Food Science - Abstract
Different substrates were used in reaction assays for rosmarinic acid synthase, an enzyme involved in rosmarinic acid biosynthesis in cell cultures of Coleus blumei. In order to introduce the cinnamoyl moiety of the ester, 4-coumaroyl-CoA and caffeoyl-CoA were applied as substrates; for the hydroxyphenyllactic acid moiety, 4-hydroxyphenyllactate and 3,4-dihydroxyphenyllactate were used. Four different reaction products were thus produced and these were analysed by ion spray mass spectrometry and tandem mass spectrometry after purification by semi-preparative high pressure liquid chromatography. The molecular masses and the fragmentation patterns obtained by tandem mass spectrometry of the reaction products formed by the catalysis of rosmarinic acid synthase were in agreement with the structures of rosmarinic acid (caffeoyl-3′,4′-dihydroxyphenyllactate) and rosmarinic acid-like esters (4-coumaroyl-4′-hydroxyphenyllactate, 4-coumaroyl-3′,4′-dihydroxyphenyllactate, caffeoyl-4′-hydroxyphenyllactate) as expected for the substrates used in the enzyme reaction.
- Published
- 1993
Catalog
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