22377
2010
eng
1241
1245
10
80
article
Elsevier Science
Kidlington, Oxford
1
--
--
--
Enantiomer-specific analysis of hexabromocyclododecane in fish from Etnefjorden (Norway)
High-performance liquid chromatography tandem mass spectrometry (HPLC–MS/MS) was applied to sterospecifically quantify the content of α-, β-, and γ-hexabromocyclododecane (HBCD) in six fish species from the Norwegian Etnefjorden. A combination of a β-PM cyclodextrin and an achiral column enabled the paired chromatographic separation of the stereoisomers in the order (-)-α-, (+)-α-, (-)-β-, (+)-β-, (+)-γ- and, (-)-γ-HBCD. The limits of detection were in the range of 6–21 pg g-1 depending on the stereoisomer and the concentrations of α-, β-, and γ-HBCD in fillets ranged from <5.4 ng g-1 to 11.1 µg g-1 lipid weight. α-HBCD enantiomers were throughout dominating, and in most cases the accumulation of the respective first eluted enantiomers ((-)-α-, (-)-β- and (+)-γ-HBCD) was observed. Deviations from the racemic EF-value were considered to be significant if it was outside of the expanded uncertainty range for each of the racemic HBCD-ratios. The composition of HBCD isomers varied between the investigated fish species and the relative high values for the γ-HBCD concentrations for the bottom-dwellers flounder and thorny skate seems to echo the HBCD pattern of ocean sediments.
Chemosphere
24898
10.1016/j.chemosphere.2010.06.019
0045-6535
0366-7111
Sonderstandort: Publica-Schrank
18.11.2010
Robert Köppen
Roland Becker
Susanne Esslinger
Irene Nehls
eng
uncontrolled
Flame retardant
eng
uncontrolled
Diastereomers
eng
uncontrolled
Chiral separation
eng
uncontrolled
Bioaccumulation
eng
uncontrolled
Enantiomeric fraction
Verlagsliteratur
Physisches Exemplar in der Bibliothek der BAM vorhanden ("Hardcopy Access")
23173
2010
eng
9705
9710
17
58
article
American Chemical Society
Columbus, Ohio
1
--
--
--
HBCD stereoisomer pattern in mirror carps following dietary exposure to pure Gamma-HBCD enantiomers
Journal of agricultural and food chemistry
25744
10.1021/jf101469q
0021-8561
1520-5118
Sonderstandort: Publica-Schrank
07.02.2011
Susanne Esslinger
Roland Becker
A. Müller-Belecke
Wolfram Bremser
Christian Jung
Irene Nehls
eng
uncontrolled
Enantiomer-specific determination
eng
uncontrolled
HPLC-MS/MS
eng
uncontrolled
Brominated flame retardant
eng
uncontrolled
Fish feeding experiment
eng
uncontrolled
Enantiomer fraction
eng
uncontrolled
Bioisomerization
Verlagsliteratur
Physisches Exemplar in der Bibliothek der BAM vorhanden ("Hardcopy Access")
23837
2011
eng
3938
3944
9
45
article
ACS Publ.
Washington, DC
American Chemical Society
1
--
--
--
Hexabromocyclododecane enantiomers: microsomal degradation and patterns of hydroxylated metabolites
The degradation of the enantiomers of α-, β-, and γ-hexabromocyclododecane (HBCD) by phase I metabolism was investigated using induced rat liver microsomes. HBCD isomers were quantified using HPLC-MS/MS (ESI-) after separation on a combination of a reversed phase and a chiral analytical column. The degradation of all six isomers followed first-order kinetics and the estimated half-lives ranged from 6.3 min for both β-HBCD enantiomers to 32.3 min in case of (+)-γ-HBCD. (+)-α- and (–)-γ-HBCD displayed significantly shorter half-lives than their corresponding antipodes. It could be shown that this degradation led to a significant enrichment of the first eluting enantiomers (–)-α- and (+)-γ-HBCD. Individual patterns of mono- and dihydroxylated derivatives obtained from each α- and γ-HBCD enantiomer were seen to be distinctly characteristic. The patterns of monohydroxylated HBCD derivatives detected in liver and muscle tissues of pollack, mackerel and in herring gull eggs were largely similar to those observed in the in vitro experiments with rat liver microsomes. This enabled individual hydroxy-HBCDs to be assigned to their respective parent HBCD enantiomers.
Environmental science & technology
26440
10.1021/es1039584
0013-936X
1520-5851
16.06.2011
Susanne Esslinger
Roland Becker
Ronald Maul
Irene Nehls
eng
uncontrolled
Brominated flame retardant
eng
uncontrolled
Cytochromes
eng
uncontrolled
Phase I metabolism
eng
uncontrolled
Hydroxylation
eng
uncontrolled
HPLC-MS/MS
Verlagsliteratur
Datei im Netzwerk der BAM verfügbar ("Closed Access")
27263
2011
eng
730
733
73
article
1
--
--
--
Phase I oxidation of alpha- and gamma-hexabromocyclododecane by cytochrome P450 enzymes: simulation of the steroisomerism of hydroxylated metabolites
Organohalogen compounds
30069
http://www.dioxin20xx.org/pdfs/2011/1810.pdf
1026-4892
Sonderstandort: Publica-Schrank
DIOXIN 2011
Brussels, Belgium
2011-08-21
2011-08-24
05.12.2012
O. Scharkoi
Susanne Esslinger
Roland Becker
M. Weber
Irene Nehls
eng
uncontrolled
Bromierte Falmmschutzmittel
eng
uncontrolled
Hexabromcyclododecan
eng
uncontrolled
Cytochrom
eng
uncontrolled
Metaboliten
eng
uncontrolled
HPLC
eng
uncontrolled
Simulation
Verlagsliteratur
Physisches Exemplar in der Bibliothek der BAM vorhanden ("Hardcopy Access")
30492
2015
eng
538
546
7
41
article
Gordon and Breach
New York, NY
1
--
--
--
Predicting sites of cytochrome P450-mediated hydroxylation applied to CYP3A4 and hexabromocyclododecane
This article describes a simple and quick in silico method for the prediction of cytochrome P450 (CYP)-mediated hydroxylation of drug-like compounds. Testosterone and progesterone, two known substrates of CYP3A4, are used to test the method. Further, we apply the procedure to predict sites of hydroxylation of isomers of the flame retardant hexabromocyclododecane by CYP3A4. Within the method, the compound is rotated in the binding pocket of the cytochrome, so that each hydrogen under consideration is placed near the active centre. Afterwards, short molecular dynamics simulations are provided for each step of the rotation. All steps of the simulation are compared concerning the distances between the hydrogens and the active centre and the corresponding energies. The computational results correlate well with experimental results.
Molecular simulation
33466
10.1080/08927022.2014.898845
0892-7022
1029-0435
07.04.2014
O. Scharkoi
Roland Becker
Susanne Esslinger
M. Weber
Irene Nehls
eng
uncontrolled
Predicting sites of metabolism
eng
uncontrolled
Cytochrome P450
eng
uncontrolled
Hydroxylation
eng
uncontrolled
Metabolism of HBCD
Verlagsliteratur
Datei im Netzwerk der BAM verfügbar ("Closed Access")
22907
2010
deu
364
4
22
article
Springer
Heidelberg
Verband für Geoökologie in Deutschland
0
--
--
--
Hexabromcyclododecan - Untersuchungen zum Phase I Metabolismus
Umweltwissenschaften und Schadstoff-Forschung
25467
0934-3504
1865-5084
Sonderstandort: Publica-Schrank
Susanne Esslinger
Roland Becker
Ronald Maul
Irene Nehls
Verlagsliteratur
Physisches Exemplar in der Bibliothek der BAM vorhanden ("Hardcopy Access")
22906
2010
deu
441
4
22
article
Springer
Heidelberg
Verband für Geoökologie in Deutschland
0
--
--
--
Enantiomerenspezifischer Vergleich von HBCD-Gehalten maritimer Lebewesen zweier norwegischer Fjorde
Umweltwissenschaften und Schadstoff-Forschung
25466
0934-3504
1865-5084
Sonderstandort: Publica-Schrank
Susanne Esslinger
Robert Köppen
Roland Becker
Irene Nehls
Verlagsliteratur
Physisches Exemplar in der Bibliothek der BAM vorhanden ("Hardcopy Access")
19911
2009
deu
901
904
9
57
article
Wiley-VCH Verl.
Weinheim
Gesellschaft Deutscher Chemiker
1
--
--
--
Hexabromcyclododecan in heimischen Süßwasserfischen
Hexabromcyclododecan senkt als Flammschutzmittel die Entflammbarkeit von Polymeren und verhindert damit Brände. Als persistente Verbindung reichert es sich in der belebten und in der unbelebten Umwelt an und steht daher im Fokus öffentlichen Interesses.
Nachrichten aus der Chemie
22173
10.1002/nadc.200967612
1439-9598
1521-3854
Sonderstandort: Publica-Schrank
25.09.2009
Robert Köppen
Susanne Esslinger
Roland Becker
Irene Nehls
Verlagsliteratur
Physisches Exemplar in der Bibliothek der BAM vorhanden ("Hardcopy Access")
23351
2011
eng
161
167
2
83
article
Elsevier Science
Kidlington, Oxford
1
--
--
--
Temporal trend (1988-2008) of hexabromocyclododecane enantiomers in herring gull eggs from the german coastal region
Levels of α-, β-, and γ-hexabromocyclododecane (HBCD) were determined in pooled eggs from herring gulls (Larus argentatus) sampled on three bird sanctuaries near the German North Sea coast between 1988 and 2008 (Mellum and Trischen) and the German Baltic Sea coast between 1998 and 2008 (Heuwiese) and archived by the German Environmental Specimen Bank. Pressurized fluid extraction, gel permeation chromatography, and LCMS/MS using 13C12-labelled isotope standards and a chiral column were applied. α-HBCD was the dominating diastereomer and ranged between 3.7 and 107 ng g-1 lw while β- and γ-HBCD were throughout close to LOQ. The highest α-HBCD concentration was found in eggs from Mellum sampled in the year 2000. Interestingly, HBCD in eggs from the three islands displayed similar time courses with levels increasing to a peak contamination around 2000 and decreasing levels ever since. Chiral signatures of α-HBCD in eggs differed among the islands but indicated a preferential enrichment of the first eluting enantiomer (-)-α-HBCD.
Chemosphere
25929
10.1016/j.chemosphere.2010.12.047
0045-6535
0366-7111
17.03.2011
Susanne Esslinger
Roland Becker
Christian Jung
C. Schröter-Kermani
Wolfram Bremser
Irene Nehls
eng
uncontrolled
Brominated flame retardant
eng
uncontrolled
Chiral separation
eng
uncontrolled
HPLC-ESI-MS/MS
eng
uncontrolled
Enantiomer-specific bioaccumulation
Verlagsliteratur
Datei im Netzwerk der BAM verfügbar ("Closed Access")