%0 Journal Article
%A Gabriel, F. L. P.
%A Routledge, E.J.
%A Heidlberger, A.
%A Rentsch, D.
%A Günther, K.
%A Giger, W.
%A Sumpter, J.P.
%A Kohler, H.-P.E.
%T Isomer-specific degradation and endocrine disrupting activity of nonylphenols
%J Environmental Science & Technology
%V 42
%@ 0013-936X
%C Columbus, Ohio
%I American Chemical Society
%M PreJuSER-432
%P 6399 - 6408
%D 2008
%Z This research was supported by the Swiss National Science Foundation within the framework of the National Research Programme NFP50 "Endocrine Disruptors: Relevance to Humans, Animals, and Ecosystems". We thank Dr. Ian Purvis and others at GlaxoSmithKline for kindly supplying the genetically modified yeast strain.
%X Degradation of technical nonylphenol by Sphingobium xenophagum Bayram led to a significant shift in the isomers composition of the mixture. By means of gas chromatography-mass spectrometry, we could observe a strong correlation between transformation of individual isomers and their a-substitution pattern, as expressed by their assignment to one of six mass spectrometric groups. As a rule, isomers with less bulkiness at the a-carbon and those with an optimally sized main alkyl chain (4-6 carbon atoms) were degraded more efficiently. By mass spectrometric analysis, we identified the two most recalcitrant main isomers of the technical mixture (Group4) as 4-(1,2-dimethyl-1-propylbutyl) phenols (NP193a and NP193b, which are diastereomers with a bulky alpha-CH3, alpha-CH(CH3)C2H5 substitution. Our experiments with strain Bayram show that the selective enrichment of isomers with bulky a-substitutions observed in nonylphenol fingerprints of natural systems can be caused by microbial ipso-hydroxylation. Based on the yeast estrogen assay (YES), we established an estrogenicity ranking with a variety of single isomers and compared it to rankings obtained with different reporter cell systems. Structure-activity relationships derived from these data suggest that Group 4 isomers have a high estrogenic potency. This indicates a substantial risk that enrichment of highly estrogenic isomers during microbial degradation by ipso-substitution will increase the specific estrogenicity of aging material.
%K J (WoSType)
%F PUB:(DE-HGF)16
%9 Journal Article
%U <Go to ISI:>//WOS:000258883300019
%$ pmid:18800507
%R 10.1021/es800577a
%U https://juser.fz-juelich.de/record/432