Accessibility navigation


Degradation pathway of bisphenol A: Does ipso substitution apply to phenols containing a quaternary alpha-carbon structure in the para position?

Kolvenbach, B., Schlaich, N., Raoui, Z., Prell, J., Zuhlke, S., Schaffer, A., Guengerich, F. P. and Corvini, P. F. X. (2007) Degradation pathway of bisphenol A: Does ipso substitution apply to phenols containing a quaternary alpha-carbon structure in the para position? Applied and Environmental Microbiology, 73 (15). pp. 4776-4784. ISSN 0099-2240

Full text not archived in this repository.

It is advisable to refer to the publisher's version if you intend to cite from this work. See Guidance on citing.

To link to this item DOI: 10.1128/aem.00329-07

Abstract/Summary

The degradation of bisphenol A and nonylphenol involves the unusual rearrangement of stable carboncarbon bonds. Some nonylphenol isomers and bisphenol A possess a quaternary alpha-carbon atom as a common structural feature. The degradation of nonylphenol in Sphingomonas sp. strain TTNP3 occurs via a type II ipso substitution with the presence of a quaternary alpha-carbon as a prerequisite. We report here a new degradation pathway of bisphenol A. Consequent to the hydroxylation at position C-4, according to a type 11 ipso substitution mechanism, the C-C bond between the phenolic moiety and the isopropyl group of bisphenol A is broken. Besides the formation of hydroquinone and 4-(2-hydroxypropan-2-yl) phenol as the main metabolites, further compounds resulting from molecular rearrangements consistent with a carbocationic intermediate were identified. Assays with resting cells or cell extracts of Sphingomonas sp. strain TTNP3 under an 18 02 atmosphere were performed. One atom of 180, was present in hydroquinone, resulting from the monooxygenation of bisphenol A and nonylphenol. The monooxygenase activity was dependent on both NADPH and flavin adenine dinucleotide. Various cytochrome P450 inhibitors had identical inhibition effects on the conversion of both xenobiotics. Using a mutant of Sphingomonas sp. strain TTNP3, which is defective for growth on nonylphenol, we demonstrated that the reaction is catalyzed by the same enzymatic system. In conclusion, the degradation of bisphenol A and nonylphenol is initiated by the same monooxygenase, which may also lead to ipso substitution in other xenobiotics containing phenol with a quaternary a-carbon.

Item Type:Article
Refereed:Yes
Divisions:Faculty of Life Sciences > School of Biological Sciences
ID Code:10032
Uncontrolled Keywords:SP STRAIN TTNP3, SPHINGOMONAS-XENOPHAGA BAYRAM, NONYLPHENOL ISOMERS, METABOLIC PATHWAY, MICROBIAL-DEGRADATION, ESTROGENIC ACTIVITY, OXYGEN-ATOM, RIVER WATER, CYTOCHROME-P450, BIODEGRADATION

University Staff: Request a correction | Centaur Editors: Update this record

Page navigation