当前位置： SCI文献检索 > APPLIED AND ENVIRONMENTAL MICROBIOLOGY期刊下所有文献 > Degradation pathway of bisphenol A: does ipso substitution apply to phenols containing a quaternary alpha-carbon structure in the para position?

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

Abstract：

:The degradation of bisphenol A and nonylphenol involves the unusual rearrangement of stable carbon-carbon 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 II 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)O(2) atmosphere were performed. One atom of (18)O(2) 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 alpha-carbon.

journal_name

Appl Environ Microbiol

journal_title

Applied and environmental microbiology

authors

Kolvenbach B,Schlaich N,Raoui Z,Prell J,Zühlke S,Schäffer A,Guengerich FP,Corvini PF

doi

10.1128/AEM.00329-07

subject

Has Abstract

pub_date

2007-08-01 00:00:00

pages

4776-84

issue

eissn

0099-2240

issn

1098-5336

pii

AEM.00329-07

journal_volume

pub_type

杂志文章

在线工具

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