The mechanism of the reductive dehalogenation of polyhalogenated compounds by microsomal cytochrome P450

Nastainczyk, W; Ahr, HJ; Ulrich, V

HERO ID

699840

Reference Type

Book/Book Chapter

Year

1982

Language

English

PMID

7344494

HERO ID 699840
Year 1982
Title The mechanism of the reductive dehalogenation of polyhalogenated compounds by microsomal cytochrome P450
Book Title Biological reactive intermediates II: Chemical mechanisms and biological effects
Authors Nastainczyk, W; Ahr, HJ; Ulrich, V
Editor Snyder, R.
Publisher Text Plenum Press
City New York, NY
Volume 136 Pt. A
Page Numbers 799-808
Abstract Polyhalogenated ethanes are metabolized by reductive dehalogenation under anaerobic and also hypoxic conditions in vitro in the presence of NADPH and hepatic microsomal cytochrome P450. The cytochrome P450 dependence was shown by induction and inhibition experiments using microsomal fractions from livers of rats receiving various pretreatments. The main products of the in vitro metabolism of hexa- and pentachloroethane were tetra- and trichloroethene, respectively. Minor products were penta- (0.5%) and 1.1.2.2.-tetrachloroethane (4%). The stoichiometry of NADPH-oxidation and product formation was 1:1. From these results and earlier investigations on polyhalogenated methanes, a reaction scheme is proposed. The reductive dehalogenation probably proceeds by two sequential one electron reductions forming first a radical and then a carbanion. The carbanion may undergo protonation, alpha-, or beta-elimination forming a monodehalogenated haloalkane, an olefin or a carbene, respectively.
Pmid 7344494
Is Certified Translation No
Dupe Override No
Series Advances in Experimental Medicine and Biology
Isbn 9780306408021
Conference Name 2nd International Symposium on Biological Reactive Intermediates
Comments Conference location and date: Surrey, UK, July 14-17, 1980
Is Public Yes
Language Text English
Is Qa No
Tags
IRIS
Hexachloroethane (HCE) (Final, 2011)