||Oxidative 4-Dechlorination of Polychlorinated Phenols Is Catalyzed by Extracellular Fungal Lignin Peroxidases (Journal Version).
Hammel, K. E. ;
Tardone, P. J. ;
||State Univ. of New York at Syracuse. Coll. of Environmental Science and Forestry.;Environmental Protection Agency, Cincinnati, OH. Risk Reduction Engineering Lab.
Air pollution ;
Aromatic polycyclic hydrocarbons ;
Air purification ;
||Some EPA libraries have a fiche copy filed under the call number shown.
||The extracellular lignin peroxidases (ligninases) of Phanerochaete chrysosporium catalyzed H2O2-dependent spectral changes in several environmentally significant polychlorinated phenols: 2,4-dichloro-,2,4,5-trichloro-, and pentachlorophenol. Gas chromatography/mass spectrometry showed that lignin peroxidase catalyzed a 4-dechlorination of the starting phenol to yield a p-benzoquinone. The oxidation of 2,4-dichlorophenol also yielded a dechlorinated coupling dimer, tentatively identified as 2-chloro-6-(2,4-dichlorophenoxyl)-p-benzoquinone. Experiments on the stoichiometry of 2,4,6-trichlorophenol oxidation showed that this substrate was quantitatively dechlorinated to give the quinone and inorganic chloride. H2(sup 18)O-labeling experiments on 2,4,6-trichlorophenol oxidation demonstrated that water was the source of the new 4-oxo substituent in 2,6-dichloro-p-benzoquinone. Results indicate a mechanism whereby lignin peroxidase oxidizes a 4-chlorinated phenol to an electrophilic intermediate, perhaps the 4-chlorocyclohexadienone cation. Nucleophilic attack by water and elimination of HCl then ensue at the 4-position, which produces the quinone. It appears that these peroxidases could also catalyze the initial dechlorination of certain polychlorinated phenols in vivo. (Copyright (c) 1988 American Chemical Society.)
||Sponsored by Environmental Protection Agency, Cincinnati, OH. Risk Reduction Engineering Lab.
||Pub. in Biochemistry, v27 p6563-6568 1988.
|NTIS Title Notes
||Reprint: Oxidative 4-Dechlorination of Polychlorinated Phenols Is Catalyzed by Extracellular Fungal Lignin Peroxidases (Journal Version).
||68A; 57C; 99D
||Not available NTIS