US EPA

1470340 

Technical Report 

Stereochemistry and evidence for an arene oxide-NIH shift pathway in the fungal metabolism of naphthalene 

Cerniglia, CE; Althaus, JR; Evans, FE; Freeman, JP; Mitchum, RK; Yang, SK 

1983 

Yes 

Chemico-Biological Interactions
ISSN: 0009-2797
EISSN: 1872-7786 

HEEP/85/00298 

BIOL INTERACT 

1-2 

1-2 

English 

6406078 

10.1016/0009-2797(83)90134-5 

WOS:A1983QS20500010 

https://www.proquest.com/scholarly-journals/stereochemistry-evidence-arene-oxide-nih-shift/docview/13617197/se-2?accountid=171501
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HEEP COPYRIGHT: BIOL ABS. The mechanism of naphthalene oxidation by the filamentous fungus Cunninghamella elegans is described. C. elegans oxidized naphthalene predominately to trans-1,2-dihydroxy-1,2-dihydronaphthalene. A trans configuration was assigned for the dihydrodiol by NMR spectroscopy at 500 MHz which showed a large coupling constant (J1,2) of 11.0 Hz. Comparison of the circular dichroism spectrum of the fungal trans-1,2-dihydroxy-1,2-dihydronaphthalene to that formed by mammalian enzyme systems indicated that the fungal dihydrodiol contained 76% (+)-(1S,2S)-dihydrodriol as the predominant enantiomer. Other naphthalene metabolites formed by C. elegans were identified as 1-naphthol, 2-naphthol and 4-hydroxy-1-tetralone. Incubation of C. elegans with naphthalene and 18O2 indicated that the trans-1,2-dihydroxy-1,2-dihydronaphthalene contained 1 atom of molecular O2 which indicated a monooxygenase catalyzed reaction while similar incubations with naphthalene and H218O indicated that the other oxygen atom in trans-1,2-dihydroxy-1,2-dihydronaphthalene was derived from water. Mass spectral analysis of the acid-catalyzed dehydration products of the dihydrodiol indicated that the naphthalene dihdyrodiol forms via the addition of water at the C-2 position of naphthalene-1,2-oxide. Fungal metabolism of (1-2H)naphthalene yielded 1-naphthol which retained 78% of the deuterium. NMR analysis of the deuterated 1-naphthol indicated an NIH shift mechanism in which deuterium migrated from the C-1 position to the C-2 position. Naphthelane-1,2-oxide is an intermediate in the fungal metabolism of naphthalene. The fungal enzymes are highly stereoselective in the formation of trans-1,2-dihdyroxy-1,2-dihydronaphthalene. 

stereospecificity; naphthalene; Microbiology Abstracts A: Industrial & Applied Microbiology; Microbiology Abstracts C: Algology, Mycology & Protozoology; biodegradation; Cunninghamella elegans; A 01063:Utilization; A 01016:Microbial degradation; K 03098:Spoilage & biodegradation