Fungal cytochrome P450s catalyzing hydroxylation of substituted toluenes to form their hydroxymethyl derivatives.
The degradation of a series of nitroaromatic compounds by the lignin-degrading fungus Phanerochaete chrysosporium was examined. From 4-nitrotoluene (4-NT), several metabolic intermediates were identified. Initially, 4-NT was converted to 4-nitrobenzyl alcohol (4-NBA), followed by the oxidation reactions to form 4-nitrobenzaldehyde and 4-nitrobenzoic acid, albeit slowly. Exogenously added 4-nitrobenzaldehyde and 4-nitrobenzoic acid were predominantly reduced to 4-NBA. The fungal formation of 4-NBA was inhibited by piperonyl butoxide, a cytochrome P450 inhibitor, suggesting the involvement of cytochrome P450 in the hydroxylation of the methyl group. Similarly, 2-, and 3-nitrotoluenes and 4-chlorotoluene were converted to the corresponding arylalcohols by P. chrysosporium. On the other hand, toluene and 4-methoxytoluene were not converted. Thus, P. chrysosporium possesses an alkyl hydroxylation activity against aromatic compounds substituted with a strong electron-withdrawing group.
Teramoto
Hiroshi
H
Faculty of Agriculture, Department of Forest and Forest Products Sciences, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581, Japan.
Tanaka
Hiroo
H
Wariishi
Hiroyuki
H
D002851:Chromatography, High Pressure Liquid; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism*; D005656:Fungal Proteins / Q000378:metabolism; D006900:Hydroxylation; D020075:Phanerochaete / Q000201:enzymology*; D013379:Substrate Specificity; D014050:Toluene / Q000031:analogs & derivatives* / Q000378:metabolism*
D005656:Fungal Proteins; D014050:Toluene; D003577:Cytochrome P-450 Enzyme System