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8165455 
Journal Article 
Hydroxylation catalyzed by peroxidase 
Buhler, DR; Mason, HS; , 
1961 
Yes 
Archives of Biochemistry and Biophysics
ISSN: 0003-9861
EISSN: 1096-0384 
92 
3 
424-437 
English 
1. 1. The influence of substituents upon the orientation of aromatic hydroxylation by the dihydroxyfumarate-peroxidase-oxygen and the ascorbate-iron-oxygen systems, has been studied. 2. 2. Phenolic hydroxyl directs the entering hydroxyl group to the ortho and para positions in both systems. 3. 3. The nitro group directs the entering hydroxyl to all positions in the dihydroxyfumarate system; m-nitrophenol is formed in preponderance. 4. 4. The yield of phenolic products from the hydroxylation of nitrobenzene, benzole acid, and salicylic acid under comparable conditions is 1.45, 8.95, and 9.40 μmoles, respectively. The relative yields appear to be more characteristic of free radical attack than electrophilic substitution. 5. 5. Hydrogen peroxide does not substitute for oxygen in the dihydroxyfumarateperoxidase system, and manganese inhibits hydroxylation. These and other properties are explained by the assumption that the hydroxylating agent is perhydroxyl or a related radical, formed in accordance with the Yamazaki peroxidase-oxidase mechanism. © 1961.