There is provided a process for enhancing the activity of a 
phenol oxidizing 
enzyme, comprising adding to the 
enzyme, as an 
enhancer for the activity of the 
enzyme, one or more compounds having the formula:wherein:A is an optionally substituted 
electron-withdrawing group, chosen from the group consisting of 
nitrile, carboxyl, and esters and salts thereof, amides, aldehydes, ketones, sulfoxides, sulfones, or sulphonates, andB is an optionally substituted 
electron-donating group, chosen from the group consisting of the 
oxide anion, 
sulfide anion, oxides, amines, imines, hydroxides, sulfides, ethers, carboxylic acids, and 
halogen substituents, andR1-R5 may each independently represent 
hydrogen, hydroxy, 
halogen, 
nitroso, formyl, carboxyl, and esters and salts thereof, carbamoyl, sulfo, and esters and salts hereof, sulfamoyl, nitro, amino, phenyl, C1-C20 
alkyl, C1-C8 alkoxy, carbonyl-C1-C6-alkoxy, 
aryl-C1-C6-
alkyl, and R2 and R5 together may form an alkylene group or an alkenylene group.