Screening for natural mediators based on decolorization of Reactive Black 5 (50 μM) after a 2-h treatment with P. cinnabarinus laccase in the presence of 44 phenolic compounds (50 μM) monitored at 598 nm. No decolorization was obtained with the following 18 compounds (even with a 500 μM concentration): 4-aminobenzoic acid, 4-aminophenol, catechol, 3,5-diaminobenzoic acid, ferulic acid, histidine, homovanillyl alcohol, hydroxylamine, 4-hydroxyacetophenone, 1,4-hydroquinone, 2-methoxyhydroquinone, 4-methoxyphenol, 4-(methylamino)benzoic acid, 2-methyl-1,4-hydroquinone, methyl 4-hydroxybenzoate, phenylalanine, protocatechuic acid, and vanillylacetone.