1,2-cis-dihydrodiol dehydrogenase 3-hydroxybenzoate 4-monooxygenase 4-hydroxybenzoate 3-monooxygenase (NAD(P)H) 4-sulfobenzoate 3,4-dioxygenase vanillate monooxygenase 3,4-dihydroxyphthalate decarboxylase 4,5-dihydroxyphthalate decarboxylase Degradation enzymes The enzyme protocatechuate decarboxylase uses 3,4-dihydroxybenzoate to produce catechol and CO2. The enzyme protocatechuate 3,4-dioxygenase uses 3,4-dihydroxybenzoate and O2 to produce 3-carboxy-cis,cis-muconate. See also Ethyl protocatechuate References Dihydroxybenzoic acids Phenol antioxidants Vinylogous carboxylic acids Catechols