Catechol oxidase

Catechol oxidase is an enzyme that catalyses the oxidation of phenols such as catechol. Catechol oxidase is a copper-containing enzyme whose activity is similar to that of tyrosinase, a related class of copper oxidases.

Catechol oxidase carries out the oxidation of phenols such as catechol, using dioxygen (O2). In the presence of catechol, benzoquinone is formed (see reaction below). Hydrogens removed from catechol combine with oxygen to form water. This reaction, producing the brown compound benzoquinone, is a form of enzymatic browning exhibited in many foods upon exposure to oxygen (e.g., in bananas).