Quercetin 2,3-dioxygenase

In enzymology, a quercetin 2,3-dioxygenase is an enzyme that catalyzes the chemical reaction


 * quercetin + O2 $$\rightleftharpoons$$ 2-(3,4-dihydroxybenzoyloxy)-4,6-dihydroxybenzoate + CO + H+

Thus, the two substrates of this enzyme are quercetin and O2, whereas its three products are 2-(3,4-dihydroxybenzoyloxy)-4,6-dihydroxybenzoate, CO, and H+.

This enzyme belongs to the family of oxidoreductases, specifically those acting on single donors with O2 as oxidant and incorporation of two atoms of oxygen into the substrate (oxygenases). The oxygen incorporated need not be derived from O2. The systematic name of this enzyme class is quercetin:oxygen 2,3-oxidoreductase (decyclizing). Other names in common use include quercetinase and flavonol 2,4-oxygenase. It has two cofactors: iron and copper.

Structural studies
As of late 2007, six crystal structures have been solved for this class of enzymes, with PDB accession codes, , , , , and.