In enzymology, a 7,8-dihydroxykynurenate 8,8a-dioxygenase () is an enzyme that catalyzes the chemical reaction
Thus, the two substrates of this enzyme are 7,8-dihydroxykynurenate and O<sub>2</sub>, whereas its product is 5-(3-carboxy-3-oxopropenyl)-4,6-dihydroxypyridine-2-carboxylate.
This enzyme belongs to the family of oxidoreductases, specifically those acting on single donors with O<sub>2</sub> as oxidant and incorporation of two atoms of oxygen into the substrate (oxygenases). The oxygen incorporated need not be derived from O<sub>2</sub>. The systematic name of this enzyme class is 7,8-dihydroxykynurenate:oxygen 8,8a-oxidoreductase (decyclizing). Other names in common use include 7,8-dihydroxykynurenate oxygenase, and 7,8-dihydroxykynurenate 8,8alpha-dioxygenase. This enzyme participates in tryptophan metabolism. It employs one cofactor, iron.