2 Hydroxy 1,4 benzoxazin 3 one monooxygenase

2-Hydroxy-1,4-benzoxazin-3-one monooxygenase (EC 1.14.13.140, BX5 (gene), CYP71C3 (gene)) is an enzyme with systematic name 2-hydroxy-2H-1,4-benzoxazin-3(4H)-one,NAD(P)H:oxygen oxidoreductase (N-hydroxylating). This enzyme catalyses the following chemical reaction

2-hydroxy-2H-1,4-benzoxazin-3(4H)-one + NAD(P)H + H⁺ + O₂ ⇌ 2,4-dihydroxy-2H-1,4-benzoxazin-3(4H)-one + NAD(P)+ + H₂O

2-Hydroxy-1,4-benzoxazin-3-one monooxygenase is involved in the biosynthesis of protective and allelophatic benzoxazinoids in some plants.