In enzymology, a 2-hydroxypyridine 5-monooxygenase is an enzyme that catalyzes the chemical reaction 2-hydroxypyridine + AH2 + O2 ⇌ {\displaystyle \rightleftharpoons } 2,5-dihydroxypyridine + A + H2OThe 3 substrates of this enzyme are 2-hydroxypyridine, an electron acceptor AH2, and O2, whereas its 3 products are 2,5-dihydroxypyridine, the reduction product A, and H2O. Wikipedia