7-Methylxanthine demethylase (EC 1.14.13.128) is an enzyme with systematic name 7-methylxanthine:oxygen oxidoreductase (demethylating). This enzyme catalyses the following chemical reaction 7-methylxanthine + O2 + NAD(P)H + H+ xanthine + NAD(P)+ + H2O + formaldehyde 7-Methylxanthine demethylase is a non-heme iron oxygenase.