The AO also catalyzes the oxidation of heterocycles, which involves a nucleophilic attack located at the carbon atom beside the heteroatom.

Aldehyde oxidase is a member of the molybdenum flavoprotein family[1] and has a very complex evolutionary profile—as the genes of AO varies according to animal species.

The active sites of AO has been found to have a superimposed structure to that of XO, in studies involving mouse liver.

AO is capable of oxidizing many drugs in the liver (such as N-1-methylnicotinamide, N-methylphthalazinium, benzaldehyde, retinal, and vanillin), because of its broad substrate specificity.

[8] The birth control drug Ethinyl estradiol inhibits AO, but its typical concentration is so low that the potential for drug-drug interaction is essentially zero.

[8] A select few medications have been identified as potentially significant inhibitors of AO, including Clozapine and Chlorpromazine.