Oxidase that catalyzes the oxidation of medium chain hydroxyacids such as 2-hydroxyoctanoate, to the correspondong 2-oxoacids. Its role in the oxidation of 2-hydroxy fatty acids may contribute to the general pathway of fatty acid alpha-oxidation. Active in vitro with the artificial electron acceptor 2,6-dichlorophenolindophenol (DCIP), but O2 is believed to be the physiological electron acceptor, leading to the production of H2O2. Is not active on glycolate, glyoxylate, L-lactate, 2-hydroxybutanoate and 2-hydroxyhexadecanoate. a (2S)-2-hydroxycarboxylate + O2 = a 2-oxocarboxylate + H2O2 2-hydroxyoctanoate + O2 = 2-oxooctanoate + H2O2 Lipid metabolism; fatty acid metabolism. Homotetramer. Pancreas. Belongs to the FMN-dependent alpha-hydroxy acid dehydrogenase family. Was originally thought to originate from human.