Fungal riboflavin 5'-hydroxymethyl dehydrogenase catalyzes formation of both the aldehyde (riboflavinal) and the acid (riboflavinoic acid).

@article{Chen1997FungalR5,
  title={Fungal riboflavin 5'-hydroxymethyl dehydrogenase catalyzes formation of both the aldehyde (riboflavinal) and the acid (riboflavinoic acid).},
  author={Hongwei Chen and D B Mccormick},
  journal={Biochimica et biophysica acta},
  year={1997},
  volume={1342 2},
  pages={116-8}
}
The purified enzyme from Schizophyllum commune that readily catalyzes the oxidation of the 5'-hydroxymethyl function of riboflavin (vitamin B2) with a redox dye and O2 to form the 5'-aldehyde can more slowly further oxidize the 5'-aldehyde to the 5'-acid. Hence, the formation of these so-called 'schizoflavins' can be accounted for by the action of one enzyme.