The molecule is the pteridine that is lumazine substituted with a hydroxymethyl group at C-6 and a 1-D-ribityl group at N-8. It derives from a ribitol and a lumazine.
6-(hydroxymethyl)-8-[(2S,3S,4R)-2,3,4,5-tetrahydroxypentyl]pteridine-2,4-dione