3,4-Dihydroxy-2-butanone 4-phosphate is biosynthesised from ribulose 5-phosphate and serves as the biosynthetic precursor for the xylene ring of riboflavin. Sometimes found as a bifunctional enzyme with Pfam:PF00925.

1: Biosynthesis of riboflavin: 3,4-dihydroxy-2-butanone -4-phosphate synthase. Richter G, Krieger C, Volk R, Kis K, Ritz H, Gotze E, Bacher A; Methods Enzymol 1997;280:374-382. PMID:9211332