EC - Flavonol synthase

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IntEnz Enzyme Nomenclature


Accepted name:
flavonol synthase
Other names:
flavonoid 2-oxoglutarate-dependent dioxygenase
Systematic name:
dihydroflavonol,2-oxoglutarate:oxygen oxidoreductase




In addition to the desaturation of (2R,3R)-dihydroflavonols to flavonols, the enzyme from the satsuma Citrus unshiu also has a non-specific activity that trans-hydroxylates the flavanones (2S)-naringenin and the unnatural (2R)-naringenin at C-3 to kaempferol and (2R,3R)-dihydrokaempferol, respectively [2]. Requires Fe2+.

Links to other databases

Enzymes and pathways: NC-IUBMB , BRENDA , DIAGRAM , DIAGRAM , DIAGRAM , ExplorEnz , ENZYME@ExPASy , KEGG , MetaCyc , UniPathway
Protein domains and families: PROSITE:PDOC51471
Structural data: CSA , EC2PDB
Gene Ontology: GO:0045431
CAS Registry Number: 146359-76-4
UniProtKB/Swiss-Prot: (13) [show] [UniProt]


  1. Wellmann, F., Lukačin, R., Moriguchi, T., Britsch, L., Schiltz, E. and Matern, U.
    Functional expression and mutational analysis of flavonol synthase from Citrus unshiu.
    Eur. J. Biochem. 269 : 4134-4142 (2002). [PMID: 12180990]
  2. Lukačin, R., Wellmann, F., Britsch, L., Martens, S. and Matern, U.
    Flavonol synthase from Citrus unshiu is a bifunctional dioxygenase.
    Phytochemistry 62 : 287-292 (2003). [PMID: 12620339]
  3. Martens, S., Forkmann, G., Britsch, L., Wellmann, F., Matern, U. and Lukačin, R.
    Divergent evolution of flavonoid 2-oxoglutarate-dependent dioxygenases in parsley.
    FEBS Lett. 544 : 93-98 (2003). [PMID: 12782296]
  4. Turnbull, J.J., Nakajima, J., Welford, R.W., Yamazaki, M., Saito, K. and Schofield, C.J.
    Mechanistic studies on three 2-oxoglutarate-dependent oxygenases of flavonoid biosynthesis: anthocyanidin synthase, flavonol synthase, and flavanone 3β-hydroxylase.
    J. Biol. Chem. 279 : 1206-1216 (2004). [PMID: 14570878]

[EC created 2004 as EC, transferred 2018 to EC]