EC - 4'-methoxyisoflavone 2'-hydroxylase

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IntEnz Enzyme Nomenclature


Accepted name:
4'-methoxyisoflavone 2'-hydroxylase
Other names:
isoflavone 2'-monooxygenase [ambiguous]
isoflavone 2'-hydroxylase [ambiguous]
Systematic name:
formononetin,[reduced NADPH—hemoprotein reductase]:oxygen oxidoreductase (2'-hydroxylating)




A cytochrome P450 (heme-thiolate) protein. Acts on isoflavones with a 4'-methoxy group, such as formononetin and biochanin A. Involved in the biosynthesis of the pterocarpin phytoalexins medicarpin and maackiain. EC, isoflavone 2'-hydroxylase, is less specific and acts on other isoflavones as well as 4'-methoxyisoflavones.

Links to other databases

Enzymes and pathways: NC-IUBMB , BRENDA , DIAGRAM , ExplorEnz , ENZYME@ExPASy , KEGG , MetaCyc , UniPathway
Protein domains and families: PROSITE:PDOC00081
Structural data: CSA , EC2PDB
Gene Ontology: GO:0047957
CAS Registry Number: 110183-49-8


  1. Hinderer, W., Flentje, U. and Barz, W.
    Microsomal isoflavone 2'-hydroxylases and 3'-hydroxylases from chickpea (Cicer arietinum L) cell-suspensions induced for pterocarpan phytoalexin formation.
    FEBS Lett. 214 : 101-106 (1987).
  2. Akashi, T., Aoki, T., Ayabe, S.
    CYP81E1, a cytochrome P450 cDNA of licorice (Glycyrrhiza echinata L.), encodes isoflavone 2'-hydroxylase.
    Biochem. Biophys. Res. Commun. 251 : 67-70 (1998). [PMID: 9790908]
  3. Liu, C. J., Huhman, D., Sumner, L. W., Dixon, R. A.
    Regiospecific hydroxylation of isoflavones by cytochrome p450 81E enzymes from Medicago truncatula.
    Plant J. 36 : 471-484 (2003). [PMID: 14617078]

[EC created 1992 as EC, modified 2005, transferred 2018 to EC]