IUBMB Enzyme Nomenclature


Accepted name: 4'-methoxyisoflavone 2'-hydroxylase

Reaction: formononetin + NADPH + H+ + O2 = 2'-hydroxyformononetin + NADP+ + H2O

For diagram click here.

Other name(s): isoflavone 2'-monooxygenase (ambiguous); isoflavone 2'-hydroxylase (ambiguous)

Systematic name: formononetin,NADPH:oxygen oxidoreductase (2'-hydroxylating)

Comments: A heme-thiolate protein (P-450). 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: BRENDA, EXPASY, KEGG, Metacyc, 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 (1987) 101-106.

[EC created 1992, modified 2005]

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