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 18.104.22.168, 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.