IUBMB Enzyme Nomenclature


Accepted name: flavonoid 3'-monooxygenase

Reaction: a flavonoid + [reduced NADPH—hemoprotein reductase] + O2 = a 3'-hydroxyflavonoid + [oxidized NADPH—hemoprotein reductase] + H2O

For diagram of reaction click here or click here.

Other name(s): CYP75B1 (gene name); flavonoid 3'-hydroxylase; flavonoid 3-hydroxylase (incorrect); NADPH:flavonoid-3'-hydroxylase (incorrect); flavonoid 3-monooxygenase (incorrect)

Systematic name: flavonoid,[reduced NADPH—hemoprotein reductase]:oxygen oxidoreductase (3'-hydroxylating)

Comments: A cytochrome P-450 (heme-thiolate) protein found in plants. Acts on a number of flavonoids, including the flavanone naringenin and the flavone apigenin. Does not act on 4-coumarate or 4-coumaroyl-CoA.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number:


1. Forkmann, G., Heller, W. and Grisebach, H. Anthocyanin biosynthesis in flowers of Matthiola incana flavanone 3- and flavonoid 3'-hydroxylases. Z. Naturforsch. C: Biosci. 35 (1980) 691-695.

2. Brugliera, F., Barri-Rewell, G., Holton, T.A. and Mason, J.G. Isolation and characterization of a flavonoid 3'-hydroxylase cDNA clone corresponding to the Ht1 locus of Petunia hybrida. Plant J. 19 (1999) 441-451. [PMID: 10504566]

3. Schoenbohm, C., Martens, S., Eder, C., Forkmann, G. and Weisshaar, B. Identification of the Arabidopsis thaliana flavonoid 3'-hydroxylase gene and functional expression of the encoded P450 enzyme. Biol. Chem. 381 (2000) 749-753. [PMID: 11030432]

[EC created 1983 as EC, transferred 2018 to EC]

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