IUBMB Enzyme Nomenclature


Accepted name: flavanone 2-hydroxylase

Reaction: a flavanone + [reduced NADPH—hemoprotein reductase] + O2 = a 2-hydroxyflavanone + [oxidized NADPH—hemoprotein reductase] + H2O

For diagram of reaction click here or click here

Other name(s): CYP93G2 (gene name); CYP93B1 (gene name); (2S)-flavanone 2-hydroxylase; ; licodione synthase

Systematic name: flavanone,[reduced NADPH—hemoprotein reductase]:oxygen oxidoreductase (2-hydroxylating)

Comments: A cytochrome P-450 (heme thiolate) plant enzyme that catalyses the 2-hydroxylation of multiple flavanones such as (2S)-naringenin, (2S)-eriodictyol, (2S)-pinocembrin, and (2S)-liquiritigenin. The products are meta-stable and exist in an equilibrium with open forms such as 1-(4-hydroxyphenyl)-3-(2,4,6-trihydroxyphenyl)propane-1,3-dione.

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


1. Otani, K., Takahashi, T., Furuya, T. and Ayabe, S. Licodione synthase, a cytochrome P450 monooxygenase catalyzing 2-hydroxylation of 5-deoxyflavanone, in cultured Glycyrrhiza echinata L. cells. Plant Physiol. 105 (1994) 1427-1432. [PMID: 12232298]

2. Akashi, T., Aoki, T. and Ayabe, S. Identification of a cytochrome P450 cDNA encoding (2S)-flavanone 2-hydroxylase of licorice (Glycyrrhiza echinata L.; Fabaceae) which represents licodione synthase and flavone synthase II. FEBS Lett. 431 (1998) 287-290. [PMID: 9708921]

3. Du, Y., Chu, H., Chu, I.K. and Lo, C. CYP93G2 is a flavanone 2-hydroxylase required for C-glycosylflavone biosynthesis in rice. Plant Physiol. 154 (2010) 324-333. [PMID: 20647377]

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

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