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EC 1.14.20.4 Details
show Brenda entryEC number
1.14.20.4
Accepted name
anthocyanidin synthase
Reaction
a (2R,3S,4S)-leucoanthocyanidin + 2-oxoglutarate + O2 = an anthocyanidin + succinate + CO2 + 2 H2O (overall reaction);;(1a) a (2R,3S,4S)-leucoanthocyanidin + 2-oxoglutarate + O2 = a (4S)- 2,3-dehydroflavan-3,4-diol + succinate + CO2 + H2O;;(1b) a (4S)- 2,3-dehydroflavan-3,4-diol = an anthocyanidin + H2O
Other name(s)
leucocyanidin oxygenase,
leucocyanidin,2-oxoglutarate:oxygen oxidoreductase,
ANS (gene name)
Systematic name
(2R,3S,4S)-leucoanthocyanidin,2-oxoglutarate:oxygen oxidoreductase
CAS registry number
180984-01-4
Comment
The enzyme requires Fe(II) and ascorbate. It is involved in the pathway by which many flowering plants make anthocyanin flower pigments (glycosylated anthocyandins). The enzyme hydroxylates the C-3 carbon, followed by a trans diaxial elimination, forming a C-2,C-3 enol. The product loses a second water molecule to form anthocyanidins. When assayed in vitro, non-enzymic epimerization of the product can lead to formation of dihydroflavanols. Thus when the substrate is leucocyanidin, a mixture of (+)-taxifolin and (+)-epitaxifolin are formed. The enzyme can also oxidize the formed (+)-taxifolin to quercetin (cf. EC 1.14.20.6, flavonol synthase) [2,3].
History
created 2001 as EC 1.14.11.19, transferred 2018 to EC 1.14.20.4
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1 Oxidoreductases
1.1 Acting on the CH-OH group of donors
1.6.7.1 created 1972, deleted 1978 1.6.7.2 created 1972, deleted 1978 1.6.7.3 created 1978, deleted 1978 1.6.8.1 created 1981, deleted 2002 1.6.8.2 created 1982, deleted 2002
