IUBMB Enzyme Nomenclature


Accepted name: trans-4-coumaroyl-CoA 2-hydroxylase

Reaction: trans-4-coumaroyl-CoA + 2-oxoglutarate + O2 = 2,4-dihydroxycinnamoyl-CoA + succinate + CO2

Glossary: trans-4-coumaroyl-CoA = (2E)-3-(4-hydroxyphenyl)prop-2-enoyl-CoA
2,4-dihydroxycinnamoyl-CoA = (2E)-3-(2,4-dihydroxyphenyl)prop-2-enoyl-CoA
umbelliferone = 7-hydroxycoumarin

Other name(s): Diox4 (gene name); C2'H (gene name)

Systematic name: (2E)-3-(4-hydroxyphenyl)prop-2-enoyl-CoA,2-oxoglutarate:oxygen oxidoreductase (2-hydroxylating)

Comments: Requires iron(II) and ascorbate. The product spontaneously undergoes trans-cis isomerization followed by lactonization and cyclization, liberating CoA and forming umbelliferone. The enzymes from the plants Ruta graveolens and Ipomoea batatas also act on trans-feruloyl-CoA (cf. EC, feruloyl-CoA 6-hydroxylase).

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


1. Vialart, G., Hehn, A., Olry, A., Ito, K., Krieger, C., Larbat, R., Paris, C., Shimizu, B., Sugimoto, Y., Mizutani, M. and Bourgaud, F. A 2-oxoglutarate-dependent dioxygenase from Ruta graveolens L. exhibits p-coumaroyl CoA 2'-hydroxylase activity (C2'H): a missing step in the synthesis of umbelliferone in plants. Plant J. 70 (2012) 460-470. [PMID: 22168819]

2. Matsumoto, S., Mizutani, M., Sakata, K. and Shimizu, B. Molecular cloning and functional analysis of the ortho-hydroxylases of p-coumaroyl coenzyme A/feruloyl coenzyme A involved in formation of umbelliferone and scopoletin in sweet potato, Ipomoea batatas (L.) Lam. Phytochemistry 74 (2012) 49-57. [PMID: 22169019]

[EC created 2019]

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