IUBMB Enzyme Nomenclature


Accepted name: 5'-oxoaverantin cyclase

Reaction: 5'-oxoaverantin = (1'S,5'S)-averufin + H2O

For diagram of reaction click here.

Glossary: 5'-oxoaverantin = 1,3,6,8-tetrahydroxy-2-[(1S)-1-hydroxy-5-oxohexyl]anthracene-9,10-dione
averufin = 7,9,11-trihydroxy-2-methyl-3,4,5,6-tetrahydro-2,6-epoxy-2H-anthra[2,3-b]oxocin-8,13-dione

Other name(s): OAVN cyclase

Systematic name: 5'-oxoaverantin hydro-lyase [(1'S,5'S)-averufin forming]

Comments: Isolated from the aflatoxin-producing mold Aspergillus parasiticus. The enzyme also catalyses the conversion of versiconal to versicolorin B (EC, versicolorin B synthase). Involved in aflatoxin biosynthesis.

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


1. Sakuno, E., Yabe, K. and Nakajima, H. Involvement of two cytosolic enzymes and a novel intermediate, 5'-oxoaverantin, in the pathway from 5'-hydroxyaverantin to averufin in aflatoxin biosynthesis. Appl. Environ. Microbiol. 69 (2003) 6418-6426. [PMID: 14602595]

2. Sakuno, E., Wen, Y., Hatabayashi, H., Arai, H., Aoki, C., Yabe, K. and Nakajima, H. Aspergillus parasiticus cyclase catalyzes two dehydration steps in aflatoxin biosynthesis. Appl. Environ. Microbiol. 71 (2005) 2999-3006. [PMID: 15932995]

[EC created 2013]

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