IUBMB Enzyme Nomenclature


Accepted name: versicolorin B synthase

Reaction: versiconal = versicolorin B + H2O

For diagram of reaction click here.

Glossary: versiconal = (2S,3S)-2,4,6,8-tetrahydroxy-3-(2-hydroxyethyl)anthra[2,3-b]furan-5,10-dione
versicolorin B = (3aR,12bS)-8,10,12-trihydroxy-1,2,3a,12b-tetrahydroanthra[2,3-b]furo[3,2-d]furan-6,11-dione

Other name(s): versiconal cyclase; VBS

Systematic name: versiconal hydro-lyase (versicolorin-B forming)

Comments: Isolated from the aflatoxin-producing mold Aspergillus parasiticus. Involved in aflatoxin biosynthesis.

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


1. Lin, B.K. and Anderson, J.A. Purification and properties of versiconal cyclase from Aspergillus parasiticus. Arch. Biochem. Biophys. 293 (1992) 67-70. [PMID: 1731640]

2. McGuire, S.M., Silva, J.C., Casillas, E.G. and Townsend, C.A. Purification and characterization of versicolorin B synthase from Aspergillus parasiticus. Catalysis of the stereodifferentiating cyclization in aflatoxin biosynthesis essential to DNA interaction. Biochemistry 35 (1996) 11470-11486. [PMID: 8784203]

3. Silva, J.C., Minto, R.E., Barry, C.E., 3rd, Holland, K.A. and Townsend, C.A. Isolation and characterization of the versicolorin B synthase gene from Aspergillus parasiticus. Expansion of the aflatoxin b1 biosynthetic gene cluster. J. Biol. Chem. 271 (1996) 13600-13608. [PMID: 8662689]

4. Silva, J.C. and Townsend, C.A. Heterologous expression, isolation, and characterization of versicolorin B synthase from Aspergillus parasiticus. A key enzyme in the aflatoxin B1 biosynthetic pathway. J. Biol. Chem. 272 (1997) 804-813. [PMID: 8995367]

[EC created 2013]

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