IUBMB Enzyme Nomenclature


Accepted name: cyclopeptine synthase

Reaction: 2 ATP + S-adenosyl-L-methionine + anthranilate + L-phenylalanine = cyclopeptine + 2 AMP + 2 diphosphate + S-adenosyl-L-homocysteine

For diagram of reaction click here.

Glossary: cyclopeptine = (3S)-3-benzyl-4-methyl-3,4-dihydro-1H-1,4-benzodiazepine-2,5-dione

Systematic name: S-adenosyl-L-methionine:anthranilate:L-phenylalanine ligase (cyclopeptine forming)

Comments: Cyclopeptine synthase is the key enzyme of benzodiazepine alkaloid biosynthesis in several fungi species. The enzyme is a non-ribosomal peptide synthase. It is also active with O-methyl--tyrosine forming 4′-methoxycyclopeptine.

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


1. Lerbs, W. and Luckner, M. Cyclopeptine synthetase activity in surface cultures of Penicillium cyclopium. J. Basic Microbiol. 25 (1985) 387-391. [PMID: 2995633]

2. Gerlach, M, Schwelle, N., Lerbs, W. and Luckner, M. Enzymatic synthesis of cyclopeptine intermediates in Penicillium cyclopium. Phytochemistry 24 (1985) 1935-1939.

3. Ishikawa, N., Tanaka, H., Koyama, F., Noguchi, H., Wang, C.C., Hotta, K. and Watanabe, K. Non-heme dioxygenase catalyzes atypical oxidations of 6,7-bicyclic systems to form the 6,6-quinolone core of viridicatin-type fungal alkaloids. Angew. Chem. Int. Ed. Engl. 53 (2014) 12880-12884. [PMID: 25251934]

[EC created 2013]

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