IUBMB Enzyme Nomenclature


Accepted name: prosolanapyrone-III cycloisomerase

Reaction: prosolanapyrone III = (–)-solanapyrone A

For diagram of reaction click here

Glossary: prosolanapyrone III = 4-methoxy-2-oxo-6-(1E,7E,9E)-undeca-1,7,9-trien-1-yl-2H-pyran-3-carboxaldehyde
(–)-solanapyrone A = 4-methoxy-6-((1R,2S,4aR,8aR)-2-methyl-1,2,4a,5,6,7,8,8a-octahydronaphthalen-1-yl)-2-oxo-2H-pyran-3-carboxaldehyde

Other name(s): Sol5 (ambiguous); SPS (ambiguos); solanapyrone synthase (bifunctional enzyme: prosolanapyrone II oxidase/prosolanapyrone III cyclosiomerase)

Systematic name: prosolanapyrone-III:(–)-solanapyrone A isomerase

Comments: The enzyme is involved in the biosynthesis of the phytotoxin solanapyrone in some fungi. The bifunctional enzyme catalyses the oxidation of prosolanapyrone II and the subsequent Diels Alder cycloisomerization of the product prosolanapyrone III to (–)-solanapyrone A (cf. EC, prosolanapyrone II oxidase).

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

[EC created 2011]


1. Kasahara, K., Miyamoto, T., Fujimoto, T., Oguri, H., Tokiwano, T., Oikawa, H., Ebizuka, Y. and Fujii, I. Solanapyrone synthase, a possible Diels-Alderase and iterative type I polyketide synthase encoded in a biosynthetic gene cluster from Alternaria solani. Chembiochem. 11 (2010) 1245-1252. [PMID: 20486243]

2. Katayama, K., Kobayashi, T., Oikawa, H., Honma, M. and Ichihara, A. Enzymatic activity and partial purification of solanapyrone synthase: first enzyme catalyzing Diels-Alder reaction. Biochim. Biophys. Acta 1384 (1998) 387-395. [PMID: 9659400]

3. Katayama, K., Kobayashi, T., Chijimatsu, M., Ichihara, A. and Oikawa, H. Purification and N-terminal amino acid sequence of solanapyrone synthase, a natural Diels-Alderase from Alternaria solani. Biosci. Biotechnol. Biochem. 72 (2008) 604-607. [PMID: 18256508]

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