EC - β-amyrin synthase

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IntEnz Enzyme Nomenclature


Accepted name:
β-amyrin synthase
Other names:
2,3-oxidosqualene β-amyrin cyclase
Systematic name:
(3S)-2,3-epoxy-2,3-dihydrosqualene mutase (cyclizing, β-amyrin-forming)



Some organism possess a monofunctional β-amyrin synthase [3,4,6-11], other have a multifunctional enzyme that also catalyses the synthesis of α-amyrin (EC [5] or lupeol (EC [6].

Links to other databases

Enzymes and pathways: NC-IUBMB , BRENDA , DIAGRAM , ExplorEnz , ENZYME@ExPASy , KEGG , MetaCyc , UniPathway
Structural data: CSA , EC2PDB
UniProtKB/Swiss-Prot: (11) [show] [UniProt]


  1. Abe, I, Ebizuka, Y., Seo, S. and Sankawa, U.
    Purification of squalene-2,3-epoxide cyclases from cell suspension cultures of Rabdosia japonica Hara.
    FEBS Lett. 249 : 100-104 (1989).
  2. Abe, I., Sankawa, U. and Ebizuka, Y.
    Purification of 2,3-oxdosqualene:β-amyrin cyclase from pea seedlings.
    Chem. Pharm. Bull. 37 : 536-536 (1989).
  3. Kushiro, T., Shibuya, M., Ebizuka, Y.
    β-amyrin synthase--cloning of oxidosqualene cyclase that catalyzes the formation of the most popular triterpene among higher plants.
    Eur. J. Biochem. 256 : 238-244 (1998). [PMID: 9746369]
  4. Hayashi, H., Huang, P., Kirakosyan, A., Inoue, K., Hiraoka, N., Ikeshiro, Y., Kushiro, T., Shibuya, M., Ebizuka, Y.
    Cloning and characterization of a cDNA encoding β-amyrin synthase involved in glycyrrhizin and soyasaponin biosyntheses in licorice.
    Biol. Pharm. Bull. 24 : 912-916 (2001). [PMID: 11510484]
  5. Husselstein-Muller, T., Schaller, H., Benveniste, P.
    Molecular cloning and expression in yeast of 2,3-oxidosqualene-triterpenoid cyclases from Arabidopsis thaliana.
    Plant Mol. Biol. 45 : 75-92 (2001). [PMID: 11247608]
  6. Iturbe-Ormaetxe, I., Haralampidis, K., Papadopoulou, K., Osbourn, A. E.
    Molecular cloning and characterization of triterpene synthases from Medicago truncatula and Lotus japonicus.
    Plant Mol. Biol. 51 : 731-743 (2003). [PMID: 12683345]
  7. Zhang, H., Shibuya, M., Yokota, S., Ebizuka, Y.
    Oxidosqualene cyclases from cell suspension cultures of Betula platyphylla var. japonica: molecular evolution of oxidosqualene cyclases in higher plants.
    Biol. Pharm. Bull. 26 : 642-650 (2003). [PMID: 12736505]
  8. Hayashi, H., Huang, P., Takada, S., Obinata, M., Inoue, K., Shibuya, M., Ebizuka, Y.
    Differential expression of three oxidosqualene cyclase mRNAs in Glycyrrhiza glabra.
    Biol. Pharm. Bull. 27 : 1086-1092 (2004). [PMID: 15256745]
  9. Kajikawa, M., Yamato, K. T., Fukuzawa, H., Sakai, Y., Uchida, H., Ohyama, K.
    Cloning and characterization of a cDNA encoding β-amyrin synthase from petroleum plant Euphorbia tirucalli L.
    Phytochemistry 66 : 1759-1766 (2005). [PMID: 16005035]
  10. Basyuni, M., Oku, H., Tsujimoto, E., Kinjo, K., Baba, S., Takara, K.
    Triterpene synthases from the Okinawan mangrove tribe, Rhizophoraceae.
    FEBS J. 274 : 5028-5042 (2007). [PMID: 17803686]
  11. Liu, Y., Cai, Y., Zhao, Z., Wang, J., Li, J., Xin, W., Xia, G., Xiang, F.
    Cloning and functional analysis of a β-amyrin synthase gene associated with oleanolic acid biosynthesis in Gentiana straminea MAXIM.
    Biol. Pharm. Bull. 32 : 818-824 (2009). [PMID: 19420748]

[EC created 2011]