IUBMB Enzyme Nomenclature


Accepted name: costunolide synthase

Reaction: germacra-1(10),4,11(13)-trien-12-oate + NADPH + H+ + O2 = (+)-costunolide + NADP+ + 2 H2O

For diagram of reaction click here.

Systematic name: germacra-1(10),4,11(13)-trien-12-oate,NADPH:oxygen oxidoreductase (6α-hydroxylating)

Comments: A heme-thiolate protein (P-450). The enzyme hydroxylates carbon C-6 of germacra-1(10),4,11(13)-trien-12-oate to give 6α-hydroxygermacra-1(10),4,11(13)-trien-12-oate, which probably spontaneously cyclises to form the lactone ring.

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


1. de Kraker, J.W., Franssen, M.C., Joerink, M., de Groot, A. and Bouwmeester, H.J. Biosynthesis of costunolide, dihydrocostunolide, and leucodin. Demonstration of cytochrome p450-catalyzed formation of the lactone ring present in sesquiterpene lactones of chicory. Plant Physiol. 129 (2002) 257-268. [PMID: 12011356]

[EC created 2011]

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