Reaction: (+)-pulegone + [reduced NADPH—hemoprotein reductase] + O2 = (+)-menthofuran + [oxidized NADPH—hemoprotein reductase] + H2O
For diagram of reaction click here or for mechanism click here.
Other name(s): menthofuran synthase; (+)-pulegone 9-hydroxylase; (+)-MFS; cytochrome P450 menthofuran synthase
Systematic name: (+)-pulegone,[reduced NADPH—hemoprotein reductase]:oxygen oxidoreductase (9-hydroxylating)
Comments: A cytochrome P-450 (heme-thiolate) protein. The conversion of substrate into product involves the hydroxylation of the syn-methyl (C9), intramolecular cyclization to the hemiketal and dehydration to the furan [1]. This is the second cytochrome P-450-mediated step of monoterpene metabolism in peppermint, with the other step being catalysed by EC 1.14.14.99, (S)-limonene 3-monooxygenase [1].
Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number:
References:
1. Bertea, C.M., Schalk, M., Karp, F., Maffei, M. and Croteau, R. Demonstration that menthofuran synthase of mint (Mentha) is a cytochrome P450 monooxygenase: cloning, functional expression, and characterization of the responsible gene. Arch. Biochem. Biophys. 390 (2001) 279-286. [PMID: 11396930]
2. Mahmoud, S.S. and Croteau, R.B. Menthofuran regulates essential oil biosynthesis in peppermint by controlling a downstream monoterpene reductase. Proc. Natl. Acad. Sci. USA 100 (2003) 14481-14486. [PMID: 14623962]