Reaction: (1) (–)-menthone + NADPH + H+ + O2 = (4R,7S)-7-isopropyl-4-methyloxepan-2-one + NADP+ + H2O
(2) dihydrocarvone + NADPH + H+ + O2 = 4-isopropenyl-7-methyloxepan-2-one + NADP+ + H2O
(3) (iso)-dihydrocarvone + NADPH + H+ + O2 = 6-isopropenyl-3-methyloxepan-2-one + NADP+ + H2O
(4a) 1-hydroxymenth-8-en-2-one + NADPH + H+ + O2 = 7-hydroxy-4-isopropenyl-7-methyloxepan-2-one + NADP+ + H2O
(4b) 7-hydroxy-4-isopropenyl-7-methyloxepan-2-one = 3-isopropenyl-6-oxoheptanoate (spontaneous)
For diagram of reaction click here or click here or click here.
Other name(s): 1-hydroxy-2-oxolimonene 1,2-monooxygenase; dihydrocarvone 1,2-monooxygenase; MMKMO
Systematic name: (–)-menthone,NADPH:oxygen oxidoreductase
Comments: A flavoprotein (FAD). This Baeyer-Villiger monooxygenase enzyme from the Gram-positive bacterium Rhodococcus erythropolis DCL14 has wide substrate specificity, catalysing the lactonization of a large number of monocyclic monoterpene ketones and substituted cyclohexanones [2]. Both (1R,4S)- and (1S,4R)-1-hydroxymenth-8-en-2-one are metabolized, with the lactone product spontaneously rearranging to form 3-isopropenyl-6-oxoheptanoate [1].
Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number:
References:
1. van der Werf, M.J., Swarts, H.J. and de Bont, J.A. Rhodococcus erythropolis DCL14 contains a novel degradation pathway for limonene. Appl. Environ. Microbiol. 65 (1999) 2092-2102. [PMID: 10224006]
2. Van Der Werf, M.J. Purification and characterization of a Baeyer-Villiger mono-oxygenase from Rhodococcus erythropolis DCL14 involved in three different monocyclic monoterpene degradation pathways. Biochem. J. 347 (2000) 693-701. [PMID: 10769172]
3. van der Werf, M.J. and Boot, A.M. Metabolism of carveol and dihydrocarveol in Rhodococcus erythropolis DCL14. Microbiology 146 (2000) 1129-1141. [PMID: 10832640]