Catalyzes the NADPH- and oxygen-dependent oxidation of the monocyclic monoterpene ketones 1-hydroxy-2-oxolimonene, dihydrocarvone and menthone. Is able to convert all enantiomers of these natural substrates with almost equal efficiency. Is thus involved in the conversion of the monocyclic monoterpene ketone intermediates formed in the degradation pathways of all stereoisomers of three different monocyclic monoterpenes, i.e. limonene, (dihydro)carveol and menthol, which likely make R.erythropolis able to grow on these compounds as the sole source of carbon and energy. 1-hydroxylimonen-2-one + NADPH + O2 = 3-isopropenyl-6-oxoheptanoate + H2O + NADP(+) (1R,4S)-1-hydroxylimonen-2-one + H(+) + NADPH + O2 = (4S,7S)-7-hydroxy-4-isopropenyl-7-methyloxepan-2-one + H2O + NADP(+) (1S,4R)-1-hydroxylimonen-2-one + H(+) + NADPH + O2 = (4R,7R)-7-hydroxy-4-isopropenyl-7-methyloxepan-2-one + H2O + NADP(+) (1R,4R)-dihydrocarvone + H(+) + NADPH + O2 = (4R,7R)-4-isopropenyl-7-methyloxepan-2-one + H2O + NADP(+) (1S,4R)-menthone + H(+) + NADPH + O2 = (4S,7R)-7-isopropyl-4-methyloxepan-2-one + H2O + NADP(+) (1R,4S)-menthone + H(+) + NADPH + O2 = (4R,7S)-7-isopropyl-4-methyloxepan-2-one + H2O + NADP(+) (1S,4R)-isodihydrocarvone + H(+) + NADPH + O2 = (3S,6R)-6-isopropenyl-3-methyloxepan-2-one + H2O + NADP(+) kcat is 3.9 sec(-1) with (4R)-dihydrocarvone as substrate. kcat is 4.9 sec(-1) with (1R,4S)-1-hydroxy-2-oxolimonene as substrate. kcat is 3.9 sec(-1) with (1S,4R)-1-hydroxy-2-oxolimonene as substrate. kcat is 3.6 sec(-1) with (1R,4S)-menthone as substrate. kcat is 6.0 sec(-1) with (1S,4R)-menthone as substrate. Optimum pH is 9.5. Optimum temperature is about 36 degrees Celsius. Terpene metabolism; monoterpene degradation. Monomer. Induced by growth on limonene, carveol, dihydrocarveol or (1R,3R,4S)-menthol. The 7-hydroxy-4-isopropenyl-7-methyloxepan-2-one lactone obtained from 1-hydroxylimonen-2-one is unstable and undergoes a spontaneous rearrangement to 3-isopropenyl-6-oxoheptanoate.