Biosynthesis of menthofuran in Mentha x piperita: stereoselective and mechanistic studies.
Mentha x piperita shoot tips and first leaf pair were fed with aqueous solutions of [(2)H(2)]- and [(2)H(2)]/[(18)O]-labeled pulegone. The essential oil was analyzed by solid phase microextraction and enantioselective multidimensional gas chromatography/mass spectrometry. After feeding experiments with labeled pulegone racemate, both labeled (S)-menthofuran and (R)-menthofuran were detectable simultaneously together with genuine (R)-menthofuran. It could be shown that both labeled pulegone enantiomers are converted by Mentha x piperita to the corresponding labeled menthofuran enantiomers, favoring the labeled analogue of the nongenuine (S)-pulegone. The oxygen in menthofuran is introduced by enzymatic oxidation of pulegone, as concluded from feeding experiments with mixed labeled [(2)H(2)]/[(18)O]pulegone.
Fuchs
S
S
Institut für Lebensmittelchemie, Johann Wolfgang Goethe-Universität Frankfurt, Marie-Curie-Strasse 9, D-60439 Frankfurt (Main), Germany.
Zinn
S
S
Beck
T
T
Mosandl
A
A
D000081005:Cyclohexane Monoterpenes; D003903:Deuterium; D008401:Gas Chromatography-Mass Spectrometry; D007553:Isotope Labeling; D019686:Lamiaceae / Q000737:chemistry / Q000378:metabolism*; D008610:Menthol / Q000031:analogs & derivatives / Q000737:chemistry; D039821:Monoterpenes; D010103:Oxygen Isotopes; D010936:Plant Extracts / Q000032:analysis; D013237:Stereoisomerism; D013729:Terpenes / Q000737:chemistry / Q000378:metabolism*
D000081005:Cyclohexane Monoterpenes; D039821:Monoterpenes; D010103:Oxygen Isotopes; D010936:Plant Extracts; D013729:Terpenes; D008610:Menthol; C054487:menthofuran; C039648:pulegone; D003903:Deuterium