Mentha x piperita L. shoot tip and first leaf pair wen fed with aqueous sol
utions of deuterium-labelled racemic piperitone and achiral piperitenone. T
he essential oil was extracted by solid phase microextraction (SPME) and su
bsequently analyzed using enantioselective multidimensional gas chromatogra
phy/mass spectrometry (enantio-MDGC-MS). Both labelled precursors led to th
e corresponding IR-configured p-menthan-3-ones (-)-menthone and (+)-isoment
hone, favouring the labelled (+)-isomenthone. Copyright (C) 2000 John Wiley
& Sons. Ltd.