Biosynthesis of monoterpenes and norisoprenoids in raspberry fruits (Rubus idaeus L.): the role of cytosolic mevalonate and plastidial methylerythritol phosphate pathway.
The biosynthesis of the monoterpenes (-)-alpha-pinene, linalool, and the norisoprenoids alpha- and beta-ionone in raspberry fruits (rubus idaeus L.) was investigated by in vivo feeding experiments with [5,5-(2)H2]-mevalonic acid lactone and [5,5-(2)H2]-1-deoxy-D-xylulose. The volatile compounds were extracted by stirbar sorptive extraction and analyzed using thermal desorption-multidimensional gas chromatography-mass spectrometry (TD-enantio-MDGC-MS). The feeding experiments demonstrate that (-)-alpha-pinene and (S)-linalool are exclusively synthesized via the cytosolic mevalonic acid pathway. In contrast, (2)H-labeled (R)-(E)-alpha-ionone and (2)H-labeled (E)-beta-ionone are detectable after application of d2-1-deoxy-D-xylulose and d2-mevalonic acid lactone, respectively. However, (R)-linalool reveals no incorporation of either one of the fed precursors, even though this enantiomer is detectable in the fruit tissue.
Hampel
Daniela
D
Institut für Lebensmittelchemie, Johann Wolfgang Goethe-Universität, Max-von-Laue-Strasse 9, D-60438 Frankfurt/Main, Germany.
Swatski
Anna
A
Mosandl
Armin
A
Wüst
Matthias
M
D005638:Fruit / Q000378:metabolism*; D008798:Mevalonic Acid / Q000378:metabolism*; D039821:Monoterpenes / Q000378:metabolism*; D045792:Norisoprenoids / Q000096:biosynthesis*; D010710:Phosphates / Q000378:metabolism*; D027824:Rosaceae / Q000378:metabolism*; D014996:Xylulose / Q000031:analogs & derivatives / Q000378:metabolism
D039821:Monoterpenes; D045792:Norisoprenoids; D010710:Phosphates; D014996:Xylulose; C029724:1-deoxy-2-pentulose; D008798:Mevalonic Acid