Biosynthesis of Monoterpenes and Norisoprenoids in Raspberry Fruits (Rubus idaeus L.): The Role of Cytosolic Mevalonate and Plastidial Methylerythritol Phosphate Pathway

• Published in: Journal of agricultural and food chemistry Vol. 55; no. 22; pp. 9296 - 9304
• Main Authors: Hampel, Daniela, Swatski, Anna, Mosandl, Armin, Wüst, Matthias
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 31.10.2007
• Subjects: biochemical pathways; Biological and medical sciences; biosynthesis; cytosolic and plastidial pathways; cytosolic mevalonate; food analysis; Food engineering; Food industries; Fruit - metabolism; Fruit and vegetable industries; fruit aroma; fruit composition; fruit extracts; fruit quality; Fundamental and applied biological sciences. Psychology; General aspects; in vivo studies; mevalonic acid; Mevalonic Acid - metabolism; Monoterpenes - metabolism; monoterpenoids; norisoprenoids; Norisoprenoids - biosynthesis; Phosphates - metabolism; plastidial methylerythritol phosphate pathway; raspberries; Rosaceae; Rosaceae - metabolism; Rubus idaeus; stir bar sorptive extraction (SBSE); terpenoids; thermal desorption-multidimensional gas chromatography–mass spectrometry (TD-MDGC-MS); Xylulose - analogs & derivatives; Xylulose - metabolism; terpenoids; stir bar sorptive extraction (SBSE); cytosolic and plastidial pathways; fruit aroma; Rosaceae; thermal desorption-multidimensional gas chromatography–mass spectrometry (TD-MDGC-MS); Phosphates; Multidimensional chromatography; Terpenoid; thermal desorption-multidimensional gas chromatography-mass spectrometry (TD- MDGC-MS); Fruit; Biosynthesis; Desorption; Gas chromatography; Dicotyledones; Angiospermae; Raspberry; Monoterpene; Spermatophyta; Extraction; Rubus idaeus; Aroma
• ISSN: 0021-8561; 1520-5118
• DOI: 10.1021/jf071311x

The biosynthesis of the monoterpenes (−)-α-pinene, linalool, and the norisoprenoids α- and β-ionone in raspberry fruits (rubus idaeus L.) was investigated by in vivo feeding experiments with [5,5-2H2]-mevalonic acid lactone and [5,5-2H2]-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 (−)-α-pinene and (S)-linalool are exclusively synthesized via the cytosolic mevalonic acid pathway. In contrast, 2H-labeled (R)-(E)-α-ionone and 2H-labeled (E)-β-ionone are detectable after application of d 2-1-deoxy-D-xylulose and d 2-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.