TY - JOUR
T1 - Metabolic fate of isotopes during the biological transformation of carbohydrates to 2,5-dimethyl-4-hydroxy-3(2H)-furanone in strawberry fruits
AU - Wein, Martina
AU - Lewinsohn, Efraim
AU - Schwab, Wilfried
PY - 2001
Y1 - 2001
N2 - Isotopically labeled D-glucose, D-fructose, 1-deoxy-D-fructose, and 6-deoxyhexoses were applied to detached ripening strawberry (Fragaria x ananassa) fruits, and the incorporation of the isotopes into the key strawberry aroma compounds 2,5-dimethyl-4-hydroxy-3(2H)-furanone (DMHF, 1) and 2,5-dimethyl-4-methoxy-3(2H)-furanone (DMMF, 2) was determined by gas chromatography-mass spectrometry. In contrast to previous reports the data clearly showed that 6-deoxy-D-fructose/6-deoxy-D-glucose and 1-deoxy-D-fructose are not natural precursors of the furanones. However, isotopically labeled 1 and 2 were observed after the application of [1-2H]-, [2-2H]-, and [6,6-2H2]-D-glucose as well as [U-13C6]-, [1-13C]-, [1-2H]-, [6,6-2H2]-D-fructose. The isotope label of [4-2H]-D-glucose was not recovered in the furanones. In contrast, [2-2H]-D-glucose was converted to [1- or 6-2H]-1 and [1- or 6-2H]-2 by the strawberry fruits. The observed isotope shift can be explained by the catalysis of phosphohexose isomerase in the course of the biogenesis of the hydroxyfuranone (1) and the methoxyfuranone (2) from D-glucose. Thus, the applied D-glucose is metabolized to D-fructose-6-phosphate prior to the transformation into the furanones.
AB - Isotopically labeled D-glucose, D-fructose, 1-deoxy-D-fructose, and 6-deoxyhexoses were applied to detached ripening strawberry (Fragaria x ananassa) fruits, and the incorporation of the isotopes into the key strawberry aroma compounds 2,5-dimethyl-4-hydroxy-3(2H)-furanone (DMHF, 1) and 2,5-dimethyl-4-methoxy-3(2H)-furanone (DMMF, 2) was determined by gas chromatography-mass spectrometry. In contrast to previous reports the data clearly showed that 6-deoxy-D-fructose/6-deoxy-D-glucose and 1-deoxy-D-fructose are not natural precursors of the furanones. However, isotopically labeled 1 and 2 were observed after the application of [1-2H]-, [2-2H]-, and [6,6-2H2]-D-glucose as well as [U-13C6]-, [1-13C]-, [1-2H]-, [6,6-2H2]-D-fructose. The isotope label of [4-2H]-D-glucose was not recovered in the furanones. In contrast, [2-2H]-D-glucose was converted to [1- or 6-2H]-1 and [1- or 6-2H]-2 by the strawberry fruits. The observed isotope shift can be explained by the catalysis of phosphohexose isomerase in the course of the biogenesis of the hydroxyfuranone (1) and the methoxyfuranone (2) from D-glucose. Thus, the applied D-glucose is metabolized to D-fructose-6-phosphate prior to the transformation into the furanones.
KW - Biosynthesis
KW - Flavor
KW - Fragaria x ananassa
KW - Furaneol
KW - Strawberry
UR - http://www.scopus.com/inward/record.url?scp=0034841687&partnerID=8YFLogxK
U2 - 10.1021/jf010072p
DO - 10.1021/jf010072p
M3 - Article
C2 - 11368615
AN - SCOPUS:0034841687
SN - 0021-8561
VL - 49
SP - 2427
EP - 2432
JO - Journal of agricultural and food chemistry
JF - Journal of agricultural and food chemistry
IS - 5
ER -