文摘
Formation of the flavor compound and precursor 4-hydroxy-5-methyl-3[2H]-furanone (HMF, norfuraneol) was demonstrated in cytosolic protein extracts obtained from Zygosaccharomyces rouxii afterincubation with a number of carbohydrate phosphates. 4-Hydroxy-5-methyl-3[2H]-furanone wasproduced from D-fructose-1,6-diphosphate, D-fructose-6-phosphate, D-glucose-6-phosphate, 6-phosphogluconate, D-ribose-5-phosphate, and D-ribulose-1,5-diphosphate. Enzyme assays revealedD-fructose-1,6-diphosphatase, phosphohexose isomerase, D-glucose-6-phosphate dehydrogenase,and 6-phosphogluconate dehydrogenase activity in the cytosolic extracts. Model studies showed thespontaneous formation of HMF from D-ribulose-5-phosphate. It is assumed that D-ribulose-5-phosphateis generated in cytosolic extracts by the action of the investigated enzymes from the carbohydratephosphates and is then chemically transformed to HMF. The hypothesis was proven by the productionof HMF in solutions containing commercially available enzymes and [6-13C]-D-glucose-6-phosphate.Keywords: Norfuraneol; Zygosaccharomyces rouxii; yeast; D-ribulose-5-phosphate