Journal of Biochemistry vol:119 issue:1 pages:180-185
Of the all-carbon-13 compounds, glucose is one of the most easily accessible, and therefore we applied C-13-NMR technique to the metabolic study of glucose-related compounds, 1,5-anhydro-D-glucitol and 1,5-anhydro-D-fructose (AF). Applying an INADEQUATE method to the substitutes of these novel sugars fully labeled with carbon-13, we could trace out the entire carbon skeleton with high sensitivity and confirm the chemical structures of these sugars. The method also provided a much easier way to optimize the enzymatic oxidation for AF preparation: we selectively and continuously monitored the quantities, as well as their structures in aqueous solution, of the substrate and products in a noninvasive manner. Similarly relying upon information from the C-13-NMR, we developed a valuable derivatization method of AF for its GC-MS application, which was so sensitive that we were able to demonstrate the natural occurrence of AF in rat liver.