title: Milieu dependence of isomeric composition of 1-deoxy-D-erythro-hexo-2,3-diulose in aqueous solution determined by high-resolution NMR spectroscopy.
abstract: In this study, high-resolution (1)H (600.03 MHz) and (13)C NMR spectroscopy (150.89 MHz) were used to elucidate the structures of the identifiable isomers of a complex mixture of equilibrating 1-deoxy-D-erythro-hexo-2,3-diulose (1-DG) (1) isomers in aqueous solution. Approximately 15 isomers were formed from the investigated deoxy-ketohexose, and the equilibrium of the isomers is dependent on the pH values and temperature. In contrast to non-hydrated isomers, hydrated 1-DG (1) isomers were exclusively formed in aqueous solution. Their relative concentration increased when the pH was increased to more basic conditions. An increase in solution temperature led to the elimination of water and an increase in the relative concentration of the non-hydrated 1-DG (1) isomers. The observed influence of different conditions on the isomeric composition was explained for all isomers. Also, these observations provided information for structure elucidation. Furthermore, the reaction behaviour of 1-DG (1) under basic conditions at high temperatures (up to 347.5K) was interpreted and described.
authors.affiliation: Berlin Institute of Technology, Department of Food Chemistry and Food Analysis, Gustav-Meyer-Allee 25, TIB 4/3-1, D-13355 Berlin, Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Kaufmann
authors.forename: Paul T
authors.initials: PT
authors.lastname: Haase
authors.forename: Clemens
authors.initials: C
authors.lastname: Mügge
authors.forename: Lothar W
authors.initials: LW
authors.lastname: Kroh
mesh_terms: D002244:Carbon / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D007536:Isomerism; D007661:Ketoses / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D015416:Maillard Reaction; D008968:Molecular Conformation; D012996:Solutions / Q000737:chemistry; D012997:Solvents / Q000737:chemistry; D013696:Temperature; D013997:Time Factors; D014867:Water / Q000737:chemistry
chemical_list: C421122:1-deoxy-erythro-hexo-2,3-diulose; D007661:Ketoses; D012996:Solutions; D012997:Solvents; D014867:Water; D002244:Carbon