Program

Poster Presentations

Day 2, May 16（Wed.）　　Poster

2P-17　　PDF

Analysis of monosaccharide isomer using borate complexes and mass spectrometry

(Noguchi Inst.)
^oMasaki Kurogochi, Mamoru Mizuno, Akio Matsuda

All monosaccharides consist of a chain of chiral hydroxymethylene units, and have at least one asymmetric carbon atom. Due to the fact that monosaccharides contain multiple stereo-centers, many isomers including enantiomers, diastereomers, and epimers exist. Although mass spectrometry is capable of molecular weight determination, sequence identification of compounds, qualitative and quantitative analysis of components in a mixture, the characteristics of mass spectrometry have the inherent difficulty of distinguishing between different stereoisomer. Thus, it is difficult to distinguish between different diastereomers, such as glucose, galactose, mannose, allose, etc using mass spectrometry.
In aqueous solution, organoboronic acids have the ability to form boronate esters reversibly with multiple hydroxyl groups on monosaccharides. When organoboronic acids binds multi-hydroxyl groups of monosaccharides, the tetrahedral boron anion is formed at the boron atom. The boron anions can be detected as negative ion in the mass spectrometry and tandem mass spectrometry, profiling their fragment anions provides information on the stereo- and regiochemical configurations of the hydroxyl groups on the monosaccharides. Borate fragment anions derived from organoboronic acids show differential connections with hydroxyl groups, which reflect the steric structure of the monosaccharide. Thus, we developed the analysis of monosaccharide isomers using these characteristics of borate complexes.