- Day 1, May 15（Wed.） Room P (Multi-purpose Hall)
Isomeric Analysis of Saccharide in Alkaloid and Flavonoid Glycosides Using Borate Complexes and Tandem Mass Spectrometry
Glycoconjugates control a lot of biological processes such as molecular recognition and cellular interaction, etc. They are carbohydrates that are covalently linked with proteins (glycoproteins, peptidoglycans), peptides (glycopeptides), lipids (glycolipids), flavonoids, alkaloids (glycosides). The structure of carbohydrate is described by its composition, connectivity, and configuration. 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, such as saccharides.
In aqueous solution, organoboronic acids have the ability to form boronate esters reversibly with multiple hydroxyl groups on saccharides. When organoboronic acids bind multi-hydroxyl groups of saccharides, the tetrahedral boron anion is formed at the boron atom. We thought that the boron anions can be detected as negative ion in the mass spectrometry and tandem mass spectrometry, their fragment anion’s profiling presents stereo- and regio- information of hydroxyl groups on the saccharides. Thus, we performed the analysis of saccharide isomers on the alkaloid and flavonoid glycosides using these characteristics of borate complexes.