Fast atom bombardment of flavonols

Abstract

The positive ion fast atom bombardment (FAB) mass spectra of flavonols show reasonably abundant [M + H]+ ions. The protonated aglycone is the base peak in the spectra of all compounds investigated. The various protonated aglycones show structure-specific fragmentation reactions, which are more distinct in their metastable ion and collisional activation spectra. Discrimination between isomeric aglycones is possible using these characteristics. The number and size of the monosaccharides in the glycosides can be established. Their positional identity, however, cannot be derived from FAB spectra.