Mass Spectrometry of Flavonoids

Abstract

Electron impact mass spectrometry of both flavonoid aglycones and glycosides serves as a valuable aid in determining their structures, especially when only very small quantities (1.e. less than 1 mg) of the compounds are available. It has been applied successfully to all classes of flavonoid aglycones (Porter and Baldas, 1971) and more recently to a number of different types of glycosides including mono- and di-C-glycosylflavones and mono- to tetra-O-glycosides. In contrast, chemical ionization (CI), using methane as the reactant gas, has only been applied to a few aglycones and gives few diagnostic fragments except for flavanones and dihydroflavonols (Kingston and Fales, 1973); therefore, this account will be largely restricted to electron impact mass spectrometry of flavonoids.