The Mass Spectra of Flavonoids

The fragmentation of flavonoids by electron impact has been studied and the following results described: 1) Chalcones gave the usual fragmentation pattern; however, 2′-hydroxychalcones showed complex spectra according to the isomerization of chalcone to flavanone. 2) The fragmentation pathways of flavones were decided by comparison with many kinds of halogen-substituted flavones. 3) Isoflavone gave the M-1ion as the base peak, and no loss of CO was observed. 4) Some natural flavanones-desmethoxymatteucinol and sakuranetin derivatives-were also measured. The mass spectra were consistent with their structures.