STRUCTURAL-ANALYSES OF CARBON CHAINS IN 5-ALK(EN)YLRESORCINOLS OF RYEAND WHEAT WHOLE FLOUR BY TANDEM MASS-SPECTROMETRY

The locations of double bonds and the linearity of each carbon chain i n 5-alk(en)ylresorcinols present in rye and wheat whole flour were det ermined from collision-activated dissociation (CAD) spectra by tandem mass spectrometry. Among the determined alk(en)ylresorcinols, eleven a lkenylresorcinols (C-17 to C-23) and four alkadienylresorcinols (C-19 to C-25) had not been previously identified. In this study, we found t hat identification of a radical-anion fragment peak due to a simple al lylic cleavage on the methyl side was essential for determining the lo cations of double bonds in positionally isomeric alkenylresorcinols. I n addition, an analysis of the CAD spectra of lithium-adduct cations a s precursor ions was useful for determining the locations of the homoc onjugated (Z,Z)-diene group in alkadienylresorcinols.