Figure 2.

(A) MALDI-TOF MS/MS spectrum of the ion [3-AQ/M + H]⁺ at m/z 1055.360 from the digestion of gum arabic with the enzyme cocktail and list of the possible isomers of Pent₂Hex₂dHexHexA. The fragmented Y-ions (noted as Y, Y’ and Y” to distinguish the isomers) are observed. (B) MALDI-TOF MS/MS spectrum of the ion [3-AQ/M + H]⁺ at m/z 1187.409 from the digestion of gum arabic with the enzyme cocktail and list of the possible oligosaccharidic isomers of Pent₃Hex₂dHexHexA (a–f) and Pent₂Hex₃dHex₂ (g,h). The fragmented Y-ions (noted as Y, Y’, Y” and Y”’ to distinguish the isomers) are observed. The y axis of spectra is the relative intensity.