Evidence for linkage position determination in known feruloylated mono- and disaccharides using electrospray ion trap mass spectrometry.
Various feruloylated arabinose- and galactose-containing mono- and disaccharides with known linkage configurations (2-O-(trans-feruloyl)-L-arabinopyranose, 5-O-(trans-feruloyl)-L-arabinofuranose, O-[2-O-(trans-feruloyl)-alpha-L-arabinofuranosyl]-(1-->5)-L-arabinofuranose, and O-[6-O-(trans-feruloyl)-beta-D-galactopyranosyl]-(1-->4)-D-galactopyranose) were analyzed by electrospray ionization mass spectrometry using an ion trap or a quadrupole time-of-flight (Q-TOF) mass analyzer. Collision-induced dissociation (CID) experiments using the two mass analyzers generated similar tandem mass spectrometric (MS/MS) fragmentation patterns. However, the ester-bond cleavage ions were more abundant using the Q-TOF mass analyzer. Compared with the positive ion mode, the negative ion mode produces simpler and more useful CID product-ion patterns. For arabinose-containing feruloylated compounds, results obtained with both analyzers show that it is possible to assign the location of the feruloyl group to the O-2 or O-5 of arabinosyl residues. In the characterization of the 2-O-feruloyl and 5-O-feruloyl linkages, the relative abundance of the cross-ring fragment ions at m/z 265 (-60 u or -62 u after 18O-labelling) and at m/z 217 (-108 u or -110 u after 18O-labelling) play a relevant role. For galactose-containing feruloylated compounds, losses of 60, 90 and 120 Da observed in MS3 experiment correspond to the production of 0,2A1, 0,3A1 and (0,2A1-60 Da) cross-ring cleavage ions, respectively, fixing the location of feruloyl group at the O-6 of the galactose residue.
Quéméner
Bernard
B
Institut National de la Recherche Agronomique, Unité de Recherche sur les Polysaccharides, leurs Organisations et Interactions, rue de la Géraudière, BP 71627, 44316 Nantes Cedex 03, France. quemener@nantes.inra.fr
Ralet
Marie-Christine
MC
D001089:Arabinose / Q000031:analogs & derivatives* / Q000737:chemistry; D003373:Coumaric Acids / Q000737:chemistry*; D004187:Disaccharides / Q000737:chemistry*; D005690:Galactose / Q000031:analogs & derivatives / Q000737:chemistry; D009005:Monosaccharides / Q000737:chemistry*; D010944:Plants / Q000737:chemistry*; D021241:Spectrometry, Mass, Electrospray Ionization
D003373:Coumaric Acids; D004187:Disaccharides; D009005:Monosaccharides; C431714:arabinofuranose; C056853:6-O-galactopyranosylgalactose; C004999:ferulic acid; D001089:Arabinose; D005690:Galactose