Assignment of acetyl groups to O-2 and/or O-3 of pectic oligogalacturonides using negative electrospray ionization ion trap mass spectrometry.
Partially acetylated and methylated oligogalacturonides produced by enzymatic hydrolysis of sugar beet pectin were analysed by negative electrospray ionization ion trap mass spectrometry (ESI-ITMS). The (18)O labelling of the oligomer reducing end allowed the precise assignment of the fragments resulting from glycosidic bond and cross-ring cleavages. The collisional-induced dissociation of the C(i) and Z(j) fragment ions through sequential MS(n) experiments always displayed (0, 2)A-type cross-ring cleavage ions which were related to C(2)H(4)O(2) losses. These (0, 2)A ions appeared to be highly diagnostic ions allowing the precise location of the acetyl groups to the O-2 and/or O-3 of the acetylated galacturonic acid residues.
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, France. quemener@nantes.inra.fr
Cabrera Pino
Juan Carlos
JC
Ralet
Marie-Christine
MC
Bonnin
Estelle
E
Thibault
Jean-François
JF
D000107:Acetylation; D027461:Beta vulgaris / Q000737:chemistry; D002240:Carbohydrate Sequence; D008969:Molecular Sequence Data; D009844:Oligosaccharides / Q000032:analysis* / Q000737:chemistry*; D010368:Pectins / Q000737:chemistry*; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*
D009844:Oligosaccharides; C412763:oligogalacturonic acid; D010368:Pectins