title: Deciphering the complexity of sainfoin (Onobrychis viciifolia) proanthocyanidins by MALDI-TOF mass spectrometry with a judicious choice of isotope patterns and matrixes.
abstract: Use of superdihydroxybenzoic acid as the matrix enabled the analysis of highly complex mixtures of proanthocyanidins from sainfoin (Onobrychis viciifolia) by MALDI-TOF mass spectrometry. Proanthocyanidins contained predominantly B-type homopolymers and heteropolymers up to 12-mers (3400 Da). Use of another matrix, 2,6-dihydroxyacetophenone, revealed the presence of A-type glycosylated dimers. In addition, we report here how a comparison of the isotopic adduct patterns, which resulted from Li and Na salts as MALDI matrix additives, could be used to confirm the presence of A-type linkages in complex proanthocyanidin mixtures. Preliminary evidence suggested the presence of A-type dimers in glycosylated prodelphinidins and in tetrameric procyanidins and prodelphinidins.
authors.affiliation: Chemistry & Biochemistry Laboratory, Animal Science Research Group, Department of Agriculture, University of Reading, P.O. Box 236, 1 Earley Gate, Reading RG6 6AT, United Kingdom. e.stringano@reading.ac.uk
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Stringano
authors.forename: Rainer
authors.initials: R
authors.lastname: Cramer
authors.forename: Wayne
authors.initials: W
authors.lastname: Hayes
authors.forename: Celia
authors.initials: C
authors.lastname: Smith
authors.forename: Trevor
authors.initials: T
authors.lastname: Gibson
authors.forename: Irene
authors.initials: I
authors.lastname: Mueller-Harvey
mesh_terms: D000098:Acetophenones / Q000737:chemistry; D019281:Dimerization; D007887:Fabaceae / Q000737:chemistry*; D006031:Glycosylation; D007553:Isotope Labeling; D044945:Proanthocyanidins / Q000032:analysis*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*
chemical_list: D000098:Acetophenones; D044945:Proanthocyanidins; C019339:2,6-dihydroxyacetophenone