title: Study of isobaric grape seed proanthocyanidins by MALDI-TOF MS.
abstract: Positive matrix-assisted laser desorption ionization (MALDI) spectra of grape seed raw extracts show the signals of putative proanthocyanidin (PA) oligomers, including those of several sodium and potassium adducts with the same nominal molecular weight. As a result, the MALDI time-of-flight profiles are characterized by several isobaric signals from different PAs. The presence of isobaric PA adducts was studied by sodium and potassium exchange experiments on the seed extracts of six grape varieties. This approach was effective in differentiating PAs with isobaric signals, and 15 different PAs were identified in the MALDI spectra of all samples.
authors.affiliation: CRA-VIT, Viale XXVIII aprile 26, 31015, Conegliano, Treviso, Italy.
authors.forename: Fabiola
authors.initials: F
authors.lastname: De Marchi
authors.forename: Roberta
authors.initials: R
authors.lastname: Seraglia
authors.forename: Laura
authors.initials: L
authors.lastname: Molin
authors.forename: Pietro
authors.initials: P
authors.lastname: Traldi
authors.forename: Antonio
authors.initials: A
authors.lastname: Dalla Vedova
authors.forename: Massimo
authors.initials: M
authors.lastname: Gardiman
authors.forename: Mirko
authors.initials: M
authors.lastname: De Rosso
authors.forename: Riccardo
authors.initials: R
authors.lastname: Flamini
keywords: MS; grape seeds, MALDI-TOF; isobaric; proanthocyanidins