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Titre du document / Document title

Tandem mass spectrometry of the B-type procyanidins in wine and B-type dehydrodicatechins in an autoxidation mixture of (+)-catechin and (-)-epicatechin

Auteur(s) / Author(s)

WEIXING SUN (1) ; MILLER Jack M. (1) ;

Affiliation(s) du ou des auteurs / Author(s) Affiliation(s)

(1) Chemistry Department, Brock University, St. Catharines, Ontario, L2S 3A1, CANADA

Résumé / Abstract

We describe the characterization of the B-type procyanidins in wine and the B-type dehydrodicatechins (dimeric flavan-3-ols) obtained for the autoxidation of (+)-catechin and (-)-epicatechin by tandem mass spectrometry (MS/MS) coupled to reversed-phase high-performance liquid chromatography (HPLC). The MS/MS analysis demonstrates that the interesting major fragments derive from the dissociations of the C-ring on the catechin or epicatechin unit, such as retro-Diels-Alder reactions. The two kinds of dimers give completely different fragmentations because of the striking effect of the C-C interflavan linkage (IFL). For the natural dimers in wine, a catechin or epicatechin unit linking to the C-4 position stabilizes the product ions by forming a large n-n hyperconjugated system, whereas a similar π-π system is formed within dehydrodicatechin B through the C-C IFL. Thus dissociation in MS/MS experiments was inhibited. Apparently, the fragmentations of the dimers differ from that of the monomer, which is very important in the study of the gas-phase ion behaviour of the polymeric flavan-3-ols. In addition, two specific fragment ions at m/z 451 for native dimers and at m/z 393 for autoxidation species in HPLC/MS/MS were found to be very useful for analysing mixtures of B-type procyanidins and B-type dehydrodicatechins in food and beverages.

Revue / Journal Title

Journal of mass spectrometry    ISSN  1076-5174 

Source / Source

2003, vol. 38, no4, pp. 438-446 [9 page(s) (article)] (20 ref.)

Langue / Language

Anglais

Editeur / Publisher

Wiley, Chichester, ROYAUME-UNI  (1995) (Revue)

Mots-clés anglais / English Keywords

Mass spectrometry

;

Coupled method

;

Electrospray

;

Mass spectrometry MS/MS

;

Autoxidation

;

Dimer

;

Enantiomer

;

Epimer

;

Catechin

;

Phenols

;

Polyphenol

;

Flavonoid

;

Wine

;

Chemical analysis

;

Mots-clés français / French Keywords

Flavane dérivé

;

1-Benzopyrane dérivé

;

Procyanidine B2

;

Procyanidine

;

Spectrométrie masse

;

Méthode couplée

;

Electrospray

;

Spectrométrie masse tandem

;

Autooxydation

;

Dimère

;

Enantiomère

;

Epimère

;

Catéchine

;

Phénols

;

Polyphénol

;

Flavonoïde

;

Vin

;

Analyse chimique

;

Mots-clés espagnols / Spanish Keywords

Espectrometría masa

;

Método acoplado

;

Electrospray

;

Espectrometría masa en tandem

;

Autooxidación

;

Dímero

;

Enantiómero

;

Epímero

;

Catequina

;

Fenoles

;

Polifenol

;

Flavonoide

;

Vino

;

Análisis químico

;

Mots-clés d'auteur / Author Keywords

tandem mass spectrometry

;

B-type procyanidins

;

B-type dehydrodicatechins

;

interflavan linkage

;

Localisation / Location

INIST-CNRS, Cote INIST : 22950, 35400011103620.0100

Nº notice refdoc (ud4) : 14708334



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