It is the first time that such an exhaustive prodelphinidin dimers and trimers analysis is made in wines.
New prodelphinidin dimers and trimers were found.
The fragmentation patterns also suggest the presence of new procyanidins in wines.
A new nomenclature for procyanidins and prodelphinidins is suggested.
Proanthocyanidins (PAs) are one of the most important polyphenolic compounds in wine. Among PAs, prodelphinidin (PD) dimers and trimers have not been widely detected in wines due to the lack of available commercial standards and the difficulty to detect and isolate them from natural sources. LC–ESI-MS (liquid chromatography–electrospray ionization-mass spectrometry) with the right chromatographic conditions has proven to be a powerful tool for PAs detection and identification in complex samples. This technique has been applied to an exhaustive study of PA composition of two Portuguese red wines made with teinturier grapes, especially for the identification of PD dimers and trimers. Tandem mass spectrometry (MS/MS) with ion trap provided additional information about the structures of these compounds through the fragmentation patterns of the pseudomolecular ions. A LC–ESI-MS method was optimized and 41 different compounds were found. Among them are included 8 PD dimers and 13 PD trimers.