Flavanols, occurrence

Biosynthesis Chemical reactions Flavan-3,4-diols Flavan-3-ols Flavan-4-ols Flavanols Occurrence Proanthocyanidins Stmctural features... 

Salas, E. et ah. Demonstration of the occurrence of flavanol-anthocyanin adducts in wine and in model solutions. Anal. Chim. Acta, 513, 325, 2004. 

Hollman PCH and Arts ICW. 2000. Flavonols, flavones and flavanols nature, occurrence and dietary burden. J SciFood Agric 80 1081-1093. 

Evidence of such adducts in wine fractions has been provided, as detailed in Chapter 9A. These include F-A+ (Alcalde-Eon et al. 2006 Boido et al. 2006) and F-A-A+ (Alcalde-Eon et al. 2006) adducts based on different flavanol and anthocyanin units and (F) -A+ adducts deriving from different flavanols monomers and oligomers (Hayasaka and Kennedy 2003). Proanthocyanidins arising from these reactions cannot be distinguished from those extracted from grapes. However, detection of F-A+ adducts without prior fractionation (Morel-Salmi et al. 2006) confirmed the occurrence of the acid-catalyzed interflavanic bond breaking process in wines. 

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