Anthocyanins high speed countercurrent

Degenhardt, A., Knapp, H., and Winterhalter, P, Separation and purification of anthocyanins by high-speed countercurrent chromatography and screening for antioxidant activity, J. Agric. Food Chem., 48, 338, 2000. 

Schwarz, M. et al.. Application of high-speed countercurrent chromatography to the large-scale isolation of anthocyanins, Biochem. Eng. J., 14, 179, 2003. 

Anthocyanin may also dimerize yielding A-A dimers. Such dimers were tentatively identified by ESI-MS in grape skin extracts (Vidal et al, 2004), as well as in red wine fractions obtained by high-speed countercurrent chromatography (Salas et al, 2005) and by fractionation on Toyopearl after bisulfite bleaching (Alcalde-Eon et al, 2007). Two structures have been proposed for A-A+ A-type bond (C4-C8 and C2-0-C7) flavan-fiavylium dimers and B-type bond (C4-C8) flavene-flavylium (Vidal et al, 2004). Oligomers consisting of a flavanol residue directly linked to an anthocyanin dimer (F-A-A" ) have also been recently identified in red wine fractions (Alcalde-Eon et al., 2007). 

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