Blue anthocyanin-derived pigments

Mateus, N. et al., A new class of blue anthocyanin-derived pigments isolated from red wines. J. Agric. Food Chem. 51, 1919, 2003. 

Mateus, N., Silva, A. M. S., Rivas-Gonzalo, J. C., Santos-Buelga, C., de Freitas, V. A. P. (2003). A new class of blue anthocyanin-derived pigments isolated from red wines. J. Agric. Food Chem., 51, 1919-1923. 

Structural Changes of Anthocyanins during Red Wine Aging Portisins A New Class of Blue Anthocyanin-Derived Pigments... 

Mateus N, Silva AMS, Rivas-Gonzalo JC, Santos-Buelga C, de Freitas V (2003) A New Class of Blue Anthocyanin-Derived Pigments Isolated from Red Wines. J Agric Food Chem 51 1919-1923... 

Bloor, S.J., Blue flower colour derived from flavonol-anthocyanin co-pigmentation in Ceanothus papillosus, Phytochemistry, 45, 1399, 1997. 

The majority of the plant pigments hitherto isolated from woods in pure form are the flavonoids, such as flavone, flavanone, isoflavone, isoflavanone, pterocar-pane, and chalcone derivatives, along with the phenols stilbene and xanthone, which are almost white or yellow in color. Other flavonoids such as aurone and neoflavone derivatives (orange pigments) have a limited distribution and sometimes occur as wood extractives in species of the Anacardiaceae and Leguminosae (4, 7). The presence of the typical anthocyanin derivatives of flowers and fruits is extremely rare in wood, but their leuco-compounds such as flavan-3-ol and flavan-3,4-diol have been found to occur in the wood of a considerable number of tree species (14). Besides anthocyanidin, the few other deep-colored (red, purple, or blue) pigments from woods usually possess a quinone structure. 

Tertiary oxonium salts derived from benzopyranole (chromanole) occur in the anthocyanin series, the red and blue pigments of many flowers and fruits (R. Willstatter, P. Karrer, R. Robinson). 

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