Submitted to: American Chemical Society National Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 5/15/2007
Publication Date: 8/19/2007
Citation: Prior, R.L., Howard, L., Wu, X., Hager, T. 2007. Absorption of anthocyanins from berries: Metabolic products and influence of glycoside [abstract]. American Chemical Society 234th National Meeting and Exposition, August 19-23, 2007, Boston, Massachusetts. Abstract AGFD 4. 2007 CDROM.
Interpretive Summary: Anthocyanins (ACNs) are the flavonoid compounds in some fruits and berries that give them the dark blue or deep red colors. There are 6 common basic structures of ACNs, but numerous different sugars may be attached to this basic structure, giving over 300 different ACNs in different foods. The absorption and metabolism of ACNs is altered by the different sugar and the amounts consumed. ACNs are unique among the flavonoids in that they are absorbed with the sugars attached, whereas other flavonoids in fruits require the sugars to be removed before absorption. Complex ACNs containing two or three sugars disappear more slowly from the gastrointestinal tract than those with only one sugar, and those that are absorbed are not metabolized to any great extent. Bacteria in the cecum and colon of the gastrointestinal tract can metabolize ACNs to simple phenolic acids. The data clearly demonstrate that the number of sugars can alter apparent absorption and metabolism of ACNs.
Technical Abstract: Anthocyanins (ACNs) are unique among the flavonoids in that they are absorbed as the intact glycoside. Berries are rich sources of anthocyanins; differences among the berries in aglycone as well as in sugar moieties provide opportunities to study factors that influence absorption/metabolism. The relative proportions of different metabolites depended upon concentrations, amounts consumed, and type of glycosides of ACNs. Cyanidin aglycone with different sugar moieties varied in recovery within the gastrointestinal tract (GIT) with sambubiose>sambubiose-rhamnose=rutinose>>glucose. Complex ACNs containing di- or tri-glycosides disappeared more slowly than simple monoglycoside ACNs. Phenolic acids (protocatechuic acid and 3-hydroxybenzoic acid) were recovered in the GIT, which appeared to be formed from ACNs. Homoprotocatechuic acid was a major phenolic acid detected in the cecum/colon. Cyanidin and other ACN monoglycosides were metabolized via methylation and glucuronidation as well as by formation of both derivatives on the same ACN molecule. Over 80% of the ACN compounds containing rutinose or sambubiose excreted in urine were excreted intact. The data clearly demonstrate that the sugar moieties can alter apparent absorption and metabolism of ACNs.