Biotransformation of anthocyanins from Vitis amurensis Rupr of "Beibinghong" extract by human intestinal microbiota.

1. Anthocyanins (ACNs) are a subclass of polyphenolic pigments belonging to the flavonoids and constitute an important group of human diets. There is accumulated evidence that consumption of ACN-rich diets such as Vitis amurensis Rupr of "Beibinghong" exerts protective activities against some human diseases. These beneficial properties may be due to the biotransformation by intestinal microbiota and its related bacterial dependent metabolism of ACNs. However, despite the compositional characterization of ACNs in extracts from V. amurensis Rupr, the biotransformation pathways of these compounds in the human intestinal tract have not been investigated so far. 2. In this study, the biotransformation of ACNs by the human intestinal microbiota and the derived metabolites were analyzed and characterized by RRLC-Q-TOF-MS and MS/MS methods. Eight kinds of ACNs were identified and could be bio-transformed under the action of human intestinal microbiota. The biotransformation pathway analysis showed that the microbiota acted by removing all glucosides to produce the corresponding aglycones, which were subsequently converted to phenolic acid and aldehydes. 3. These findings shed light on the mechanisms of ACNs degradation by the human intestinal microbiota and will lay a foundation for the industrial and pharmacological applications of the ACNs.