Elderberry (Sambucus nigra L.) was selected because of its content of anthocynins predominantly in the form of cyanidin as the aglycon. 10 fruit extracts of different varieties of elderberry were analysed in vitro for their interaction with copper and iron. Both cyanidin and extracts were able to chelate iron but their copper chelating properties were much lower.
All extracts and cyanidin reduced both mentioned metals. Notwithstanding standardization to the cyanidin content, the effect was not equal.
Possible biological importance is discussed.