It contains
high amounts of the flavonoids (−)- epicatechin (EC), (+)- catechin and their dimers procyanidins B2 (PB2) and B1, and other polyphenols such as quercetin, isoquercitrin (quercetin 3 - O - glucoside), quercetin 3 - O -
arabinose, hyperoside (quercetin 3 - O - galactoside), naringenin, luteolin and apigenin have also been found in minor quantities.