procyanidin procyanidin B2 A proanthocyanidin consisting of two molecules of (-)-epicatechin joined by a bond between positions 4 and 8' in a beta-configuration. Procyanidin B2 can be found in Cinchona pubescens (Chinchona, in the rind, bark and cortex), in Cinnamomum verum (Ceylon cinnamon, in the rind, bark and cortex), in Crataegus monogyna (Common hawthorn, in the flower and blossom), in Uncaria guianensis (Cat's claw, in the root), in Vitis vinifera (Common grape vine, in the leaf), in Litchi chinensis (litchi, in the pericarp), in the apple, in Ecdysanthera utilis and in red wine.