Procyanidin B1 is a polyphenol flavonoid existing as a dimer of (+)-catechin and (−)-epicatechin . It inhibits hepatitis C virus RNA replication (EC50 = 72 μM), while (+)-catechin and (−)-epicatechin do not, up to concentrations of 200 μM. Procyanidin B1 (10 μg/ml) prevents phosphorylation of ERK1/2 and the production of reactive oxygen species (ROS) in THP-1 cells. It decreases TNF-α, phosphorylated p38 MAPK, and NF-κB levels following LPS administration.
ChEBI: Procyanidin B1 is a proanthocyanidin consisting of (-)-epicatechin and (+)-catechin units joined by a bond between positions 4 and 8' respectively in a beta-configuration.. Procyanidin B1 can be found in Cinnamomum verum (Ceylon cinnamon, in the rind, bark or cortex), in Uncaria guianensis (cat's claw, in the root), and in Vitis vinifera (common grape vine, in the leaf) or in peach. It has a role as a metabolite, an EC 3.4.21.5 (thrombin) inhibitor and an anti-inflammatory agent. It is a hydroxyflavan, a proanthocyanidin, a biflavonoid and a polyphenol. It is functionally related to a (-)-epicatechin and a (+)-catechin.