French maritime pine bark extract (Pinus maritima, PBE) is a complex mixture of bioflavonoids, with oligometric proanthocyanidins (OPCs) as the major constituents. OPCs are dimers or oligomers of catechin, epicatechin, and their gallic acid esters. The major OPCs in PBE are proanthocyanidin B1 (epicatechin-(4β→8)-catechin), catechin, and epicatechin.1