Proanthocyanidins, also known as oligomeric proanthocyanidins (OPCs) or condensed tannins, are polymeric flavonoids composed of catechin and epicatechin subunits. They are extracted primarily from grape seeds (Vitis vinifera), pine bark (Pinus pinaster), and cranberry (Vaccinium macrocarpon).
OPCs possess antioxidant capacity 20-50 times greater than vitamins C and E, effectively scavenging free radicals and chelating metal ions. They cross-link collagen fibers, strengthen capillary walls, and inhibit enzymatic degradation of connective tissue. Commercially, proanthocyanidins are a flagship antioxidant ingredient in dietary supplements, cosmeceuticals, and cardiovascular health formulations.
