Synonyms--- Proanthocyanidin B4 Proanthocyanidin B4 is a B type proanthocyanidin.Proanthocyanidin-B4 is a catechin-(4α→8)-epicatechin dimer. It is found in the litchi pericarp, in grape seeds, and, along with 4-cis-isomer of procyanidin B4, in beer. Chemical Name: CAS Number: 29106-51-2 Molecular Formula: C30H26O12 Mol. Wt.: 578.52 Molecular Structure: Vitis vinifera (Common Grape Vine) is a species of Vitis, native to the Mediterranean region, central Europe, and southwestern Asia, from Morocco and Spain north to southern Germany and east to northern Iran. It is a liana growing to 35 m tall, with flaky bark. The leaves are alternate, palmately lobed, 5–20 cm long and broad. The fruit is a berry, known as a grape; in the wild species it is 6 mm diameter and ripens dark purple to blackish with a pale wax bloom; in cultivated plants it is usually much larger, up to 3 cm long, and can be green, red, or purple. The species typically occurs in humid forests and streamsides. Oligomeric proanthocyanidins (OPCs) are some of the most abundant polyphenolic substances in the plant kingdom. Proanthocyanidins are an integral part of the human diet, found in high concentrations in fruits such as apple, pear, and grapes, and in chocolate, wine, and tea. OPCs in nutritional supplements are generally extracted from grape seeds or pine bark. Due to potent antioxidant activity, OPCs have been the subject of recent research, demonstrating anticarcinogenic, anti-inflammatory, antimicrobial, and vasodilatory properties, making them a potentially valuable therapeutic tool for the treatment of a variety of conditions. The Grape Seed Extract used in dietary supplements is derived from the seeds of the plant grape(Vitis vinifera L.).