Grape Seed Extrac contains active ingredient named OPC Proanthocyanidin (also known as procyanidin oligomeric proanthocyanidin (OPC), pycnogenol, leukocyanidin, leucoanthocyanin and condensed tannins ... 0.47 +/- 0.15 mmol of TE, and 2.42 +/- 0.88 mmol of TE of ORAC/day, respectively. ... of grape juice averages 124 milligrams OPCs, while a 5 ounce serving of red wine averages 91 milligrams.Many ...