... ), also known as procyanidin, oligomeric proanthocyanidin (OPC), leukocyanidin, leucoanthocyanin and condensed tannins, is a class of flavanols. Proanthocyanidins are essentially polymer chains ... and other sugars) and phenylpropanoids, such as lignins, flavonoids, and condensed tannins. -Proanthocyanidins 99% 95%-Polyphenols 95% 90% 85% 80%;-Oligomeric Proanthocyanidins ...