Oligomeric Proanthocyanidins

Figure 1. The chemical structure of different forms of Proanthocyanidins.

Proanthocyanidins are a class of polyphenols found in many plants, such as cranberry, blueberry, and grape seeds. Proanthocyanidins are Bioflavonoids with oligomeric chemical structure (i.e. a molecule which consists of a few repeating units). Many Proanthocyanidins are oligomers of catechin and epicatechin and their gallic acid esters. More complex polyphenols, having the same polymeric building block, form the group of tannins.

Oligomeric Proanthocyanidins strictly refers to oligomers of catechins. Some common food sources of Oligomeric Proanthocyanidins include:

• Grape seeds and skins
• Red wine
• Cocoa
• Nuts
• Plums (with skin)
• Cherries (with skin)
• Peaches (with skin)
• Nectarines (with skin)
• Apricots (with skin)
• Cinnamon bark
• Blueberries
• Cranberries
• Aronia (or Chokeberries)
• Hawthorn
• Rosehip
• Sea Buckthorn

Taken as a dietary supplement, Oligomeric Proanthocyanidins are commonly promoted to help with urinary tract infections. Oligomeric Proanthocyanidins may be important in certain protein binding processes (such as those present in the fimbriae of the E. coli bacteria) which inhibit bacterial infections.

Oligomeric Proanthocyanidins, being a Bioflavanoid, are also promoted for antioxidant, anticancer, antidiabetic, and neuroprotective abilities. However, there is insufficient scientific evidence presently to conclusively determine the efficacy of Oligomeric Proanthocyanidins in these applications.