Cinnamtannin A2 – CAS 86631-38-1

Procyanidins are a sub class of proanthocyanidins (PACs), formed from (+) catechin and (-) epicatechin subunits. Procyanidins can be categorized into A-type and B-type, depending on the nature of the interflavan bonds. B-type procyanidins have a single interflavan bond. A-type procyanidins differentiate themselves from B-type procyanidins by containing a second interflavan bond between at least one set of subunits. The most abundant B-type tetrameric procyanidin is Cinnamtannin A2 ((−)-epicatechin tetramer,) (CAS 86631-38-1), which is found in popular dietary products such as apple skins, cocoa, and grapes.

Cinnamtannin A2 is being studied for a wide range of applications. It was reported to enhance GLP-1 and insulin secretion in mice, while also upregulating the expression of corticotrophin releasing hormone. It exhibits antioxidant, anti-diabetic, and nephroprotective effects. The compound has shown HIV-related and antioxidant activities. The epicatechin tetramer is also being studied for its ability to attenuate skeletal muscle disuse atrophy in mice. Dosage with the procyanidin tetramer have shown a shift to decreased muscle loss (Muta et al.). 

The most significant dietary sources of the procyanidin tetramer are apples and cocoa products. However, roasted cocoa products tend to show significantly decreases in concentrations of Cinnamtannin A2 as well as other procyanidins.

You can find additional procyanidin reference standards here.