Phlobaphene

[5] Phlobaphenes from hawthorn fruits (Fructus Crataegi) may have a specific action on the coronary circulation[citation needed].

[6] Natural phlobaphenes are the common bark, pericarp, cob glume and seed coat (testa) pigments.

[7] In bark, phlobaphenes accumulate in the phellem layer of cork cambium, part of the suberin mixture.

[11] They are common in redwoods barks like Sequoia sempervirens[12] or in oak barks where the chief constituent, quercitannic acid, a molecule also present in quercitron, is an unstable substance, having a tendency to give off water to form anhydrides (phlobaphenes), one of which is called oak-red (C28H22O11).

[18] Phlobaphenes are not present in the model plant Arabidopsis thaliana but can be studied as the pigment responsible for the red color in some monocot cereals, including wheat,[19] maize[20] or sorghum.

This type of extract is rich in condensed tannins of natural high molecular weight (phlobaphenes), which are not easily soluble.

The main properties of these extracts are: a very rapid penetration, a high tannin content and a relatively low percentage of non-tannins.