Wiktionary
phlobaphene
n. Any of various reddish-brown phenolic substances found in the bark of oak, etc.
Wikipedia
Phlobaphene
Phlobaphenes (or phlobaphens, CAS No.:71663-19-9) are reddish, alcohol-soluble and water-insoluble phenolic substances. They can be extracted from plants, or be the result from treatment of tannin extracts with mineral acids (tanner's red). The name phlobaphen come from the Greek roots φλoιὀς (phloios) meaning bark and βαφή (baphe) meaning dye.
No biological activities have currently been reported for phlobaphenes. Phlobaphenes from hawthorn fruits (Fructus Crataegi) may have a specific action on the coronary circulation. They are converted into humins in soils.