Category: polyphenol
Aliases: Proanthocyanidins (yohimbe), Condensed tannins
The astringent condensed-tannin (proanthocyanidin) fraction of yohimbe bark (Pausinystalia johimbe) — oligo/polymeric flavan-3-ols built from catechin and epicatechin units. Pharmacognosy describes the bark as tannin-rich and notes the tannins precipitate the bark alkaloids. As a polymeric, ill-defined mixture it has no single molecular weight and no characterised receptor pharmacology.