The main constituents found in the galls of Quercus infectoria are tannin (50-70%, the highest naturally occurring tannin concentration)[REF] and small amounts (2-4% each) of free gallic acid and ellagic acid, which are polymerized to make tannins [REF].
Hydrolyzable tannins are present in many different plant species but are found in particularly high concentrations in nut galls growing on Rhus semialata (Chinese and Korean gallotannins) and Quercus infectoria (Turkish and Chinese gallotannins), the seedpods of Caesalpinia spinosa (Tara tannins), and the fruits of Terminalia chebula.