DESCRIPTION

Tannic Acid occurs as an amorphous powder, as glistening scales, or as spongy masses, varying in color from yellow-white to light brown. It is odorless or has a faint, characteristic odor and an astringent taste. It is a complex polyphenolic organic structure that yields gallic acid and either glucose or quinic acid as hydrolysis products. It is obtained by solvent extraction from the nutgalls or the excrescences that form on the young twigs of Quercus infectoria Olivier and allied species of Quercus L. (Fam. Fagaceae); from the seed pods of Tara (Caesalpinia spinosa) (Fam. Leguminosa); or from the nutgalls of various sumac species, including Rhus semialata, R. coriaria, R. galabra, and R. typhia (Fam. Anacardiaceae). Tannic acid is very soluble in water, in acetone, and in alcohol; slightly soluble in absolute alcohol; and practically insoluble in chloroform, in ether, and in solvent hexane. One g dissolves in about 1 mL of warm glycerin.