Tara (Caesalpinia spinosa Kuntze), also known as spiny holdback, is an evergreen shrub of the genus Caesalpinia in the legume family. It grows in northwestern South America, mainly in Peru and Ecuador, primarily in valleys and river basins of the Andes Mountains near the Pacific coast.

Appearance: Light brown amorphous powder

A natural compound extracted and isolated from tara pods. An ester composed of galloyl and polygalloyl groups combined with quinic acid, with an average of 4–5 galloyl groups per quinic acid unit.

The chemical structure of tara tannin is a polygallic acid ester with 3,4,5-tri-O-galloyl-quinic acid as the “core,” equivalent to one quinic acid combined with 4–5 galloyl groups, with an average molecular formula of C₃₅H₂₈O₃₂. The galloyl group structure in tara tannin molecules is the same as that in Chinese gallnut tannin.

Tara tannin belongs to the hydrolyzable tannin class.