ellagitannin
image:Castalagin.svg, 130px, Castalagin is a representative ellagitannin, characterized by coupled gallic acid substituents
The ellagitannins are a diverse class of hydrolyzable tannins, a type of polyphenol formed primarily from the oxidative link ...
. It can be found in '' Cowania mexicana'', '' Coleogyne ramosissima'' and '' Quercus stenophylla''.Tannins and related compounds part 26: isolation and structures of stenophyllanins A, B, and C, novel tannins from Quercus stenophylla, G. Nonaka, H. Nishimura, I. Nishioka, J. Chem. Soc. Perkin Trans. 1, 1985, pp. 163–172,