Polyphenol

Representative chemical structure of one of many plant-derived polyphenols that comprise tannic acid. Such compounds are formed by esterification of phenylpropanoid-derived gallic acid to a monosaccharide (glucose) core.

Polyphenols (/ˌpɒliˈfiːnoʊl, -nɒl/) are a large family of naturally occurring phenols. They are abundant in plants and structurally diverse. Polyphenols include phenolic acids, flavonoids, tannic acid, and ellagitannin, some of which have been used historically as dyes and for tanning garments.

Curcumin, a bright yellow component of turmeric (Curcuma longa), is a well-studied polyphenol.