پلی‌فنل

Also known as polyphenols, polyhydroxyphenol, polyphenolic compound

290px|thumb|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 () 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.