Before revision: Definition Ellagic acid, a polyphenol The term polyphenol is not well-defined, but is generally agreed that they are natural products with " one or more hydroxyl groups on aromatic rings" including four principal classes: "phenolic acids, flavonoids, stilbenes, and lignans".
After revision: Definition Ellagic acid, a polyphenol The term polyphenol is not well-defined, but is generally agreed that they are natural products with " several hydroxyl groups on aromatic rings" including four principal classes: "phenolic acids, flavonoids, stilbenes, and lignans".