Any of a family of yellow pigments which are chemically similar to tannins and somewhat similar in use; flavonoids have been used for bruising, hay fever and menorrhagia. Flavonoids can be classified into:
- flavonoids or bioflavonoids
- isoflavonoids, derived from 3-phenylchromen-4-one (3-phenyl-1,4-benzopyrone) structure
- neoflavonoids, derived from 4-phenylcoumarine (4-phenyl-1,2-benzopyrone) structure