File:2-Phenyl-1,4-benzopyrone.svg<unk>  are a class of flavonoids based on the backbone of 2-phenylchromen-4-one (2-phenyl-1-benzopyran-4-one) shown on the right.
Natural<unk>  include Apigenin (4',5,7-trihydroxyflavone, Luteolin (3',4',5,7-tetrahydroxyflavone) and Tangeritin (4',5,6,7,8-pentamethoxyflavone). Synthetic<unk>  are Diosmin and Flavoxate
Flavones
Flavonoid
Oxoacid
Furan
Indole alkaloid
Terpene
Starch
Polycyclic aromatic hydrocarbon