Table 1

Some examples of subclasses of naturally occurring flavonoids

Class	Flavonoids	Substituents
Class	Flavonoids	3	5	7	3′	4′	5′
Flavan-3-ols	(⁺)-Catechin	OH	OH	OH	OH	OH	H
Anthocyanidins	Cyanidin	OH	OH	OH	OH	OH	H
	Pelargonidin	OH	OH	OH	OH	H	H
Flavones	Apigenin	H	OH	OH	H	OH	H
	Diosmin	H	OH	Oru	OH	Ome	H
	Luteolin	H	OH	OH	OH	OH	H
Flavanones	Naringenin	H	OH	OH	H	OH	H
	Naringin	H	OH	Oru	H	OH	H
	Hesperetin	H	OH	OH	OH	Ome	H
	Hesperedin	H	OH	Oru	OH	Ome	H
Chalcones	Phloretin	OH (2)^3-a	OH (4)	OH (6)	H	H	OH (6′)
	Phloridzin	Ogl (2)	H (4)	OH (6)	H	H	OH (6′)
Flavon-3-ols	Quercetin	OH	OH	OH	H	OH	H
	Kaempferol	OH	OH	OH	H	OH	H
	Myricetin	OH	OH	OH	OH	OH	OH
	Fisetin	OH	H	OH	OH	OH	H
	Morin^3-b	OH	OH	OH	H	OH	H

ru, rutinose.
↵3-a Number in parentheses denotes additional similar substituent at the position indicated by the number.
↵3-b Morin has one more OH group at position 2′.