Hydroxybenzoic Acid Derivatives	R1	R2	R3	Hydroxycinnamic Acid Derivatives	R1	R2	R3
p-Hydroxybenzoic	H	OH	H	p-Coumaric	H	OH	H
Protocatechuic	OH	OH	H	Caffeic	OH	OH	H
Vanillic	OCH3	OH	H	Ferulic	OCH3	OH	H
Syringic	OCH3	OH	OCH3	Sinapic	OCH3	OH	OCH3
Gallic	OH	OH	H