Hydroxycinnamic Acid Antioxidants: An Electrochemical Overview

Table 1

Hydroxycinnamic acids and ester derivatives.

	R1	R2	R3
p-Coumaric	H	H	H
Caffeic acid	OH	H	H
5-Bromocaffeic acid	OH	Br	H
Methyl caffeate	OH	H	CH3
Ethyl caffeate	OH	H	CH2CH3
Ethyl 5-bromocaffeate	OH	Br	CH2CH3
Propyl caffeate	OH	H	CH2CH2CH3
Butyl caffeate	OH	H	CH2(CH2)2CH3
Hexyl caffeate	OH	H	CH2(CH2)4CH3
3,4,5-Trihydroxycinnamic acid	OH	OH	H
Ethyl 3,4,5-trihydroxycinnamate	OH	OH	CH2CH3
Ferulic acid	OCH3	H	H
5-Bromoferulic acid	OCH3	Br	H
Methyl ferulate	OCH3	H	CH3
Ethyl ferulate	OCH3	H	CH2CH3
Ethyl 5-bromoferulate	OCH3	Br	CH2CH3
Propyl ferulate	OCH3	H	CH2CH2CH3
Butyl ferulate	OCH3	H	CH2(CH2)2CH3
Hexyl ferulate	OCH3	H	CH2(CH2)4CH3
Sinapic acid	OCH3	OCH3	H
Methyl sinapate	OCH3	OCH3	CH3
Ethyl sinapate	OCH3	OCH3	CH2CH3
Propyl sinapate	OCH3	OCH3	CH2CH2CH3
Butyl sinapate	OCH3	OCH3	CH2(CH2)2CH3