BioMed Research International / 2013 / Article / Tab 4 / Review Article
Hydroxycinnamic Acid Antioxidants: An Electrochemical Overview Table 4 Redox potentials and antioxidant activity of hydroxycinnamic acids, ester and amide derivatives.
Compound MW (gmol−1 ) DPPH (TE)* DPPH (IC50 )*†
(mV)Reference p -Coumaric164.16 >100 +736 [6 ] Caffeic acid 180.16 1.29 16.6 +183 [7 , 8 ] Hydrocaffeic acid 182.18 2.05 15.4# +139 [8 ] 5-Bromocaffeic acid 259.05 1.01 +182 [7 ] Methyl caffeate 194.18 14.0 +165 [9 ] Ethyl caffeate 208.21 13.5 +170 [9 ] Ethyl 5-bromocaffeate 287.11 0.938 +174 [7 ] Propyl caffeate 222.24 14.5 +173 [9 ] Butyl caffeate 236.26 14.1 +176 [9 ] Hexylcaffeate 264.32 0.970 +175 [8 ] Hexylhydrocaffeate 266.34 0.990 +125 [8 ] Caffeoylhexylamide 263.34 1.11 +162 [8 ] Hydrocaffeoylhexylamide 265.35 1.00 +125 [8 ] Ferulic acid 194.19 0.781 44.6 +335; +447 [7 ] Hydroferulic acid 196.20 84.0# +410 [8 ] 5-Bromoferulic acid 273.08 0.808 +335; +442 [7 ] Methyl ferulate 208.21 74.7 +375 [9 ] Ethyl ferulate 222.24 66.7 +370 [9 ] Ethyl 5-bromoferulate 301.13 0.558 +365 [7 ] Propyl ferulate 236.26 64.1 +364 [9 ] Butyl ferulate 250.29 56.3 +343 [9 ] Hexylferulate 278.35 +328 [8 ] Hexylhydroferulate 280.36 +434 [8 ] Feruloylhexylamide 277.36 +322 [8 ] Hydroferuloylhexylamide 279.38 +388 [8 ] Sinapic acid 224.21 0.862 32.2 +188; +295 [10 ] Methyl sinapate 238.24 48.7 +219 [10 ] Ethyl sinapate 252.26 51.9 +189 [10 ] Propyl sinapate 266.29 50.6 +182 [10 ] Butyl sinapate 280.32 50.1 +190 [10 ] 3,4,5-Trihydroxycinnamic acid 196.16 11.8 +11; +384 [11 ] Ethyl 3,4,5-trihydroxycinnamate 224.21 15.1 +26; +133 [11 ]
*The results of DPPH assays are usually expressed as TEAC (trolox equivalent antioxidant capacity) or IC50 (concentration which is required to scavenge 50% of DPPH free radicals). These values are not convertible.† IC50 is presented in μ mol L−1 .
# Unpublished results.