Synonyms: 2-Propenoicacid, 3-(3,4-dihydroxyphenyl)-, (E)-; Cinnamic acid, 3,4-dihydroxy-, (E)-(8CI); Cinnamic acid, 3,4-dihydroxy-, trans- (7CI);(2E)-(3,4-Dihydroxyphenyl)-2-propenoic acid; (E)-3,4-Dihydroxycinnamic acid;(E)-3-(3,4-Dihydroxyphenyl)-2-propenoic acid; (E)-Caffeic acid;3,4-Dihydroxy-trans-cinnamic acid; trans-3,4-Dihydroxycinnamic acid;trans-Caffeic acid