3,4-Dihydroxybenzoic acid 99-50-3 3, 4-Dihydroxybenzoic acid 3,4-dihydrobenzoic acid SMR000528167 protocatechuic acid DHB CHEBI:36062 4-Carboxy-1,2-dihydroxybenzene Benzoic acid, 3,4-dihydroxy- NSC16631 InChI=1/C7H6O4/c8-5-2-1-4(7(10)11)3-6(5)9/h1-3,8-9H,(H,10,11 37580_FLUKA 4,5-Dihydroxybenzoic acid 4-10-00-01459 (Beilstein Handbook Reference) BRN 1448841 Benzoic acid, 3,4-dihydroxy- (9CI) CCRIS 6291 EINECS 202-760-0 NSC 16631 Protocatehuic acid AIDS-002961 AIDS002961 MLS000737807 AIDS-082396 AIDS082396 Oxidative polymer of protocatechuic acid Protocatechuic acid polymer C00230 TULIP017459