3,4-DIHYDROXYBENZOIC ACID; protocatechuic acid; 99-50-3; 4-Carboxy-1,2-dihydroxybenzene; Protocatehuic acid; protocatechuate; Benzoic acid, 3,4-dihydroxy-; 4,5-Dihydroxybenzoic acid; 3,4-Dihydroxybenzoicacid; protocatechuicacid; MFCD00002509; Catechol-4-carboxylic Acid; CCRIS 6291; 3, 4-Dihydroxybenzoic acid; CHEMBL37537; MLS000737807; 36R5QJ8L4B; DTXSID4021212; EINECS 202-760-0; CHEBI:36062; NSC 16631; BRN 1448841; NSC-16631; 1ykp; 3,4-Dihydroxy Benzoic Acid; NSC16631; DB03946; SMR000528167; UNII-36R5QJ8L4B; C00230; D-3487; Hypogallic acid; b-Resorcylate; beta-Resorcylate; b-resorcylic acid; 4fht; Protacatechuic Acid; ZINCSELENITE; Carbohydroquinonic acid; cid_72; Protocatechuic Acid,(S); PROTOCATECHOIC ACID; Protocatechuic acid (M1); bmse000328; 3,4-dihydroxy-benzoic acid; SCHEMBL39435; 3,4-Dihydroxybenzoate, VIII; Pyrocatechol-4-carboxylic Acid; DTXCID601212; FEMA NO. 4430; PROTOCATECHUIC ACID [MI]; ZINC13246; PROTOCATECHUIC ACID (PCA); HMS2270A17; KUC104409N; ACT07872; HY-N0294; Tox21_200167; BBL012232; BDBM50100861; DIHYDROXYBENZOIC ACID, 3,4-; s3975; STL163570; AKOS000119632; AC-9617; CCG-207950; CS-6092; KSC-10-128; CAS-99-50-3; NCGC00246757-01; NCGC00246757-02; NCGC00257721-01; 3,4-DIHYDROXYBENZOIC ACID [INCI]; AS-10808; SY014104; DB-021903; AM20060767; FT-0600028; 3,4-Dihydroxybenzoic acid, >=97.0% (T); EN300-21544; 3,4-Dihydroxybenzoic acid, analytical standard; F11285; 3,4-dihydroxybenzoate;3,4-Dihydroxybenzoic acid; A846038; AE-562/40524392; DROXIDOPA METABOLITE (PROTOCATECHOIC ACID); Q418599; 976C8CCE-B25D-4E0A-9A6F-3CEEA7A6964F; Z104501142; 3,4-Dihydroxybenzoic acid, Vetec(TM) reagent grade, 97%; Protocatechuic acid, primary pharmaceutical reference standard; PROTOCATECHOIC ACID (CONSTITUENT OF MARITIME PINE) [DSC]; Protocatechuic acid, United States Pharmacopeia (USP) Reference Standard; 1225528-47-1