Synonyms: 2,5-Dihydroxybenzoic Acid, Mesalazine Imp. G (EP), 2,5-DHBA, 2,5-Dioxybenzoic acid, 3,6-Dihydroxybenzoic acid, 5-Hydroxysalicylic acid, Carboxyhydroquinone, Gensigen, Gensigon, Gentisic acid, Gentisinic acid, Hydroquinonecarboxylic acid, NSC 27224, NSC 49098, NSC 78825, Mesalazine Impurity G