4-Aminosalicylic Acid

4-Aminosalicylic acid is an antimetabolite of p-aminobenzoic acid (PABA; Item No. 18659) that has antibacterial activity.{62101,62102} It is active against streptomycin-sensitive and -resistant strains of M. tuberculosis (MICs = 0.78 and 0.39 µg/ml, respectively), an effect that can be reversed by PABA.{62101} 4-Aminosalicylic acid is an alternative substrate for mycobacterial dihydropteroate synthase (FolP1) and misincorporation into the folate pathway leads to accumulation of several folate-dependent metabolites including serine, homocysteine, dUMP, and AICAR, markers of folate pathway inhibition, in a concentration-dependent manner.{62102} It reverses manganese-induced increases in rat hippocampal levels of NOD-like receptor protein 3 (NLRP3), cleaved caspase-1, and phosphorylated p65, markers of NLRP3 inflammasome-dependent pyroptosis, when administered at a dose of 300 mg/kg.{62103} 4-Aminosalycilic acid is also a building block that has been used in the synthesis of luminescent lanthanide complexes.{62104} Formulations containing 4-aminosalicylic acid have been used in the treatment of tuberculosis.