4-Aminosalicylic acid, structure

Figure 14.7. Chemical structures of some chelators and enhancers used in time-resolved fluoroimmunoas-says 1, isothiocyanatophenyl-EDTA 2, Ari-p-(isothiocyanatobenzyl)-diethylenetriaminetetraaceticacid 3, diethylenetriaminepentaacetic anhydride (DTPA) 4, Tb3+-DTPA-/t-aminosalicylic acid S, Eu3+-pyridine-bisfmethylaminodiacetic acid) 6, benzoyltrifluoroacetone (BTA, a /i-diketone) 7, trifluoroacetylacetone (a/jt-diketone) 8,4,7-bis(chlorosulfonylphenyl)-l,10-phenanthroline-2,9-dicarboxylic acid (BCPDA).

Regulatory bodies such as the Food and Drug Administration (FDA) in the United States require the identification of all impurities above the 0.1% level in formulated pharmaceuticals. Once identified, the structure of the impurity is typically confirmed through synthesis to provide absolute structure identification and for use as standards in subsequent quality assurance analyses. Together, LC-MS and LC-NMR play important roles in stability testing. For example, parallel analysis by LC-NMR and LC-MS was used for the rapid structure elucidation of an unknown impurity in 5-aminosalicylic acid, which is marketed for the treatment of acute ulcerative colitis and Chron s disease [57]. In another study, Fukutsu et al. [58] used a combination... 

Para-aminosalicylic Acid (PAS), like the sulfonamides (see Chapter 44), is a structural analogue of p-aminobenzoic acid (PABA). It is a folate synthesis antagonist that interferes with the incorporation of PABA into folic acid. PAS is bacteriostatic, and in vitro, most strains of M. tuberculosis are sensitive to a concentra-... 

Aminosalicylic acid (Paser, PAS) exerts its effects in a manner similar to the sulfonamide drugs that is, aminosalicylic acid is structurally similar to para-aminobenzoic acid (PABA) and inhibits folic acid synthesis by competing with PABA in tuberculosis... 

Aminosalicylic acid is a folate synthesis antagonist that is active almost exclusively againstM tuberculosis. It is structurally similar to /i-aminobenzoic aid (PABA) and to the sulfonamides (see Chapter 46 Sulfonamides, Trimethoprim, Quinolones). 

A series of compounds containing the same chelating moiety, namely 4-aminosalicylic acid, with different alkyl chains, was synthesized. The structure of the ligands (PAS-C ) is the following ... 

F. Bertinotti, G. Giacomello, and A. M. Liquori. Acta Cryst. 7, 808-12 (1954). Crystal structure />-aminosalicylic acid. 

Forbes, R.T. York, P. Fawcett, V. Shields, L. Physicochemical properties of salts of p-aminosalicylic acid. I. correlation of crystal structure and hydrate stability. Pharm. Res. 1992, 9 (11), 1428-1435. 

Figure 6. Molecular structure of 5-aminosalicylic acid, salicylic acid, phenacetin and p-aminophenol.

Oxidation mechanisms for drug substances depend on the chemical structure of the drug and the presence of reactive oxygen species or other oxidants. Catechols such as methyl-dopa180 and epinephrine181 are readily oxidized to quinones, as shown in Scheme 45. 5-Aminosalicylic acid undergoes oxidation and forms quinoneimine,182 which is further degraded to polymeric compounds (Scheme 46).183 Ethanolamines such as procaterol are oxidized to formyl compounds (Scheme 47),184 whereas thiols such as 6-mercaptopurine,185... 

Aminosalicylic acid is a structural analog of pava-aminobenzoic acid, and has the same mechanism of action as the sulfonamides fsee Chapter 43). Nonetheless, the sulfonamides are ineffective against M. tuberculosis, and aminosalicylic acid is inactive against sulfonamide-susceptible bacteria. Resistant strains of tubercle bacilli emerge slowly in patients treated with aminosalicylic acid. 

The efficiency of energy transfer from the liposomes to the chelated lanthanide ions can be further enhanced by incorporating the aminosalicylic acids in the structure of the polymerizable lipids (Figure 10.10). MalUk and co-workers... 

Other Names Salicylic acid, 5-amino- 2-Hydroxy-5-aminobenzoic acid 3-Carboxy-4-hydroxy-aniline 5-ASA 5-Amino-2-hydroxybenzoic acid 5-Aminosalicylic add Asacol Asacolitin Asacolon Canasa Claversal Fisalamine Ipocol Lixacol Mesacol Mesalamine Mesalazine Mesasal NSC 38877 Pentasa Rowasa Salofalk Salozinal m-Aminosalicylic acid CA Index Name Benzoic acid, 5-amino-2-hydroxy-CAS Registry Number 89-57-6 Merck Index Number 5904 Chemical Structure... 

A pH-sensitive membrane forcolon-sp ecific drug delivery was synthesised by the covalent bonding of glycine on EVAL membranes. The processes of surface modification of the membrane structure were observed by SEM. Permeation of aminosalicylic acid through the membranes was studied. 18 refs. 

Figure 8.21 Fragments of crystal structures of complexes involving silver nitrate and 4-aminosalicylic acid (a) the monohydrate 1-D coordination polymer and (b) a 2-D sheet of the anhydrous compound. ...

Aluminum diisopropoxy acetylacetonate, polymerization with bis (/3-diketones), 233 Aluminum isopropoxide, polymers with ethylene diamine, 331 Aluminum soaps, structure of, 247 Aluminum triisopropoxide, polymers with ethylene diamine, 340 p-Aminosalicylic acid, diazotized... 

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