Diethylenetriaminepentaacetic anhydride

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).

Open-chain ligands were the first evaluated for complexation studies with indium and yttrium. The use of diethylenetriaminepentaacetic acid (DTPA) anhydride permitted early evaluation of labeled chelate-conjugates (Figure 2).80 The use of this activated chelating agent was quite popular, until the drawbacks associated with its crosslinking of proteins became apparent. 

Figure 6.7-8. Metal chelators that can be conjugated to monoclonal antibodies or peptides for labeling with " In. cDTPAA Bicyclic anhydride of diethylenetriaminepentaacetic acid p-SCN-Bz-DTPA p-isothiocyanatobenzyl-diethylenetriaminepentaacetic acid. Chemically reactive groups for conjugation to the antibodies or peptides are shaded.

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