Carbostyril-DTPA

Figure 9.55 A carbostyril-DTPA europium chelator is a strong enhancer of lanthanide luminescence. The chemical structure and three-dimensional structure of the chelator are shown.

Fig. 6.8. Structures of some common fluorophores. DPH = diphenylhexatriene NBD = nitrobenzoxadiazole Tb-DTPA-csl24 = terbium diethylenetriaminepentacetate-carbostyril 124, DAPI = 4, 6-diamidino-2-phenylindole Nile red = 9-(diethylamino)-5H-benzo-[a]phenoxazin-5-one.

A solid state Eu3+ complex of DTPA-csl24 was studied [27]. It was found that it is present as dimeric units, the carbostyril moiety of one unit is bound to the lanthanide of the other unit via the quinolinone a-oxygen atom. In this case, no water molecule is coordinated directly to Eu3+. This unusual behavior is ascribed to stacking properties of the carbostyril unit and to the presence of the a-oxygen atom in a position advantageous for coordination. 

Fig. 10. Structure or terbium chelate, namely, terbium diethylenetriaminepentaacetic acid coupled to carbostyril 124. The carbostyril absorbs light (maximally at 327 nm) and transfers energy to the terbium. The net result is an increase in the effective absorbance of the terbium by several thousandfold. The DTPA chelate shields the terbium from the quenching effects of water and allows for easy attachment to macromolecules. Here the macromolecule is an 8-mer DNA oligomer modified with a primary amine on the 5 end. The acceptor, fluorescein, is attached to the 5 end of a complementary DNA oligomer. 

Recent advances in detecting renal function include the development of fluorescently labeled novel compounds (hydrophilic pyrazine dyes, carbostyril 124-DTPA-Eu, fluorescein-labeled poly-D-lysine) and their detection via in vivo fluorescence imaging or through transcutaneous detection (Dorshow et al., 1998 Rabito et al., 2005 Rajagopalan et al, 2011 Poreddy et al, 2012). Both the hydrophilic pyrazine dyes (see Fig. 34.1) and the modified DTPA are cleared exclusively by glomerular filiation, and... 

Fig. 2 Emission spectra of sensitiser-modified DTPA complexes. The visibly luminescent terbium (III) complex [23, 24] contains a carbostyril sensitiser, excited at 320 nm. The NIR luminescent ytterbium(in), neodymium(III) and erbium(III) complexes [18] are based on an eosin antenna chromophore, excited at 520 nm. DTPA diethylenetriaminepentaacetic acid...

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