Diethylenetriamine pentaacetic acid DTPA

Singh et al. (2006) also used cycloaddition to prepare carbon nanotubes containing indium labeled diethylenetriamine pentaacetic acid (DTPA) derivatives (Figure 15.17). In the initial modification, a SWNT was derivatized to contain a primary amine at the end of a short PEG spacer. The resultant water-soluble nanotube then was reacted with DTPA to create a metal chelating group at the end of the chain. Subsequent loading of the chelate with mIn created a radionuclide-SWNT complex for in vivo biodistribution studies. 

The free ion, Cu2+, appears to be the major species of Cu taken up by plants (Graham, 1981 Jones and Jarvis, 1981). Hence Cu complexation will decrease uptake (DeKock and Mitchell, 1957) unless the complex can dissociate and/or diffuse quickly enough to maintain a constant supply of Cu2+ at the root surface. In the case of Zn, the presence of humic acid (Chen and Aviad, 1990) and carboxylic acids (EDTA, diethylenetriamine pentaacetic acid (DTPA), nitrilotriacetic acid (NTA) DeKock and Mitchell, 1957) has been found to decrease absorption but it is not known whether Zn uptake is correlated with Zn2+ in solution because Zn speciation was not estimated. Other work has shown that Zn initially complexed with citrate is taken up by barley from nutrient solutions (Chairidchai and Ritchie, 1993) and the presence of chelates (EDTA, citrate) can speed up the diffusion of Zn to a root surface in soils (Hodgson et al., 1967 Elgawhary et al., 1970). Speciation in solution is particularly important in the uptake of iron because of its extremely low solubility in the absence of complexing anions... 

Tc-DTPA Arterial perfusion accounts for 20%-40% of the circulation in portal hypertension, cirrhosis causes arterial perfusion to increase to over 60%. In portal vein thrombosis, only an arterial curve is visible. Liver metastasis usually displays relatively high arterial perfusion. In (rare) occlusions of the hepatic artery, only a portal venous curve is visible. When a bolus injection of 400 MBq "Tc-diethylenetriamine pentaacetic acid (DTPA) is applied, scintigraphy is able to reveal a bi-phasic time-activity curve. The initial increase of activity is produced by the arterial influence and the second peak by the portal venous inflow. Both curves can be evaluated quantitatively. (36) Perfusion scintigraphy may be useful in the case of liver trauma, TIPS, hyper-vascularized hepatic tumours and partial liver resection as well as after liver transplantation. 

Other metal cations that may form complexes with the toxicant may have a profound effect on toxicity. The toxicity of ethylenedi-amine tetraacetic acid (EDTA) and diethylenetriamine pentaacetic acid (DTPA) and their metal complexes has been examined in daphnids. The results are relevant both for the effect on the toxicity of metal cations and for the influence of complexation on these toxicities. For the acute toxicity (ECS0, 24 h) to Daphnia magna, the following results (mg/1) were obtained (Sorvari and Silanpaa 1996) ... 

Because of the involvement of metal ions in degradation reactions, the inclusion of a chelating agent is often advocated. The most commonly used chelating agent are the various salts of EDTA. In addition, (3-hydroxyethylenediaminetriacetic acid (HEDTA), diethylenetriamine-pentaacetic acid (DTPA) and nitrilotriacetate (NTA) have been assessed for their efficiency in stabilizing, e.g., isoniazid solutions (Ammar et al. 1982). 

Diethylenetriamine pentaacetic acid (DTPA) 97% purity, ethylenediamine and carbonyldiimidazole were purchased from Aldrich and used as supplied. Acetic anhydride, pyridine, dimethylsulfoxide and dimethylformamide, also from Aldrich, were of Analar purity, and were dried over molecular sieves 3A before use. Dextran (MW 40000), di-t-butyl dicarbonate of 97% purity and Dowex 50Wx8x200 ion exchange resin, were supplied by Sigma. 

Diethylenetriamine pentaacetic acid (DTPA) and Ethylenediaminetetraacetic acid (EDTA) derivatives... 

Few results are reported for PVA-based membranes in DEFC, and most of them correspond to alkaline DEFC, which will be discussed in Sect 6.9. The unique study of ethanol permeability in a PVA-based membrane corresponds to PVA crosslinked with (diethylenetriamine) pentaacetic acid (DTPA) and doped with phosphotungstic acid [363]. Ethanol permeation through these membranes a factor 100 lower than in Nafion, but the protrui conductivity of the membranes is lower than 10 mS.cm and DEFC performance test has not been reported. 

Very interesting work was also reported by Piwnica-Worms and coworkers. They prepared Tat-peptide derivatives like 90 dual-labeled with Tc and fluorescein for scintigraphy and fluorescence microscopy (Scheme 5.45) [218]. Tat-peptide basic regions have been intensely studied because of their ability to translocate across cell membranes, seemingly independent of receptor-mediated endocytosis. The peptides were prepared by SPPS with an N-terminal His ligand, to which Tc(CO)3 or Re(CO)3 is coordinated in solution after cleavage and purification. As an alternative to histidine, diethylenetriamine-pentaacetic acid (DTPA) was also used as an N-terminal metal chelator. The C-terminal cysteine was reacted with fluorescein-5-maleimide already on the resin, thus providing both labels in the same peptide, as shown for 90 in Scheme 5.45. Cellular localization of these... 

We observed the bactericidal effect of various hydroperoxides in the presence of various heme compounds e.g., hemoglobin, myoglobin, hemin, and cytochrome c, but it was not observed in the reaction with diethylenetriamine-pentaacetic acid (DTPA)-Fe (6). Furthermore, bactericidal potential was... 

Chavatte K, Mertens J, Van Den Winkel P. Method for effective T1(III) labelling of diethylenetriamine pentaacetic acid (DTPA)-functionahzed peptides radiosynthesis of Tl(ni)DTPA-neurotensin(8-13). J Labelled Cpd Radiopharm 2000 43 1227-1234. 

The most direct but by no means the sole therapeutic use of chelating agents aims at the removal of toxic (stable or radioactive) metals from the body or at the treatment of diseases (e.g. haemochromatosis, Wilson s disease) which are related to an excessive storage of particular metal ions. Of the vast number of compounds which have been tested from this point of view, we shall cite only those which have proved to be of significant clinical value (1) ethylenediamine-tetra-acetic acid (EDTA), which has been or should be replaced by its more effective derivative (2) diethylenetriamine-pentaacetic acid (DTPA) (3) D-penidllamine and (4) desferrioxamine B. EDTA and DTPA are effective in removing almost all metals which are important in toxicology whereas the action of desferrioxamine B is limited to Fe alone, and D-penicillamine is superior to other chelators in mobilizing Cu, Co, and Hg" ". ... 

Kubota et al. (1993) compared the extraction equilibria and extraction mechanism of the lanthanides with 2-ethylhexyl phosphonic acid mono-2-ethylhexyl ester (PC-88A) in n-heptane diluent and HDEHP and in the presence of diethylenetriamine-pentaacetic acid (DTPA). The extraction equilibrium of PC-88A in n-heptane can be expressed as... 

Genwa, K. R. Khatri, N. C. Comparative study of photosensitizing dyes in photogalvanic cells for solar energy conversion and storage Brij-35-diethylenetriamine pentaacetic acid (DTPA) system. Energy Fuels 2009, 23, 1024—1031. 

Another system for the polymerization of amylamide are chelating polyaminocarboxylic acids with Ce(IV) [146-148]. In these systems, the redox reaction is followed by a decarboxylation to yield the initiating carbon-centered radical. It w found that diethylenetriamine pentaacetic acid (DTPA) is slightly mcwe effective than ethylenediamine tetraacetic acid (EDTA). The efficiency of nitrilotriacctic acid (NDA) [see Eq. (48)] is smaller than that of EDTA. 

---