Pentetic acid: Difference between revisions
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'''Pentetic acid''' or '''diethylene triamine pentaacetic acid''' ('''DTPA''') is a [[polyamino carboxylic acid]] consisting of a [[diethylenetriamine]] backbone with five carboxymethyl groups. The molecule can be viewed as an expanded version of [[Ethylenediaminetetraacetic acid|EDTA]] and |
'''Pentetic acid''' or '''diethylene triamine pentaacetic acid''' ('''DTPA''') is a [[polyamino carboxylic acid]] consisting of a [[diethylenetriamine]] backbone with five carboxymethyl groups. The molecule can be viewed as an expanded version of [[Ethylenediaminetetraacetic acid|EDTA]] and is used similarly. It is a white, water-soluble solid. |
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==Coordination properties== |
==Coordination properties== |
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The [[Conjugate acid|conjugate base]] of DTPA has a high affinity for metal cations. Thus, the penta-anion DTPA<sup>5-</sup> is potentially an [[denticity|octadentate ligand]] |
The [[Conjugate acid|conjugate base]] of DTPA has a high affinity for metal cations. Thus, the penta-anion DTPA<sup>5-</sup> is potentially an [[denticity|octadentate ligand]] assuming that each nitrogen centre counts as a and each COO<sup>–</sup>-group counts as a centre for coordination.</ref> The [[Stability constants of complexes|formation constants]] for its complexes are about 100 greater than those for EDTA.<ref name=Ullmann>J. Roger Hart "Ethylenediaminetetraacetic Acid and Related Chelating Agents" in Ullmann's Encyclopedia of Industrial Chemistry, Wiley-VCH, Weinheim, 2005.{{DOI|10.1002/14356007.a10_095}}</ref> As a [[Chelation|chelating agent]], DTPA wraps around a metal ion by forming up to eight bonds. Transition metals, however, usually form less than eight [[Dipolar bond|coordination bonds]]. So, after forming a complex with a metal, DTPA still has the ability to bind to other reagents, as is shown by its derivative [[pendetide]]. For example, in its complex with copper(II), DTPA binds in a hexadentate manner utilizing the three amine centres and three of the five carboxylates.<ref>V. V. Fomenko, T. N. Polynova, M. A. Porai-Koshits, G. L. Varlamova and N. I. Pechurova ''Crystal structure of copper (II) diethylenetriaminepentaacetate monohydrate'' Journal of Structural Chemistry, 1973, Vol. 14, 529. {{DOI|10.1007/BF00747020}}</ref> |
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As a [[Chelation|chelating agent]], DTPA wraps around a metal ion by forming up to eight bonds. Transition metals, however, usually have a limited coordination capacity and can form less than eight [[Dipolar bond|coordination bonds]] with [[ligand]]s. So, after forming a complex with a metal, DTPA still has the ability to bind to other reagents, as is shown by its derivative [[pendetide]]. For example, in its complex with copper(II), DTPA binds in a hexadentate manner utilizing the three amine centres and three of the five carboxylates.<ref>Fomenko, et al. [http://www.springerlink.com/content/u17110526v864754/ ''Crystal structure of copper (II) diethylenetriaminepentaacetate monohydrate''] Journal of Structural Chemistry, Vol. 14, Nr. 3 (1973). [http://www.springerlink.com/content/u17110526v864754/fulltext.pdf?page=1 PDF]</ref> Like many other chelating agents, DTPA has been considered for treatment of internal contamination from radioactive materials such as [[plutonium]], [[americium]] and other [[actinide]]s. In theory, these complexes are more apt to be eliminated in urine. It is normally administered as the [[calcium]] or [[zinc]] salt. Additionally, DTPA has been seen to have made aqueous complexes with Thorium(IV), Uranium(IV), Neptunium(IV), and Cerium(III/IV). <ref>(2) Brown, M. A.; Paulenova, A.; Gelis, A. V. Aqueous Complexation of Thorium(IV), Uranium(IV), Neptunium(IV), Plutonium(III/IV), and Cerium(III/IV) with DTPA. Inorganic Chemistry 2012, 51, 7741-7748. </ref> |
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==Applications== |
==Applications== |
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Like the more common EDTA, DTPA is mainly used for [[sequestering agent|sequestering]] metal ions that otherwise decompose [[hydrogen peroxide]], which is used to [[bleaching of wood pulp|bleach pulp]] in paper making. Several million kilograms are produced for this purpose annually.<ref name=Ullmann/> |
Like the more common EDTA, DTPA is mainly used for [[sequestering agent|sequestering]] metal ions that otherwise decompose [[hydrogen peroxide]], which is used to [[bleaching of wood pulp|bleach pulp]] in paper making. Several million kilograms are produced for this purpose annually.<ref name=Ullmann/> |
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Its chelating properties are |
Its chelating properties are useful in deactivating calcium and magnesium ions in hair products. DTPA is used in over 150 cosmetic products.<ref>Burnett, L. C. "Final Report on the Safety Assessment of Pentasodium Pentetate and Pentetic Acid as Used in Cosmetics" International Journal of Toxicology 2008, 27, 71-92.</ref> Additionally, DTPA is used in MRI contrasting agents. DTPA improves MRI images by forming a complex with a gadolinium ion, which alters the properties of nearby water molecules.<ref>Caravan, Peter; Ellison, Jeffrey J.; McMurry, Thomas J. ; Lauffer, Randall B. "Gadolinium(III) Chelates as MRI Contrast Agents: Structure, Dynamics, and Applications" Chem. Revs. 1999, volume 99, pp. 2293–2342.</ref> |
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DTPA has been considered for treatment of radioactive materials such as [[plutonium]], [[americium]], and other [[actinide]]s. In theory, these complexes are more apt to be eliminated in urine. It is normally administered as the [[calcium]] or [[zinc]] salt, since these ions are readily displaced by more highly charged cations. DTPA forms complexes with thorium(IV), uranium(IV), neptunium(IV), and cerium(III/IV).<ref>(2) Brown, M. A.; Paulenova, A.; Gelis, A. V. "Aqueous Complexation of Thorium(IV), Uranium(IV), Neptunium(IV), Plutonium(III/IV), and Cerium(III/IV) with DTPA" Inorganic Chemistry 2012, volume 51, 7741-7748. {{DOI|10.1021/ic300757k}}</ref> |
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Additionally, DTPA is used in MRI contrasting agents. DTPA improves MRI images by forming a complex with a gadolinium ion, which alters the properties of nearby water molecules. <ref>Caravan, Peter; Ellison, Jeffrey J.; McMurry, Thomas J. ; Lauffer, Randall B. Gadolinium(III) Chelates as MRI Contrast Agents: Structure, Dynamics, and Applications. Chem. Revs. 1999, 99 (9): 2293–2342 </ref> |
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==Related compounds== |
==Related compounds== |
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Revision as of 14:07, 13 November 2012
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| Names | |
|---|---|
| IUPAC name
2-[Bis[2-[bis(carboxymethyl)amino]ethyl]amino]acetic acid
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| Other names
DTPA; H5dtpa; Diethylenetriaminepentaacetic acid; Penta(carboxymethyl)diethylenetriamine[1]
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| Identifiers | |
3D model (JSmol)
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| ChEBI | |
| ChEMBL | |
| ChemSpider | |
| ECHA InfoCard | 100.000.593 |
| KEGG | |
PubChem CID
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| RTECS number |
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| UNII | |
CompTox Dashboard (EPA)
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| Properties | |
| C14H23N3O10 | |
| Molar mass | 393.349 g·mol−1 |
| Appearance | White crystalline solid |
| Melting point | 220 °C (428 °F; 493 K) |
| Boiling point | decomposes at a higher temp. |
| <0.5 g/100 mL | |
| Acidity (pKa) | ~1.80 (20°C) [2] |
| Hazards | |
| Flash point | Does not burn |
| Related compounds | |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Pentetic acid or diethylene triamine pentaacetic acid (DTPA) is a polyamino carboxylic acid consisting of a diethylenetriamine backbone with five carboxymethyl groups. The molecule can be viewed as an expanded version of EDTA and is used similarly. It is a white, water-soluble solid.
Coordination properties
The conjugate base of DTPA has a high affinity for metal cations. Thus, the penta-anion DTPA5- is potentially an octadentate ligand assuming that each nitrogen centre counts as a and each COO–-group counts as a centre for coordination.</ref> The formation constants for its complexes are about 100 greater than those for EDTA.[3] As a chelating agent, DTPA wraps around a metal ion by forming up to eight bonds. Transition metals, however, usually form less than eight coordination bonds. So, after forming a complex with a metal, DTPA still has the ability to bind to other reagents, as is shown by its derivative pendetide. For example, in its complex with copper(II), DTPA binds in a hexadentate manner utilizing the three amine centres and three of the five carboxylates.[4]
Applications
Like the more common EDTA, DTPA is mainly used for sequestering metal ions that otherwise decompose hydrogen peroxide, which is used to bleach pulp in paper making. Several million kilograms are produced for this purpose annually.[3]
Its chelating properties are useful in deactivating calcium and magnesium ions in hair products. DTPA is used in over 150 cosmetic products.[5] Additionally, DTPA is used in MRI contrasting agents. DTPA improves MRI images by forming a complex with a gadolinium ion, which alters the properties of nearby water molecules.[6]
DTPA has been considered for treatment of radioactive materials such as plutonium, americium, and other actinides. In theory, these complexes are more apt to be eliminated in urine. It is normally administered as the calcium or zinc salt, since these ions are readily displaced by more highly charged cations. DTPA forms complexes with thorium(IV), uranium(IV), neptunium(IV), and cerium(III/IV).[7]
Related compounds
Compounds that are structurally related to DTPA are used in medicine, taking advantage of the high affinity of the triaminopentacarboxylate scaffold for metal ions.
- In ibritumomab tiuxetan, the chelator tiuxetan is a modified version of DTPA whose carbon backbone contains an isothiocyanatobenzyl and a methyl group.[8]
- In capromab pendetide and satumomab pendetide, the chelator pendetide (GYK-DTPA) is a modified DTPA containing a peptide linker used to connect the chelate to an antibody.[9]
- Pentetreotide is a modified DTPA attached to a peptide segment.[10]
- DTPA and derivatives are used to chelate gadolinium to form a MRI contrast agent, such as Magnevist.
- Technetium is chelated with DTPA for ventilation perfusion scan (V/Q scan) and renal scan.[citation needed]
See also
References
- ^ Anonymous Pentetic Acid. In Dictionary of Organic Compounds, Sixth Edition; Buckingham, J., Macdonald, F., Eds.; CRC Press: 1996; Vol. 5, pp 1188.
- ^ Moeller, T.; Thompson, L. C. Observations on the rare earths—LXXV(1): The stabilities of diethylenetriaminepentaacetic acid chelates. Journal of Inorganic and Nuclear Chemistry 1962, 24, 499.
- ^ a b J. Roger Hart "Ethylenediaminetetraacetic Acid and Related Chelating Agents" in Ullmann's Encyclopedia of Industrial Chemistry, Wiley-VCH, Weinheim, 2005.doi:10.1002/14356007.a10_095
- ^ V. V. Fomenko, T. N. Polynova, M. A. Porai-Koshits, G. L. Varlamova and N. I. Pechurova Crystal structure of copper (II) diethylenetriaminepentaacetate monohydrate Journal of Structural Chemistry, 1973, Vol. 14, 529. doi:10.1007/BF00747020
- ^ Burnett, L. C. "Final Report on the Safety Assessment of Pentasodium Pentetate and Pentetic Acid as Used in Cosmetics" International Journal of Toxicology 2008, 27, 71-92.
- ^ Caravan, Peter; Ellison, Jeffrey J.; McMurry, Thomas J. ; Lauffer, Randall B. "Gadolinium(III) Chelates as MRI Contrast Agents: Structure, Dynamics, and Applications" Chem. Revs. 1999, volume 99, pp. 2293–2342.
- ^ (2) Brown, M. A.; Paulenova, A.; Gelis, A. V. "Aqueous Complexation of Thorium(IV), Uranium(IV), Neptunium(IV), Plutonium(III/IV), and Cerium(III/IV) with DTPA" Inorganic Chemistry 2012, volume 51, 7741-7748. doi:10.1021/ic300757k
- ^ Milenic, Diane E. (2004-06). "Antibody-targeted radiation cancer therapy". Nat Rev Drug Discov. 3 (6): 488–99. doi:10.1038/nrd1413. ISSN 1474-776. PMID 15173838.
{{cite journal}}: Check|issn=value (help); Check date values in:|date=(help); Unknown parameter|coauthors=ignored (|author=suggested) (help) - ^ Kahn, Daniel (1999). "A Phase II Study of [90Y] Yttrium-Capromab Pendetide in the Treatment of Men with Prostate Cancer Recurrence Following Radical Prostatectomy". Cancer Biotherapy & Radiopharmaceuticals. 14 (2): 99–111. doi:10.1089/cbr.1999.14.99.
{{cite journal}}: Unknown parameter|coauthors=ignored (|author=suggested) (help) - ^ Liu, Shuang (2008-09-15). "Bifunctional coupling agents for radiolabeling of biomolecules and target-specific delivery of metallic radionuclides". Advanced Drug Delivery Reviews. 60 (12): 1347–70. doi:10.1016/j.addr.2008.04.006. ISSN 0169-409X. PMC 2539110. PMID 18538888.
- This article incorporates material from Facts about DTPA, a fact sheet produced by the United States Centers for Disease Control and Prevention.