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The elements of life and medicines.

Chellan P, Sadler PJ - Philos Trans A Math Phys Eng Sci (2015)

Bottom Line: In general, genes do not code for the elements themselves, but for specific chemical species, i.e. for the element, its oxidation state, type and number of coordinated ligands, and the coordination geometry.Future advances in the design of inorganic drugs require more knowledge of their mechanism of action, including target sites and metabolism.Temporal speciation of elements in their biological environments at the atomic level is a major challenge, for which new methods are urgently needed.

View Article: PubMed Central - PubMed

Affiliation: Department of Chemistry, University of Warwick, Coventry CV4 7AL, UK.

ABSTRACT
Which elements are essential for human life? Here we make an element-by-element journey through the periodic table and attempt to assess whether elements are essential or not, and if they are, whether there is a relevant code for them in the human genome. There are many difficulties such as the human biochemistry of several so-called essential elements is not well understood, and it is not clear how we should classify elements that are involved in the destruction of invading microorganisms, or elements which are essential for microorganisms with which we live in symbiosis. In general, genes do not code for the elements themselves, but for specific chemical species, i.e. for the element, its oxidation state, type and number of coordinated ligands, and the coordination geometry. Today, the biological periodic table is in a position somewhat similar to Mendeleev's chemical periodic table of 1869: there are gaps and we need to do more research to fill them. The periodic table also offers potential for novel therapeutic and diagnostic agents, based on not only essential elements, but also non-essential elements, and on radionuclides. Although the potential for inorganic chemistry in medicine was realized more than 2000 years ago, this area of research is still in its infancy. Future advances in the design of inorganic drugs require more knowledge of their mechanism of action, including target sites and metabolism. Temporal speciation of elements in their biological environments at the atomic level is a major challenge, for which new methods are urgently needed.

No MeSH data available.


The intravenous MRI contrast agent [Gd(DTPA)(H2O)]2−. The paramagnetic 4f7 Gd3+ ion is large (ionic radius 1.2 Å) and can accommodate eight coordinating atoms from the chelating DTPA ligand and a water molecule. Exchange of coordinated water with bulk water is important for producing contrast in the magnetic resonance image.
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RSTA20140182F18: The intravenous MRI contrast agent [Gd(DTPA)(H2O)]2−. The paramagnetic 4f7 Gd3+ ion is large (ionic radius 1.2 Å) and can accommodate eight coordinating atoms from the chelating DTPA ligand and a water molecule. Exchange of coordinated water with bulk water is important for producing contrast in the magnetic resonance image.

Mentions: Millions of doses of gadolinium (Z=64) are now administered every year as contrast agents for MRI. Gadolinum(III) with its seven unpaired electrons and slow electronic relaxation time is effective for relaxing H2O protons which can give rise to contrast in MR images. Thanks to the high thermodynamic and kinetic stability of chelated complexes such as [Gd(DTPA)(H2O)]2− (figure 18, approved for clinical use in 1988 as gadopentetate dimeglumine, Magnevist) [278] and [Gd(DOTA)(H2O)]− (Dotarem), they can be safely injected in gram quantities. The large GdIII ion (radius ca 1.2 Å) can accommodate eight coordinating atoms from the chelating ligand plus a water ligand which exchanges rapidly with bulk water. There is concern about possible side-effects arising from any release of Gd(III) (e.g. displacement by Ca(II)) in the body, especially for less stable contrast agents. Currently, phase IV clinical trials are underway to evaluate Gd retention in the bones of patients with impaired renal function [279].Figure 18.


The elements of life and medicines.

Chellan P, Sadler PJ - Philos Trans A Math Phys Eng Sci (2015)

The intravenous MRI contrast agent [Gd(DTPA)(H2O)]2−. The paramagnetic 4f7 Gd3+ ion is large (ionic radius 1.2 Å) and can accommodate eight coordinating atoms from the chelating DTPA ligand and a water molecule. Exchange of coordinated water with bulk water is important for producing contrast in the magnetic resonance image.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4342972&req=5

RSTA20140182F18: The intravenous MRI contrast agent [Gd(DTPA)(H2O)]2−. The paramagnetic 4f7 Gd3+ ion is large (ionic radius 1.2 Å) and can accommodate eight coordinating atoms from the chelating DTPA ligand and a water molecule. Exchange of coordinated water with bulk water is important for producing contrast in the magnetic resonance image.
Mentions: Millions of doses of gadolinium (Z=64) are now administered every year as contrast agents for MRI. Gadolinum(III) with its seven unpaired electrons and slow electronic relaxation time is effective for relaxing H2O protons which can give rise to contrast in MR images. Thanks to the high thermodynamic and kinetic stability of chelated complexes such as [Gd(DTPA)(H2O)]2− (figure 18, approved for clinical use in 1988 as gadopentetate dimeglumine, Magnevist) [278] and [Gd(DOTA)(H2O)]− (Dotarem), they can be safely injected in gram quantities. The large GdIII ion (radius ca 1.2 Å) can accommodate eight coordinating atoms from the chelating ligand plus a water ligand which exchanges rapidly with bulk water. There is concern about possible side-effects arising from any release of Gd(III) (e.g. displacement by Ca(II)) in the body, especially for less stable contrast agents. Currently, phase IV clinical trials are underway to evaluate Gd retention in the bones of patients with impaired renal function [279].Figure 18.

Bottom Line: In general, genes do not code for the elements themselves, but for specific chemical species, i.e. for the element, its oxidation state, type and number of coordinated ligands, and the coordination geometry.Future advances in the design of inorganic drugs require more knowledge of their mechanism of action, including target sites and metabolism.Temporal speciation of elements in their biological environments at the atomic level is a major challenge, for which new methods are urgently needed.

View Article: PubMed Central - PubMed

Affiliation: Department of Chemistry, University of Warwick, Coventry CV4 7AL, UK.

ABSTRACT
Which elements are essential for human life? Here we make an element-by-element journey through the periodic table and attempt to assess whether elements are essential or not, and if they are, whether there is a relevant code for them in the human genome. There are many difficulties such as the human biochemistry of several so-called essential elements is not well understood, and it is not clear how we should classify elements that are involved in the destruction of invading microorganisms, or elements which are essential for microorganisms with which we live in symbiosis. In general, genes do not code for the elements themselves, but for specific chemical species, i.e. for the element, its oxidation state, type and number of coordinated ligands, and the coordination geometry. Today, the biological periodic table is in a position somewhat similar to Mendeleev's chemical periodic table of 1869: there are gaps and we need to do more research to fill them. The periodic table also offers potential for novel therapeutic and diagnostic agents, based on not only essential elements, but also non-essential elements, and on radionuclides. Although the potential for inorganic chemistry in medicine was realized more than 2000 years ago, this area of research is still in its infancy. Future advances in the design of inorganic drugs require more knowledge of their mechanism of action, including target sites and metabolism. Temporal speciation of elements in their biological environments at the atomic level is a major challenge, for which new methods are urgently needed.

No MeSH data available.