Chelating agents

Chemicals that combine with metal ions and remove them from their sphere of action, also called sequestrants, e.g. citrates, tartrates, phosphates, and EDTA.


Chemical used to form stable complexes with metals.


A molecule capable of binding metal atoms. The chelating agent/metal complex is held together by coordination bonds which have a strong polar character. One example of a common chelating agent is ethylenediamine tetraacetate (EDTA) which tightly and reversibly binds Mg^^ and other divalent cations (positively charged ions). If a chelate is allowed to bind to metal ions required for enzyme activity, the enzyme will be inactivated (inhibited). Cobalamin (vitamin B12), EDTA and the iron-porphyrin complex of heme (which provides the red color of blood) are other examples of chelates.


A chemical compound which can combine with some metals, used as a treatment for metal poisoning.


Substances that can bond strongly to metal ions. Medical applications of chelation came into use during the 1940s to combat poisoning with heavy metals, such as arsenic, lead, iron, mercury, copper, and aluminum. Chelation therapy involves the person receiving a series of these agents that will bind with the metals to help remove them from storage sites in the body, such as the liver or kidney, while promoting their excretion by the urine. Chelating agents may be given orally, by injection, or by intravenous infusion. Examples of chelating agents include penicillamine, dimercaprol (BAL), ethylene-diaminetetraacetic acid (EDTA), and succimer (Chemet).


A chemical compound that forms complexes by binding metal ions. Some chelating agents, including deferoxamine and penicillamine, are drugs used to treat metal poisoning: the metal is bound to the drug and excreted safely. Chelating agents often form the active centers of enzymes.


Chelating agents are compounds that will render an ion (usually a metal) biologically inactive by incorporating it into an inner ring structure in the molecule. (Hence the name, from the Greek chele = claw.) When the complex formed in this way is harmless to the body and is excreted in the urine, such an agent is an effective way of ridding the body of toxic metals such as mercury. The main chelating agents are dimercaprol, penicillamine, desferrioxamine and sodium calciumedetate — used, for example, in iron poisoning.


A drug, such as calcium disodium edetate, that is used to chelate substances, especially toxic chemicals in  body.


To counteract the effects of metal poisoning, various chemical compounds can be employed that interact with toxic metals like lead, arsenic, and mercury, facilitating the formation of less harmful compounds. One commonly utilized chelating agent is penicillamine.


 


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