chelating agents are Certain organic compounds capable of forming coordinate bonds (see chemical bond) with metals through two or more atoms of the organic compound; such organic compounds are called chelating agents. The compound formed by a chelating agent and a metal is called a chelate. A chelating agent that has two coordinating atoms is called bidentate; one that has three, tridentate; and so on. EDTA, or ethylenediaminetetraacetate, (-O2CH2)2NCH2CH2N(CH2CO2-)2, is a common hexadentate chelating agent. Chelating agents are important in textile dyeing, water softening, and enzyme deactivation and as bacteriocides. These are widely found in living systems and are of importance in cellular metabolism. For example, chlorophyll is a chelate of magnesium and hemoglobin is a chelate of iron.
- Hydrophilic chelators most effectively promote renal metal excretion, but they complex intracellular metal deposits inefficiently
- Lipophilic chelators can decrease intracellular stores but may redistribute toxic metals to,for example, the brain. In chronic metal-induced disease, where life-long chelation may benecessary, possible toxicity or side effects of the administered chelator may be limiting.
- Natural chelators: water, carbohydrates, including polysaccharides, organic acids with more than one, coordination group, lipids, steroids, amino acids and related compounds, peptides, phosphates, nucleotides, tetrapyrroles, ferrioxamines, ionophores, such as gramicidin, monensin, valinomycin, phenolics etc. Chlorella, Activated charcoal, Cilantro being the natural chelators
- Synthetic chelators: BAL, deferoxamine, deferiprone, DMPS, DMSA, D-penicillamine, DTPA, EDTA, tetrathiomolybdate, Prussian blue, etc.