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Selenium is toxic in high concentrations. As sodium selenite, the chronic toxic dose for human beings was described as about 2.4 to 3 milligrams of selenium per day. [7] In 2000, the US Institute of Medicine set the adult Tolerable upper intake levels (UL) for selenium from all sources - food, drinking water and dietary supplements - at 400 μg/day. [8]
For example, selenomethionine and selenocysteine are selenium-containing amino acids present in the human body. Selenomethionine participates in the synthesis of selenoproteins . [ 2 ] The reduction potential and pKa (5.47) of selenocysteine are lower than those of cysteine , making some proteins have antioxidant activity. [ 3 ]
Large amounts of selenium are toxic; however, it is physiologically necessary for animals in extremely small amounts.Many other uncharacterized selenium-containing organic chemicals are also produced by a method similar to that of selenomethionine; some have recently been characterized but remain relatively unknown, such as S-seleno-methyl-glutathione and glutathione-S-selenoglutathione.
Selenomethionine is readily available as a dietary supplement. It has been suggested by nutritionists that selenomethionine, as an organic form of selenium, is easier for the human body to absorb than selenite, which is an inorganic form. [8] It was determined in a clinical trial that selenomethionine is absorbed 19% better than selenite. [8]
The chronic toxic dose of selenite for humans is about 2400 to 3000 micrograms of selenium per day for a long time. [20] Hydrogen selenide is an extremely toxic, corrosive gas. [ 21 ] Selenium also occurs in organic compounds, such as dimethyl selenide, selenomethionine , selenocysteine and methylselenocysteine , all of which have high ...
Selenite refers to the anion with the chemical formula Se O 2− 3. It is the oxyanion of selenium. It is the selenium analog of the sulfite ion, SO 2− 3. Thus selenite is pyramidal and selenium is assigned oxidation state +4. Selenite also refers to compounds that contains this ion, for example sodium selenite Na 2 SeO 3 which is a common ...
Bill Clinton “Hillary and I mourn the passing of President Jimmy Carter and give thanks for his long, good life,” Clinton, the country's 42nd president, said in a statement on Sunday.
Selenomethionine is a selenide-containing amino acid that also occurs naturally, but is generated by post-transcriptional modification. Organoselenium chemistry in organic synthesis [ edit ]