Search results
Results from the WOW.Com Content Network
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]
Owing to its similarity to sulfur-containing methionine, selenomethionine is mistaken for an amino acid by the yeast anabolism and incorporated in its proteins. It has been claimed that selenomethionine makes a better source of dietary selenium in animal nutrition, since it is an organic chemical compound sometimes found in some common crops ...
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 ]
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]
Sodium selenate is produced by oxidation of selenium, first with nitric acid, producing selenous acid. The selenous acid is neutralized to form sodium selenite. The sodium selenite is oxidized in a basic medium hydrogen peroxide to form a selenate, which is then spray-dried. [3] Se + 2HNO 3 → H 2 SeO 3 + NO + NO 2 H 2 SeO 3 + Na 2 CO 3 → Na ...
For example, upon analysis of garlic using the technique of high-performance liquid chromatography combined with inductively coupled plasma mass spectrometry (HPLC-ICP-MS), it was found that γ-glutamyl-Se-methylselenocysteine was the major Se-containing component, along with lesser amounts of Se-methylselenocysteine.
The chronic toxic dose of selenite for humans is about 2400 to 3000 micrograms of selenium per day. [140] Hydrogen selenide is an extremely toxic, corrosive gas. [ 141 ] Selenium also occurs in organic compounds, such as dimethyl selenide, selenomethionine , selenocysteine and methylselenocysteine , all of which have high bioavailability and ...
Sodium hydrogen selenite. Sodium hydrogen selenite is an inorganic chemical consisting of a ratio of one hydrogen, one sodium, three oxygen, and one selenium atom. It is the sodium salt of the conjugate base of selenous acid. This compound finds therapeutic application for providing the essential trace element selenium.