描述
Prothrombogenic vitamin (synthetic)
A synthetic naphthoquinone without the isoprenoid side chain and biological activity, but can be converted to active vitamin K2, menaquinone, after alkylation in vivo. -- Pubchem; Despite the fact that it can serve as a precursor to various types of vitamin K, menadione is generally not used as a nutritional supplement. Large doses of menadione have been reported to cause adverse outcomes including hemolytic anemia due to G6PD deficiency, neonatal brain or liver damage, or neonatal death in some cases. Moreover, menadione supplements have been banned by the FDA because of their high toxicity.; It is sometimes called vitamin K3, although derivatives of naphthoquinone without the sidechain in the 3-position cannot exert all the functions of the K vitamins. Menadione is a vitamin precursor of K2 which utilizes alkylation in the liver to yield menaquinones (MK-n, n=1-13; It is also known as "menaphthone".; It is sometimes called vitamin K3, although derivatives of naphthoquinone without the side chain in the 3-position cannot exert all the functions of the K vitamins. Menadione is a vitamin precursor of K2 which utilizes alkylation to yield menaquinones (MK-n, n=1-13; K2 vitamers), and hence, is better classified as a provitamin.; K2 vitamers), and hence, is better classified as a provitamin. -- Wikipedia; Menadione (Vitamin K3) is a fat-soluble vitamin precursor that is converted into menaquinone in the liver. Vitamin K1 and K2 are the naturally occurring types of vitamin K. The former, which is also known as phylloquinone, is synthesized by plants and can be found in such foods as spinach, broccoli, lettuce, and soybeans. The latter, sometimes alternatively referred to as menaquinone, is primarily produced by bacteria in the anterior part of the gut and the intestines. Vitamin K3, on the other hand, is one of the many manmade versions of vitamin Kand is also called menadione, this yellowish, synthetic crystalline substance is converted into the active form of the K2 vitamin inside of the animal body. While a vitamin K deficiency can be dangerous, especially to infants that may easily suffer from extensive hemorrhaging, an overdose can be as equally detrimental. Newborns that are administered too great a dosage of vitamin K3 can suffer from kernicterus, a form of severe brain damage that may produce decreased movement, loss of appetite, seizures, deafness, mental retardation, and even death. This condition is associated with an abnormally high concentration of bilirubin, a bile pigment, in the tissues of the brain, which can be caused by the presence of K3. For this reason, K3 is less often utilized medically than it was in former times.; Menadione is a polycyclic aromatic ketone, based on 1,4-naphthoquinone, with a 2-methyl substituent.