Menadione is a
polycyclicPolycyclic may refer to:* Polycyclic compound, in organic chemistry, a cyclic compound with more than one hydrocarbon loop or ring structures* Polycyclic group, in mathematics, a solvable group that satisfies the maximal condition on subgroups...
aromatic
ketoneIn organic chemistry, a ketone is a type of compound that features a carbonyl group bonded to two other carbon atoms, i.e., R3CCO-CR3 where R can be a variety of atoms and groups of atoms...
, based on 1,4-naphthoquinone, with a 2-methyl
substituentIn organic chemistry and biochemistry, a substituent is an atom or group of atoms substituted in place of a hydrogen atom on the parent chain of a hydrocarbon...
.
It is sometimes called vitamin K
3, 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 K
2 which utilizes alkylation to yield menaquinones (MK-n, n=1-13; K
2 vitamers), and hence, is better classified as a provitamin.
It is also known as "menaphthone".
Despite the fact that it can serve as a precursor to various types of
vitamin KVitamin K denotes a group of lipophilic, hydrophobic vitamins that are needed for the posttranslational modification of certain proteins, mostly required for blood coagulation...
, menadione is generally not used as a nutritional supplement.
Menadione is a
polycyclicPolycyclic may refer to:* Polycyclic compound, in organic chemistry, a cyclic compound with more than one hydrocarbon loop or ring structures* Polycyclic group, in mathematics, a solvable group that satisfies the maximal condition on subgroups...
aromatic
ketoneIn organic chemistry, a ketone is a type of compound that features a carbonyl group bonded to two other carbon atoms, i.e., R3CCO-CR3 where R can be a variety of atoms and groups of atoms...
, based on 1,4-naphthoquinone, with a 2-methyl
substituentIn organic chemistry and biochemistry, a substituent is an atom or group of atoms substituted in place of a hydrogen atom on the parent chain of a hydrocarbon...
.
Terminology
It is sometimes called vitamin K
3, 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 K
2 which utilizes alkylation to yield menaquinones (MK-n, n=1-13; K
2 vitamers), and hence, is better classified as a provitamin.
It is also known as "menaphthone".
Uses
Despite the fact that it can serve as a precursor to various types of
vitamin KVitamin K denotes a group of lipophilic, hydrophobic vitamins that are needed for the posttranslational modification of certain proteins, mostly required for blood coagulation...
, menadione is generally not used as a nutritional supplement. Large doses of menadione have been reported to cause adverse outcomes including
hemolytic anemiaHemolytic anemia is anemia due to hemolysis, the abnormal breakdown of red blood cells either in the blood vessels or elsewhere in the body . It has numerous possible causes, ranging from relatively harmless to life-threatening. The general classification of hemolytic anemia is either acquired or...
due to
G6PD deficiencyGlucose-6-phosphate dehydrogenase deficiency is an X-linked recessive hereditary disease characterised by abnormally low levels of glucose-6-phosphate dehydrogenase , a metabolic enzyme involved in the pentose phosphate pathway, especially important in red blood cell metabolism...
, neonatal brain or liver damage, or neonatal death in some cases. Moreover, menadione supplements have been banned by the U.S. Food and Drug Administration (FDA) because of their high toxicity. Menadione has been used experimentally as a chemotherapic agent for
cancerCancer is a class of diseases in which a group of cells display uncontrolled growth , invasion , and sometimes metastasis...
, ca 1945, but has lost ground to much safer, human form, vitamin K
2 vitamers. Low level menadione is still used as an inexpensive micronutrient for livestock in many countries. Forms of Menadione are also included in some pet foods as a source of vitamin K.
Lately, menadione has been mentioned again as a treatment for
cancerCancer is a class of diseases in which a group of cells display uncontrolled growth , invasion , and sometimes metastasis...
in conjunction with
vitamin CVitamin C or L-ascorbic acid is an essential nutrient for humans, in which it functions as a vitamin. Ascorbate is required for a range of essential metabolic reactions in all animals and plants...
(See "The end of cancer" by April Kirkendoll) but modern researchers and trials are investigating nontoxic K
2 vitamers such as menaquinone-4 in conjunction with more comprehensive regimens.