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Record Information
Creation Date2012-09-11 17:34:11 UTC
Update Date2016-02-11 01:47:15 UTC
Secondary Accession NumbersNone
Metabolite Identification
Common NameVitamin K2
DescriptionVitamin K2 is found in brassicas. Vitamin K2 is widely distributed in green leaves and vegetables. It is a fat soluble dietary factor effective in controlling blood coagulation. All members of the vitamin K group of vitamins share a methylated naphthoquinone ring structure, and vary in the aliphatic side chain attached at the 3-position. Phylloquinone (also known as vitamin K1) invariably contains in its side chain four isoprenoid residues, one of which is unsaturated. Human milk contains between 1 and 4 micrograms/litre of vitamin K1, while formula derived milk can contain up to 100 micrograms/litre in supplemented formulas. Vitamin K2 concentrations in human milk appear to be much lower than those of vitamin K1. It is estimated that there is a 0.25 to 1.7 percent occurrence of vitamin K deficiency bleeding in the first week of the infant's life with a prevalence of 2-10 cases per 100,000 births. The biochemistry of how Vitamin K is used to convert Glu to Gla has been elucidated over the past thirty years in academic laboratories throughout the world. Within the cell, Vitamin K undergoes electron reduction to a reduced form of Vitamin K (called Vitamin K hydroquinone) by the enzyme Vitamin K epoxide reductase (or VKOR). Another enzyme then oxidizes Vitamin K hydroquinone to allow carboxylation of Glu to Gla; this enzyme is called the gamma-glutamyl carboxylase or the Vitamin K-dependent carboxylase. The carboxylation reaction will only proceed if the carboxylase enzyme is able to oxidize Vitamin K hydroquinone to vitamin K epoxide at the same time; the carboxylation and epoxidation reactions are said to be coupled reactions. Vitamin K epoxide is then re-converted to Vitamin K by the Vitamin K epoxide reductase. These two enzymes comprise the so-called Vitamin K cycle. Vitamin K2 is one of the reasons why Vitamin K is rarely deficient in a human diet is because Vitamin K is continually recycled in our cells. Vitamin K1 is also known as phylloquinone or phytomenadione (also called phytonadione). Vitamin K2 (menaquinone, menatetrenone) is normally produced by bacteria in the Large Intestine, and dietary deficiency is extremely rare unless the intestines are heavily damaged, are unable to absorb the molecule, or due to decreased production by normal flora, as seen in broad spectrum antibiotic use. Vitamin k2 belongs to the family of Polyprenylbenzoquinones. These are compounds containing a polyisoprene chain attached to a quinone at the second ring position.
Chemical FormulaC41H56O2
Average Molecular Weight580.8821
Monoisotopic Molecular Weight580.428031036
IUPAC Name2-[(2E,6E,10E,14E,18E)-3,7,11,15,19,23-hexamethyltetracosa-2,6,10,14,18,22-hexaen-1-yl]-3-methyl-1,4-dihydronaphthalene-1,4-dione
Traditional Namevitamin K2
CAS Registry NumberNot Available
InChI Identifier
Chemical Taxonomy
DescriptionThis compound belongs to the class of organic compounds known as vitamin k compounds. These are quinone lipids containing a methylated naphthoquinone ring structure, and vary in the aliphatic side chain attached at the 3-position.
KingdomOrganic compounds
Super ClassLipids and lipid-like molecules
ClassPrenol lipids
Sub ClassQuinone and hydroquinone lipids
Direct ParentVitamin K compounds
Alternative Parents
  • Sesterterpenoid
  • Menaquinone
  • Naphthoquinone
  • Naphthalene
  • Aryl ketone
  • Quinone
  • Benzenoid
  • Ketone
  • Hydrocarbon derivative
  • Organooxygen compound
  • Carbonyl group
  • Aromatic homopolycyclic compound
Molecular FrameworkAromatic homopolycyclic compounds
External Descriptors
StatusExpected but not Quantified
  • Endogenous
  • Food
  • Cell signaling
  • Fuel and energy storage
  • Fuel or energy source
  • Membrane integrity/stability
  • Nutrient
  • Stabilizers
  • Surfactants and Emulsifiers
Cellular locations
  • Extracellular
  • Membrane
Physical Properties
StateNot Available
Experimental Properties
Melting PointNot AvailableNot Available
Boiling PointNot AvailableNot Available
Water SolubilityNot AvailableNot Available
LogPNot AvailableNot Available
Predicted Properties
Water Solubility0.000266 mg/mLALOGPS
pKa (Strongest Basic)-7.2ChemAxon
Physiological Charge0ChemAxon
Hydrogen Acceptor Count2ChemAxon
Hydrogen Donor Count0ChemAxon
Polar Surface Area34.14 Å2ChemAxon
Rotatable Bond Count17ChemAxon
Refractivity193.11 m3·mol-1ChemAxon
Polarizability74.54 Å3ChemAxon
Number of Rings2ChemAxon
Rule of FiveYesChemAxon
Ghose FilterYesChemAxon
Veber's RuleYesChemAxon
MDDR-like RuleYesChemAxon
Spectrum TypeDescriptionSplash Key
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 10V, PositiveNot Available
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 20V, PositiveNot Available
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 40V, PositiveNot Available
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 10V, NegativeNot Available
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 20V, NegativeNot Available
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 40V, NegativeNot Available
Biological Properties
Cellular Locations
  • Extracellular
  • Membrane
Biofluid LocationsNot Available
Tissue LocationNot Available
PathwaysNot Available
Normal Concentrations
Not Available
Abnormal Concentrations
Not Available
Associated Disorders and Diseases
Disease ReferencesNone
Associated OMIM IDsNone
DrugBank IDNot Available
DrugBank Metabolite IDNot Available
Phenol Explorer Compound IDNot Available
Phenol Explorer Metabolite IDNot Available
FoodDB IDFDB001310
KNApSAcK IDNot Available
Chemspider ID4446660
KEGG Compound IDC00828
BioCyc IDNot Available
BiGG IDNot Available
Wikipedia LinkVitamin_K2
NuGOwiki LinkHMDB30017
Metagene LinkHMDB30017
METLIN IDNot Available
PubChem Compound5283547
PDB IDNot Available
ChEBI IDNot Available
Synthesis ReferenceNot Available
Material Safety Data Sheet (MSDS)Not Available
General References
  1. Yannai, Shmuel. (2004) Dictionary of food compounds with CD-ROM: Additives, flavors, and ingredients. Boca Raton: Chapman & Hall/CRC.


General function:
Involved in electron carrier activity
Specific function:
The enzyme apparently serves as a quinone reductase in connection with conjugation reactions of hydroquinons involved in detoxification pathways as well as in biosynthetic processes such as the vitamin K-dependent gamma-carboxylation of glutamate residues in prothrombin synthesis.
Gene Name:
Uniprot ID:
Molecular weight:
Vitamin K2 + Hydrogen Ion + NADH → Menaquinol + NADdetails
General function:
Involved in vitamin-K-epoxide reductase (warfarin-sensi
Specific function:
Involved in vitamin K metabolism. Catalytic subunit of the vitamin K epoxide reductase (VKOR) complex which reduces inactive vitamin K 2,3-epoxide to active vitamin K.
Gene Name:
Uniprot ID:
Molecular weight:
2,3-Epoxymenaquinone + 1,4-Dithiothreitol → Vitamin K2 + Oxidized dithiothreitol + Waterdetails