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Record Information
Creation Date2007-05-22 18:20:36 UTC
Update Date2016-02-11 01:07:25 UTC
Secondary Accession NumbersNone
Metabolite Identification
Common NameErcalcitriol
DescriptionErcalcitriol is the active circulating metabolite of vitamin D2. Vitamin D2 is modified by 25-hydroxylase in the liver and 25-hydroxyvitamin D *-hydroxylase in the kidney to form the active metabolite, ercalcitriol, which is then metabolized by 25-hydroxyvitamin D-24-hydroxylase (24-OHase, CYP24A1, EC The binding of ercalcitriol or their analogs to Vitamin D receptor (VDR), a nuclear receptor, activates VDR to interact with retinoid X receptor (RXR) and forms the VDR/RXR/cofactor complex, which binds to Vitamin D response elements in the promoter region of target genes to regulate gene transcription. The kidney is the major site of 25-hydroxyvitamin D*-hydroxylase (CYP27B1, EC, which is responsible for the activation of 25-hydroxyvitamin D. Of all the steroid hormones, ercalcitriol represents the most difficult challenge to the analytical biochemist with respect to quantization. Ercalcitriol circulates at pmol concentrations, is highly lipophilic and its precursor, 25-hydroxyvitamin D2, circulates at nmol levels. (PMID: 16242929 , 17867378 , 17197173 ).
  1. 1,25-Dihydroxycalciferol
  2. 1,25-Dihydroxyergocalciferol
  3. 1,25-Dihydroxyvitamin D2
  4. 1a,25-Dihydroxycalciferol
  5. 1a,25-Dihydroxyergocalciferol
  6. 1a,25-Dihydroxyvitamin D2
  7. Ro 17-6218
Chemical FormulaC28H44O3
Average Molecular Weight428.6472
Monoisotopic Molecular Weight428.329045274
IUPAC Name(1R,3S,5Z)-5-{2-[(1R,3aS,4E,7aR)-1-[(2R,3E,5S)-6-hydroxy-5,6-dimethylhept-3-en-2-yl]-7a-methyl-octahydro-1H-inden-4-ylidene]ethylidene}-4-methylidenecyclohexane-1,3-diol
Traditional Name(1R,3S,5Z)-5-{2-[(1R,3aS,4E,7aR)-1-[(2R,3E,5S)-6-hydroxy-5,6-dimethylhept-3-en-2-yl]-7a-methyl-hexahydro-1H-inden-4-ylidene]ethylidene}-4-methylidenecyclohexane-1,3-diol
CAS Registry Number60133-18-8
InChI Identifier
Chemical Taxonomy
DescriptionThis compound belongs to the class of organic compounds known as triterpenoids. These are terpene molecules containing 8 isoprene units.
KingdomOrganic compounds
Super ClassLipids and lipid-like molecules
ClassPrenol lipids
Sub ClassTriterpenoids
Direct ParentTriterpenoids
Alternative Parents
  • Polycyclic triterpenoid
  • Triterpenoid
  • Steroid
  • Cyclohexanol
  • Tertiary alcohol
  • Cyclic alcohol
  • Secondary alcohol
  • Hydrocarbon derivative
  • Organooxygen compound
  • Alcohol
  • Aliphatic homopolycyclic compound
Molecular FrameworkAliphatic homopolycyclic compounds
External Descriptors
StatusExpected but not Quantified
  • Endogenous
  • Food
  • Cell signaling
  • Fuel and energy storage
  • Fuel or energy source
  • Hormones, Membrane component
  • Membrane integrity/stability
  • Nutrients
  • Stabilizers
  • Surfactants and Emulsifiers
Cellular locations
  • Extracellular
  • Membrane
  • Mitochondria
Physical Properties
Experimental Properties
Melting PointNot AvailableNot Available
Boiling PointNot AvailableNot Available
Water SolubilityNot AvailableNot Available
LogPNot AvailableNot Available
Predicted Properties
Water Solubility0.007 mg/mLALOGPS
pKa (Strongest Acidic)14.39ChemAxon
pKa (Strongest Basic)-1ChemAxon
Physiological Charge0ChemAxon
Hydrogen Acceptor Count3ChemAxon
Hydrogen Donor Count3ChemAxon
Polar Surface Area60.69 Å2ChemAxon
Rotatable Bond Count5ChemAxon
Refractivity132.12 m3·mol-1ChemAxon
Polarizability52.28 Å3ChemAxon
Number of Rings3ChemAxon
Rule of FiveYesChemAxon
Ghose FilterYesChemAxon
Veber's RuleYesChemAxon
MDDR-like RuleYesChemAxon
SpectraNot Available
Biological Properties
Cellular Locations
  • Extracellular
  • Membrane
  • Mitochondria
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 IDFDB023845
KNApSAcK IDNot Available
Chemspider ID7826183
KEGG Compound IDNot Available
BiGG ID2289254
Wikipedia LinkNot Available
NuGOwiki LinkHMDB06225
Metagene LinkHMDB06225
METLIN IDNot Available
PubChem Compound9547243
PDB IDNot Available
ChEBI IDNot Available
Synthesis ReferenceSicinski, Rafal R.; Tanaka, Yoko; Schnoes, Heinrich K.; DeLuca, Hector F. Synthesis of 1a, 25-dihydroxyvitamin D2, its 24 epimer and related isomers, and their binding affinity for the 1,25-dihydroxyvitamin D3 receptor. Bioorganic Chemistry (1985), 13(2), 158-69.
Material Safety Data Sheet (MSDS)Download (PDF)
General References
  1. Nakane M, Fey TA, Dixon DB, Ma J, Brune ME, Li YC, Wu-Wong JR: Differential effects of Vitamin D analogs on bone formation and resorption. J Steroid Biochem Mol Biol. 2006 Jan;98(1):72-7. Epub 2005 Oct 20. [16242929 ]
  2. Hollis BW: Assessment of circulating 25(OH)D and 1,25(OH)2D: emergence as clinically important diagnostic tools. Nutr Rev. 2007 Aug;65(8 Pt 2):S87-90. [17867378 ]
  3. Hollis BW, Horst RL: The assessment of circulating 25(OH)D and 1,25(OH)2D: where we are and where we are going. J Steroid Biochem Mol Biol. 2007 Mar;103(3-5):473-6. Epub 2007 Jan 2. [17197173 ]


General function:
Involved in monooxygenase activity
Specific function:
Catalyzes the conversion of 25-hydroxyvitamin D3 (25(OH)D) to 1-alpha,25-dihydroxyvitamin D3 (1,25(OH)2D) plays an important role in normal bone growth, calcium metabolism, and tissue differentiation.
Gene Name:
Uniprot ID:
Molecular weight:
General function:
Involved in monooxygenase activity
Specific function:
Has a role in maintaining calcium homeostasis. Catalyzes the NADPH-dependent 24-hydroxylation of calcidiol (25-hydroxyvitamin D(3)) and calcitriol (1-alpha,25-dihydroxyvitamin D(3)). The enzyme can perform up to 6 rounds of hydroxylation of calcitriol leading to calcitroic acid. It also shows 23-hydroxylating activity leading to 1-alpha,25-dihydroxyvitamin D(3)-26,23-lactone as end product.
Gene Name:
Uniprot ID:
Molecular weight: