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Record Information
Version5.0
StatusDetected and Quantified
Creation Date2005-11-16 15:48:42 UTC
Update Date2022-03-07 02:49:00 UTC
HMDB IDHMDB0000305
Secondary Accession Numbers
  • HMDB00305
Metabolite Identification
Common NameVitamin A
DescriptionVitamin A (retinol) is a yellow fat-soluble, antioxidant vitamin important in vision and bone growth. It belongs to the family of chemical compounds known as retinoids. Retinol is ingested in a precursor form; animal sources (milk and eggs) contain retinyl esters, whereas plants (carrots, spinach) contain pro-vitamin A carotenoids. Hydrolysis of retinyl esters results in retinol while pro-vitamin A carotenoids can be cleaved to produce retinal. Retinal, also known as retinaldehyde, can be reversibly reduced to produce retinol or it can be irreversibly oxidized to produce retinoic acid. Retinol and derivatives of retinol that play an essential role in metabolic functioning of the retina, the growth of and differentiation of epithelial tissue, the growth of bone, reproduction, and the immune response. Dietary vitamin A is derived from a variety of carotenoids found in plants. It is enriched in the liver, egg yolks, and the fat component of dairy products.
Structure
Thumb
Synonyms
Chemical FormulaC20H30O
Average Molecular Weight286.4516
Monoisotopic Molecular Weight286.229665582
IUPAC Name(2E,4E,6E,8E)-3,7-dimethyl-9-(2,6,6-trimethylcyclohex-1-en-1-yl)nona-2,4,6,8-tetraen-1-ol
Traditional Nameα-sol
CAS Registry Number68-26-8
SMILES
C\C(=C/CO)\C=C\C=C(/C)\C=C\C1=C(C)CCCC1(C)C
InChI Identifier
InChI=1S/C20H30O/c1-16(8-6-9-17(2)13-15-21)11-12-19-18(3)10-7-14-20(19,4)5/h6,8-9,11-13,21H,7,10,14-15H2,1-5H3/b9-6+,12-11+,16-8+,17-13+
InChI KeyFPIPGXGPPPQFEQ-OVSJKPMPSA-N
Chemical Taxonomy
Description Belongs to the class of organic compounds known as retinoids. These are oxygenated derivatives of 3,7-dimethyl-1-(2,6,6-trimethylcyclohex-1-enyl)nona-1,3,5,7-tetraene and derivatives thereof.
KingdomOrganic compounds
Super ClassLipids and lipid-like molecules
ClassPrenol lipids
Sub ClassRetinoids
Direct ParentRetinoids
Alternative Parents
Substituents
  • Retinoid skeleton
  • Diterpenoid
  • Fatty alcohol
  • Fatty acyl
  • Organic oxygen compound
  • Hydrocarbon derivative
  • Primary alcohol
  • Organooxygen compound
  • Alcohol
  • Aliphatic homomonocyclic compound
Molecular FrameworkAliphatic homomonocyclic compounds
External Descriptors
Ontology
Physiological effectNot Available
Disposition
Biological locationSource
Process
Role
Physical Properties
StateSolid
Experimental Molecular Properties
PropertyValueReference
Melting Point61 - 63 °CNot Available
Boiling PointNot AvailableNot Available
Water SolubilityNot AvailableNot Available
LogP5.68BIOBYTE (1995)
Experimental Chromatographic PropertiesNot Available
Predicted Molecular Properties
Predicted Chromatographic Properties
Spectra
Biological Properties
Cellular Locations
  • Cytoplasm
  • Extracellular
  • Membrane (predicted from logP)
Biospecimen Locations
  • Blood
  • Feces
  • Saliva
Tissue Locations
  • Adipose Tissue
  • Epidermis
  • Fibroblasts
  • Intestine
  • Kidney
  • Liver
  • Neuron
  • Placenta
  • Spleen
  • Testis
Pathways
Normal Concentrations
Abnormal Concentrations
BiospecimenStatusValueAgeSexConditionReferenceDetails
BloodDetected but not QuantifiedNot QuantifiedAdult (>18 years old)Both
Bladder cancer
details
BloodDetected and Quantified2.50 +/- 0.86 uMAdult (>18 years old)BothHemodialysis details
BloodDetected and Quantified0.45 uMAdult (>18 years old)Male
Abetalipoproteinemia
details
BloodDetected and Quantified2.0 (1.2-2.5) uMAdult (>18 years old)FemaleEndometrial cancer details
BloodDetected and Quantified1.466 +/- 0.349 uMAdult (>18 years old)FemalePregnancy details
Associated Disorders and Diseases
Disease References
Hemodialysis
  1. Cabral PC, Diniz Ada S, de Arruda IK: Vitamin A and zinc status in patients on maintenance haemodialysis. Nephrology (Carlton). 2005 Oct;10(5):459-63. [PubMed:16221095 ]
Endometrial cancer
  1. Jeong NH, Song ES, Lee JM, Lee KB, Kim MK, Yun YM, Lee JK, Son SK, Lee JP, Kim JH, Hur SY, Kwon YI: Preoperative levels of plasma micronutrients are related to endometrial cancer risk. Acta Obstet Gynecol Scand. 2009;88(4):434-9. doi: 10.1080/00016340902767187. [PubMed:19235557 ]
Pregnancy
  1. Mikkelsen TB, Osler M, Olsen SF: Validity of protein, retinol, folic acid and n-3 fatty acid intakes estimated from the food-frequency questionnaire used in the Danish National Birth Cohort. Public Health Nutr. 2006 Sep;9(6):771-8. [PubMed:16925883 ]
Abetalipoproteinemia
  1. Lazaro RP, Dentinger MP, Rodichok LD, Barron KD, Satya-Murti S: Muscle pathology in Bassen-Kornzweig syndrome and vitamin E deficiency. Am J Clin Pathol. 1986 Sep;86(3):378-87. [PubMed:2944375 ]
Associated OMIM IDs
DrugBank IDDB00162
Phenol Explorer Compound IDNot Available
FooDB IDFDB023841
KNApSAcK IDC00031437
Chemspider IDNot Available
KEGG Compound IDC17276
BioCyc IDCPD-13524
BiGG IDNot Available
Wikipedia LinkVitamin_A
METLIN IDNot Available
PubChem Compound445354
PDB IDNot Available
ChEBI ID17336
Food Biomarker OntologyNot Available
VMH IDRETINOL
MarkerDB IDMDB00000141
Good Scents IDrw1131351
References
Synthesis ReferenceIsler, O.; Ronco, A.; Guex, W.; Hindley, N. C.; Huber, W.; Dialer, K.; Kofler, M. Esters and ethers of synthetic vitamin A. Helvetica Chimica Acta (1949), 32 489-505.
Material Safety Data Sheet (MSDS)Not Available
General References

Only showing the first 10 proteins. There are 20 proteins in total.

Enzymes

General function:
Involved in diacylglycerol O-acyltransferase activity
Specific function:
Catalyzes the terminal and only committed step in triacylglycerol synthesis by using diacylglycerol and fatty acyl CoA as substrates. In contrast to DGAT2 it is not essential for survival. May be involved in VLDL (very low density lipoprotein) assembly. In liver, plays a role in esterifying exogenous fatty acids to glycerol. Functions as the major acyl-CoA retinol acyltransferase (ARAT) in the skin, where it acts to maintain retinoid homeostasis and prevent retinoid toxicity leading to skin and hair disorders.
Gene Name:
DGAT1
Uniprot ID:
O75907
Molecular weight:
55277.735
Reactions
Acyl-CoA + Vitamin A → Coenzyme A + Retinyl esterdetails
Acyl-CoA + Vitamin A → Coenzyme A + Retinyl esterdetails
Palmityl-CoA + Vitamin A → Coenzyme A + Retinyl palmitatedetails
General function:
Involved in oxidoreductase activity
Specific function:
Stereospecific 11-cis retinol dehydrogenase, which catalyzes the final step in the biosynthesis of 11-cis retinaldehyde, the universal chromophore of visual pigments. Also able to oxidize 9-cis-retinol and 13-cis-retinol, but not all-trans-retinol. Active in the presence of NAD as cofactor but not in the presence of NADP.
Gene Name:
RDH5
Uniprot ID:
Q92781
Molecular weight:
34978.425
General function:
Involved in zinc ion binding
Specific function:
Not Available
Gene Name:
ADH4
Uniprot ID:
P08319
Molecular weight:
40221.335
Reactions
Vitamin A + NAD → Retinal + NADH + Hydrogen Iondetails
General function:
Involved in zinc ion binding
Specific function:
Class-III ADH is remarkably ineffective in oxidizing ethanol, but it readily catalyzes the oxidation of long-chain primary alcohols and the oxidation of S-(hydroxymethyl) glutathione.
Gene Name:
ADH5
Uniprot ID:
P11766
Molecular weight:
39723.945
Reactions
Vitamin A + NAD → Retinal + NADH + Hydrogen Iondetails
General function:
Involved in zinc ion binding
Specific function:
Not Available
Gene Name:
ADH1B
Uniprot ID:
P00325
Molecular weight:
39835.17
Reactions
Vitamin A + NAD → Retinal + NADH + Hydrogen Iondetails
General function:
Involved in zinc ion binding
Specific function:
Could function in retinol oxidation for the synthesis of retinoic acid, a hormone important for cellular differentiation. Medium-chain (octanol) and aromatic (m-nitrobenzaldehyde) compounds are the best substrates. Ethanol is not a good substrate but at the high ethanol concentrations reached in the digestive tract, it plays a role in the ethanol oxidation and contributes to the first pass ethanol metabolism.
Gene Name:
ADH7
Uniprot ID:
P40394
Molecular weight:
41480.985
Reactions
Vitamin A + NAD → Retinal + NADH + Hydrogen Iondetails
General function:
Involved in zinc ion binding
Specific function:
Not Available
Gene Name:
ADH1A
Uniprot ID:
P07327
Molecular weight:
39858.37
Reactions
Vitamin A + NAD → Retinal + NADH + Hydrogen Iondetails
General function:
Involved in zinc ion binding
Specific function:
Not Available
Gene Name:
ADH6
Uniprot ID:
P28332
Molecular weight:
39072.275
Reactions
Vitamin A + NAD → Retinal + NADH + Hydrogen Iondetails
General function:
Involved in zinc ion binding
Specific function:
Not Available
Gene Name:
ADH1C
Uniprot ID:
P00326
Molecular weight:
39867.27
Reactions
Vitamin A + NAD → Retinal + NADH + Hydrogen Iondetails
General function:
Involved in phosphatidylcholine-retinol O-acyltransfera
Specific function:
Transfers the acyl group from the sn-1 position of phosphatidylcholine to all-trans retinol, producing all-trans retinyl esters. Retinyl esters are storage forms of vitamin A. LRAT plays a critical role in vision. It provides the all-trans retinyl ester substrates for the isomerohydrolase which processes the esters into 11-cis-retinol in the retinal pigment epithelium; due to a membrane-associated alcohol dehydrogenase, 11 cis-retinol is oxidized and converted into 11-cis-retinaldehyde which is the chromophore for rhodopsin and the cone photopigments.
Gene Name:
LRAT
Uniprot ID:
O95237
Molecular weight:
25702.635
Reactions
Phosphatidylcholine + Vitamin A → 2-Acyl-sn-glycero-3-phosphocholine + Retinyl esterdetails

Only showing the first 10 proteins. There are 20 proteins in total.