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Record Information
Version3.6
Creation Date2005-11-16 15:48:42 UTC
Update Date2016-02-11 01:02:32 UTC
HMDB IDHMDB00305
Secondary Accession NumbersNone
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
ValueSource
(2E,4E,6E,8E)-3,7-Dimethyl-9-(2,6,6-trimethylcyclohex-1-en-1-yl)nona-2,4,6,8-tetraen-1-olChEBI
all-trans-Retinyl alcoholChEBI
all-trans-Vitamin a alcoholChEBI
AlphalinChEBI
Chocola aChEBI
RetinolChEBI
Vitamin a1ChEBI
(all-e)-3,7-Dimethyl-9-(2,6,6-trimethyl-1-cyclohexen-1-yl)-2,4,6,8-nonatetraen-1-olHMDB
all-trans-RetinolHMDB
b-RetinolHMDB
beta-RetinolHMDB
trans-RetinolHMDB
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 KeyInChIKey=FPIPGXGPPPQFEQ-OVSJKPMPSA-N
Chemical Taxonomy
DescriptionThis compound 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
  • Hydrocarbon derivative
  • Primary alcohol
  • Organooxygen compound
  • Alcohol
  • Aliphatic homomonocyclic compound
Molecular FrameworkAliphatic homomonocyclic compounds
External Descriptors
Ontology
StatusDetected and Quantified
Origin
  • Drug
  • Endogenous
  • Food
Biofunction
  • Cell signaling
  • Component of Retinol metabolism
  • Essential vitamins
  • Fuel and energy storage
  • Fuel or energy source
  • Membrane integrity/stability
  • Transcriptional activator
Application
  • Nutrients
  • Stabilizers
  • Surfactants and Emulsifiers
Cellular locations
  • Cytoplasm
  • Extracellular
  • Membrane (predicted from logP)
Physical Properties
StateSolid
Experimental Properties
PropertyValueReference
Melting Point61 - 63 °CNot Available
Boiling PointNot AvailableNot Available
Water SolubilityNot AvailableNot Available
LogP5.68BIOBYTE (1995)
Predicted Properties
PropertyValueSource
Water Solubility0.0076 mg/mLALOGPS
logP6.38ALOGPS
logP4.69ChemAxon
logS-4.6ALOGPS
pKa (Strongest Acidic)16.44ChemAxon
pKa (Strongest Basic)-2.2ChemAxon
Physiological Charge0ChemAxon
Hydrogen Acceptor Count1ChemAxon
Hydrogen Donor Count1ChemAxon
Polar Surface Area20.23 Å2ChemAxon
Rotatable Bond Count5ChemAxon
Refractivity97.92 m3·mol-1ChemAxon
Polarizability36.43 Å3ChemAxon
Number of Rings1ChemAxon
Bioavailability1ChemAxon
Rule of FiveYesChemAxon
Ghose FilterYesChemAxon
Veber's RuleYesChemAxon
MDDR-like RuleYesChemAxon
Spectra
Spectra
Spectrum TypeDescriptionSplash Key
LC-MS/MSLC-MS/MS Spectrum - Quattro_QQQ 10V, Positive (Annotated)splash10-000i-0290000000-25c523b646154b291da8View in MoNA
LC-MS/MSLC-MS/MS Spectrum - Quattro_QQQ 25V, Positive (Annotated)splash10-05gj-3900000000-a63c286f931608f650a3View in MoNA
LC-MS/MSLC-MS/MS Spectrum - Quattro_QQQ 40V, Positive (Annotated)splash10-05mo-9700000000-e627db30469c74bb037fView in MoNA
MSMass Spectrum (Electron Ionization)splash10-052r-2950000000-c24ec8ff8d0ba6c1f23fView in MoNA
2D NMR[1H,13C] 2D NMR SpectrumNot Available
Biological Properties
Cellular Locations
  • Cytoplasm
  • Extracellular
  • Membrane (predicted from logP)
Biofluid Locations
  • Blood
  • Saliva
Tissue Location
  • Adipose Tissue
  • Fibroblasts
  • Intestine
  • Kidney
  • Liver
  • Myelin
  • Placenta
  • Skin
  • Spleen
  • Stratum Corneum
  • Testes
Pathways
NameSMPDB LinkKEGG Link
Retinol MetabolismSMP00074map00830
Vitamin A DeficiencySMP00336Not Available
Normal Concentrations
BiofluidStatusValueAgeSexConditionReferenceDetails
BloodDetected and Quantified0.78 +/- 0.33 uMChildren (1-13 years old)BothNormal
    • Geigy Scientific ...
details
BloodDetected and Quantified1.84 +/- 0.46 uMAdult (>18 years old)MaleNormal
    • Geigy Scientific ...
details
BloodDetected and Quantified1.76 +/- 0.44 uMAdult (>18 years old)FemaleNormal
    • Geigy Scientific ...
details
BloodDetected and Quantified1.02 (0.34-2.1) uMAdolescent (13-18 years old)BothNormal details
BloodDetected and Quantified279.28-1871.17 uMInfant (0-1 year old)Both
Normal
    • CALIPER Paediatri...
details
BloodDetected and Quantified960.0226-1550.0000698 uMChildren (1 - <11 years old)Both
Normal
    • CALIPER Paediatri...
details
BloodDetected and Quantified869.26-1920.05 uMAdolescent (11 - <16 years old)Both
Normal
    • CALIPER Paediatri...
details
BloodDetected and Quantified1001.91-2621.73 uMAdolescent (16 - <19 years old)Both
Normal
    • CALIPER Paediatri...
details
BloodDetected and Quantified2.3 (1.2-3.5) uMAdult (>18 years old)FemaleNormal details
SalivaDetected and Quantified0.015 +/- 0.010 uMAdult (>18 years old)BothNormal
    • Zerihun T. Dame, ...
details
Abnormal Concentrations
BiofluidStatusValueAgeSexConditionReferenceDetails
BloodDetected but not QuantifiedNot ApplicableAdult (>18 years old)Both
Bladder cancer
details
BloodDetected and Quantified2.50 +/- 0.86 uMAdult (>18 years old)BothHemodialysis details
BloodDetected and Quantified2.0 (1.2-2.5) uMAdult (>18 years old)FemaleCancer details
Associated Disorders and Diseases
Disease References
Thyroid 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. [19235557 ]
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. [16221095 ]
Associated OMIM IDsNone
DrugBank IDNot Available
DrugBank Metabolite IDNot Available
Phenol Explorer Compound IDNot Available
Phenol Explorer Metabolite IDNot Available
FoodDB IDFDB013828
KNApSAcK IDC00031437
Chemspider ID393012
KEGG Compound IDC00473
BioCyc IDRETINOL
BiGG ID35081
Wikipedia LinkVitamin A
NuGOwiki LinkHMDB00305
Metagene LinkHMDB00305
METLIN IDNot Available
PubChem Compound445354
PDB IDRTL
ChEBI ID17336
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)Download (PDF)
General References
  1. Norum KR, Blomhoff R: McCollum Award Lecture, 1992: vitamin A absorption, transport, cellular uptake, and storage. Am J Clin Nutr. 1992 Oct;56(4):735-44. [1414975 ]
  2. Graham-Maar RC, Schall JI, Stettler N, Zemel BS, Stallings VA: Elevated vitamin A intake and serum retinol in preadolescent children with cystic fibrosis. Am J Clin Nutr. 2006 Jul;84(1):174-82. [16825693 ]
  3. Sorenson AW, Delhumeau C, Bernstein MS, Costanza MC, Morabia A: Impact of 'Mad Cow Disease' publicity on trends in meat and total vitamin A consumption in Geneva between 1993 and 2000. Eur J Clin Nutr. 2003 Jan;57(1):177-85. [12548314 ]
  4. Alberts D, Ranger-Moore J, Einspahr J, Saboda K, Bozzo P, Liu Y, Xu XC, Lotan R, Warneke J, Salasche S, Stratton S, Levine N, Goldman R, Islas M, Duckett L, Thompson D, Bartels P, Foote J: Safety and efficacy of dose-intensive oral vitamin A in subjects with sun-damaged skin. Clin Cancer Res. 2004 Mar 15;10(6):1875-80. [15041701 ]
  5. Wieringa FT, Dijkhuizen MA, West CE, Thurnham DI, Muhilal, Van der Meer JW: Redistribution of vitamin A after iron supplementation in Indonesian infants. Am J Clin Nutr. 2003 Mar;77(3):651-7. [12600856 ]
  6. Egeland GM, Berti P, Soueida R, Arbour LT, Receveur O, Kuhnlein HV: Age differences in vitamin A intake among Canadian Inuit. Can J Public Health. 2004 Nov-Dec;95(6):465-9. [15622799 ]
  7. Ribaya-Mercado JD, Solon FS, Fermin LS, Perfecto CS, Solon JA, Dolnikowski GG, Russell RM: Dietary vitamin A intakes of Filipino elders with adequate or low liver vitamin A concentrations as assessed by the deuterated-retinol-dilution method: implications for dietary requirements. Am J Clin Nutr. 2004 Apr;79(4):633-41. [15051608 ]
  8. Kieu NT, Yurie K, Hung NT, Yamamoto S, Chuyen NV: Simultaneous analysis of retinol, beta-carotene and tocopherol levels in serum of Vietnamese populations with different incomes. Asia Pac J Clin Nutr. 2002;11(2):92-7. [12074187 ]
  9. Torma H, Vahlquist A: Vitamin A esterification in human epidermis: a relation to keratinocyte differentiation. J Invest Dermatol. 1990 Jan;94(1):132-8. [2295828 ]
  10. Allen LH, Haskell M: Estimating the potential for vitamin A toxicity in women and young children. J Nutr. 2002 Sep;132(9 Suppl):2907S-2919S. [12221269 ]
  11. Ribaya-Mercado JD, Solomons NW, Medrano Y, Bulux J, Dolnikowski GG, Russell RM, Wallace CB: Use of the deuterated-retinol-dilution technique to monitor the vitamin A status of Nicaraguan schoolchildren 1 y after initiation of the Nicaraguan national program of sugar fortification with vitamin A. Am J Clin Nutr. 2004 Nov;80(5):1291-8. [15531678 ]
  12. Marquez M, Yepez CE, Sutil-Naranjo R, Rincon M: [Basic aspects and measurement of the antioxidant vitamins A and E] Invest Clin. 2002 Sep;43(3):191-204. [12229281 ]
  13. Mills JP, Penniston KL, Tanumihardjo SA: Extra-hepatic vitamin A concentrations in captive Rhesus (Macaca mulatta) and Marmoset (Callithrix jacchus) monkeys fed excess vitamin A. Int J Vitam Nutr Res. 2005 Mar;75(2):126-32. [15929633 ]
  14. Penniston KL, Tanumihardjo SA: The acute and chronic toxic effects of vitamin A. Am J Clin Nutr. 2006 Feb;83(2):191-201. [16469975 ]
  15. Jumpsen JA, Brown NE, Thomson AB, Paul Man SF, Goh YK, Ma D, Clandinin MT: Fatty acids in blood and intestine following docosahexaenoic acid supplementation in adults with cystic fibrosis. J Cyst Fibros. 2006 May;5(2):77-84. Epub 2006 Feb 28. [16507353 ]

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
hexadecanoyl-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
General function:
Involved in oxidoreductase activity
Specific function:
NAD-dependent oxidoreductase with broad substrate specificity that shows both oxidative and reductive activity (in vitro). Has 17-beta-hydroxysteroid dehydrogenase activity towards various steroids (in vitro). Converts 5-alpha-androstan-3-alpha,17-beta-diol to androsterone and estradiol to estrone (in vitro). Has 3-alpha-hydroxysteroid dehydrogenase activity towards androsterone (in vitro). Has retinol dehydrogenase activity towards all-trans-retinol (in vitro). Can convert androsterone to epi-androsterone. Androsterone is first oxidized to 5-alpha-androstane-3,17-dione and then reduced to epi-andosterone. Can act on both C-19 and C-21 3-alpha-hydroxysteroids.
Gene Name:
HSD17B6
Uniprot ID:
O14756
Molecular weight:
35965.41
Reactions
Vitamin A + NAD → Retinal + NADH + Hydrogen Iondetails
General function:
Involved in transferase activity, transferring acyl groups other than amino-acyl groups
Specific function:
Essential acyltransferase that catalyzes the terminal and only committed step in triacylglycerol synthesis by using diacylglycerol and fatty acyl CoA as substrates. Required for synthesis and storage of intracellular triglycerides. Probably plays a central role in cytosolic lipid accumulation. In liver, is primarily responsible for incorporating endogenously synthesized fatty acids into triglycerides (By similarity). Functions also as an acyl-CoA retinol acyltransferase (ARAT).
Gene Name:
DGAT2
Uniprot ID:
Q96PD7
Molecular weight:
39043.88
Reactions
Acyl-CoA + Vitamin A → Coenzyme A + Retinyl esterdetails
General function:
Involved in estradiol 17-beta-dehydrogenase activity
Specific function:
Retinol dehydrogenase with a clear preference for NADP. Converts all-trans-retinal to all-trans-retinol. May play a role in the regeneration of visual pigment at high light intensity (By similarity).
Gene Name:
RDH8
Uniprot ID:
Q9NYR8
Molecular weight:
35804.24
Reactions
Vitamin A + NADP → Retinal + NADPHdetails
General function:
Involved in oxidoreductase activity
Specific function:
Exhibits an oxidoreductive catalytic activity towards retinoids. Most efficient as an NADPH-dependent retinal reductase. Displays high activity towards 9-cis and all-trans-retinol. Also involved in the metabolism of short-chain aldehydes. No steroid dehydrogenase activity detected.
Gene Name:
RDH11
Uniprot ID:
Q8TC12
Molecular weight:
35385.955
Reactions
Vitamin A + NADP → Retinal + NADPHdetails
General function:
Involved in oxidoreductase activity
Specific function:
Retinol dehydrogenase with a clear preference for NADP. Converts all-trans-retinol to all-trans-retinal. Has no detectable activity towards 11-cis-retinol, 9-cis-retinol and 13-cis-retinol.
Gene Name:
RDH10
Uniprot ID:
Q8IZV5
Molecular weight:
38087.16
Reactions
Vitamin A + NADP → Retinal + NADPHdetails
General function:
Involved in transferase activity, transferring acyl groups other than amino-acyl groups
Specific function:
Acyltransferase that predominantly esterify long chain (wax) alcohols with acyl-CoA-derived fatty acids to produce wax esters. Wax esters are enriched in sebum, suggesting that it plays a central role in lipid metabolism in skin. Has a preference for arachidyl alcohol as well as decyl alcohol, demonstrating its relatively poor activity using saturated long chain alcohols (C16, C18, and C20).
Gene Name:
AWAT1
Uniprot ID:
Q58HT5
Molecular weight:
37758.815
General function:
Involved in transferase activity, transferring acyl groups other than amino-acyl groups
Specific function:
Acyltransferase that predominantly esterify long chain (wax) alcohols with acyl-CoA-derived fatty acids to produce wax esters. Wax esters are enriched in sebum, suggesting that it plays a central role in lipid metabolism in skin. Has no activity using decyl alcohol and significantly prefers the C16 and C18 alcohols. May also have 2-acylglycerol O-acyltransferase (MGAT) and acyl-CoA:retinol acyltransferase (ARAT) activities, to catalyze the synthesis of diacylglycerols and retinyl esters; however this activity is unclear in vivo.
Gene Name:
AWAT2
Uniprot ID:
Q6E213
Molecular weight:
38093.25
Reactions
Acyl-CoA + Vitamin A → Coenzyme A + Retinyl esterdetails
Acyl-CoA + Vitamin A → Coenzyme A + Retinyl esterdetails
hexadecanoyl-CoA + Vitamin A → Coenzyme A + Retinyl palmitatedetails
General function:
Involved in electron carrier activity
Specific function:
Retinol saturase carrying out the saturation of the 13-14 double bond of all-trans-retinol to produce all-trans-13,14-dihydroretinol. Has activity toward all-trans-retinol as substrate. Does not use all-trans-retinoic acid nor 9-cis, 11-cis or 13-cis-retinol isomers as substrates. May play a role in the metabolism of vitamin A (By similarity).
Gene Name:
RETSAT
Uniprot ID:
Q6NUM9
Molecular weight:
66818.935
Reactions
All-trans-13,14-dihydroretinol + acceptor → Vitamin A + reduced acceptordetails
All-trans-13,14-dihydroretinol + Acceptor → Vitamin A + Reduced acceptordetails
General function:
Involved in oxidoreductase activity
Specific function:
Catalyzes the reduction of all-trans-retinal to all-trans-retinol in the presence of NADPH.
Gene Name:
DHRS3
Uniprot ID:
O75911
Molecular weight:
33548.115
Reactions
Vitamin A + NADP → Retinal + NADPHdetails
General function:
Not Available
Specific function:
Oxidoreductase with strong preference for NAD. Active in both the oxidative and reductive directions. Oxidizes all-trans-retinol in all-trans-retinaldehyde. No activity was detected with 11-cis-retinol or 11-cis-retinaldehyde as substrates with either NAD(+)/NADH or NADP(+)/NADPH.
Gene Name:
SDR16C5
Uniprot ID:
Q8N3Y7
Molecular weight:
34095.0
Reactions
Vitamin A + NAD → Retinal + NADH + Hydrogen Iondetails