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Record Information
Version3.6
Creation Date2006-05-22 14:17:53 UTC
Update Date2016-02-11 01:05:40 UTC
HMDB IDHMDB02434
Secondary Accession NumbersNone
Metabolite Identification
Common NameHydroquinone
DescriptionHydroquinone, also benzene-1,4-diol, is an aromatic organic compound which is a type of phenol, having the chemical formula C6H4(OH)2. Its chemical structure has two hydroxyl groups bonded to a benzene ring in a para position. Hydroquinone is commonly used as a biomarker for benzene exposure. The presence of hydroquinone in normal individuals stems mainly from direct dietary ingestion, catabolism of tyrosine and other substrates by gut bacteria, ingestion of arbutin containing foods, cigarette smoking, and the use of some over-the-counter medicines. Hydroquinone is a white granular solid at room temperature and pressure. The hydroxyl groups of hydroquinone are quite weakly acidic. Hydroquinone can lose an H+ from one of the hydroxyls to form a monophenolate ion or lose an H+ from both to form a diphenolate ion. Hydroquinone has a variety of uses principally associated with its action as a reducing agent which is soluble in water. It is a major component in most photographic developers where, with the compound Metol, it reduces silver halides to elemental silver.
Structure
Thumb
Synonyms
ValueSource
1,4-BenzenediolChEBI
1,4-DihydroxybenzeneChEBI
4-HydroxyphenolChEBI
EldoquinChEBI
P-BenzenediolChEBI
P-HydroquinoneChEBI
P-HydroxyphenolChEBI
QuinolChEBI
1,4-Dihydroxy-benzeenHMDB
1,4-Dihydroxy-benzolHMDB
1,4-DihydroxybenzenHMDB
1,4-DiidrobenzeneHMDB
a-HydroquinoneHMDB
alpha-HydroquinoneHMDB
b-QuinolHMDB
BenzohydroquinoneHMDB
BenzoquinolHMDB
beta-QuinolHMDB
DihydroquinoneHMDB
DihydroxybenzeneHMDB
HydrochinonHMDB
HydrochinoneHMDB
HydroquinolHMDB
HydroquinoleHMDB
Hydroquinone for synthesisHMDB
Hydroquinone GRHMDB
HydroquinoueHMDB
IdrochinoneHMDB
MelanexHMDB
P-DihydroxybenzeneHMDB
P-DioxobenzeneHMDB
P-DioxybenzeneHMDB
P-HydroxybenzeneHMDB
PhiaquinHMDB
Solaquin forteHMDB
Chemical FormulaC6H6O2
Average Molecular Weight110.1106
Monoisotopic Molecular Weight110.036779436
IUPAC Namebenzene-1,4-diol
Traditional Nameα-hydroquinone
CAS Registry Number123-31-9
SMILES
OC1=CC=C(O)C=C1
InChI Identifier
InChI=1S/C6H6O2/c7-5-1-2-6(8)4-3-5/h1-4,7-8H
InChI KeyInChIKey=QIGBRXMKCJKVMJ-UHFFFAOYSA-N
Chemical Taxonomy
DescriptionThis compound belongs to the class of organic compounds known as hydroquinones. These are compounds containing a hydroquinone moiety, which consists of a benzene ring with a hydroxyl groups at positions 1 and 4.
KingdomOrganic compounds
Super ClassBenzenoids
ClassBenzene and substituted derivatives
Sub ClassPhenols and derivatives
Direct ParentHydroquinones
Alternative Parents
Substituents
  • Hydroquinone
  • Hydrocarbon derivative
  • Organooxygen compound
  • Aromatic homomonocyclic compound
Molecular FrameworkAromatic homomonocyclic compounds
External Descriptors
Ontology
StatusDetected and Quantified
Origin
  • Cosmetic
BiofunctionNot Available
ApplicationNot Available
Cellular locations
  • Cytoplasm
Physical Properties
StateSolid
Experimental Properties
PropertyValueReference
Melting Point172.3 °CNot Available
Boiling PointNot AvailableNot Available
Water Solubility72.0 mg/mL at 25 °CNot Available
LogP0.59HANSCH,C ET AL. (1995)
Predicted Properties
PropertyValueSource
Water Solubility95.5 mg/mLALOGPS
logP0.71ALOGPS
logP1.37ChemAxon
logS-0.06ALOGPS
pKa (Strongest Acidic)9.68ChemAxon
pKa (Strongest Basic)-5.9ChemAxon
Physiological Charge0ChemAxon
Hydrogen Acceptor Count2ChemAxon
Hydrogen Donor Count2ChemAxon
Polar Surface Area40.46 Å2ChemAxon
Rotatable Bond Count0ChemAxon
Refractivity30.02 m3·mol-1ChemAxon
Polarizability10.75 Å3ChemAxon
Number of Rings1ChemAxon
Bioavailability1ChemAxon
Rule of FiveYesChemAxon
Ghose FilterYesChemAxon
Veber's RuleYesChemAxon
MDDR-like RuleYesChemAxon
Spectra
Spectra
Spectrum TypeDescriptionSplash Key
GC-MSGC-MS Spectrum - GC-MS (2 TMS)splash10-0f79-2490000000-6b4fec222a3499d93790View in MoNA
LC-MS/MSLC-MS/MS Spectrum - Quattro_QQQ 10V, Positive (Annotated)splash10-03di-9600000000-e670ba090cb27367db12View in MoNA
LC-MS/MSLC-MS/MS Spectrum - Quattro_QQQ 25V, Positive (Annotated)splash10-01p6-9000000000-5fc32c7688c1612df1e7View in MoNA
LC-MS/MSLC-MS/MS Spectrum - Quattro_QQQ 40V, Positive (Annotated)splash10-000i-9000000000-c5853ce8ef225ea5c353View in MoNA
LC-MS/MSLC-MS/MS Spectrum - EI-B (Unknown) , Positivesplash10-03di-9800000000-c90fd4986fea9691ecbfView in MoNA
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 10V, Positivesplash10-03di-0900000000-8d8328e4f7cd2ebaa27dView in MoNA
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 20V, Positivesplash10-03di-1900000000-9290fcb93f170fc3143fView in MoNA
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 40V, Positivesplash10-01si-9200000000-9f707b9d0c4ad0b73b30View in MoNA
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 10V, Negativesplash10-0a4i-0900000000-d3aae38632ac4c40fd4fView in MoNA
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 20V, Negativesplash10-0a4i-0900000000-74f15490ba4f49cf8c18View in MoNA
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 40V, Negativesplash10-0a4i-9800000000-1cb01248e88fce387578View in MoNA
MSMass Spectrum (Electron Ionization)splash10-03di-9500000000-1fa8477944a662535e76View in MoNA
1D NMR1H NMR SpectrumNot Available
1D NMR1H NMR SpectrumNot Available
1D NMR13C NMR SpectrumNot Available
2D NMR[1H,13C] 2D NMR SpectrumNot Available
Biological Properties
Cellular Locations
  • Cytoplasm
Biofluid Locations
  • Blood
  • Urine
Tissue Location
  • Bone Marrow
  • Fibroblasts
  • Kidney
  • Liver
  • Skin
  • Stratum Corneum
Pathways
NameSMPDB LinkKEGG Link
D-glyceric aciduraSMP00529Not Available
Familial lipoprotein lipase deficiencySMP00530Not Available
Glycerol Kinase DeficiencySMP00187Not Available
Glycerol Phosphate ShuttleSMP00124Not Available
Glycerolipid MetabolismSMP00039map00561
Riboflavin MetabolismSMP00070map00740
Normal Concentrations
BiofluidStatusValueAgeSexConditionReferenceDetails
BloodExpected but not QuantifiedNot ApplicableNot AvailableNot Available
Normal
  • Not Applicable
details
UrineDetected and Quantified<1 nmol/mmol creatinineAdult (>18 years old)BothNormal details
Abnormal Concentrations
Not Available
Associated Disorders and Diseases
Disease ReferencesNone
Associated OMIM IDsNone
DrugBank IDNot Available
DrugBank Metabolite IDNot Available
Phenol Explorer Compound ID660
Phenol Explorer Metabolite IDNot Available
FoodDB IDFDB000885
KNApSAcK IDC00002656
Chemspider ID764
KEGG Compound IDC00530
BioCyc ID236-TRICHLOROHYDROQUINONE
BiGG IDNot Available
Wikipedia LinkHydroquinone
NuGOwiki LinkHMDB02434
Metagene LinkHMDB02434
METLIN ID6681
PubChem Compound785
PDB IDHQE
ChEBI ID17594
References
Synthesis ReferenceMiyanohara, Isao; Yanagihara, Tadahisa. Hydroquinone. Jpn. Kokai Tokkyo Koho (1977), 4 pp.
Material Safety Data Sheet (MSDS)Download (PDF)
General References
  1. McDonald TA, Holland NT, Skibola C, Duramad P, Smith MT: Hypothesis: phenol and hydroquinone derived mainly from diet and gastrointestinal flora activity are causal factors in leukemia. Leukemia. 2001 Jan;15(1):10-20. [11243376 ]
  2. Gaskell M, McLuckie KI, Farmer PB: Comparison of the repair of DNA damage induced by the benzene metabolites hydroquinone and p-benzoquinone: a role for hydroquinone in benzene genotoxicity. Carcinogenesis. 2005 Mar;26(3):673-80. Epub 2004 Dec 23. [15618234 ]
  3. Inayat-Hussain SH, McGuinness SM, Johansson R, Lundstrom J, Ross D: Caspase-dependent and -independent mechanisms in apoptosis induced by hydroquinone and catechol metabolites of remoxipride in HL-60 cells. Chem Biol Interact. 2000 Aug 15;128(1):51-63. [10996300 ]
  4. Carbonnelle P, Lison D, Leroy JY, Lauwerys R: Effect of the benzene metabolite, hydroquinone, on interleukin-1 secretion by human monocytes in vitro. Toxicol Appl Pharmacol. 1995 Jun;132(2):220-6. [7540334 ]
  5. Keh ES, Hayakawa I, Takahashi H, Watanabe A, Iwasaki Y, Akiyoshi K, Nakabayashi N: Improving a self-curing dental resin by eliminating oxygen, hydroquinone and water from its curing process. Dent Mater J. 2002 Dec;21(4):373-82. [12608426 ]
  6. Subrahmanyam VV, Kolachana P, Smith MT: Hydroxylation of phenol to hydroquinone catalyzed by a human myeloperoxidase-superoxide complex: possible implications in benzene-induced myelotoxicity. Free Radic Res Commun. 1991;15(5):285-96. [1666626 ]
  7. Li X, Zhuang Z, Liu J, Huang H, Wei Q, Yang X: [Protein changes in human embryonic lung fibroblasts after hydroquinone stimulation using proteomic technique] Wei Sheng Yan Jiu. 2004 Nov;33(6):654-7. [15727168 ]
  8. Bucks DA, McMaster JR, Guy RH, Maibach HI: Percutaneous absorption of hydroquinone in humans: effect of 1-dodecylazacycloheptan-2-one (azone) and the 2-ethylhexyl ester of 4-(dimethylamino)benzoic acid (Escalol 507). J Toxicol Environ Health. 1988;24(3):279-89. [3260963 ]
  9. Barber ED, Hill T, Schum DB: The percutaneous absorption of hydroquinone (HQ) through rat and human skin in vitro. Toxicol Lett. 1995 Oct;80(1-3):167-72. [7482585 ]
  10. Boyle J, Kennedy CT: Hydroquinone concentrations in skin lightening creams. Br J Dermatol. 1986 Apr;114(4):501-4. [3964548 ]
  11. Nilsson LB: High sensitivity determination of the remoxipride hydroquinone metabolite NCQ-344 in plasma by coupled column reversed-phase liquid chromatography and electrochemical detection. Biomed Chromatogr. 1998 Mar-Apr;12(2):65-8. [9568272 ]
  12. Oliveira NL, Kalf GF: Induced differentiation of HL-60 promyelocytic leukemia cells to monocyte/macrophages is inhibited by hydroquinone, a hematotoxic metabolite of benzene. Blood. 1992 Feb 1;79(3):627-33. [1732008 ]
  13. Wester RC, Melendres J, Hui X, Cox R, Serranzana S, Zhai H, Quan D, Maibach HI: Human in vivo and in vitro hydroquinone topical bioavailability, metabolism, and disposition. J Toxicol Environ Health A. 1998 Jun 26;54(4):301-17. [9638901 ]
  14. Kooyers TJ, Westerhof W: [Toxicological aspects and health risks associated with hydroquinone in skin bleaching formula] Ned Tijdschr Geneeskd. 2004 Apr 17;148(16):768-71. [15129564 ]

Enzymes

General function:
Involved in oxidoreductase activity
Specific function:
This is a copper-containing oxidase that functions in the formation of pigments such as melanins and other polyphenolic compounds. Catalyzes the rate-limiting conversions of tyrosine to DOPA, DOPA to DOPA-quinone and possibly 5,6-dihydroxyindole to indole-5,6 quinone.
Gene Name:
TYR
Uniprot ID:
P14679
Molecular weight:
60392.69
Reactions
Hydroquinone + Oxygen → Quinone + Waterdetails
General function:
Involved in arylesterase activity
Specific function:
Has low activity towards the organophosphate paraxon and aromatic carboxylic acid esters. Rapidly hydrolyzes lactones such as statin prodrugs (e.g. lovastatin). Hydrolyzes aromatic lactones and 5- or 6-member ring lactones with aliphatic substituents but not simple lactones or those with polar substituents.
Gene Name:
PON3
Uniprot ID:
Q15166
Molecular weight:
39607.185
Reactions
4-Hydroxyphenyl acetate + Water → Hydroquinone + Acetic aciddetails
General function:
Involved in arylesterase activity
Specific function:
Hydrolyzes the toxic metabolites of a variety of organophosphorus insecticides. Capable of hydrolyzing a broad spectrum of organophosphate substrates and lactones, and a number of aromatic carboxylic acid esters. Mediates an enzymatic protection of low density lipoproteins against oxidative modification and the consequent series of events leading to atheroma formation.
Gene Name:
PON1
Uniprot ID:
P27169
Molecular weight:
39730.99
Reactions
4-Hydroxyphenyl acetate + Water → Hydroquinone + Acetic aciddetails
General function:
Involved in arylesterase activity
Specific function:
Capable of hydrolyzing lactones and a number of aromatic carboxylic acid esters. Has antioxidant activity. Is not associated with high density lipoprotein. Prevents LDL lipid peroxidation, reverses the oxidation of mildly oxidized LDL, and inhibits the ability of MM-LDL to induce monocyte chemotaxis.
Gene Name:
PON2
Uniprot ID:
Q15165
Molecular weight:
39380.535
Reactions
4-Hydroxyphenyl acetate + Water → Hydroquinone + Acetic aciddetails
General function:
Involved in electron carrier activity
Specific function:
The enzyme apparently serves as a quinone reductase in connection with conjugation reactions of hydroquinones 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:
NQO2
Uniprot ID:
P16083
Molecular weight:
25918.4
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:
NQO1
Uniprot ID:
P15559
Molecular weight:
30867.405