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Record Information
Version5.0
StatusDetected and Quantified
Creation Date2006-05-22 14:17:53 UTC
Update Date2022-03-07 02:49:15 UTC
HMDB IDHMDB0002434
Secondary Accession Numbers
  • HMDB02434
Metabolite Identification
Common NameHydroquinone
DescriptionHydroquinone, also known as 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 of most photographic developers where, with the compound Metol, it reduces silver halides to elemental silver.
Structure
Data?1601265749
Synonyms
ValueSource
1,4-BenzenediolChEBI
1,4-DihydroxybenzeneChEBI
4-HydroxyphenolChEBI
Benzene-1,4-diolChEBI
EldoquinChEBI
p-BenzenediolChEBI
p-HydroquinoneChEBI
p-HydroxyphenolChEBI
QuinolChEBI
ArtraMeSH
EldopaqueMeSH
EsotericaMeSH
HidroquilaudeMeSH
HidroquinMeSH
Hidroquinona isdinMeSH
LicostrataMeSH
LustraMeSH
MelanasaMeSH
MelanexMeSH
MelpaqueMeSH
MelquinMeSH
Neostrata HQMeSH
PhiaquinMeSH
SolaquinMeSH
UltraquinMeSH
beta-QuinolMeSH
Hydroquinone, copper (1+) saltMeSH
Hydroquinone, lead (2+) salt (2:1)MeSH
Hydroquinone, monocopper (2+) saltMeSH
1,4-Dihydroxy-benzeenHMDB
1,4-Dihydroxy-benzolHMDB
1,4-DihydroxybenzenHMDB
1,4-DiidrobenzeneHMDB
a-HydroquinoneHMDB
alpha-HydroquinoneHMDB
b-QuinolHMDB
BenzohydroquinoneHMDB
BenzoquinolHMDB
DihydroquinoneHMDB
DihydroxybenzeneHMDB
HydrochinonHMDB
HydrochinoneHMDB
HydroquinolHMDB
HydroquinoleHMDB
Hydroquinone for synthesisHMDB
Hydroquinone GRHMDB
HydroquinoueHMDB
IdrochinoneHMDB
p-DihydroxybenzeneHMDB
P-DioxobenzeneHMDB
p-DioxybenzeneHMDB
P-HydroxybenzeneHMDB
Solaquin forteHMDB
Eldoquin forteMeSH, HMDB
Stratus brand 1 OF hydroquinoneMeSH, HMDB
ICN brand 1 OF hydroquinoneMeSH, HMDB
Plough brand 2 OF hydroquinoneMeSH, HMDB
Eldopaque forteMeSH, HMDB
ICN brand 4 OF hydroquinoneMeSH, HMDB
Black and whiteMeSH, HMDB
ICN brand 2 OF hydroquinoneMeSH, HMDB
ICN brand 3 OF hydroquinoneMeSH, HMDB
Plough brand 1 OF hydroquinoneMeSH, HMDB
Stratus brand 2 OF hydroquinoneMeSH, HMDB
1,4-BenzoquinolPhytoBank
1,4-PhenylenediolPhytoBank
1,4-p-BenzenediolPhytoBank
p-DihydroquinonePhytoBank
p-PhenylenediolPhytoBank
p-QuinolPhytoBank
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 KeyQIGBRXMKCJKVMJ-UHFFFAOYSA-N
Chemical Taxonomy
Description Belongs to the class of organic compounds known as hydroquinones. Hydroquinones 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
ClassPhenols
Sub ClassBenzenediols
Direct ParentHydroquinones
Alternative Parents
Substituents
  • Hydroquinone
  • 1-hydroxy-2-unsubstituted benzenoid
  • Monocyclic benzene moiety
  • Organic oxygen compound
  • Hydrocarbon derivative
  • Organooxygen compound
  • Aromatic homomonocyclic compound
Molecular FrameworkAromatic homomonocyclic compounds
External Descriptors
Ontology
Physiological effect

Adverse health effect

Disposition

Biological location

Source

Process

Naturally occurring process

Physical Properties
StateSolid
Experimental Molecular Properties
PropertyValueReference
Melting Point172.3 °CNot Available
Boiling Point286.00 to 288.00 °C. @ 760.00 mm HgThe Good Scents Company Information System
Water Solubility72 mg/mL at 25 °CNot Available
LogP0.59HANSCH,C ET AL. (1995)
Experimental Chromatographic Properties

Experimental Collision Cross Sections

Adduct TypeData SourceCCS Value (Å2)Reference
[M-H]-Baker119.0730932474
[M+H]+Baker128.78930932474
[M-H]-Not Available119.07http://allccs.zhulab.cn/database/detail?ID=AllCCS00001918
[M+H]+Not Available128.789http://allccs.zhulab.cn/database/detail?ID=AllCCS00001918
Predicted Molecular Properties
PropertyValueSource
Water Solubility95.5 g/LALOGPS
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 ŲChemAxon
Rotatable Bond Count0ChemAxon
Refractivity30.02 m³·mol⁻¹ChemAxon
Polarizability10.75 ųChemAxon
Number of Rings1ChemAxon
BioavailabilityYesChemAxon
Rule of FiveYesChemAxon
Ghose FilterNoChemAxon
Veber's RuleNoChemAxon
MDDR-like RuleNoChemAxon
Predicted Chromatographic Properties

Predicted Collision Cross Sections

PredictorAdduct TypeCCS Value (Å2)Reference
DarkChem[M+H]+121.10331661259
DarkChem[M-H]-117.47231661259
DeepCCS[M+H]+121.37330932474
DeepCCS[M-H]-118.13430932474
DeepCCS[M-2H]-154.90430932474
DeepCCS[M+Na]+129.95430932474

Predicted Kovats Retention Indices

Underivatized

MetaboliteSMILESKovats RI ValueColumn TypeReference
HydroquinoneOC1=CC=C(O)C=C12599.4Standard polar33892256
HydroquinoneOC1=CC=C(O)C=C11342.2Standard non polar33892256
HydroquinoneOC1=CC=C(O)C=C11268.9Semi standard non polar33892256

Derivatized

Derivative Name / StructureSMILESKovats RI ValueColumn TypeReference
Hydroquinone,1TMS,isomer #1C[Si](C)(C)OC1=CC=C(O)C=C11346.1Semi standard non polar33892256
Hydroquinone,2TMS,isomer #1C[Si](C)(C)OC1=CC=C(O[Si](C)(C)C)C=C11413.9Semi standard non polar33892256
Hydroquinone,1TBDMS,isomer #1CC(C)(C)[Si](C)(C)OC1=CC=C(O)C=C11578.8Semi standard non polar33892256
Hydroquinone,2TBDMS,isomer #1CC(C)(C)[Si](C)(C)OC1=CC=C(O[Si](C)(C)C(C)(C)C)C=C11848.6Semi standard non polar33892256
Spectra

GC-MS Spectra

Spectrum TypeDescriptionSplash KeyDeposition DateSourceView
Experimental GC-MSGC-MS Spectrum - Hydroquinone GC-MS (2 TMS)splash10-0f79-2490000000-6b4fec222a3499d937902014-06-16HMDB team, MONA, MassBankView Spectrum
Experimental GC-MSGC-MS Spectrum - Hydroquinone EI-B (Non-derivatized)splash10-03di-9800000000-c90fd4986fea9691ecbf2017-09-12HMDB team, MONA, MassBankView Spectrum
Experimental GC-MSGC-MS Spectrum - Hydroquinone EI-B (Non-derivatized)splash10-03e9-9300000000-f8b11742557329691e8a2017-09-12HMDB team, MONA, MassBankView Spectrum
Experimental GC-MSGC-MS Spectrum - Hydroquinone GC-MS (Non-derivatized)splash10-0f79-2490000000-6b4fec222a3499d937902017-09-12HMDB team, MONA, MassBankView Spectrum
Experimental GC-MSGC-MS Spectrum - Hydroquinone GC-EI-TOF (Non-derivatized)splash10-0f79-2690000000-7306adcc7121a11d67cc2017-09-12HMDB team, MONA, MassBankView Spectrum
Predicted GC-MSPredicted GC-MS Spectrum - Hydroquinone GC-MS (Non-derivatized) - 70eV, Positivesplash10-03di-5900000000-954dc96d8e3eb85b83242017-07-27Wishart LabView Spectrum
Predicted GC-MSPredicted GC-MS Spectrum - Hydroquinone GC-MS (2 TMS) - 70eV, Positivesplash10-00e9-8950000000-512c0cf5ddc0b120ec8e2017-10-06Wishart LabView Spectrum
Predicted GC-MSPredicted GC-MS Spectrum - Hydroquinone GC-MS (Non-derivatized) - 70eV, PositiveNot Available2021-10-12Wishart LabView Spectrum
Predicted GC-MSPredicted GC-MS Spectrum - Hydroquinone GC-MS (Non-derivatized) - 70eV, PositiveNot Available2021-10-12Wishart LabView Spectrum
MSMass Spectrum (Electron Ionization)splash10-03di-9500000000-1fa8477944a662535e762014-09-20Not AvailableView Spectrum

MS/MS Spectra

Spectrum TypeDescriptionSplash KeyDeposition DateSourceView
Experimental LC-MS/MSLC-MS/MS Spectrum - Hydroquinone Quattro_QQQ 10V, Positive-QTOF (Annotated)splash10-03di-9600000000-e670ba090cb27367db122012-07-25HMDB team, MONAView Spectrum
Experimental LC-MS/MSLC-MS/MS Spectrum - Hydroquinone Quattro_QQQ 25V, Positive-QTOF (Annotated)splash10-01p6-9000000000-5fc32c7688c1612df1e72012-07-25HMDB team, MONAView Spectrum
Experimental LC-MS/MSLC-MS/MS Spectrum - Hydroquinone Quattro_QQQ 40V, Positive-QTOF (Annotated)splash10-000i-9000000000-c5853ce8ef225ea5c3532012-07-25HMDB team, MONAView Spectrum
Experimental LC-MS/MSLC-MS/MS Spectrum - Hydroquinone EI-B (Unknown) , Positive-QTOFsplash10-03di-9800000000-c90fd4986fea9691ecbf2012-08-31HMDB team, MONAView Spectrum
Experimental LC-MS/MSLC-MS/MS Spectrum - Hydroquinone , negative-QTOFsplash10-0a4i-0900000000-5635f0157cd37deb11212017-09-14HMDB team, MONAView Spectrum
Experimental LC-MS/MSLC-MS/MS Spectrum - Hydroquinone , positive-QTOFsplash10-03di-2900000000-05be113033a709130eed2017-09-14HMDB team, MONAView Spectrum
Experimental LC-MS/MSLC-MS/MS Spectrum - Hydroquinone 20V, Negative-QTOFsplash10-0a4i-9600000000-e0d15b2e4ea35a7a76be2021-09-20HMDB team, MONAView Spectrum
Experimental LC-MS/MSLC-MS/MS Spectrum - Hydroquinone 20V, Positive-QTOFsplash10-01r6-9000000000-946504408977df40269a2021-09-20HMDB team, MONAView Spectrum
Experimental LC-MS/MSLC-MS/MS Spectrum - Hydroquinone 10V, Negative-QTOFsplash10-0a4i-0900000000-c16180dd26c1275631552021-09-20HMDB team, MONAView Spectrum
Experimental LC-MS/MSLC-MS/MS Spectrum - Hydroquinone 40V, Positive-QTOFsplash10-03dl-9000000000-cea1cb486f12ea31e3a12021-09-20HMDB team, MONAView Spectrum
Experimental LC-MS/MSLC-MS/MS Spectrum - Hydroquinone 10V, Positive-QTOFsplash10-01ox-9000000000-3a9d5710c88793e698f12021-09-20HMDB team, MONAView Spectrum
Experimental LC-MS/MSLC-MS/MS Spectrum - Hydroquinone 40V, Negative-QTOFsplash10-0006-9000000000-60eeaa79bff371773b2e2021-09-20HMDB team, MONAView Spectrum
Experimental LC-MS/MSLC-MS/MS Spectrum - Hydroquinone 20V, Negative-QTOFsplash10-0a4i-0900000000-3a9e293da186985db7fa2021-09-20HMDB team, MONAView Spectrum
Experimental LC-MS/MSLC-MS/MS Spectrum - Hydroquinone 40V, Negative-QTOFsplash10-0pb9-9000000000-84bb0a9b4c3cd16da2a72021-09-20HMDB team, MONAView Spectrum
Experimental LC-MS/MSLC-MS/MS Spectrum - Hydroquinone 10V, Negative-QTOFsplash10-0a4i-7900000000-2256214c81a3e04e01b72021-09-20HMDB team, MONAView Spectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - Hydroquinone 10V, Positive-QTOFsplash10-03di-0900000000-8d8328e4f7cd2ebaa27d2015-05-26Wishart LabView Spectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - Hydroquinone 20V, Positive-QTOFsplash10-03di-1900000000-9290fcb93f170fc3143f2015-05-26Wishart LabView Spectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - Hydroquinone 40V, Positive-QTOFsplash10-01si-9200000000-9f707b9d0c4ad0b73b302015-05-26Wishart LabView Spectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - Hydroquinone 10V, Negative-QTOFsplash10-0a4i-0900000000-d3aae38632ac4c40fd4f2015-05-27Wishart LabView Spectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - Hydroquinone 20V, Negative-QTOFsplash10-0a4i-0900000000-74f15490ba4f49cf8c182015-05-27Wishart LabView Spectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - Hydroquinone 40V, Negative-QTOFsplash10-0a4i-9800000000-1cb01248e88fce3875782015-05-27Wishart LabView Spectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - Hydroquinone 10V, Negative-QTOFsplash10-0a4i-0900000000-9f2c82efe2cba7470e172021-09-22Wishart LabView Spectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - Hydroquinone 20V, Negative-QTOFsplash10-0a4i-0900000000-9f2c82efe2cba7470e172021-09-22Wishart LabView Spectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - Hydroquinone 40V, Negative-QTOFsplash10-0f6x-9000000000-8213c13cc381b346f9762021-09-22Wishart LabView Spectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - Hydroquinone 10V, Positive-QTOFsplash10-03di-0900000000-fd10fd64675560620b8d2021-09-22Wishart LabView Spectrum

NMR Spectra

Spectrum TypeDescriptionDeposition DateSourceView
Experimental 1D NMR1H NMR Spectrum (1D, 600 MHz, H2O, experimental)2012-12-05Wishart LabView Spectrum
Predicted 1D NMR13C NMR Spectrum (1D, 100 MHz, D2O, predicted)2021-09-16Wishart LabView Spectrum
Predicted 1D NMR1H NMR Spectrum (1D, 100 MHz, D2O, predicted)2021-09-16Wishart LabView Spectrum
Predicted 1D NMR13C NMR Spectrum (1D, 200 MHz, D2O, predicted)2021-09-16Wishart LabView Spectrum
Predicted 1D NMR1H NMR Spectrum (1D, 200 MHz, D2O, predicted)2021-09-16Wishart LabView Spectrum
Predicted 1D NMR13C NMR Spectrum (1D, 300 MHz, D2O, predicted)2021-09-16Wishart LabView Spectrum
Predicted 1D NMR1H NMR Spectrum (1D, 300 MHz, D2O, predicted)2021-09-16Wishart LabView Spectrum
Predicted 1D NMR13C NMR Spectrum (1D, 400 MHz, D2O, predicted)2021-09-16Wishart LabView Spectrum
Predicted 1D NMR1H NMR Spectrum (1D, 400 MHz, D2O, predicted)2021-09-16Wishart LabView Spectrum
Predicted 1D NMR13C NMR Spectrum (1D, 500 MHz, D2O, predicted)2021-09-16Wishart LabView Spectrum
Predicted 1D NMR1H NMR Spectrum (1D, 500 MHz, D2O, predicted)2021-09-16Wishart LabView Spectrum
Predicted 1D NMR13C NMR Spectrum (1D, 600 MHz, D2O, predicted)2021-09-16Wishart LabView Spectrum
Predicted 1D NMR1H NMR Spectrum (1D, 600 MHz, D2O, predicted)2021-09-16Wishart LabView Spectrum
Predicted 1D NMR13C NMR Spectrum (1D, 700 MHz, D2O, predicted)2021-09-16Wishart LabView Spectrum
Predicted 1D NMR1H NMR Spectrum (1D, 700 MHz, D2O, predicted)2021-09-16Wishart LabView Spectrum
Predicted 1D NMR13C NMR Spectrum (1D, 800 MHz, D2O, predicted)2021-09-16Wishart LabView Spectrum
Predicted 1D NMR1H NMR Spectrum (1D, 800 MHz, D2O, predicted)2021-09-16Wishart LabView Spectrum
Predicted 1D NMR13C NMR Spectrum (1D, 900 MHz, D2O, predicted)2021-09-16Wishart LabView Spectrum
Predicted 1D NMR1H NMR Spectrum (1D, 900 MHz, D2O, predicted)2021-09-16Wishart LabView Spectrum
Predicted 1D NMR13C NMR Spectrum (1D, 1000 MHz, D2O, predicted)2021-09-16Wishart LabView Spectrum
Predicted 1D NMR1H NMR Spectrum (1D, 1000 MHz, D2O, predicted)2021-09-16Wishart LabView Spectrum
Experimental 2D NMR[1H, 13C]-HSQC NMR Spectrum (2D, 600 MHz, H2O, experimental)2012-12-05Wishart LabView Spectrum
Biological Properties
Cellular Locations
  • Cytoplasm
Biospecimen Locations
  • Blood
  • Urine
Tissue Locations
  • Bone Marrow
  • Epidermis
  • Fibroblasts
  • Kidney
  • Liver
Pathways
Normal Concentrations
BiospecimenStatusValueAgeSexConditionReferenceDetails
BloodExpected but not QuantifiedNot QuantifiedNot AvailableNot Available
Normal
      Not Available
details
UrineDetected and Quantified<1 nmol/mmol creatinineAdult (>18 years old)BothNormal details
Abnormal Concentrations
BiospecimenStatusValueAgeSexConditionReferenceDetails
BloodDetected and Quantified0.460 +/- 0.770 uMAdult (>18 years old)Both
Uremia
details
UrineDetected but not QuantifiedNot QuantifiedAdult (>18 years old)BothBladder cancer details
Associated Disorders and Diseases
Disease References
Uremia
  1. Vanholder R, De Smet R, Glorieux G, Argiles A, Baurmeister U, Brunet P, Clark W, Cohen G, De Deyn PP, Deppisch R, Descamps-Latscha B, Henle T, Jorres A, Lemke HD, Massy ZA, Passlick-Deetjen J, Rodriguez M, Stegmayr B, Stenvinkel P, Tetta C, Wanner C, Zidek W: Review on uremic toxins: classification, concentration, and interindividual variability. Kidney Int. 2003 May;63(5):1934-43. doi: 10.1046/j.1523-1755.2003.00924.x. [PubMed:12675874 ]
Associated OMIM IDsNone
DrugBank IDDB09526
Phenol Explorer Compound ID660
FooDB IDFDB000885
KNApSAcK IDC00002656
Chemspider ID764
KEGG Compound IDC00530
BioCyc IDHYDROQUINONE
BiGG IDNot Available
Wikipedia LinkHydroquinone
METLIN ID6681
PubChem Compound785
PDB IDNot Available
ChEBI ID17594
Food Biomarker OntologyNot Available
VMH IDHQN
MarkerDB IDNot Available
Good Scents IDrw1250911
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. [PubMed: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. [PubMed: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. [PubMed: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. [PubMed: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. [PubMed: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. [PubMed: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. [PubMed: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. [PubMed: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. [PubMed:7482585 ]
  10. Boyle J, Kennedy CT: Hydroquinone concentrations in skin lightening creams. Br J Dermatol. 1986 Apr;114(4):501-4. [PubMed: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. [PubMed: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. [PubMed: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. [PubMed: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. [PubMed: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 transferase activity, transferring hexosyl groups
Specific function:
UDPGT is of major importance in the conjugation and subsequent elimination of potentially toxic xenobiotics and endogenous compounds. This isoform glucuronidates bilirubin IX-alpha to form both the IX-alpha-C8 and IX-alpha-C12 monoconjugates and diconjugate. Is also able to catalyze the glucuronidation of 17beta-estradiol, 17alpha-ethinylestradiol, 1-hydroxypyrene, 4-methylumbelliferone, 1-naphthol, paranitrophenol, scopoletin, and umbelliferone.
Gene Name:
UGT1A1
Uniprot ID:
P22309
Molecular weight:
59590.91
Reactions
Hydroquinone → 3,4,5-trihydroxy-6-(4-hydroxyphenoxy)oxane-2-carboxylic aciddetails
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