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Record Information
Version4.0
StatusDetected and Quantified
Creation Date2006-05-22 14:17:53 UTC
Update Date2020-04-23 20:56:15 UTC
HMDB IDHMDB0002434
Secondary Accession Numbers
  • HMDB02434
Metabolite Identification
Common NameHydroquinone
DescriptionHydroquinone, also known as quinol or eldoquin, 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. Numerous studies have revealed that hydroquinone can cause exogenous ochronosis, a disfiguring disease in which blue-black pigments are deposited onto the skin, if taken orally; however, skin preparations containing the ingredient are administered topically. Hydroquinone is an extremely weak basic (essentially neutral) compound (based on its pKa). Hydroquinone exists in all living organisms, ranging from bacteria to humans. 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. glycerol 3-phosphate and hydroquinone can be biosynthesized from dihydroxyacetone phosphate and quinone through its interaction with the enzyme glycerol-3-phosphate dehydrogenase, mitochondrial. In humans, hydroquinone is involved in glycerolipid metabolism. Outside of the human body, Hydroquinone is found, on average, in the highest concentration within sweet oranges. Hydroquinone has also been detected, but not quantified in, several different foods, such as horned melons, lovages, lingonberries, pot marjorams, and anises. This could make hydroquinone a potential biomarker for the consumption of these foods. Hydroquinone, also benzene-1,4-diol, is an aromatic organic compound which is a type of phenol. It can be used alone, but is more frequently found in combination with other agents such as alpha-hydroxy acids, corticosteroids, retinoids, or sunscreen. In human medicine, hydroquinone is used as a topical application in skin whitening to reduce the color of skin. The FDA has classified hydroquinone currently as a safe product, as currently used. The FDA stated that hydroquinone cannot be ruled out as a potential carcinogen. Hydroquinone is a potentially toxic compound. Hydroquinone is a topical lightening product found in OTC products, and is used to correct skin discoloration associated with disorders of hyperpigmentation including melasma, post-inflammatory hyperpigmention, sunspots, and freckles. Hydroquinone takes several months to take effect.
Structure
Data?1582752249
Synonyms
ValueSource
1,4-BenzenediolChEBI
1,4-DihydroxybenzeneChEBI
4-HydroxyphenolChEBI
Benzene-1,4-diolChEBI
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
Eldoquin forteHMDB
LustraHMDB
MelpaqueHMDB
Neostrata HQHMDB
Stratus brand 1 OF hydroquinoneHMDB
UltraquinHMDB
Hydroquinone, lead (2+) salt (2:1)HMDB
EsotericaHMDB
HidroquilaudeHMDB
ICN brand 1 OF hydroquinoneHMDB
MelquinHMDB
Plough brand 2 OF hydroquinoneHMDB
Hydroquinone, copper (1+) saltHMDB
ArtraHMDB
EldopaqueHMDB
Eldopaque forteHMDB
HidroquinHMDB
ICN brand 4 OF hydroquinoneHMDB
LicostrataHMDB
Hydroquinone, monocopper (2+) saltHMDB
Black and whiteHMDB
Hidroquinona isdinHMDB
ICN brand 2 OF hydroquinoneHMDB
ICN brand 3 OF hydroquinoneHMDB
MelanasaHMDB
Plough brand 1 OF hydroquinoneHMDB
SolaquinHMDB
Stratus brand 2 OF hydroquinoneHMDB
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

Health effect:

Disposition

Route of exposure:

Source:

Biological location:

Process

Naturally occurring process:

Role

Indirect biological role:

Environmental role:

Industrial application:

Physical Properties
StateSolid
Experimental Properties
PropertyValueReference
Melting Point172.3 °CNot Available
Boiling PointNot AvailableNot Available
Water Solubility72 mg/mL at 25 °CNot Available
LogP0.59HANSCH,C ET AL. (1995)
Predicted 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
Spectra
Spectrum TypeDescriptionSplash KeyView
GC-MSGC-MS Spectrum - GC-MS (2 TMS)splash10-0f79-2490000000-6b4fec222a3499d93790Spectrum
GC-MSGC-MS Spectrum - EI-B (Non-derivatized)splash10-03di-9800000000-c90fd4986fea9691ecbfSpectrum
GC-MSGC-MS Spectrum - EI-B (Non-derivatized)splash10-03e9-9300000000-f8b11742557329691e8aSpectrum
GC-MSGC-MS Spectrum - GC-MS (Non-derivatized)splash10-0f79-2490000000-6b4fec222a3499d93790Spectrum
GC-MSGC-MS Spectrum - GC-EI-TOF (Non-derivatized)splash10-0f79-2690000000-7306adcc7121a11d67ccSpectrum
Predicted GC-MSPredicted GC-MS Spectrum - GC-MS (Non-derivatized) - 70eV, Positivesplash10-03di-5900000000-954dc96d8e3eb85b8324Spectrum
Predicted GC-MSPredicted GC-MS Spectrum - GC-MS (2 TMS) - 70eV, Positivesplash10-00e9-8950000000-512c0cf5ddc0b120ec8eSpectrum
LC-MS/MSLC-MS/MS Spectrum - Quattro_QQQ 10V, Positive (Annotated)splash10-03di-9600000000-e670ba090cb27367db12Spectrum
LC-MS/MSLC-MS/MS Spectrum - Quattro_QQQ 25V, Positive (Annotated)splash10-01p6-9000000000-5fc32c7688c1612df1e7Spectrum
LC-MS/MSLC-MS/MS Spectrum - Quattro_QQQ 40V, Positive (Annotated)splash10-000i-9000000000-c5853ce8ef225ea5c353Spectrum
LC-MS/MSLC-MS/MS Spectrum - EI-B (Unknown) , Positivesplash10-03di-9800000000-c90fd4986fea9691ecbfSpectrum
LC-MS/MSLC-MS/MS Spectrum - , negativesplash10-0a4i-0900000000-5635f0157cd37deb1121Spectrum
LC-MS/MSLC-MS/MS Spectrum - , positivesplash10-03di-2900000000-05be113033a709130eedSpectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 10V, Positivesplash10-03di-0900000000-8d8328e4f7cd2ebaa27dSpectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 20V, Positivesplash10-03di-1900000000-9290fcb93f170fc3143fSpectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 40V, Positivesplash10-01si-9200000000-9f707b9d0c4ad0b73b30Spectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 10V, Negativesplash10-0a4i-0900000000-d3aae38632ac4c40fd4fSpectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 20V, Negativesplash10-0a4i-0900000000-74f15490ba4f49cf8c18Spectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 40V, Negativesplash10-0a4i-9800000000-1cb01248e88fce387578Spectrum
MSMass Spectrum (Electron Ionization)splash10-03di-9500000000-1fa8477944a662535e76Spectrum
1D NMR1H NMR SpectrumNot AvailableSpectrum
1D NMR1H NMR SpectrumNot AvailableSpectrum
1D NMR13C NMR SpectrumNot AvailableSpectrum
2D NMR[1H,13C] 2D NMR SpectrumNot AvailableSpectrum
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
References
Synthesis ReferenceMiyanohara, Isao; Yanagihara, Tadahisa. Hydroquinone. Jpn. Kokai Tokkyo Koho (1977), 4 pp.
Material Safety Data Sheet (MSDS)Download (PDF)
General References
  1. 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 ]
  2. 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 ]
  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