Record Information
Version 1.0
Creation Date 2009-03-06 11:57:54 -0700
Update Date 2013-04-25 02:32:26 -0600
Accession Number T3D0009
Identification
Common Name Benzo[a]pyrene
Description Benzo[a]pyrene is one of over 100 different polycyclic aromatic hydrocarbons (PAHs). PAHs are chemicals that are formed during the incomplete burning organic substances, such as fossil fuels. They are usually found as a mixture containing two or more of these compounds. (R028)
Compound Type
  • Organic Compound
  • Aromatic Hydrocarbon
  • Industrial By-product/Pollutant
  • Polycyclic Aromatic Hydrocarbon
Chemical Structure
Thumb
Synonyms
  1. 1,2-Benzpyrene
  2. 3,4 Benzopyrene
  3. 3,4 Benzpyrene
  4. 3,4-Benz(a)pyrene
  5. 3,4-Benzo(a)pyrene
  6. 3,4-Benzopirene [Italian]
  7. 3,4-Benzopyrene (carcinogen)
  8. 3,4-Benzpyren [German]
  9. 3,4-Benzpyrene
  10. 3,4-Benzypyrene
  11. 3,4-benzylpyrene
  12. 4,5-Benzpyrene
  13. 6,7-Benzopyrene
  14. Benz(a)pyrene
  15. Benzo(a)pyrene
  16. Benzo(a)pyrene [polycyclic aromatic compounds]
  17. Benzo(a)pyrene [polycyclic aromatic hydrocarbons]
  18. Benzo(d,e,f)chrysene
  19. Benzo(def)chrysene
  20. Benzo[PQR]tetraphene
  21. Benzo[a]pyrene
  22. Benzo[a]pyrene solution
  23. Benzo[d,e,f]chrysene
  24. Benzo[def]chrysene
  25. Benzopyrene
  26. Benzpyrene
  27. benzo[def]chrysene
Chemical Formula C20H12
Average Molecular Weight 252.3093
Monoisotopic Molecular Weight 252.093900384
Chemical IUPAC Name
benzo(A)pyrene
CAS Registry Number 50-32-8
SMILES
C1=CC=C2C(=C1)C=C1C=CC3=C4C(C=CC2=C14)=CC=C3
InChI Identifier
InChI=1S/C20H12/c1-2-7-17-15(4-1)12-16-9-8-13-5-3-6-14-10-11-18(17)20(16)19(13)14/h1-12H
InChI Key InChIKey=FMMWHPNWAFZXNH-UHFFFAOYSA-N
Chemical Taxonomy
Kingdom Organic Compounds
Super Class Benzenoids
Class Acenes and Derivatives
Sub Class Pyrenes
Direct Parent Benzopyrenes
Alternative Parents
  • Chrysenes
  • Anthracenes
  • Benzene and Substituted Derivatives
Molecular Framework Aromatic Homopolycyclic Compounds
Substituents
  • chrysene
  • anthracene
  • phenanthrene
  • benzene
External Descriptors
  • ortho- and peri-fused polycyclic arene(ChEBI)
DrugBank ID Not Available
PubChem Compound ID 2336
KEGG ID C07535
UniProt ID Not Available
OMIM ID Not Available
ChEBI ID 29865
BioCyc ID Not Available
CTD ID D001564
Stitch ID Benzo[a]pyrene
PDB ID Not Available
ACToR ID 141
Wikipedia Link http://en.wikipedia.org/wiki/Benzo(a)pyrene
Physical Properties
Appearance Pale yellow solid.
Melting Point 176.5 C
Solubility 1.62e-06 mg/mL at 25 °C [MAY,WE et al. (1983)]
Predicted LogP 5.273404237333333
Toxicity Profile
Route of Exposure Oral (R028) ; inhalation (R028 ; dermal (R028)
Mechanism of Action The ability of PAH's to bind to blood proteins such as albumin allows them to be transported throughout the body. Many PAH's induce the expression of cytochrome P450 enzymes, especially CYP1A1, CYP1A2, and CYP1B1, by binding to the aryl hydrocarbon receptor or glycine N-methyltransferase protein. These enzymes metabolize PAH's into their toxic intermediates. The reactive metabolites of PAHs (epoxide intermediates, dihydrodiols, phenols, quinones, and their various combinations) covalently bind to DNA and other cellular macromolecules, initiating mutagenesis and carcinogenesis. The main carcinogenic metabolite of benzo(a)pyrene is the diol-epoxide trans-9,10-epoxy-7,8-dihydrodiol. (R028, R060, R068, R073)
Metabolism PAH metabolism occurs in all tissues, usually by cytochrome P-450 and its associated enzymes. PAHs are metabolized into reactive intermediates, which include epoxide intermediates, dihydrodiols, phenols, quinones, and their various combinations. The phenols, quinones, and dihydrodiols can all be conjugated to glucuronides and sulfate esters; the quinones also form glutathione conjugates. (R028)
Toxicity Values LD50: 250 mg/kg (Intraperitoneal, Mouse) (R270)
Lethal Dose Not Available
Carcinogenicity (IARC Classification) 1, carcinogenic to humans. (R264)
Uses/Sources PAHs are released into the environment via the combustion of fossil fuels, coke oven emissions and vehicle exhausts, as well as naturally from forest fires and volcanic eruptions. PAHs from these sources may contaminate nearly water systems. They are also found in coal tar and charbroiled food. (R028)
Minimum Risk Level Not Available
Health Effects PAHs are carcinogens and have been associated with the increased risk of skin, respiratory tract, bladder, stomach, and kidney cancers. They may also cause reproductive effects and depress the immune system. (R028)
Symptoms Acute exposure to PAHs causes irritation and inflammation of the skin and lung tissue. (R034)
Treatment There is no known antidote for PAHs. Exposure is usually handled with symptomatic treatment. (R028)
References
General References
  • R028 — ATSDR - Agency for Toxic Substances and Disease Registry (1995). Toxicological profile for PAHs. U.S. Public Health Service in collaboration with U.S. Environmental Protection Agency (EPA). [Link]
  • R060 — Wikipedia. Benzopyrene. Last Updated 22 January 2009. [Link]
  • R068 — Uno S, Dragin N, Miller ML, Dalton TP, Gonzalez FJ, Nebert DW: Basal and inducible CYP1 mRNA quantitation and protein localization throughout the mouse gastrointestinal tract. Free Radic Biol Med. 2008 Feb 15;44(4):570-83. Epub 2007 Nov 12. [17997381 ]
  • R073 — Padros J, Pelletier E: In vivo formation of (+)-anti-benzo[a]pyrene diol-epoxide-plasma albumin adducts in fish. Mar Environ Res. 2000 Jul-Dec;50(1-5):347-51. [11460716 ]
  • R270 — HSDB: Hazardous Substances Data Bank. National Library of Medicine (2001). [Link]
  • R264 — International Agency for Research on Cancer (2009). IARC Monographs on the Evaluation of Carcinogenic Risks to Humans. [Link]
  • R034 — Santodonato J, Howard P, Basu D: Health and ecological assessment of polynuclear aromatic hydrocarbons. J Environ Pathol Toxicol. 1981 Sep;5(1):1-364. [7310260 ]

Targets

1. Aryl hydrocarbon receptor

Ligand-activated transcriptional activator. Binds to the XRE promoter region of genes it activates. Activates the expression of multiple phase I and II xenobiotic chemical metabolizing enzyme genes (such as the CYP1A1 gene). Mediates biochemical and toxic effects of halogenated aromatic hydrocarbons. Involved in cell-cycle regulation. Likely to play an important role in the development and maturation of many tissues.

Many PAH's induce the expression of cytochrome P450 enzymes, especially CYP1A1, CYP1A2, and CYP1B1, by binding to the aryl hydrocarbon receptor or glycine N-methyltransferase protein. These enzymes metabolize PAH's into their toxic intermediates. The reactive metabolites of PAHs (epoxide intermediates, dihydrodiols, phenols, quinones, and their various combinations) covalently bind to DNA and other cellular macromolecules, initiating mutagenesis and carcinogenesis. (R028, R060, R068, R073)
UniProt ID: P35869
Gene: AHR
Protein Sequence: FASTA
Gene Sequence: FASTA
SNPs: SNPJam Report
References:

2. Glycine N-methyltransferase

Catalyzes the methylation of glycine by using S-adenosylmethionine (AdoMet) to form N-methylglycine (sarcosine) with the concomitant production of S-adenosylhomocysteine (AdoHcy). Possible crucial role in the regulation of tissue concentration of AdoMet and of metabolism of methionine.

Many PAH's induce the expression of cytochrome P450 enzymes, especially CYP1A1, CYP1A2, and CYP1B1, by binding to the aryl hydrocarbon receptor or glycine N-methyltransferase protein. These enzymes metabolize PAH's into their toxic intermediates. The reactive metabolites of PAHs (epoxide intermediates, dihydrodiols, phenols, quinones, and their various combinations) covalently bind to DNA and other cellular macromolecules, initiating mutagenesis and carcinogenesis. (R028, R060, R068, R073)
UniProt ID: Q14749
Gene: GNMT
Protein Sequence: FASTA
Gene Sequence: FASTA
SNPs: SNPJam Report
References:

3. Cytokine receptor common subunit beta

High affinity receptor for interleukin-3, interleukin-5 and granulocyte-macrophage colony-stimulating factor.

The reactive metabolites of PAHs (epoxide intermediates, dihydrodiols, phenols, quinones, and their various combinations) covalently bind to DNA and other cellular macromolecules, initiating mutagenesis and carcinogenesis. (R028, R060, R068, R073)
UniProt ID: P32927
Gene: CSF2RB
Protein Sequence: FASTA
Gene Sequence: FASTA
SNPs: SNPJam Report
References: