![Benzo[a]pyrene diol epoxide](/upload/0319/V109391.png)
| Size | Price | Stock | Qty |
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| 1mg |
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| Other Sizes |
| Targets |
BPDE has no therapeutic target; it is an environmental carcinogen. It targets DNA, specifically the N2 position of guanine bases and the N6 position of adenine bases in the human genome. It is a highly reactive electrophile that attacks nucleophilic sites on DNA bases. Its primary mechanism of action is the covalent modification of DNA, forming stable (+/-)-anti-BPDE-N2-dG adducts. Two distinct classes of adducts exist: Type I (intercalative) and Type II (externally solvent-exposed). The predominance of Type II adducts is associated with the higher tumorigenicity of (+)-BPDE in mammalian cells.
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| ln Vitro |
In vitro, BPDE is a potent mutagen in bacterial and mammalian cell mutation assays. It induces a high frequency of point mutations, particularly G to T transversions, in the Ames test (Salmonella typhimurium TA100). BPDE is a substrate for nucleotide excision repair (NER); the repair kinetics of BPDE-DNA adducts are studied in cell-free extracts. The (+)-anti-BPDE enantiomer is more tumorigenic and mutagenic than the (-)-anti-enantiomer in mammalian cells, correlating with the predominance of Type II DNA adducts. The half-life of BPDE in aqueous solution is short (minutes), due to rapid hydrolysis to tetrols.
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| ln Vivo |
The compound is not administered in vivo. However, when benzo[a]pyrene is administered to animals, it is metabolized in the liver by cytochrome P450 enzymes (CYP1A1, CYP1B1) and epoxide hydrolase to form the reactive BPDE intermediate, which then forms DNA adducts. In vivo, the levels of BPDE-DNA adducts in tissues are measured as a biomarker of BaP exposure and carcinogenic risk. BPDE-DNA adducts have been detected in the lung, liver, and lymphocytes of animals and humans exposed to cigarette smoke or environmental PAHs. The adducts persist in the body for days to weeks.
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| Enzyme Assay |
DNA adduct formation is measured by the 32P-postlabeling assay, which involves enzymatic digestion of DNA to 3'-monophosphates, followed by 5'-32P-labeling and separation by thin-layer chromatography (TLC) or HPLC. For BPDE-specific adducts, a synchronous fluorescence spectroscopy (SFS) method at low temperatures (77 K) can resolve the two distinct classes of adducts (Type I and Type II) in covalent BPDE-DNA adducts. The reaction is as follows: calf thymus DNA (50-100 ug) is incubated with 1-10 uM BPDE in Tris-HCl buffer (pH 7.4) containing 1% acetone for 1-4 h at 37degC. Unbound BPDE is extracted with ethyl acetate, and the DNA is precipitated and washed. The adduct levels (per 10⁶ nucleotides) are quantified.
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| Cell Assay |
For cellular studies, human lymphoblastoid cells (e.g., TK6) or primary fibroblasts are treated with BPDE (0.1-10 uM, 1-4 h) in culture medium. The cells are harvested, and genomic DNA is isolated. The DNA is analyzed for BPDE-dG adducts by 32P-postlabeling, HPLC-fluorescence, or LC-MS/MS. For mutation assays, cells are treated with BPDE, allowed to recover for 48-72 h, and then plated in selective medium to detect mutations at the HPRT (hypoxanthine-guanine phosphoribosyltransferase) locus. The mutant frequency is calculated. To study DNA repair, cells are treated with BPDE, and the removal of adducts over time (0-24 h) is measured by 32P-postlabeling.
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| Animal Protocol |
BPDE-DNA adduct formation is studied in the lungs of mice. Female A/J mice (6-8 weeks old, n=5/time point) are administered benzo[a]pyrene orally (2-50 mg/kg) or intraperitoneally (2 mg/kg in corn oil). The animals are euthanized at various time points (0-72 h post-dose). Lung, liver, and other tissues are harvested, and DNA is extracted. BPDE-DNA adducts are quantified by 32P-postlabeling. To study mutation induction, the MutaMouse or Big Blue transgenic mouse models are used. Mice are treated with BaP, and the mutant frequency in the cII or lacZ transgene in the lung or liver is measured. The persistence of adducts correlates with the tumor incidence observed in chronic bioassays.
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| ADME/Pharmacokinetics |
BPDE is the ultimate carcinogenic metabolite of BaP. It is not a drug; its pharmacokinetics are studied in the context of BaP metabolism. Following BaP administration, BPDE is formed intracellularly in the liver and other target organs. Its half-life is short (< 1 min) due to spontaneous hydrolysis and conjugation with glutathione (catalyzed by glutathione S-transferases). BPDE is a substrate for epoxide hydrolase, which converts it to inactive tetrols. Because of its extreme reactivity and instability, it is not bioavailable as a parent compound. It is strictly a research reagent for adduct formation in vitro.
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| Toxicity/Toxicokinetics |
BPDE is classified as a Group 1 human carcinogen by the IARC (International Agency for Research on Cancer). It is highly toxic, reactive, and mutagenic. It causes skin tumors in mouse models and is suspected of causing lung, skin, and bladder cancers in humans exposed to BaP. The compound is also an irritant to the skin, eyes, and respiratory tract. Due to its extreme reactivity and instability, it is handled as a research chemical under strict safety protocols: use PPE (gloves, lab coat, face shield), work in a fume hood, and avoid all exposure. BPDE is a "Possible Human Carcinogen" (IARC 2A/2B).
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| References |
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| Additional Infomation |
Benzo[a]pyrene diol epoxide (BPDE; CAS# 58917-67-2) is a research-grade, highly reactive and unstable ultimate carcinogenic metabolite of benzo[a]pyrene (BaP). It is not an FDA-approved drug. It is used exclusively as a research tool to generate site-specific DNA adducts, study the mechanisms of chemical carcinogenesis, nucleotide excision repair (NER), and mutagenesis. It is a gold standard positive control for in vitro genotoxicity assays. For research use only, not for diagnostic or therapeutic applications.
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| Molecular Formula |
C20H14O3
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| Molecular Weight |
302.32
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| CAS # |
58917-67-2
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| Appearance |
Typically exists as solids at room temperature
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| HS Tariff Code |
2934.99.9001
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| Storage |
Powder -20°C 3 years 4°C 2 years In solvent -80°C 6 months -20°C 1 month |
| Shipping Condition |
Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)
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| Solubility (In Vitro) |
May dissolve in DMSO (in most cases), if not, try other solvents such as H2O, Ethanol, or DMF with a minute amount of products to avoid loss of samples
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| Solubility (In Vivo) |
Note: Listed below are some common formulations that may be used to formulate products with low water solubility (e.g. < 1 mg/mL), you may test these formulations using a minute amount of products to avoid loss of samples.
Injection Formulations
Injection Formulation 1: DMSO : Tween 80： Saline = 10 : 5 : 85 (i.e. 100 μL DMSO stock solution → 50 μL Tween 80 → 850 μL Saline)(e.g. IP/IV/IM/SC) *Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH ₂ O to obtain a clear solution. Injection Formulation 2: DMSO : PEG300 ：Tween 80 : Saline = 10 : 40 : 5 : 45 (i.e. 100 μL DMSO → 400 μLPEG300 → 50 μL Tween 80 → 450 μL Saline) Injection Formulation 3: DMSO : Corn oil = 10 : 90 (i.e. 100 μL DMSO → 900 μL Corn oil) Example: Take the Injection Formulation 3 (DMSO : Corn oil = 10 : 90) as an example, if 1 mL of 2.5 mg/mL working solution is to be prepared, you can take 100 μL 25 mg/mL DMSO stock solution and add to 900 μL corn oil, mix well to obtain a clear or suspension solution (2.5 mg/mL, ready for use in animals). View More
Injection Formulation 4: DMSO : 20% SBE-β-CD in saline = 10 : 90 [i.e. 100 μL DMSO → 900 μL (20% SBE-β-CD in saline)] Oral Formulations
Oral Formulation 1: Suspend in 0.5% CMC Na (carboxymethylcellulose sodium) Oral Formulation 2: Suspend in 0.5% Carboxymethyl cellulose Example: Take the Oral Formulation 1 (Suspend in 0.5% CMC Na) as an example, if 100 mL of 2.5 mg/mL working solution is to be prepared, you can first prepare 0.5% CMC Na solution by measuring 0.5 g CMC Na and dissolve it in 100 mL ddH2O to obtain a clear solution; then add 250 mg of the product to 100 mL 0.5% CMC Na solution, to make the suspension solution (2.5 mg/mL, ready for use in animals). View More
Oral Formulation 3: Dissolved in PEG400 (Please use freshly prepared in vivo formulations for optimal results.) |
| Preparing Stock Solutions | 1 mg | 5 mg | 10 mg | |
| 1 mM | 3.3078 mL | 16.5388 mL | 33.0775 mL | |
| 5 mM | 0.6616 mL | 3.3078 mL | 6.6155 mL | |
| 10 mM | 0.3308 mL | 1.6539 mL | 3.3078 mL |
*Note: Please select an appropriate solvent for the preparation of stock solution based on your experiment needs. For most products, DMSO can be used for preparing stock solutions (e.g. 5 mM, 10 mM, or 20 mM concentration); some products with high aqueous solubility may be dissolved in water directly. Solubility information is available at the above Solubility Data section. Once the stock solution is prepared, aliquot it to routine usage volumes and store at -20°C or -80°C. Avoid repeated freeze and thaw cycles.
Calculation results
Working concentration： mg/mL；
Method for preparing DMSO stock solution： mg drug pre-dissolved in μL DMSO (stock solution concentration mg/mL). Please contact us first if the concentration exceeds the DMSO solubility of the batch of drug.
Method for preparing in vivo formulation:：Take μL DMSO stock solution, next add μL PEG300, mix and clarify, next addμL Tween 80, mix and clarify, next add μL ddH2O，mix and clarify.
(1) Please be sure that the solution is clear before the addition of next solvent. Dissolution methods like vortex, ultrasound or warming and heat may be used to aid dissolving.
(2) Be sure to add the solvent(s) in order.
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