| Size | Price | Stock | Qty |
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| 10mg |
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| Targets |
Monoethyl phthalate-d4 is a stable isotope-labeled internal standard. Its unlabeled parent, monoethyl phthalate (MEP), is not a drug with a classical pharmacological target; instead, it is a primary metabolite of the plasticizer diethyl phthalate (DEP). MEP serves as a widely used urinary biomarker of human exposure to DEP and other phthalates. In toxicological studies, MEP has been identified as an endocrine-disrupting chemical (EDC). It has been shown to act as a weak agonist of the peroxisome proliferator-activated receptor gamma (PPARgamma) and to inhibit the activity of steroidogenic enzymes. MEP has also been reported to interfere with androgen production in the testis (Leydig cells). The molecular targets include the estrogen receptor (ER) and the androgen receptor (AR), though its binding affinity is low (microM range). MEP levels in urine are used as a surrogate marker for phthalate exposure in human populations, and elevated levels have been associated with adverse reproductive and developmental outcomes in epidemiological studies. The labeled version (MEP-d4) is used for precise quantification of this exposure biomarker.
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| ln Vitro |
Drug compounds have included stable heavy isotopes of carbon, hydrogen, and other elements, mostly as quantitative tracers while the drugs were being developed. Because deuteration may have an effect on a drug's pharmacokinetics and metabolic properties, it is a cause for concern [1].
The in vitro biological activity of Monoethyl phthalate-d4 is presumed to be identical to its unlabeled parent, MEP. MEP has been shown to possess weak endocrine-disrupting activity. In the human breast cancer cell line MCF-7 (estrogen receptor-positive), MEP (10-100 uM) induces cell proliferation (estrogenic effect) at concentrations above 50 uM, though its potency is at least 1,000-fold lower than that of the endogenous hormone 17beta-estradiol. In a yeast-based estrogen receptor (ER) reporter gene assay, MEP (1-500 uM) exhibited weak estrogenic activity, with an EC₅0 of approximately 200 uM. In contrast, in an androgen receptor (AR) reporter gene assay, MEP (10-500 uM) exhibited anti-androgenic activity, suppressing dihydrotestosterone (DHT)-induced reporter gene expression with an IC₅0 of approximately 100-200 uM. In the H295R adrenocortical carcinoma cell line (a model for steroidogenesis), MEP (10-100 uM) has been shown to alter the production of cortisol and aldosterone and to downregulate the expression of key steroidogenic enzymes (CYP17, CYP21). The labeled Monoethyl phthalate-d4 is used as an internal standard to accurately quantify MEP concentrations in the cell culture media in these in vitro studies. |
| ln Vivo |
The in vivo activity of Monoethyl phthalate-d4 is not directly evaluated; it is used as an internal standard. Its unlabeled parent, MEP, is a marker of exposure to DEP rather than a directly administered compound. However, in animal studies, DEP (the parent diester) is administered, and MEP is measured as its primary metabolite. In rats, dietary administration of DEP (500-1,000 mg/kg/day for 28-90 days) results in high urinary MEP levels. These exposures have been associated with reproductive and developmental toxicity, including decreased testosterone production in male offspring (following maternal exposure). MEP itself is also present in the urine and plasma of exposed animals. Toxicokinetic studies in rats have shown that DEP is rapidly absorbed and hydrolyzed to MEP in the gut wall and liver; MEP is then further metabolized to phthalic acid and glucuronide conjugates. The half-life of MEP in the plasma is approximately 1-2 hours. The labeled MEP-d4 is used as an internal standard to accurately quantify MEP levels in these animal studies, which is critical for establishing the relationship between exposure (internal dose) and observed adverse effects (e.g., reproductive tract malformations).
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| Enzyme Assay |
A generic non-cell-based assay for Monoethyl phthalate-d4 involves its use as an internal standard in an LC-MS/MS method for quantifying MEP in human urine. Prepare a standard stock solution of unlabeled MEP in methanol (1 mg/mL). Prepare a separate stock solution of Monoethyl phthalate-d4 at the same concentration. Prepare calibration standards by spiking the unlabeled analyte into a blank matrix (e.g., synthetic urine or control urine with low background levels) to achieve concentrations ranging from 0.5 to 500 ng/mL. Add a fixed concentration of the internal standard (e.g., 50 ng/mL) to each calibration standard. Also prepare blank and double-blank samples. For sample preparation, perform solid-phase extraction (SPE) using a mixed-mode anion exchange (MAX) cartridge. Condition the cartridge with methanol and water. Load 1 mL of urine sample. Wash with 5% ammonium hydroxide in water and then with methanol. Elute the analytes with 2% formic acid in methanol. Evaporate the eluate under nitrogen and reconstitute in 200 uL of mobile phase (methanol/water). Analyze by LC-MS/MS in negative ion mode. Monitor the mass transitions: m/z 193 → 77 (loss of C2H₅O2) for MEP, and m/z 197 → 81 for the MEP-d4 internal standard. Construct the calibration curve by plotting the peak area ratio (analyte/IS) vs. the nominal concentration.
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| Cell Assay |
A standard in vitro cell-based protocol for the unlabeled MEP involves assessing its effects on steroid hormone production in the H295R human adrenocortical carcinoma cell line. Culture H295R cells in DMEM/F12 medium supplemented with 1% ITS+ Premix (insulin, transferrin, selenium), 1% penicillin/streptomycin, and 2.5% Nu-Serum at 37degC in a 5% CO2 incubator. Seed cells in 24-well plates at 5×10⁵ cells/well in 1 mL of medium and allow to attach for 48 hours. Replace the medium with fresh medium containing increasing concentrations of unlabeled MEP (0.1, 1, 10, 50, 100, 250, 500 uM) or vehicle (DMSO, final concentration <0.1%). Include appropriate positive controls (e.g., 1 uM progesterone for maximal cortisol production). Incubate for 48 hours. After treatment, collect the cell culture supernatant. Measure the concentrations of hormones (estradiol, testosterone, cortisol, aldosterone) using commercially available ELISA kits (or by LC-MS/MS). Harvest the cells for RNA extraction and use quantitative real-time PCR (qRT-PCR) to measure the expression of key steroidogenic genes (CYP11A1, CYP17, CYP19, CYP21, HSD3B2). For validation, add Monoethyl phthalate-d4 as an internal standard and analyze the same supernatants by LC-MS/MS to determine the exact MEP concentrations to which the cells were exposed.
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| Animal Protocol |
A typical in vivo animal protocol for Monoethyl phthalate-d4 is used in a phthalate exposure biomonitoring study in rats. Use female Sprague-Dawley rats (8-10 weeks old, n = 6 per group). Administer diethyl phthalate (DEP, the parent compound) by oral gavage at doses of 0, 30, 100, 300, or 1,000 mg/kg/day (in corn oil) for 28 consecutive days (subchronic study). For toxicokinetic assessment, include a satellite group (n = 4 per dose) for serial blood sampling. Collect blood samples via tail vein at various time points on Day 1 and Day 28 (0, 0.5, 1, 2, 4, 8, 12, 24 h after dosing). Collect 24-hour urine samples using metabolic cages at baseline and at the end of the treatment period (Day 28). On Day 29, euthanize the rats and collect liver, kidney, and testis/ovary tissues. For bioanalysis, process plasma, urine, and tissue homogenate samples. Add a fixed amount of Monoethyl phthalate-d4 as the internal standard. Hydrolyze the conjugates by adding beta-glucuronidase (from E. coli) for 12 hours at 37degC. Extract the free MEP by solid-phase extraction and analyze by LC-MS/MS. Calculate the urinary excretion rate of MEP (ug/mg creatinine or ug/day). Correlate MEP levels with organ weights, histopathological findings, and serum hormone levels (e.g., estradiol, testosterone) to assess dose-dependent toxicity.
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| ADME/Pharmacokinetics |
Monoethyl phthalate-d4 is an analytical internal standard. Its unlabeled parent, MEP, is a primary metabolite of diethyl phthalate (DEP). In humans, following oral ingestion or dermal exposure to DEP (a common plasticizer in cosmetics, fragrances, and personal care products), DEP is rapidly absorbed and hydrolyzed to MEP by esterases in the gut, liver, and blood. MEP is then further metabolized to phthalic acid (by hydrolysis) and to glucuronide conjugates. The half-life of MEP in human plasma is approximately 2-4 hours, and in urine, it is approximately 5-8 hours. More than 70% of an absorbed dose of DEP is excreted in urine as MEP within 24 hours. In pregnant women, MEP can cross the placental barrier and has been detected in amniotic fluid. The concentration of MEP in urine is used as a sensitive, non-invasive biomarker of DEP exposure in epidemiological studies. The labeled MEP-d4 is essential for the accurate quantification of this biomarker via isotope dilution mass spectrometry, correcting for matrix effects and intra-individual variability in urine samples.
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| Toxicity/Toxicokinetics |
Monoethyl phthalate-d4 is a stable isotope-labeled research compound, not a pharmaceutical drug. Its unlabeled parent, MEP, is a phthalate metabolite that is generally recognized as having low acute toxicity. The oral LD₅0 of DEP (which metabolizes to MEP) in rats is >5,000 mg/kg. However, chronic exposure to high levels of phthalates (including DEP) in animal studies has been associated with reproductive and developmental toxicity, particularly in male offspring (reduced anogenital distance, testicular atrophy, and reduced testosterone production). MEP itself is thought to be a weak endocrine disruptor. It is classified as a possible endocrine-disrupting chemical (EDC) by the European Chemicals Agency (ECHA). In the workplace, exposure to high levels of DEP dust or vapors may cause mild irritation. For laboratory handling, standard safety precautions (gloves, lab coat) are sufficient. Due to its weak potential as an endocrine disruptor, it is advisable to avoid direct contact. Monoethyl phthalate-d4 should be stored at -20degC or 2-8degC in a tightly sealed container, protected from light and moisture. It is for research use only and not for human consumption.
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| References |
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| Additional Infomation |
Monoethyl phthalate-d4 is the stable isotope-labeled (deuterium-labeled) version of monoethyl phthalate (MEP), the primary urinary metabolite of the widely used plasticizer diethyl phthalate (DEP). DEP is used as a solvent and fixative in fragrances, cosmetics (e.g., perfumes, lotions, shampoos), personal care products (deodorants, soaps), and as a plasticizer in cellulose-based plastics. DEP is also found in pharmaceutical coatings and medical devices. MEP is a sensitive and specific biomarker for human phthalate exposure. Human exposure to DEP and its metabolite MEP is widespread: >90% of the US population has detectable levels of MEP in urine, according to NHANES (National Health and Nutrition Examination Survey) data. Elevated urinary MEP levels have been associated in some epidemiological studies with adverse health outcomes, including changes in hormone levels, altered neurodevelopment in children, and increased risk of preterm birth. Monoethyl phthalate-d4 is an essential tool for accurate LC-MS/MS quantification of MEP in human biomonitoring studies, allowing researchers to assess real-world exposure levels and investigate their potential health effects. For research use only, not for diagnostic or therapeutic applications.
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| Molecular Formula |
C10H6D4O4
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| Molecular Weight |
198.21
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| Exact Mass |
198.083
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| CAS # |
1219806-03-7
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| Related CAS # |
Monoethyl phthalate;2306-33-4
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| PubChem CID |
71750793
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| Appearance |
White to off-white solid powder
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| LogP |
1.561
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| Hydrogen Bond Donor Count |
1
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| Hydrogen Bond Acceptor Count |
4
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| Rotatable Bond Count |
4
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| Heavy Atom Count |
14
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| Complexity |
224
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| Defined Atom Stereocenter Count |
0
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| SMILES |
[2H]C1=C(C(=C(C(=C1[2H])C(=O)O)C(=O)OCC)[2H])[2H]
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| InChi Key |
YWWHKOHZGJFMIE-LNFUJOGGSA-N
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| InChi Code |
InChI=1S/C10H10O4/c1-2-14-10(13)8-6-4-3-5-7(8)9(11)12/h3-6H,2H2,1H3,(H,11,12)/i3D,4D,5D,6D
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| Chemical Name |
2,3,4,5-tetradeuterio-6-ethoxycarbonylbenzoic acid
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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 | 5.0452 mL | 25.2258 mL | 50.4515 mL | |
| 5 mM | 1.0090 mL | 5.0452 mL | 10.0903 mL | |
| 10 mM | 0.5045 mL | 2.5226 mL | 5.0452 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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