| Size | Price | Stock | Qty |
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| 1mg |
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| Other Sizes |
| Targets |
PDE5; major metabolite of Vardenafil
The primary molecular target of N-Desethyl vardenafil is phosphodiesterase 5 (PDE5), the same target as the parent drug vardenafil. By inhibiting PDE5, the metabolite prevents the breakdown of cyclic guanosine monophosphate (cGMP). This leads to increased cGMP levels, resulting in smooth muscle relaxation and increased blood flow to the corpus cavernosum of the penis, which facilitates penile erection. |
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| ln Vitro |
A simple, fast and sensitive HPLC method with electrochemical detection employing boron-doped diamond electrode (BDD) for the determination of sildenafil (Viagra™), vardenafil (Levitra™) and their main metabolites, N-desmethyl sildenafil and N-desethyl vardenafil in human plasma is presented. The assay involved drug extraction by tert-butyl methyl ether and isocratic reversed-phase liquid chromatography with amperometric detection. Complete separation of all analytes was achieved within 12 min. The mobile phase consisted of 20mM sodium dihydrogen phosphate with 40 mM sodium perchlorate/acetonitrile (70:30, v/v), pH 3.5. The electrode working potential was +1520 mV (vs. Pd/H(2)). Calibration curves were linear over the concentration range of 10-400 ng mL(-1). Phloretin was used as an internal standard. The limits of detection (LOD) and quantification (LOQ) for the studied analytes were within the range of 2-4 ng mL(-1) and 7.0-13.4 ng mL(-1), respectively. The developed method was applied to human plasma samples spiked with analytes at therapeutic concentrations. The study confirms the method's suitability for both pharmacokinetic studies and therapeutic monitoring[1].
N-Desethyl vardenafil is a potent PDE5 inhibitor. In vitro assays show that it relaxes pre-contracted human cavernosal tissue and inhibits PDE5 enzymatic activity with an IC50 in the low nanomolar range (sub-1 nM). Although its potency is slightly reduced compared to the parent drug vardenafil, it is still significantly more potent than the major metabolites of sildenafil (Viagra). It is a fully active metabolite. |
| ln Vivo |
Sildenafil (SDF), vardenafil (VDF) and tadalafil (TDF) are phosphodiesterase type 5 enzyme inhibitors (PDE5Is), used in the treatment of erectile disorders and to improve breathing efficiency in pulmonary hypertension. The increasing incidence of their use among young athletes has drawn the attention of the anti-doping authorities to the possible abuse of PDE5Is by athletes due to their pharmacological activities. This paper describes a method for the determination in urine of PDE5Is and their metabolites by gas chromatography/mass spectrometry (GC/MS) after liquid/liquid extraction of the analytes from urine and derivatisation to obtain trimethylsilyl derivatives. The metabolic profile was studied on real samples collected from subjects taking PDE5Is (Viagra, Levitra or Cialis); the main urinary metabolites were identified and their MS fragmentation characterized. The sample pre-treatment and GC/MS conditions for the detection of the metabolites have been optimised. A method for their preliminary screening and subsequent confirmation is described that takes into account the general requirements of a routine doping analysis to be used for the screening of large numbers of samples. The main metabolites identified can be included in a general purpose screening method and all the metabolites in a more specific confirmation method. The method developed has been applied for the screening of PDE5Is in 5000 urine samples. Based on the obtained results, the proposed method appears to be of practical use in analytical and forensic toxicology, including doping analysis[2].
The in vivo activity of N-Desethyl vardenafil contributes to the efficacy of vardenafil. After oral administration of vardenafil, the metabolite appears in the plasma. Its half-life is similar to or slightly longer than the parent drug, prolonging the window of PDE5 inhibition. In animal models (e.g., rats or dogs), administration of the metabolite would produce similar penile erections and cardiovascular effects (mild hypotension) as the parent compound. |
| Enzyme Assay |
Cell‑free PDE5 inhibition assays are standard. Recombinant human PDE5 enzyme (0.5 ug/mL) is incubated with 1 uM cGMP and 0.01 uCi [3H]cGMP in a buffer (50 mM Tris-HCl, pH 7.5, 5 mM MgCl2). Varying concentrations of N-Desethyl vardenafil (0.001-10 uM) are added. After 20 minutes at 37degC, the reaction is stopped by boiling. Snake venom 5'-nucleotidase is added to degrade 5'-GMP. The remaining [3H]cGMP is separated using ion-exchange resin and counted. IC50 is calculated.
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| Cell Assay |
Cell-based assays for PDE5 inhibition use vascular smooth muscle cells (VSMCs) or cavernosal cells. Cells are pre-contracted with a vasoconstrictor (e.g., phenylephrine). The cells are then treated with N-Desethyl vardenafil (0.1-100 nM). Cell relaxation is measured via impedance-based assays or by quantifying the increase in intracellular cGMP levels using a competitive ELISA kit. This confirms the functional activity of the metabolite.
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| Animal Protocol |
A standard in vivo protocol for PDE5 inhibitors involves measuring intracavernosal pressure (ICP) in rats. Male rats are anesthetized, and a needle is inserted into the corpus cavernosum. N-Desethyl vardenafil (0.03-1 mg/kg) is administered intravenously. The cavernosal nerve is electrically stimulated, and the ICP is recorded. An increase in ICP/mean arterial pressure ratio indicates successful erection and effective PDE5 inhibition.
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| ADME/Pharmacokinetics |
The pharmacokinetics of N-Desethyl vardenafil are well-defined. It is the major circulating metabolite of vardenafil. Tmax is typically 1-2 hours post-dose. The half-life (t½) is approximately 4-5 hours, similar to the parent drug. The plasma concentration of the metabolite is about 10-20% of the parent compound. It is primarily eliminated via the hepatic route (bile/fecal excretion). Exposure increases with CYP3A4 inhibitors.
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| Toxicity/Toxicokinetics |
N-Desethyl vardenafil is generally considered safe within the therapeutic context of vardenafil. The safety profile aligns with PDE5 inhibitors: headache, flushing, dyspepsia, and nasal congestion. It is not intended for direct administration, and specific toxicity studies on the isolated metabolite are not required for its use as an analytical standard. It is classified as a research chemical and must be handled with care.
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| References |
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| Additional Infomation |
Structure in the first source
N-Desethyl vardenafil is not a drug entity itself but a major metabolite. It is used as a reference standard for HPLC, LC-MS, and CE methods in pharmaceutical development (ANDA) and forensic toxicology. It helps verify the identity and stability of vardenafil drug products. The molecular formula is C21H2₈N₆O4S, with a molecular weight of 460.55 g/mol. It is a white to off-white solid stored at -20degC. |
| Molecular Formula |
C21H28N6O4S
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|---|---|
| Molecular Weight |
460.55
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| Exact Mass |
460.18927
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| CAS # |
448184-46-1
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| PubChem CID |
135565210
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| Appearance |
Typically exists as solids at room temperature
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| Density |
1.44g/cm3
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| Index of Refraction |
1.683
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| LogP |
1.6
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| Hydrogen Bond Donor Count |
2
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| Hydrogen Bond Acceptor Count |
8
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| Rotatable Bond Count |
7
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| Heavy Atom Count |
32
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| Complexity |
810
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| Defined Atom Stereocenter Count |
0
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| SMILES |
CCCC1=NC(=C2N1N=C(NC2=O)C3=C(C=CC(=C3)S(=O)(=O)N4CCNCC4)OCC)C
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| InChi Key |
OKUKNGDVADFTHE-UHFFFAOYSA-N
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| InChi Code |
InChI=1S/C21H28N6O4S/c1-4-6-18-23-14(3)19-21(28)24-20(25-27(18)19)16-13-15(7-8-17(16)31-5-2)32(29,30)26-11-9-22-10-12-26/h7-8,13,22H,4-6,9-12H2,1-3H3,(H,24,25,28)
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| Chemical Name |
2-(2-ethoxy-5-piperazin-1-ylsulfonylphenyl)-5-methyl-7-propyl-3H-imidazo[5,1-f][1,2,4]triazin-4-one
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| Synonyms |
N-Desethyl Vardenafil; 448184-46-1; N-Desethylvardenafil; Vardenafil (m1); NEP2V4E7Q2; Vardenafil-N-desethyl; 1-[[3-(1,4-Dihydro-5-methyl-4-oxo-7-propylimidazo[5,1-f][1,2,4]triazin-2-yl)-4-ethoxyphenyl]sulfonyl]-piperazine; UNII-NEP2V4E7Q2;
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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 | 2.1713 mL | 10.8566 mL | 21.7132 mL | |
| 5 mM | 0.4343 mL | 2.1713 mL | 4.3426 mL | |
| 10 mM | 0.2171 mL | 1.0857 mL | 2.1713 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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