Nutrabiotech Sildenafil 98% 100G Powder, 98% high purity Sildenafil powder, selective PDE5 inhibitor, NO-cGMP pathway regulator, vascular physiological research bulk raw material

Sildenafil Powder CAS 139755-83-2 | High‑Purity PDE5‑Inhibitor Biochemical Research Raw Material

High‑purity Sildenafil crystalline powder with CAS 139755‑83‑2, a well‑known selective PDE‑5 inhibitor. Our lab‑grade raw material adopts strict purification process, widely used for biochemical experiment, pharmacology research and compound formulation. White crystalline powder, stable chemical property, bulk wholesale available.

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Sildenafil (CAS 139755-83-2) PDE5 Inhibitor | cGMP-Boosting Vasodilator, Erectile-Dysfunction & Pulmonary-Hypertension Research Compound

Sildenafil CAS 139755-83-2
Selective Phosphodiesterase-5 (PDE5) Inhibitor

Sildenafil (CAS 139755-83-2), originally UK-92480 / Viagra / Revatio, is a selective inhibitor of cyclic guanosine monophosphate-specific phosphodiesterase type 5 (PDE5) with an IC50 of ~5 nM. By blocking cGMP hydrolysis it amplifies NO-coupled vasodilation in corpus cavernosum, pulmonary and vascular endothelium. Molecular formula C22H30N6O4S, MW 474.58. Research-grade with COA.

PDE5 Inhibitor cGMP Booster Vasodilator Erectile Dysfunction Pulmonary Hypertension NO Signaling Revatio / Viagra Cyclic GMP
Request a Quote Technical Specs
474.58
MW (C22H30N6O4S)
~5 nM
PDE5 IC50
PDE5
Selective vs PDE1-4/6

Molecular Information

Name: Sildenafil
CAS: 139755-83-2
Formula: C22H30N6O4S
MW: 474.58 g/mol
Class: Pyrazolopyrimidinone
Core: 1-methyl-3-propyl-7H-pyrazolo[4,3-d]pyrimidin-7-one
Target: PDE5 (cGMP-PDE)
IC50: ~5.2 nM
MP: ~187-190 C
Appearance: White to off-white powder
Synonyms: Viagra / Revatio / UK-92480
Storage: -20 C
🧪
CAS Number
139755-83-2
⚖️
Molecular Weight
474.58
🎯
Primary Activity
PDE5 Inhibitor
✅
Purity
≥99%

Product Technical Specifications

Complete physicochemical properties and QC parameters for Sildenafil (CAS 139755-83-2)

📋 Physicochemical Properties

  • Product NameSildenafil
  • IUPAC Core5-[2-ethoxy-5-[(4-methylpiperazin-1-yl)sulfonyl]phenyl]-1-methyl-3-propyl-1H,4H,7H-pyrazolo[4,3-d]pyrimidin-7-one
  • CAS Number139755-83-2
  • SynonymsViagra; Revatio; UK-92480; UK92480
  • Molecular FormulaC22H30N6O4S
  • Molecular Weight474.58 g/mol
  • SourceSynthetic small molecule (Pfizer, ex UK-92480)
  • AppearanceWhite to off-white powder
  • Melting Point~187-190 C
  • Water Solubility~22.6 mg/mL
  • Organic SolubilityDMSO ~25 mg/mL; ethanol
  • Compound ClassPyrazolopyrimidinone / PDE5 inhibitor
  • HS Code2934.99

🔬 Quality Control & Handling

  • Purity (HPLC)≥99%
  • FormCrystalline powder
  • Primary TargetPDE5 (cGMP-specific phosphodiesterase type 5)
  • Pathway ReadoutElevated cellular cGMP; p-VASP, downstream PKG
  • SelectivityHigh vs PDE1-4, PDE6 weaker; minimal vs PDE2/3
  • Storage Condition-20 C, sealed, protect from light
  • Solution StabilityAliquot DMSO stocks; avoid freeze-thaw
  • ShippingBlue ice / cold chain recommended
  • QC DocumentationCOA / HPLC / NMR / MS / MSDS
  • Pack Sizes1KG / 5KG / 10KG / 25KG / 1TON
  • Stock StatusIn Stock
  • Use StatementResearch use only; not for human/clinical use

Key Molecular Targets & Pathway Nodes

Sildenafil is exquisitely selective for PDE5; its functional reach is the cGMP signaling network that governs smooth-muscle tone across vasculature, lung and corpus cavernosum.

🧬 PDE5 (cGMP-specific phosphodiesterase) 🔄 cGMP Hydrolysis (blocked) 💨 Nitric Oxide (NO) / sGC Pathway 🩸 Vascular Smooth Muscle 🫁 Pulmonary Arteriole 🍆 Corpus Cavernosum ⚙️ PKG (cGMP-dependent protein kinase) 📈 p-VASP Readout 🌿 Endothelial Function 🫀 Right-Heart Afterload 🔬 PDE Isoform Selectivity ⚠️ PDE6 / Visual (retina)

How Sildenafil Works: Locking cGMP High to Relax Smooth Muscle

Sildenafil disables the enzyme that destroys cGMP, amplifying the nitric-oxide relaxation signal

1

NO Stimulates sGC & Builds cGMP

Sexual, hypoxic or shear stimuli activate endothelial nitric oxide synthase (eNOS), releasing NO. NO binds soluble guanylyl cyclase (sGC) in smooth-muscle cells, converting GTP to the second messenger cyclic GMP (cGMP). Under basal conditions PDE5 immediately begins hydrolyzing cGMP back to GMP, capping the signal.

2

PDE5 Inhibition Locks cGMP High

Sildenafil binds the catalytic site of PDE5 with ~5 nM potency, blocking cGMP hydrolysis. Intracellular cGMP accumulates, prolonging and amplifying the relaxation signal far beyond what NO alone achieves. Because PDE5 is enriched in corpus cavernosum, pulmonary and vascular smooth muscle, sildenafil acts preferentially at those sites.

3

cGMP Activates PKG & Vasodilation

Elevated cGMP activates protein kinase G (PKG), which phosphorylates targets including VASP, lowers intracellular calcium, opens potassium channels and relaxes smooth muscle. The result is arterial inflow (erectile tissue) or reduced pulmonary vascular resistance (PAH) — the basis of both Viagra and Revatio. p-VASP is the canonical pharmacodynamic readout.

⚖️ Sildenafil vs Tadalafil vs Vardenafil

  • Sildenafil (this product)PDE5 IC50 ~5 nM; t1/2 ~4 h; rapid onset
  • TadalafilPDE5 IC50 ~2-10 nM; t1/2 ~17.5 h; long-acting
  • VardenafilPDE5 IC50 ~0.7 nM; t1/2 ~4-5 h; potency-similar
  • Active MetaboliteN-desmethyl sildenafil (UK-103,320), also PDE5-active
  • Shared MechanismAll block cGMP hydrolysis via PDE5
  • Selectivity CaveatPDE6 cross-reactivity underlies visual side effects

♻️ Downstream Biological Consequences

  • Second MessengerElevated intracellular cGMP
  • KinasePKG activation; VASP phosphorylation
  • Smooth MuscleCalcium lowering & relaxation / vasodilation
  • Vascular BedIncreased arterial inflow (corpus cavernosum)
  • PulmonaryReduced vascular resistance (PAH)
  • EndotheliumImproved flow-mediated dilation in studies

Research Applications & Models

From the discovery that reshaped urology to a pulmonary-hypertension therapy and a cGMP-signaling tool, sildenafil spans clinical and basic research.

🍆

Erectile Dysfunction Models

The canonical PDE5-inhibition model. Sildenafil potentiates NO-mediated erection physiology and is the reference comparator for every new ED agent; used in corpus-cavernosum smooth-muscle and cavernosal-artery studies.

PDE5 / cGMP
🫁

Pulmonary Arterial Hypertension

Marketed as Revatio, sildenafil reduces pulmonary vascular resistance and improves exercise capacity in PAH. Studied in hypoxia-induced pulmonary hypertension, right-heart strain and monocrotaline models.

PAH / Right Heart
🧪

cGMP Signaling Research

A fiducial tool for the NO-sGC-cGMP-PKG axis. Standard positive control for p-VASP immunoassays, cGMP ELISA and vessel-relaxation (myograph) experiments probing endothelial and smooth-muscle biology.

NO / cGMP Axis
🫀

Cardiovascular & Endothelial Studies

Investigated for myocardial protection, ischemia-reperfusion injury, and flow-mediated dilation, where cGMP elevation modulates cardiomyocyte survival and vascular tone.

Vascular Tone
🧠

Cerebral & Cognitive Research

Explored for neurovascular coupling, cerebral blood flow and memory, leveraging cGMP's role in synaptic plasticity; also studied in altitude/cerebral-edema contexts.

Neurovascular
🔬

PDE Isoform Selectivity

Used to dissect PDE5 vs PDE6 vs PDE1-4 contributions to tone, vision and cardiac function, and benchmarked against tadalafil and vardenafil in head-to-head enzymology.

PDE Profiling
🧬

Oncologic & Antiproliferative Work

PDE5 inhibition is examined for anti-tumor and anti-metastatic effects in several cancer models via cGMP/PKG and immune modulation, an active area of repurposing research.

cGMP / PKG
⚕️

Raynaud & Vasospastic Disease

Studied for digital vasospasm and Raynaud's phenomenon where enhanced vasodilation relieves ischemic attacks, extending PDE5 science beyond its primary indications.

Vasospasm

Key Literature & Landmark Publications

The discovery, enzymology and landmark clinical validation of sildenafil.

Terrett NK, et al. Sildenafil, a potent and selective inhibitor of type 5 phosphodiesterase with utility for the treatment of male erectile dysfunction. Bioorg Med Chem Lett. 1996;6(15):1819-24.
doi: 10.1016/0960-894X(96)00353-1
Goldstein I, et al. Oral sildenafil in the treatment of erectile dysfunction. N Engl J Med. 1998;338(20):1397-404.
doi: 10.1056/NEJM199805143382001
Corbin JD, Francis SH. Pharmacology and physiology of the cGMP-specific phosphodiesterases (PDE5). (PDE5 enzymology review).
Landmark reference
Galie N, et al. Sildenafil citrate therapy for pulmonary arterial hypertension. N Engl J Med. 2005;353(20):2148-57. (SUPER-1 trial).
doi: 10.1056/NEJMoa050010
Boolell M, et al. Sildenafil: an orally active type-5 cyclic GMP-specific phosphodiesterase inhibitor for the treatment of penile erectile dysfunction. Int J Impot Res. 1996;8(2):47-52.
Landmark reference

Available Sizes & Ordering

Research-grade Sildenafil (CAS 139755-83-2) with full QC documentation; standard packs and bulk custom quantities supported.

TierPack SizeStock StatusSuitable ForLead Time
Standard1KGIn StockPDE5 / cGMP cell & myograph assaysSame/next-day ship
Medium5KGIn StockVascular, pulmonary & ED modelsSame/next-day ship
Large10KGIn StockLong-term in vivo & formulation studiesSame/next-day ship
Bulk25KGIn StockFormulation, coating and process developmentQuote to confirm
Industrial1TONMade to orderPilot/production scale, CMO supplyBatch delivery

💡 Reference sizes shown above; for exact pricing and availability please contact us for a quote. Bulk orders qualify for tiered discounts.

Frequently Asked Questions (FAQ)

What is sildenafil and what does it do?
Sildenafil (CAS 139755-83-2) is a selective inhibitor of PDE5 (phosphodiesterase type 5), the enzyme that breaks down cyclic GMP. By blocking PDE5 it raises cGMP in smooth muscle, enhancing nitric-oxide-driven vasodilation. Marketed as Viagra for erectile dysfunction and Revatio for pulmonary arterial hypertension, it is the prototypical cGMP-boosting drug. Formula C22H30N6O4S, MW 474.58, PDE5 IC50 ~5 nM.
What is the difference between sildenafil, Viagra and Revatio?
They are the same molecule. Viagra is the brand for erectile dysfunction (usually 25-100 mg tablets) and Revatio the brand for pulmonary arterial hypertension (typically lower, thrice-daily dosing). The discovery code was UK-92480. Clinicians distinguish them by indication and dose pack, not chemistry.
How does sildenafil differ from tadalafil and vardenafil?
All three are PDE5 inhibitors with the same mechanism. Sildenafil has a half-life of about 4 hours and rapid onset; tadalafil lasts ~17.5 hours (once-daily use) and vardenafil is the most PDE5-potent (~0.7 nM). Selection is driven by duration, onset and side-effect profile rather than target biology. Sildenafil's active metabolite, N-desmethyl sildenafil (UK-103,320), is itself PDE5-active.
What is the mechanism in erectile dysfunction?
Sexual stimulation triggers NO release in corpus-cavernosum nerves and endothelium. NO activates soluble guanylyl cyclase to make cGMP, which relaxes smooth muscle and allows arterial inflow. PDE5 normally shuts this off by hydrolyzing cGMP; sildenafil blocks that step, so cGMP stays high and the erectile response is amplified. Crucially, sildenafil has no effect without sexual stimulation because it depends on NO being present.
What are the key experimental readouts for PDE5 inhibition?
The canonical readout is phospho-VASP (p-VASP, Ser157/239) by Western blot or flow cytometry, reflecting intracellular cGMP. Complementary assays include cGMP ELISA, isolated-tissue myography (relaxation of pre-contracted vessels), and measurement of cAMP (to confirm PDE5 vs PDE3/4 selectivity). Retinal PDE6 cross-reactivity is the mechanistic basis of the characteristic visual side effects.
How soluble is sildenafil and how should it be prepared?
Sildenafil is reasonably soluble: ~25 mg/mL in DMSO and ~22 mg/mL in water (adjust pH if needed). For cell assays, typical working concentrations are in the low nanomolar to low micromolar range; dilute DMSO stock into pre-warmed medium keeping final DMSO ≤0.1% v/v. Store the solid at -20 C and aliquot stock solutions to avoid freeze-thaw.
Is QC documentation provided? Can I request a sample?
Every batch ships with a Certificate of Analysis (COA) including HPLC purity, NMR structural confirmation and MS data. MSDS/SDS, residual-solvent data and Certificates of Origin are available on request. Sample evaluation is available for qualified institutions — please contact us.

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Research-grade Sildenafil (CAS 139755-83-2) — purity ≥99% HPLC, COA included
The reference PDE5 / cGMP-boosting vasodilator for ED, PAH and vascular signaling research — request a quote today

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Weight 100 g

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