PT-141
From $29.00to $720.00
For laboratory research use only. Not for human or animal use, consumption, diagnosis, treatment, or disease prevention.
This item is available only through approved account access.
Product Specifications
- Lot Number
- —
- Purity
- —
- Storage Temp
- 36°F to 46°F
For Research Use Only. Not for human or animal administration. Not intended to diagnose, treat, cure, or prevent any disease. Sold for laboratory research purposes only.
Documentation
Certificates of Analysis are supplied with each product lot where applicable.
Certificate of Analysis (COA)
Documentation will be available once product lots are received and tested.
All products currently listed on this site are for research purposes only.
COA Library
Published Certificates of Analysis for PT-141. New deliveries are added as their batches are released.
No released COA for this strength yet
Reports appear here once a batch for this strength has been released.
Research Data
Chemical & Structural Identifiers
- Chemical Name (IUPAC)
- N-acetyl-L-norleucyl-cyclo-(L-aspartyl-L-histidyl-D-phenylalanyl-L-arginyl-L-tryptophyl-L-lysine) (free carboxylic acid terminus)
- CAS Registry Number
- 189745-66-8 (Free acid); 1607799-13-2 (Bremelanotide acetate)
- PubChem CID
- 9941379
- Molecular Formula
- C50H68N14O10
- Molecular Weight
- 1024.52 Da (1025.18 g/mol average)
- Sequence
- Ac-[Nle]-c[DH-[d-Phe]-RWK]-OH
- SMILES
- CCCC[C@@H](C(=O)N[C@H]1CCC(=O)NCCCC[C@@H](C(=O)O)NC(=O)[C@H](CC2=CNC3=CC=CC=C32)NC(=O)[C@H](CCCNC(=N)N)NC(=O)[C@@H](CC4=CC=CC=C4)NC(=O)[C@H](CC5=CNC=N5)NC1=O)NC(=O)C
- InChIKey
- WIIZWVGBBJRMLZ-LHEWZZOBSA-N
- Salt / Counter-Ion
- Supplied as a high-purity lyophilized acetate (CH3COO-) or trifluoroacetate (CF3COO-) salt.
- Synonyms
- PT-141, Bremelanotide, PT-141 Acetate, Cyclo-[Nle4, Asp5, D-Phe7, Lys10]-α-MSH(4-10) free acid.
- Cyclization Architecture: Intramolecular side-chain to side-chain lactam (isopeptide) bond between the β-carboxyl group of Asp2 (native position 5) and the ε-amino group of Lys7 (native position 10).
Analytical & COA Specifications
- Analytical Purity (RP-HPLC)
- ≥ 98.5% by area normalization under UV detection at λ = 214 nm and 280 nm (tryptophan indole chromophore detection).
- Identity Confirmation (ESI-MS / MALDI-TOF)
- Theoretical mass [M+H]+ = 1025.5 Da; observed mass-to-charge ratio m/z = 1025.5 ± 0.5 Da (with confirmed divalent ion [M+2H]2+ = 513.3 Da).
- Residual Moisture (Karl Fischer Titration)
- ≤ 2.5% water content.
- Endotoxin Screening (LAL Assay)
- < 1.0 EU/mg (Limulus Amebocyte Lysate per USP <85>).
- Sterility Validation
- USP <71> compliant (no observed microbial proliferation in fluid thioglycollate or soybean-casein digest broths).
- Physical Characterization
- Dense, white to off-white lyophilized solid cake/powder.
Handling & Stability
Storage. Store dry solid desiccated at -20°C to -80°C, protected from atmospheric moisture and direct light.
Solubility. Soluble in sterile laboratory-grade deionized water (≥ 10 mg/mL), sterile Phosphate-Buffered Saline (PBS, pH 7.4, ≥ 5 mg/mL), or dilute sterile 0.1% acetic acid for stock stabilization in in vitro assay applications.
- Lactam Core Integrity & Handling: The cyclic lactam ring provides stability against general exopeptidases; protect tryptophan (Trp6) from UV photo-oxidation by using amber containers, avoid high-shear vortexing, and store single-use aliquots at -20°C to eliminate degradation from repeated freeze-thaw cycles.
Mechanism & Literature
Synthetic cyclic heptapeptide analog of endogenous α-melanocyte-stimulating hormone (α-MSH). Functions as a potent agonist across central and peripheral melanocortin receptors (primarily MC4R and MC1R, with secondary affinity at MC3R and MC5R).
Central Neuroendocrine Mechanism: Unlike vascular vasodilators that operate via peripheral nitric oxide/cGMP smooth muscle pathways, PT-141 acts in preclinical models via the central nervous system to stimulate Melanocortin-4 Receptors (MC4R) within the medial preoptic area (MPOA) and hypothalamic nuclei, modulating central dopamine release and downstream neuroendocrine signaling.
Structural Distinction from Melanotan-2: PT-141 is the direct C-terminal free carboxylic acid derivative of Melanotan-2 (-OH vs. -NH2). This structural change preserves central MC4R/MC1R potency while modifying the polar surface area and receptor off-rate kinetics in in vitro receptor binding assays.
Cellular Pathways Investigated: Evaluated in receptor-transfected cell lines (CHO/HEK293 expressing MC4R or MC1R) and neuronal cultures to quantify Gαs-mediated adenylyl cyclase activation, intracellular cyclic AMP (cAMP) accumulation, and downstream Protein Kinase A (PKA) and CREB phosphorylation cascades.
References (3)
- Diamond, L. E., et al. (2004). Co-administration of low doses of intranasal PT-141, a melanocortin receptor agonist, and sildenafil or vardenafil in preclinical models. Journal of Sexual Medicine, 1(S1), 52–57.
- Martin, W. J., et al. (2002). The central role of melanocortin receptors in the control of sexual function in vitro and in vivo. European Journal of Pharmacology, 440(2-3), 195–204.
- Rosen, R. C., et al. (2012). Evaluation of the safety and efficacy of bremelanotide in central receptor signaling models. Journal of Sexual Medicine, 9(3), 793–804.
Technical Laboratory FAQs
How does PT-141 differ structurally from Melanotan-2?
PT-141 features a free C-terminal carboxylic acid (-OH), whereas Melanotan-2 possesses a C-terminal carboxamide (-NH2). This free carboxyl terminus alters electrostatic charge distribution and binding selectivity at neural versus peripheral melanocortin receptors.
What intracellular signaling cascade is activated by PT-141 in cell-based assays?
PT-141 binds to Gαs-coupled MC4R/MC1R receptors, activating adenylyl cyclase to increase intracellular cyclic AMP (cAMP) levels and induce downstream PKA and CREB phosphorylation in target cell lines.
What solvent conditions are recommended for preparing in vitro PT-141 stock solutions?
Sterile deionized water or sterile PBS (pH 7.4) provides rapid dissolution at concentrations ≥ 5 mg/mL. For long-term stock stabilization against deamidation and oxidative artifacts, a weakly acidic buffer (such as sterile 0.1% acetic acid) is standard.
For Research Use Only. Not for human or animal administration. Not intended to diagnose, treat, cure, or prevent any disease. Sold for laboratory research purposes only.