Molecular Characteristics
Complete Specifications
Structural Composition
Ac-Nle-cyclo(Asp-His-D-Phe-Arg-Trp-Lys)-OH
Physical Properties
PT-141 is a synthetic cyclic heptapeptide, an analogue of alpha-melanocyte-stimulating hormone. Cyclization between aspartic acid and lysine residues enhances conformational stability and resistance to enzymatic degradation compared to linear peptides. Structural modifications including norleucine substitution and D-phenylalanine incorporation contribute to increased stability under controlled research conditions. Lyophilized storage and protection from moisture, light exposure, and repeated freeze–thaw cycles help preserve peptide integrity and maintain analytical consistency during laboratory applications.
Analysis & Documentation
Identity
Each production lot is checked against the reference structure recorded for this compound:
- Classification — Synthetic cyclic heptapeptide
- Molecular formula — C₅₀H₆₈N₁₄O₁₀
- Expected mass — ~1,025.2 Da
- CAS registry — 189691-06-3
- Chain length — 7 amino acids (cyclic, modified)
- PubChem CID — Not listed
Analytical Methods
Testing is carried out per lot by an independent laboratory. The methods measure what the material is and how much of it is the target compound:
- RP-HPLC — reverse-phase separation of the target from process-related impurities; purity is reported as area percent of the main peak
- Mass spectrometry — observed mass compared against the expected molecular mass above
- Retention time — compared against a reference standard run under the same conditions
- Chromatogram — reproduced on the certificate so the peak and any shoulders can be inspected directly
Material & Documentation
What arrives, and how to tie it back to its paperwork:
- Appearance as supplied — White to off-white lyophilized powder
- Solubility — Water, buffered aqueous solutions (e.g., PBS)
- Lot number — printed on the container label and used to look up the certificate
- Certificate — indexed by lot at Certificates of Analysis
Laboratory Handling and Storage Protocols
Lyophilized Powder Storage
- Store at –20°C to –80°C in the original, sealed vial
- Protect from light exposure and moisture
- A desiccated storage environment is recommended
- Stability data suggests extended stability when stored at −20 °C or below.
Stability Characteristics
PT-141 is a synthetic peptide research compound that demonstrates stable handling characteristics when managed according to standard peptide laboratory protocols. Proper cold storage of the lyophilized material, protection from light, careful reconstitution, and minimized freeze–thaw exposure help preserve structural integrity and solubility. When handled appropriately, PT-141 supports consistent use in in vitro and analytical research applications.
Frequently Asked Questions
What is PT-141?
PT-141 is a synthetic cyclic heptapeptide, an analogue of alpha-melanocyte-stimulating hormone. It is supplied as a lyophilized powder and is identified by CAS registry number 189691-06-3.
Is PT-141 related to Melanotan peptides?
Yes. PT-141 shares the Ac-Nle-cyclo(Asp-His-D-Phe-Arg-Trp-Lys) ring with Melanotan II, and the two differ at the C-terminus: PT-141 carries a free acid (-OH), Melanotan II a C-terminal amide (-NH₂). The difference is visible in their molecular formulas, and each compound has its own CAS registry number.
Is PT-141 naturally occurring?
No. PT-141 is a synthetically engineered cyclic peptide and does not occur naturally in biological systems.
How is PT-141 supplied?
PT-141 is typically supplied as a lyophilized (freeze-dried) powder in sealed research vials to preserve stability during storage and shipment.
How should lyophilized PT-141 be stored?
Lyophilized PT-141 should be stored:
-
Long-term: −20 °C to −80 °C
-
Short-term: 2–8 °C
Keep vials sealed and protected from light and moisture until use.
Does PT-141 require a Certificate of Analysis (COA)?
Yes. A Certificate of Analysis (COA) should be available for each batch of PT-141, verifying identity, purity, and analytical testing results to ensure research quality and traceability.
Is PT-141 FDA-approved?
Research-grade PT-141 is not FDA-approved as a drug, supplement, or therapeutic product. It is sold exclusively as a research compound and must not be marketed or used for diagnostic, therapeutic, or consumption purposes.
This product is not for human consumption. It is sold strictly for research and educational purposes and is not intended to diagnose, treat, cure, or prevent any disease.
Any clinical data or research information referenced on this page is derived from peer-reviewed scientific literature and official publications. This information is provided for educational reference only and does not constitute medical advice or product claims.
By purchasing this product, you acknowledge that you are a qualified researcher and agree to use it in full compliance with all applicable laws and regulations.
