PT-141
£17.50
PT-141 is a synthetic cyclic seven residue peptide supplied as a lyophilised powder for in vitro laboratory research. Each lot is released with a certificate of analysis published against its lot number.
- Cyclic heptapeptide with a side chain lactam bridge and N-terminal acetyl group, 1025.2 Da
- Purity by RP-HPLC and identity by LC-MS on every lot
- Lot number on the vial matches the published certificate
4 in stock
- Research use only Not for human or veterinary use
- Certificate per lot Published against the lot number
- Independently tested RP-HPLC with LC-MS identity
- Restricted sale 18+ qualified researchers only
What is PT-141?
PT-141, also known by the name bremelanotide, is a synthetic cyclic heptapeptide supplied as a lyophilised powder for laboratory research. It is a structural analogue of the alpha-melanocyte stimulating hormone core sequence and is handled in the laboratory as a stable, water soluble peptide.
PT-141 structure and sequence
The sequence is Ac-Nle-cyclo[Asp-His-D-Phe-Arg-Trp-Lys]-OH, molecular formula C50H68N14O10, molecular weight 1025.2 Da. The ring is closed by a lactam bridge between the side chains of aspartic acid and lysine, rather than by a disulfide bond, and the N-terminus carries an acetyl group on a norleucine residue. The cyclic structure and the single D-phenylalanine make it conformationally constrained and resistant to the oxidation chemistry that affects cysteine containing peptides, which keeps the chromatography and mass assignment straightforward.
Where this material appears in the literature
Published work on PT-141 is preclinical and in vitro. It appears in the literature chiefly as a subject of melanocortin receptor binding assays and in structure and activity work on cyclic melanocortin peptide analogues. Master Biolabs supplies the material for that kind of laboratory investigation and makes no claim about what it does in any living subject.
Related material in the catalogue
PT-141 is held under Modified Peptides, which groups peptides carrying a defined chemical modification such as a metal complex, PEGylation, lipidation, cyclisation or an acyl group. Other materials in this category include PEG-MGF, Tesamorelin and AHK-Cu.
Analysis and certification
Every lot is analysed by an independent laboratory before release, using RP-HPLC for purity and LC-MS for identity confirmation. The certificate of analysis is published against the lot number rather than against the product page, so the document you read is the document for the vial you receive. The lot number printed on the vial label is the link between the two.
Purity reporting
Purity is determined for each lot by RP-HPLC peak area and stated on that lot’s certificate of analysis. Master Biolabs does not quote a single purity figure for the product as a whole, because purity is a property of a lot, not of a product page.
The certificate is the record that applies to your material. Analytical figures relate to the lot they are published against and carry no implication of suitability for any purpose beyond laboratory research.
Research use only
Master Biolabs supplies this material for laboratory research only. It is not supplied for any use in humans or animals. It is not a medicinal product, food supplement, food or cosmetic, and nothing on this page describes or implies any such use. Sale is restricted to persons aged 18 or over who are qualified researchers or who purchase on behalf of a research institution, laboratory or business.
| Compound | PT-141 |
|---|---|
| Also known as | Bremelanotide |
| Class | Synthetic cyclic peptide |
| Amino acids | 7 |
| Sequence | Ac-Nle-cyclo[Asp-His-D-Phe-Arg-Trp-Lys]-OH |
| Molecular formula | C50H68N14O10 |
| Molecular weight | 1025.2 Da |
| CAS number | 189691-06-3 |
| Appearance | White to off white lyophilised powder |
| Purity | Measured per lot by RP-HPLC, stated on the certificate of analysis |
| Purity method | RP-HPLC |
| Identity method | LC-MS |
| Solubility | Soluble in sterile water and aqueous buffers for analytical preparation |
| Labelled quantity | As stated on the vial label and certificate of analysis |
Characterisation. Values above describe the compound as supplied. The figures for the lot you receive, including measured purity, are stated on its certificate of analysis.
How this material is tested
Two separate analyses are carried out on every lot before release, and both appear on the certificate.
- RP-HPLC, for purity. Reversed phase high performance liquid chromatography separates the material by hydrophobicity. The main peak is integrated against total peak area, and that ratio is the purity figure reported on the certificate.
- LC-MS, for identity. Liquid chromatography coupled to mass spectrometry confirms that the mass of the main peak matches the expected mass for the compound, which is what distinguishes the correct sequence from a closely related one.
A complete certificate carries the compound name, the lot number, the test date, the method, the measured purity and the name of the laboratory. If any of those is missing, or the lot number on the vial does not match the certificate, contact us before using the material.
Storing PT-141
Lyophilised material should be moved into freezer storage on arrival. Store the sealed vial dry at −20°C or below, protected from light and moisture. Returned promptly to those conditions, the dry solid is the most stable form this material takes.
Preparing stock solutions
Prepare stock solutions in sterile water or an appropriate aqueous buffer at a concentration suited to your assay, expressed in mg/mL. Allow the vial to reach room temperature before opening, add solvent down the vial wall rather than directly onto the solid, and let the material dissolve without vigorous agitation. PT-141 dissolves readily in water at the concentrations used for analytical work.
Solutions are less stable than the lyophilised solid. Prepare close to the point of use, hold at 2 to 8°C for short periods only, and aliquot before freezing so that repeated freeze and thaw cycles are avoided.
On arrival
Check that the vial is intact and sealed, that the compound name and labelled quantity match your order, and that the lot number on the label matches the certificate published for it. If anything does not match, or the packaging has clearly failed in transit, contact us before using the material and report it promptly so that a carrier claim remains possible.
Handling and disposal
Assess the hazards of this material before handling it and use appropriate controls and protective equipment, in line with your COSHH assessment. It has not been characterised toxicologically and should be treated as potentially hazardous. Anyone handling it should be trained for the work.
Dispose of unused material, vials and packaging lawfully and in line with your institution's waste procedures.
Record keeping
Record the lot number in your notes at the point of first use, alongside the date the vial was opened and the concentration of any stock prepared. Certificates are published against the lot number rather than the product, so the lot number is the only reliable link between your results and the analytical data for the material that produced them. If a question arises about a result months later, that link is what keeps the work auditable.
Where do I find the certificate of analysis for my vial?
Certificates are published on the COA page against the lot number. Find the lot number printed on your vial label and match it to the certificate listed there. The certificate for that lot is the record that applies to your material.
What purity does this lot meet?
Purity is measured for each lot by RP-HPLC and stated on that lot's certificate of analysis. We do not quote a single figure for the product because purity belongs to a lot, not a product page. Check the certificate that matches the lot number on your vial.
How is identity confirmed?
Identity is confirmed by LC-MS, which checks that the mass of the main chromatographic peak matches the expected mass of PT-141 (1025.2 Da). The result is recorded on the certificate alongside the purity figure.
How should the vial be stored when it arrives?
Move the sealed vial into freezer storage at −20°C or below, dry and protected from light. Full laboratory storage and stock solution guidance is in the Storage and handling tab.
Who can buy this material?
Sale is restricted to persons aged 18 or over who are qualified researchers or who purchase on behalf of a research institution, laboratory or business. The material is supplied for laboratory research only and is not for use in humans or animals.
What if the lot number on my vial does not match a certificate?
Do not use the material. Contact us with your order number and the lot number on the label, and we will resolve it before you proceed.
Looking for something else?
Tell us the compound and quantity you are looking for and we will confirm availability and lead time. Research use only.
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