PT-141

PT-141, also called bremelanotide, is a synthetic cyclic peptide containing seven residues and acting as a melanocortin receptor agonist.

Identity

Sequence

Ac-[Nle]DH[D-Phe]RWK-OH

Residues

7

Bridges and complexes

Asp2–Lys7 (lactam)

Molecular formula

C₅₀H₆₈N₁₄O₁₀

Average molecular weight

1025.2 g/mol

Monoisotopic mass (calculated)

1024.5243 Da

CAS number

189691-06-3

PubChem CID

9941379

Other names

Bremelanotide

Identity data from: PubChem CID 9941379

Research overview

PT-141, also known as bremelanotide, is a synthetic cyclic peptide discussed in the literature on melanocortin receptor agonists [1][2]. Its seven-residue sequence is Nle-Asp-His-D-Phe-Arg-Trp-Lys. Norleucine occupies position 1 and D-phenylalanine position 4. The intervening residues are aspartic acid at position 2 and histidine at position 3; arginine, tryptophan and lysine complete the chain at positions 5, 6 and 7, respectively [1]. D-Phe4 is the D-configured phenylalanine residue in an otherwise L-configured peptide sequence.

The cyclic structure contains a lactam bridge between the aspartic acid residue at position 2 and the lysine residue at position 7. This bridge closes the section of the sequence from Asp2 through Lys7, leaving the N-terminal norleucine outside the ring. The amino terminus of the norleucine carries an acetyl group. At the other end of the sequence, the lysine has a free carboxyl terminus [1][2]. Its molecular formula is C50H68N14O10, and the molecular weight recorded for this peptide is 1025.2 g/mol.

The pharmacology review describes bremelanotide as a synthetic analogue of the neuropeptide alpha-melanocyte-stimulating hormone and a melanocortin receptor agonist, with high affinity for the melanocortin type 4 receptor [1]. The earlier development review describes PT-141 as a synthetically modified analogue of the peptide PT-14 [2].

Laboratory storage and handling

Keep the peptide in a sealed vial under the storage conditions specified for its lot, protected from moisture and light. Allow the vial to reach room temperature before opening to limit condensation on the solid. Avoid repeated freezing and thawing of laboratory stocks, and retain the lot identifier and storage record with experimental notes. Wear standard laboratory protective equipment and follow the accompanying material documentation.

Questions about PT-141

References

1. Bremelanotide: First Approval. Drugs 2019. PMID 31429064
2. PT-141 Palatin. Curr Opin Investig Drugs 2004. PMID 15134289

Identity data checked on 2026-09-24. Literature summaries describe published research models and are not specifications of any product lot.