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Purely Peptides
Research Catalog

Compound class

Cyclic melanocortin analogs

Synthetic melanocortin receptor ligands closed into a macrocycle by a side-chain to side-chain bridge, in contrast to the linear fragment and full-length melanocortin peptides.

Published: 2026-09-13Literature/identifier verification: 2026-08-23

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Neutral class definition

Synthetic melanocortin receptor ligands closed into a macrocycle by a side-chain to side-chain bridge, in contrast to the linear fragment and full-length melanocortin peptides.

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Related compounds

Compound

PT-141 (Bremelanotide)

PT-141, canonically bremelanotide, is a synthetic cyclic heptapeptide melanocortin receptor agonist, structurally the C-terminal free acid of the Melanotan II lactam scaffold.

Bremelanotide · PT 141 · PT-141 free base · PT-141

Compound

Melanotan II

Melanotan II is a synthetic cyclic heptapeptide analog of alpha-melanocyte-stimulating hormone, closed by a lactam bridge between an aspartate and a lysine side chain.

Melanotan-II · MT-II · MT-2

Compound

Setmelanotide

Setmelanotide is a synthetic disulfide-cyclized octapeptide characterised as an MC4R-preferring melanocortin receptor agonist. A review by Swan et al. (PMID 38834138) describes setmelanotide as an analogue of alpha-melanocyte-stimulating hormone; that is a review-level parent attribution, not a residue-by-residue design account.

RM-493 · BIM-22493 · IRC-022493

Compound

SHU9119

SHU9119 is a cyclic lactam melanocortin analog whose receptor behaviour is subtype-dependent: antagonist at some melanocortin receptors and agonist at others. Gimenez et al. (PMID 35404053) describe SHU9119 as a cyclic heptapeptide analogue of alpha-melanocyte-stimulating hormone.

SHU-9119 · SHU 9119

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Related molecular mechanisms

receptor

Melanocortin receptors

A family of five G protein-coupled receptors, MC1R through MC5R. ACTH recognition and signaling at MC2R depend on the accessory protein MRAP. Native hormones, peptide analogs and nonpeptide ligands differ in receptor-subtype recognition and functional direction; binding affinity, agonism and antagonism must be interpreted separately in the experimental system studied.

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Relevant glossary terms

AgonistLigandG-protein-coupled receptorPeptide analogLipidationAmidation

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Verified bibliography

  1. Reference 1

    CLIPSing Melanotan-II to Discover Multiple Functionally Selective hMCR Agonists.

    Tomassi S, Dimmito MP, Cai M, D'Aniello A, Del Bene A, Messere A, Liu Z, Zhu T, Hruby VJ, Stefanucci A, Cosconati S, Mollica A, Di Maro S

    Journal of medicinal chemistry · 2022-02-21 · Journal Article

    current
    PMID 35188390DOI 10.1021/acs.jmedchem.1c01848Melanotan IIMC1R

  2. Reference 2

    Goldilocks-Inspired Design of Mid-Size Macrocycles for Selective Targeting of Human Melanocortin Receptors.

    Merlino F, Jia L, Boccino I, Carotenuto A, Tammaro F, Santoro F, Thompson PE, Grieco P

    Journal of medicinal chemistry · 2026-08-13 · Journal Article

    current
    PMID 42340853PMC13492293DOI 10.1021/acs.jmedchem.6c01074Melanotan IIPT-141 (Bremelanotide)MC1R

Study models of these references

What kind of experiment each cited paper reports, taken from its abstract unless marked. Not a summary of results.

ReferenceStudy models
Tomassi S et al. 2022Study models reported: in vitro · from the abstract
Merlino F et al. 2026Study models reported: in vitro · from the abstract

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Related Purely Peptides research articles

No existing Research Article is mapped to this class seed record.

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Related compound classes

Melanocortin fragment peptidesLinear melanocortin analogsMelanocortin receptor ligands