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Compound monograph

Human Octanoyl-Ghrelin

Human octanoyl-ghrelin is the endogenous 28-residue acylated peptide ligand of the ghrelin receptor, carrying an n-octanoyl ester on serine 3.

Published: 2026-09-13Literature/identifier verification: 2026-09-13
Also known asLenomorelinHuman acyl-ghrelinAcyl-ghrelin
Growth hormone secretagogues

01

Identity & nomenclature

Human octanoyl-ghrelin is the endogenous 28-residue acylated peptide ligand of the ghrelin receptor, carrying an n-octanoyl ester on serine 3.

'Ghrelin' alone is not a resolved chemical identity. Species, chain length, acylated versus desacyl, and the acyl chain itself must all be specified. Desacyl-ghrelin is a different substance, not the same one differently formulated.

Canonical name: Ghrelin (human, octanoylated).

Declared aliases and development codes: Lenomorelin, Human acyl-ghrelin, Acyl-ghrelin.

02

Molecular properties

Molecular formulaC149H249N47O42
Molecular mass3370.92 Da
CAS Registry Number258279-04-8
PubChem CID91668172
UNIIUXG268Q86R
One-letter sequenceGSSFLSPEHQRVQQRKESKKPPAKLQPR
Terminal groupsFree Gly1 amino terminus; Free Arg28 carboxyl terminus

Twenty-eight residues, all L. The backbone string is NOT a complete identity: the Ser3 side-chain hydroxyl is esterified with n-octanoic acid, and that ester is required for canonical receptor activation. A registry synonym for this substance omits a lysine while a correctly specified 28-residue synonym sits alongside it — do not regard every registry synonym as equally authoritative.

03

Structural characteristics

Cryo-EM structures of the ghrelin receptor bound to ghrelin and to the synthetic secretagogue GHRP-6 reveal a distinct pocket accommodating the octanoyl group, which positions the peptide for receptor activation rather than serving only as a half-life extension. The strong requirement for acylation in canonical activation should not be restated as desacyl-ghrelin having no biological activity of any kind; that broader claim is not established by these receptor experiments.

  • Ser3 O-n-octanoylation

Terminal features: Free Gly1 amino terminus, Free Arg28 carboxyl terminus.

04

Molecular targets & mechanisms

Growth hormone secretagogue receptor

GHS-R1a · Ghrelin receptor · GHSR

A G-protein-coupled receptor distinct from the GHRH receptor. Antagonist profiling reported that ipamorelin releases growth hormone through a GHRP-like receptor rather than through the GHRH receptor, establishing the two pathways as separate.

05

Analytical considerations

Identity work must preserve and measure the Ser3 ester, not merely confirm a ghrelin backbone. Loss of the octanoyl changes the neutral composition by C8H14O, 126.1045 Da; monitoring that product reveals deacylation but does not establish that the original ester was on Ser3. An immunoassay recognising a retained epitope settles neither acylation nor chain length.

Disagreements and mix-ups

Points where sources disagree about this compound's identity, or where a name or form is easily confused with another, as noted in this record. The discrepancy register quotes the passage for each one.

What the studies reported

Each finding describes one cited study in its stated model. These observations are specific to that study and do not establish effects in other settings.

Cell and tissue studies

  • Rat stomach peptide purification and identification

    Using rat stomach peptide purification and identification, the study identified a 28-amino-acid GHS-R ligand with serine 3 n-octanoylation.

    Reference [2]

  • Gq-coupled ghrelin receptor cryo-electron microscopy preparation

    Using a Gq-coupled ghrelin receptor cryo-electron microscopy preparation, the study reported a ghrelin-bound receptor structure.

    Reference [3]

  • Gq-coupled ghrelin receptor structural and mutational assays

    Using Gq-coupled ghrelin receptor structural and mutational assays, the study identified an octanoyl-group binding pocket that positioned the peptide for receptor activation.

    Reference [3]

  • GHSR dynamic mass redistribution and calcium mobilization assays

    Using GHSR dynamic mass redistribution and calcium mobilization assays, the study reported ghrelin as a potent full agonist.

    Reference [4]

06

Verified bibliography

Cited studies by type

The 4 papers this record cites, counted by the kind of work each reports. A count is the size of this record's selection, not of the research that exists, and says nothing about results, safety, effectiveness or approval.

A paper can report more than one kind of work. Each count opens those papers in the bibliography. Compare every record on the Evidence Map.

  1. Reference 1

    1H NMR structural analysis of human ghrelin and its six truncated analogs.

    Silva Elipe MV, Bednarek MA, Gao YD

    Biopolymers · 2001-12 · Journal Article

    current
    PMID 11745115DOI 10.1002/1097-0282(200112)59:7<489::aid-bip1054>3.0.co;2-sHuman Octanoyl-GhrelinGHS-R1a

  2. Reference 2

    Ghrelin is a growth-hormone-releasing acylated peptide from stomach.

    Kojima M, Hosoda H, Date Y, Nakazato M, Matsuo H, Kangawa K

    Nature · 1999-12-09 · Journal Article

    current
    PMID 10604470DOI 10.1038/45230Human Octanoyl-GhrelinGHS-R1a

  3. Reference 3

    Molecular recognition of an acyl-peptide hormone and activation of ghrelin receptor.

    Wang Y, Guo S, Zhuang Y, Yun Y, Xu P, He X, Guo J, Yin W, Xu HE, Xie X, Jiang Y

    Nature communications · 2021-08-20 · Journal Article

    current
    PMID 34417468PMC8379176DOI 10.1038/s41467-021-25364-2Human Octanoyl-GhrelinMacimorelinGHRP-6GHS-R1a

  4. Reference 4

    In vitro pharmacological characterization of growth hormone secretagogue receptor ligands using the dynamic mass redistribution and calcium mobilization assays.

    Sturaro C, Ruzza C, Ferrari F, Pola P, Argentieri M, Frezza A, Marzola E, Bettegazzi B, Cattaneo S, Pietra C, Malfacini D, Calò G

    European journal of pharmacology · 2024-08-10 · Journal Article

    current
    PMID 39128804DOI 10.1016/j.ejphar.2024.176880Human Octanoyl-GhrelinAnamorelinGHS-R1a

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
Silva Elipe MV et al. 2001Chemical, structural or analytical study; no biological model reported
Kojima M et al. 1999Study models reported: in vitro; in vivo (subject not stated) · from the abstract
Wang Y et al. 2021Study models reported: in vitro · from the abstract
Sturaro C et al. 2024Study models reported: in vitro · from the abstract

Record history

Published 2026-09-13.

No changes to this record's content have been recorded since publication.

Each entry names the parts of this record that changed on that date. Changes to links between records and to catalogue links are not listed. This history covers the tracked record fields; study findings are not listed here.

Cite this record: Purely Peptides Research Library. Human Octanoyl-Ghrelin. Published 2026-09-13. https://purelypeptides.org/research/compounds/octanoyl-ghrelin/

10

Methodology & citation verification

Reference identity is checked against official PubMed metadata. Local deterministic receipts bind each normalized title and canonical metadata record to its verification date. Scientific values remain absent when an authoritative source has not been verified.

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