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Exogenous opioid heptapeptide (frog skin)

Deltorphin

Deltorphin (deltorphin A / dermenkephalin) is a naturally occurring opioid heptapeptide from Phyllomedusa frog skin and a potent, highly selective delta-opioid receptor agonist.

By The Peptides Codex Editorial TeamIndividual review date not recorded

Page data last changed: . Registry refreshes and identity assessments are separate from scientific content review.

Reference backbone length
7 positions
Class
Exogenous opioid heptapeptide (frog skin)
Function
Potent and highly selective delta-opioid receptor agonist
Context
Naturally occurring peptide and research tool in opioid pharmacology; not a Health Canada-authorized product

A delta-selective counterpart to the mu-selective dermorphin, also built around a position-2 D-amino acid.

Also known as: deltorphin A · dermenkephalin

Part of the Neuropeptides & signaling cluster

Overview

Deltorphin (deltorphin A / dermenkephalin) is a naturally occurring opioid heptapeptide from Phyllomedusa frog skin and a potent, highly selective delta-opioid receptor agonist. Its D-methionine confers stability and notable blood-brain barrier penetration. It is a research peptide, and this page is educational only.

Source & context

Biological / chemical source: Skin secretions of Phyllomedusa frogs (e.g. P. bicolor, P. sauvagei)

Primary research or clinical context: Naturally occurring peptide and research tool in opioid pharmacology; not a Health Canada-authorized product

Delta selectivity

Deltorphin, Tyr-D-Met-Phe-His-Leu-Met-Asp-NH2, is one of the most delta-selective opioid peptides known, contrasting with the mu selectivity of dermorphin from the same frogs. Like other frog-skin opioids it carries a D-amino acid at position 2, and it is noted for comparatively good blood-brain barrier penetration among peptide opioids.

Research role

Deltorphin is widely used to probe delta-opioid receptor pharmacology in laboratory models, helping researchers dissect the roles of mu versus delta signalling. It is not authorized by Health Canada and is not a medicine. This page describes its chemistry and biology for education only and makes no therapeutic claim.

Sequence of the selected reference form

Sequence backbone for the reference form: Deltorphin A, D-Met2 and Asp7-amide. Termini, stereochemistry and modifications are described below.

YMFHLMD

YMFHLMD

Analyze sequences in the playground →

Structure & chemistry

Molecular identity & reference confidence

Source-supported reference

The original isolation paper explicitly identifies the Tyr-D-Met-Phe-His-Leu-Met-Asp-NH2 chain in this frog species. The selected PubChem structure encodes D-Met2 and the terminal amide. Stereochemical identity is established directly, not by a mass match. The snapshot names deltorphinII and describes YAFEVVG, a different family member with different formula, mass and terminal residue. Its identifiers are not retained as identifiers of deltorphinA.

Molecular form
Deltorphin A, D-Met2 and Asp7-amide
Species
Phyllomedusa sauvagei (name used in the original isolation paper)
Termini (N / C)
Free Tyr amino terminus / Asp carboxamide

Average reference mass · Molecular identity assessment: 2026-10-05

Reference policy updated: 2026-10-05

Full sequence with modifications

H-Tyr-D-Met-Phe-His-Leu-Met-Asp-NH2

Molecular formula
C44H62N10O10S2
Average reference mass
≈ 955.2
Backbone
Deltorphin A, D-Met2 and Asp7-amide
C-terminus
Asp carboxamide
Identifiers
  • PubChem CID: 3035060
  • CAS RN: 119975-64-3

Chemistry values: curated profile, PubChem.

Concentration math

Deltorphin — reconstitution calculator

Enter how much peptide is in the vial and how much diluent (e.g. bacteriostatic water) is added. The tool returns the resulting solution concentration — and, for any amount you type, the volume it corresponds to. This is educational arithmetic, not a dosing recommendation.

Reference form: Deltorphin A, D-Met2 and Asp7-amideAverage reference mass: 955.2 Da

Syringe graduation
Solution concentration
5 mg/mL5,000 mcg/mL
mcg

Enter an amount to see the volume it corresponds to.

Educational concentration mathematics only. This tool does not recommend a dose, amount, or protocol, and nothing here is medical advice. Many peptides are not authorized by Health Canada for human use — see our reconstitution and bacteriostatic-water guides for context.

Open the Deltorphin calculator on its own page →

Change log

Dated observations from the data pipeline (registry flags, trial footprints, identifiers) and editorial reviews of this profile.

  1. ChemistryPubChem formula updated to C44H62N10O10S2.

FAQ about Deltorphin

What is Deltorphin?+

Deltorphin (deltorphin A / dermenkephalin) is a naturally occurring opioid heptapeptide from Phyllomedusa frog skin and a potent, highly selective delta-opioid receptor agonist. Its D-methionine confers stability and notable blood-brain barrier penetration. It is a research peptide, and this page is educational only.

What Canadian product status is recorded for Deltorphin?+

Canadian product status for Deltorphin has not been verified in this profile. No verified record here does not mean no authorization exists. Status depends on the product, formulation and use; consult Health Canada's product records.

What is the length of the selected reference form for Deltorphin?+

The selected reference form (Deltorphin A, D-Met2 and Asp7-amide) has 7 residues or residue-derived units in its backbone. Other forms in this family may have a different length.

Related peptides

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Gut hormone
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Obestatin
Gut hormone
Obestatin is a 23-amino-acid peptide cleaved from the same preproghrelin precursor that produces ghrelin. It was originally proposed to oppose ghrelin's appetite-stimulating effects, though its physiology and receptor remain actively debated in the research literature.
Albiglutide
Incretin mimetic (GLP-1 receptor agonist)
Albiglutide is a GLP-1 receptor agonist created by genetically fusing two modified GLP-1 sequences to human serum albumin, giving it a long half-life suited to once-weekly dosing. Approved as Tanzeum and Eperzan in 2014, it was later withdrawn from the market for commercial reasons and is now a historical case study.
Neurotensin
Neuropeptide
Neurotensin is a 13-amino-acid neuropeptide found in the brain and gut. Research examines its interactions with dopamine signaling and its roles as a neuromodulator and local hormone.

References & further reading

  1. 1.Charpentier et al. (1991). Dermenkephalin and deltorphin I reveal similarities within ligand-binding domains of mu- and delta-opioid receptors and an additional address subsite on the delta-receptor. Biochem Biophys Res Commun
  2. 2.Misicka et al. (1992). Topographical requirements for delta opioid ligands: common structural features of dermenkephalin and deltorphin. Life Sci
  3. 3.Sagan et al. (1992). The aspartic acid in deltorphin I and dermenkephalin promotes targeting to delta-opioid receptor independently of receptor binding. Biochem Biophys Res Commun
  4. 4.Misicka et al. (1997). Synthesis and biological properties of beta-MePhe3 analogues of deltorphin I and dermenkephalin: influence of biased chi 1 Phe3 residues on peptide recognition for delta-opioid receptors. J Pept Res
  5. 5.Schiller et al. (1992). Conformationally restricted deltorphin analogues. J Med Chem
  6. 6.Joukal et al. (2020). Peripheral Deltorphin II Inhibits Nociceptors Following Nerve Injury. Front Pharmacol
  7. 7.Dai et al. (2008). Endogenous opioid peptides, endomorphin-1 and -2 and deltorphin I, stimulate angiogenesis in the CAM assay. Eur J Pharmacol
  8. 8.Naim et al. (1998). Solution conformations of deltorphin-I obtained from combined use of quantitative 2D-NMR and energy calculations: a comparison with dermenkephalin. J Pept Res
  9. 9.PubMed — Opioid peptides from frog skin (review, 9949868)
  10. 10.Wikipedia — Deltorphin
Disclaimer: Educational content only. Not medical advice. Not instructions for human use. Research peptides and unapproved products may be restricted or illegal to market for human consumption in your jurisdiction. Consult qualified professionals and applicable law.
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