Melanotan II is a conformationally constrained cyclic lactam analog of alpha-melanocyte-stimulating hormone (alpha-MSH), generated by side-chain cyclization of the alpha-MSH core message sequence to increase potency and metabolic stability relative to the linear parent hormone. It behaves as a non-selective agonist across melanocortin receptor subtypes, with reported activity at MC1R, MC3R, MC4R and MC5R. In preclinical and in vitro literature it is used as a pharmacological tool compound to probe melanocortin receptor signaling, melanogenesis in cultured melanocytes and amphibian skin bioassays, and MC3R/MC4R-mediated pathways in rodent models.

Purity: ≥ 99%
Form: Lyophilized powder
Class: Cyclic lactam-bridged heptapeptide
Storage: −20 °C, desiccated, dark

Also known as MT-II, MT2, MTII.

The research interest

How pigment-producing tissue responds to peptide signals.

What was studied

The selected paper tested related ring-shaped peptides in frog and lizard skin.

Evidence context

The source concerns related peptides and animal skin. The exact molecule and experimental setting matter.

Selected-source check, not a complete clinical review. No human-use recommendation.

Cyclic peptide, 7 residues. Blue basic · light blue acidic · gray polar · light gray nonpolar.

Ac-Nle-cyclo[Asp-His-D-Phe-Arg-Trp-Lys]-NH2 (side-chain lactam bridge between Asp and Lys; contains norleucine and D-phenylalanine, so no standard one-letter linear sequence applies). Commonly supplied as the acetate salt.

Identity

CAS number: 121062-08-6
Formula: C50H69N15O9
Molecular weight: 1024.2 g/mol
Chain length: 7 residues

Material

Purity, RP-HPLC: ≥ 99%
Form: Lyophilized powder
Appearance: White to off-white lyophilized powder (typically the acetate salt)
Vial sizes: 5 mg, 10 mg

Handling

Solubility: Soluble in water and aqueous buffers; soluble in DMSO and in dilute aqueous acetic acid. Limited solubility in nonpolar organic solvents.
Storage: Store lyophilized powder at -20 °C, desiccated and protected from light; -80 °C for long-term storage. Reconstituted stocks should be aliquoted, kept frozen, and protected from repeated freeze-thaw cycles; the Trp residue is light- and oxidation-sensitive.

Potent and prolonged acting cyclic lactam analogues of alpha-melanotropin: design based on molecular dynamicsPMID 2555512 · 1989

Citations describe published preclinical and in-vitro findings for this compound class and are not a representation about this material.

Research use only

All products listed on this site are supplied strictly as chemical reference materials for in-vitro laboratory research and are labelled For Research Use Only. They are not drugs, foods, cosmetics, or medical devices. They are not intended to diagnose, treat, cure, or prevent any condition, and are not for human or veterinary consumption or administration under any circumstances.

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Overview

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