Salcie: Melanotan 2 Molecular Weight, Sequence, and Chemical Specifications

Chemical Identity and Structural Overview of Salcie and Melanotan 2

In analytical biochemistry and reference literature, queries surrounding salcie often intersect with the structural characterization of Melanotan 2 (MT-2). Melanotan 2 is a synthetic, cyclic lactam analog of the naturally occurring alpha-melanocyte-stimulating hormone (α-MSH). Its chemical structure is engineered to enhance metabolic stability and receptor binding affinity across melanocortin receptor subtypes in cell culture and animal models.

The canonical sequence for Melanotan 2 is defined as Ac-Nle-cyclo[Asp-His-D-Phe-Arg-Trp-Lys]-NH2. The inclusion of a norleucine (Nle) residue at position 4 and a D-phenylalanine (D-Phe) substitution at position 7 confers resistance to enzymatic degradation by central and peripheral proteases. The cyclic core, formed by a lactam bridge between the side chains of aspartic acid (Asp) and lysine (Lys), stabilizes the bioactive beta-turn conformation required for potent receptor engagement. Researchers reviewing the Melanotan 2 research compound can access detailed lot analytical certificates validating these structural features.

Molecular Weight, Formula, and Mass Spectrometry Specifications

Accurate mass determination is critical for quantitative solution preparation, mass spectrometry verification, and molarity calculations in assays evaluating melanocortin activity related to skin pigmentation responses. The monoisotopic mass and chemical parameters for pure Melanotan 2 are defined below:

• Chemical Formula: C50H69N15O9 • Molecular Weight: 1024.18 g/mol (1024.2 Da) • Monoisotopic Mass: 1023.53 g/mol • CAS Registry Number: 121062-08-6 • Chemical Name: Ac-Nle-cyclo[Asp-His-D-Phe-Arg-Trp-Lys]-NH2 • Core Mechanism: Non-selective melanocortin receptor agonist (MC1R, MC3R, MC4R, MC5R)

During electrospray ionization mass spectrometry (ESI-MS), the compound typically produces a dominant protonated ion peak at [M+H]+ m/z 1024.5 or doubly charged species at [M+2H]2+ m/z 512.8. Confirming these mass spectral signatures ensures that batches are free from incomplete coupling sequences or truncated peptide fragments. Researchers interested in broader peptide catalog metrics can explore all research peptides for comparison.

Comparative Analysis of Melanocortin Receptor Class Peptides

Melanotan 2 belongs to a distinct class of synthetic melanocortin analogs designed to probe receptor subtype selectivity and downstream melanogenic signaling pathways. Evaluating structural modifications across related peptides clarifies variations in molecular weight, receptor binding profiles, and enzymatic stability in laboratory protocols.

When designing comparative assays, researchers frequently contrast Melanotan 2 with related analogs such as afamelanotide Melanotan 1, bremelanotide PT-141, and the anti-inflammatory tripeptide KPV research compound. Melanotan 1 (Ac-Ser-Tyr-Ser-Nle-Glu-His-D-Phe-Arg-Trp-Gly-Lys-Pro-Val-NH2) is a linear tridecapeptide with a significantly higher molecular weight of 1646.85 g/mol, which preferentially activates MC1R. Conversely, PT-141 shares the cyclic heptapeptide core of Melanotan 2 (MW 1024.18 g/mol) but possesses a hydroxylated terminal structure evaluated primarily in central melanocortin pathway assays. Understanding these structural divergences allows investigators to select the exact molecular tool required for targeted melanocortin signaling experiments.

Analytical Purity Verification and Quality Control Criteria

To ensure experimental reproducibility across in vitro cell culture models and tissue preparations, PX1 Research subjects every synthesis lot to rigorous analytical validation in ISO 17025 accredited testing facilities. High-Performance Liquid Chromatography (RP-HPLC) and Mass Spectrometry (MS) are performed independently for every production batch.

Quality assurance benchmarks for PX1 Research compounds include: • Purity Assessment: Reverse-phase HPLC demonstrating ≥99% chromatographic purity. • Mass Verification: Electrospray ionization mass spectrometry matching theoretical molecular weight (1024.18 g/mol). • Endotoxin Control: Kinetic chromogenic LAL assay confirming endotoxin levels <0.01 EU/mg to prevent confounding immune responses in cell cultures. • Residual Solvents: Gas chromatography verification ensuring complete removal of synthesis reagents such as trifluoroacetic acid (TFA) and acetonitrile. • Manufacturing Origin: Synthesized in USA-based GMP-compliant facilities with full lot traceability.

Preclinical Research Context: Melanocortin Activity and Melanogenesis

Preclinical studies suggest that synthetic melanocortin analogs like Melanotan 2 serve as vital tools for investigating melanocortin receptor signaling cascades. The primary target in cutaneous pigmentary research is the melanocortin-1 receptor (MC1R), a G-protein coupled receptor expressed on dermal melanocytes.

In vitro data indicate that activation of MC1R by cyclic melanocortin analogs stimulates membrane-bound adenylyl cyclase, inducing an intracellular increase in cyclic adenosine monophosphate (cAMP). This upregulation activates protein kinase A (PKA), which subsequently phosphorylates the microphthalmia-associated transcription factor (MITF). MITF drives the transcription of key melanogenic enzymes, including tyrosinase, tyrosinase-related protein 1 (TYRP1), and dopachrome tautomerase (DCT), leading to synthesized eumelanin production in experimental cell cultures. Detailed biological pathway breakdowns are archived in the peptide research hub.

Laboratory Reconstitution and Solubilization Standards

Melanotan 2 is supplied as a lyophilized (freeze-dried) sterile powder to ensure maximum chemical stability during transit and long-term storage. Reconstitution protocols must follow strict aseptic technique within a certified laminar flow cabinet to preserve peptide integrity and prevent microbial contamination.

For biochemical assays, sterile bacteriostatic water or sterile phosphate-buffered saline (PBS, pH 7.4) is typically employed as the reconstituting solvent. Reconstitution should involve gently introducing the solvent along the inner glass wall of the vial, followed by mild swirling. Mechanical agitation, vortexing, or violent shaking must be avoided, as shear forces can disrupt the tertiary structure or cause peptide aggregation. Technical protocols detailing reconstituted solution handling are outlined in our reconstitution protocols guide.

Handling and Storage Protocols for Lyophilized Compounds

Proper temperature control is essential to prevent hydrolytic cleavage or oxidation of sensitive amino acid residues (such as tryptophan and histidine) within the Melanotan 2 sequence. Laboratories should implement standardized storage conditions based on compound status:

• Unreconstituted Lyophilized Powder: Store at -20°C to -80°C in a dry, dark environment. Under these conditions, the compound remains stable for up to 24 months. • Reconstituted Liquid Solution: Maintain at 2°C to 8°C for short-term experimental windows (up to 30 days). For extended utility, aliquot into single-use polypropylene tubes and freeze at -80°C to minimize freeze-thaw degradation. • Light Sensitivity: Protect both lyophilized powder and reconstituted solutions from direct light exposure due to the photosensitive indole ring of the tryptophan residue.

Comprehensive guidelines on cold-chain stability are documented in the lyophilized peptide storage protocols. Academic and institutional laboratories requiring bulk allocations can review terms through wholesale lab accounts.

PX1 Research Supply Chain and Shipping Commitments

Reliable scientific data requires uncompromised reference materials. PX1 Research maintains full control over synthesis, purification, and distribution workflows within the United States. All order fulfillment originates directly from specialized logistics hubs in California and Arizona.

Orders placed before cutoff times Monday through Friday receive same-day dispatch, reducing transit exposure and ensuring compound degradation is avoided. Every unit is accompanied by a downloadable, lot-specific Certificate of Analysis (COA) detailing HPLC purity percentages and ESI-MS mass verification, giving laboratory researchers absolute confidence in their experimental inputs.