Melanotan 2 (меланотан) is a synthetic cyclic heptapeptide melanocortin receptor agonist evaluated in preclinical models of melanogenesis and skin pigmentation response. Accurately determining its chemical solubility limits, reconstituted stability, and solvent selection is essential for preserving peptide integrity during in vitro assays. PX1 Research provides high-purity, US-manufactured research compounds verified by lot-specific third-party analytical certification.
Melanotan 2 (меланотан) is a synthetic cyclic heptapeptide melanocortin receptor agonist evaluated in preclinical models of melanogenesis and skin pigmentation response. Accurately determining its chemical solubility limits, reconstituted stability, and solvent selection is essential for preserving peptide integrity during in vitro assays. PX1 Research provides high-purity, US-manufactured research compounds verified by lot-specific third-party analytical certification.
In laboratory settings, меланотан (Melanotan 2, CAS 121062-08-6) exhibits high aqueous solubility due to its cyclic structure and basic amino acid residues. Reconstitution yields clear, colorless solutions when introduced to sterile aqueous diluents such as bacteriostatic water (0.9% benzyl alcohol) or standard physiological saline at concentrations up to 10 mg/mL. For specialized cellular assays requiring non-aqueous systems, stock solutions may be initially prepared in dimethyl sulfoxide (DMSO) before secondary diluent expansion.
The molecular formula of Melanotan 2 acetate is C50H69N15O9 with a molecular weight of approximately 1024.2 g/mol. As a non-selective melanocortin receptor agonist, research compounds like melanotan 2 exhibit affinity for MC1R, MC3R, MC4R, and MC5R. In preclinical protocols, researchers must consider how target concentration, pH, and ionic strength influence solubility rates and structural stability during in vitro research.
Melanotan 2 is a synthetic analog of alpha-melanocyte-stimulating hormone (α-MSH). Its chemical framework incorporates a lactam bridge between Lys6 and Asp10, yielding a rigid cyclic structure (Ac-Nle-cyclo[Asp-His-D-Phe-Arg-Trp-Lys]-NH2). This structural modification significantly enhances enzymatic resistance against aminopeptidases compared to native linear peptides.
Preclinical studies suggest that binding of меланотан to the cutaneous MC1R subtype stimulates adenylate cyclase activity, triggering intracellular cyclic adenosine monophosphate (cAMP) accumulation. This downstream signal cascade enhances tyrosinase expression in melanocyte cultures, driving melanogenesis. Scientists studying the broader melanocortin receptor agonist family utilize high-purity lyophilized powders to evaluate receptor signaling kinetics and pigment cell differentiation without structural interference from degraded sequences.
Selecting the correct solvent depends on the planned experimental duration and protocol requirements. For short-term assays conducted within 24 hours, sterile water for injection (SWFI) or phosphate-buffered saline (PBS, pH 7.4) is generally appropriate. However, for extended multi-day multi-well assays requiring repeated sampling from a single vial, bacteriostatic water is preferred to prevent microbial proliferation.
When preparing stock solutions of меланотан at elevated concentrations (>15 mg/mL) or under low-temperature storage parameters, pure aqueous solvents may exhibit slow dissolution rates. In these specialized instances, dissolving the lyophilized powder in molecular-grade DMSO (1–2% final assay concentration) prior to aqueous dilution prevents aggregation. Researchers should consult our detailed peptide solubility guide for specific concentration thresholds and solvent polarity considerations.
To preserve the tertiary conformation of меланотан during reconstitution, laboratory personnel should adhere to standardized aseptic protocol. Prior to diluent introduction, allow the lyophilized peptide vial to reach ambient room temperature (20°C to 25°C) to prevent moisture condensation upon opening or puncturing the stopper.
Using a sterile syringe, slowly inject the designated volume of diluent against the inner glass wall of the vial rather than directing the stream straight into the lyophilized cake. Gently swirl the vial in a circular motion until the cake dissolves completely. Avoid vigorous vortexing or rapid agitation, as mechanical shear stress can induce peptide denaturation or visible aggregation. For additional technical background on handling research peptides, review our bacteriostatic water reconstitution guide.
Melanotan 2 belongs to a distinct class of melanocortin analogs, sharing structural homology with several related compounds studied in pigment and neuro-receptor signaling research. Below is a comparative overview of key peptides in this research class:
While melanotan 1 (Afamelanotide) is a linear peptide exhibiting high selectivity for MC1R, меланотан (MT-2) features a cyclic backbone that increases its receptor half-life and potency across multiple receptor subtypes (MC1R, MC3R, MC4R, MC5R). Similarly, pt-141 (Bremelanotide)—a hydroxylated derivative of MT-2—exhibits altered receptor selectivity profiles favoring MC3R and MC4R pathways over MC1R. Another melanocortin-related fragment, kpv, acts primarily on inflammatory signalling pathways without inducing melanogenic activity. Researchers evaluating melanocortin activity choose among these analogs based on target receptor affinity and aqueous stability profiles.
Lyophilized меланотан powder demonstrates exceptional thermal stability when stored dry at -20°C or -80°C, remaining stable for up to 24 months. Protect lyophilized vials from direct light exposure to prevent photo-oxidation of tryptophan and histidine residues within the peptide sequence.
Once reconstituted in bacteriostatic water, aqueous stock solutions of меланотан remain chemically stable at 2°C to 8°C for approximately 30 to 45 days. If long-term storage of reconstituted solutions is necessary, aliquot the stock solution into single-use polypropylene microtubes and store at -80°C to prevent freeze-thaw cycles. Repeated freezing and thawing causes ice crystal formation that degrades the peptide chain, leading to fragments detectable via high-performance liquid chromatography (HPLC).
Assay reproducibility relies entirely on compound purity and lot consistency. PX1 Research enforces stringent quality control measures for every lot of меланотан manufactured in our US-based facilities. Each batch undergoes rigorous testing prior to release to ensure compliance with strict scientific specifications:
Purity is verified via Reverse-Phase High-Performance Liquid Chromatography (RP-HPLC), ensuring a purity rating of ≥99.0%. Mass Spectrometry (ESI-MS) confirms exact molecular mass matching the theoretical sequence of Melanotan 2 acetate. Furthermore, every lot is subjected to Chromogenic LAL testing to ensure endotoxin levels remain strictly below <0.01 EU/mg, minimizing cell culture interference. Researchers can inspect verifiable, lot-specific Certificates of Analysis (COAs) directly on our platform prior to sourcing all peptides.
Academic institutions, biotechnology firms, and contract research organizations (CROs) require reliable supply chains and verifiable quality. PX1 Research operates ISO 17025 accredited analytical facilities and GMP-compliant manufacturing setups in California and Arizona to support institutional research needs.
All orders placed Monday through Friday ship same-day, ensuring fast transit times and minimal exposure to adverse environmental conditions during transport. Facilities conducting large-scale preclinical studies or screening libraries can access standardized institutional pricing through our wholesale lab account portal.
What is the precise solubility of меланотан (Melanotan 2) in water?
In laboratory conditions, lyophilized меланотан powder is readily soluble in sterile water, bacteriostatic water, and physiological saline at concentrations up to 10 mg/mL. Complete dissolution typically occurs within 30 to 60 seconds of gentle swirling at room temperature.
How should меланотан be reconstituted for cell culture assays?
For cell culture assays, reconstitute the peptide using sterile bacteriostatic water or sterile phosphate-buffered saline (PBS, pH 7.4). Add the diluent down the inner vial wall and gently swirl until dissolved. Avoid vortexing to prevent mechanical shearing of the peptide.
What is the recommended storage temperature for lyophilized меланотан?
Lyophilized меланотан should be stored at -20°C or -80°C in a desiccated, dark environment. Sealed lyophilized vials remain stable for up to 24 months under these storage conditions.
How long does reconstituted меланотан remain stable in solution?
When reconstituted in bacteriostatic water (0.9% benzyl alcohol) and maintained at 2°C to 8°C, aqueous solutions remain stable for up to 30–45 days. Aliquot and store at -80°C for longer storage intervals to avoid freeze-thaw degradation.
Is organic solvent required to dissolve меланотан?
Organic solvents such as DMSO are generally not required for standard aqueous preparations because меланотан is highly hydrophilic. However, if preparing stock solutions above 15 mg/mL, an initial dissolution in 100% DMSO followed by dilution in aqueous buffer can be utilized.
What third-party testing does PX1 Research perform on меланотан?
Every lot of меланотан undergoes RP-HPLC testing for purity (≥99%), Electrospray Ionization Mass Spectrometry (ESI-MS) for sequence identification, and Chromogenic LAL assay for endotoxin quantification (<0.01 EU/mg).
How does меланотан differ structurally from Melanotan 1?
Melanotan 1 (Afamelanotide) is a linear peptide selective for MC1R. меланотан (Melanotan 2) is a cyclic heptapeptide that exhibits structural stabilization via a lactam bridge, resulting in broad affinity across MC1R, MC3R, MC4R, and MC5R.
Can reconstituted меланотан undergo repeated freeze-thaw cycles?
No. Repeated freeze-thaw cycles cause physical stress that leads to peptide aggregation and chain cleavage. Reconstituted stock solutions should be divided into single-use aliquots before freezing.
Where are PX1 Research peptides manufactured and shipped from?
All PX1 Research compounds are manufactured in US-based, GMP-compliant facilities. Orders are fulfilled and shipped same-day (Monday through Friday) from our logistics centers located in California and Arizona.
Is меланотан intended for human consumption or therapeutic use?
No. All compounds provided by PX1 Research, including меланотан, are strictly for laboratory research, in vitro experimentation, and preclinical scientific study. They are not intended for human or animal therapeutic, diagnostic, or clinical use.
All products are sold strictly for laboratory and research use only. Not for human or veterinary use, diagnosis, treatment or consumption. Statements have not been evaluated by the FDA.