Bremelanotide Bulk Powder for Research Applications

Introduction to Bremelanotide Bulk Powder

Bremelanotide is a synthetic cyclic heptapeptide designed as a potent and selective agonist of the melanocortin 4 receptor (MC4R). Derived from the endogenous melanocortin peptide α‑MSH, its primary sequence is Ac‑Nle‑cyclo[Asp‑His‑D‑Phe‑Arg‑Trp‑Lys]‑OH, with the cycle formed via a lactam bridge between the side chains of aspartic acid and lysine. This structural modification enhances metabolic stability and receptor selectivity compared to linear analogs. Bremelanotide bulk powder is supplied exclusively for laboratory research applications, offering the research community a well-characterized tool to explore melanocortin receptor biology.

Research on MC4R signaling has grown steadily since the receptor was identified as a key component in central neuroendocrine pathways and energy homeostasis in preclinical models. Bremelanotide’s high affinity and agonistic properties at MC4R make it a reference compound for in vitro pharmacological profiling, enabling scientists to dissect receptor binding, second‑messenger activation, and intracellular trafficking. All products sold under this offering are strictly for research use; they are not prepared, tested, or authorized for any human or veterinary administration, clinical investigation, or diagnostic procedure.

Chemical and Physical Properties

Bremelanotide bulk powder (CAS 189691‑06‑3) is provided as a white to off‑white lyophilized solid with the following defined characteristics:

• Molecular formula: C₅₀H₆₈N₁₄O₁₀
• Molecular weight: 1025.18 g/mol (anhydrous basis)
• Appearance: Free‑flowing, white to faintly cream-colored powder after lyophilization from aqueous solution
• Purity standard: ≥98% by reverse‑phase HPLC, with many lots meeting >99% area purity. Purity is determined by integration of the main peak relative to total peak area at 214 nm.

The peptide demonstrates good solubility in polar organic solvents such as dimethyl sulfoxide (DMSO) at concentrations exceeding 50 mg/mL. For aqueous experiments, stock solutions can be prepared at 1–2 mg/mL in sterile phosphate‑buffered saline or other buffered systems, often with gentle agitation and brief warming to 37 °C. Researchers should verify solubility in their specific assay media and avoid prolonged exposure to alkaline conditions that could promote racemization or hydrolysis.

Identity is routinely confirmed by electrospray ionization mass spectrometry (ESI‑MS), yielding a prominent [M+2H]²⁺ ion corresponding to the calculated mass. Peptide content is measured by quantitative amino acid analysis to correct for residual moisture and counterions. The product is supplied as a lyophilized powder that should be stored under the recommended conditions to maintain integrity.

Applications de la recherche

The primary research utility of Bremelanotide bulk powder lies in its ability to selectively activate MC4R in controlled in vitro environments. Because the melanocortin receptor family (MC1R through MC5R) mediates diverse physiological signals, researchers employ Bremelanotide to investigate the specific contribution of MC4R to cellular signaling cascades. Common applications include:

• Receptor‑binding assays: Competitive displacement of radiolabeled ligands (such as [¹²⁵I]‑NDP‑α‑MSH) from membranes of cells heterologously expressing MC4R. Bremelanotide typically exhibits low nanomolar binding affinity (K_i), providing a benchmark for evaluating novel ligands.
• Second‑messenger assays: Measurement of cAMP accumulation in MC4R‑transfected cell lines (e.g., HEK293, CHO‑K1) after exposure to the peptide. Functional data give EC₅₀ values in the sub‑nanomolar to low nanomolar range, depending on the expression system and assay conditions.
• Calcium mobilization studies: Fluorescent dye‑based (for example, Fluo‑4) detection of intracellular Ca²⁺ release, exploring the engagement of G_q‑coupled pathways alongside the canonical G_s pathway.
• Biased signaling analyses: Profiling of arrestin recruitment, receptor internalization, and mitogen‑activated protein kinase (MAPK) activation to delineate ligand‑directed signaling modalities.
• Pharmacological comparisons: As a reference agonist, Bremelanotide helps characterize new synthetic melanocortin peptides and small molecules in head‑to‑head experiments.

All of these applications are confined to laboratory‑scale research. The compound is not intended, qualified, or approved for any human or veterinary application, diagnostic use, or clinical study. Researchers should design experiments solely for investigational purposes and operate in accordance with institutional biosafety requirements.

Mechanism of Action in Research Contexts

At the molecular level, Bremelanotide acts as a high‑affinity ligand for MC4R, a class A G‑protein‑coupled receptor predominantly coupled to the stimulatory G protein G_αs. Binding of the peptide induces a conformational change that promotes guanine nucleotide exchange on G_αs, activating adenylyl cyclase and elevating intracellular cyclic adenosine monophosphate (cAMP). This cascade subsequently triggers protein kinase A (PKA) activation and phosphorylation of downstream targets. In multiple cell lines expressing recombinant MC4R, Bremelanotide elicits robust cAMP responses with reported EC₅₀ values typically between 0.5 and 2.0 nM.

In addition to the G_s‑mediated pathway, Bremelanotide can stimulate calcium flux in certain cellular backgrounds. This effect arises from coupling of MC4R to G_q/11 proteins, leading to phospholipase C‑β activation, inositol trisphosphate generation, and release of calcium from intracellular stores. The relative balance of G_s versus G_q activation is an active area of investigation, as it may reflect ligand‑biased signaling at the MC4R. The peptide’s activity is highly selective: in vitro binding and functional assays show that Bremelanotide has >100‑fold selectivity for MC4R over the closely related MC1R and MC5R subtypes, with negligible activation of MC2R and modest activity at MC3R. Such pharmacological fingerprinting helps researchers dissect the roles of individual melanocortin receptors in complex biological models.

Product Specifications and Quality Control

Bremelanotide bulk powder is manufactured under rigorous quality management systems suitable for research‑grade reagents. Each production batch undergoes a suite of analytical tests to verify identity, purity, and physical characteristics. The following specification points are typical for the product:

• HPLC purity: ≥98%. The chromatogram shows a single dominant peak with retention time consistent with the reference standard. Trace impurities are individually <1.0%.
• Mass spectrometry: Observed mass consistent with theoretical molecular weight (within ±0.5 Da). The ESI‑MS spectrum provides the expected multiply‑charged ion envelope.
• Peptide content: Determined by amino acid analysis or nitrogen determination, reported as net peptide weight per total product weight. Typical content >80%–85%, with the balance comprised of residual water and counterions.
• Solubility confirmation: A sample of the batch is dissolved in DMSO or aqueous buffer at a defined concentration to ensure complete dissolution without particulate matter.
• Appearance: White to off‑white powder without discoloration or clumping.

A Certificate of Analysis (CoA) accompanies each shipment, summarizing the actual results for the specific lot. Additional quality controls, such as endotoxin testing (acceptable limit <1.0 EU/mg upon request), residual solvent analysis, and trifluoroacetic acid content, can be performed for special orders. Long‑term stability under recommended storage conditions is supported by real‑time and accelerated aging studies; the product retains ≥97% purity for at least 24 months when stored according to the guidelines. Researchers should aliquot and store the material appropriately after initial opening to prevent repeated freeze‑thaw cycles that may accelerate degradation.

Packaging and Storage Guidelines

Bremelanotide bulk powder is dispensed into sealed, inert containers chosen to maintain peptide integrity during shipment and long‑term storage. For research quantities up to 10 grams, the standard container is a clear borosilicate glass vial with a PTFE‑lined screw cap, backfilled with dry argon or nitrogen to displace oxygen and moisture. Multi‑gram bulk orders may be packaged in high‑density polyethylene (HDPE) bottles with a desiccant pouch, further protected inside a secondary aluminum‑foil barrier bag. All containers bear a label with product name, lot number, net weight, and storage instructions.

Recommended storage conditions are as follows:

• Temperature: –20 °C (±5 °C) in a non‑frost‑free freezer. Brief excursions during shipment at ambient temperature are acceptable provided the material is promptly placed at –20 °C upon receipt.
• Humidity control: Keep the container tightly closed and desiccated. Exposure to ambient moisture can lead to peptide aggregation and loss of solubility.
• Light protection: Store in the original opaque secondary packaging or wrap the container in aluminum foil to prevent photodegradation.

Under these conditions, the shelf life is 24 months from the date of manufacture. After reconstitution in a solvent, solutions should be used immediately or aliquoted into single‑use volumes and stored at –20 °C. Avoid repeated freeze‑thaw cycles, as they can cause precipitation and reduced biological activity. Laboratory personnel handling Bremelanotide powder or solutions should wear appropriate personal protective equipment, including nitrile gloves, safety goggles, and a lab coat. Weighing and dissolution procedures should be performed in a fume hood or biosafety cabinet to minimize aerosol inhalation and cross‑contamination. Spills should be cleaned immediately following institutional chemical hygiene protocols.

Ordering Information

Bremelanotide bulk powder is offered to qualified research institutions, pharmaceutical companies, and authorized distributors. The standard minimum order quantity is 1 gram, though smaller sample amounts may be available for preliminary method development on a case‑by‑case basis. Larger scale requirements (tens to hundreds of grams or kilograms) can be accommodated through custom synthesis runs, providing batch‑to‑batch consistency essential for multi‑phase research programs.

Typical lead time from confirmation of order to dispatch is 5 to 10 business days for quantities up to 100 grams. Larger orders or those requiring additional quality tests may extend the lead time slightly; an estimated production schedule is communicated at the time of quotation.

Researchers can request custom specifications, such as purity higher than 99% by HPLC, defined counterion (e.g., acetate instead of trifluoroacetate), or packaging suitable for automated dispensing systems. All custom requests are subject to a feasibility assessment. For pricing, bulk discounts, and lot reservations, interested parties should contact the sales department with the required quantity, desired purity, and any specific analytical deliverables beyond the standard CoA. The supplier does not distribute Bremelanotide for any purpose that would involve administration to humans or animals; all inquiries must confirm that the intended use is solely for laboratory research.

Regulatory and Compliance Notes

This Bremelanotide bulk powder is produced as a research chemical and is explicitly labeled “For Research Use Only. Not for Human or Veterinary Use.” It has not been evaluated by any regulatory authority for use as a pharmaceutical ingredient, medical device component, or diagnostic reagent. No representation is made regarding its performance in clinical applications, its ability to detect any physiological condition, or its safety when administered to living organisms. The product is intended exclusively for in vitro experiments performed by trained technical staff within properly equipped laboratories.

Purchasers are expected to be familiar with and comply with all applicable local, national, and international regulations governing the import, storage, handling, and disposal of research peptides. This includes adherence to guidelines on occupational safety, controlled substances, and dual‑use materials where relevant. The supplier will not knowingly sell this compound to individuals or organizations that intend to use it for non‑research purposes. Any deviation from the stated research‑use restriction constitutes a breach of the terms of sale and may void the warranty and liability protections. Shipments are accompanied by a safety data sheet (SDS) outlining proper handling and emergency procedures.

À usage exclusivement scientifique : This product is intended strictly for in vitro laboratory research. It is not for use in humans, animals, or any clinical, diagnostic, or interventional procedure. Researchers must handle it in accordance with institutional safety guidelines and relevant regulatory requirements. No therapeutic claims, clinical performance assertions, or medical applications are associated with this chemical.