Professional Product Parameters of CAS 189691-06-3 (Bremelanotide / PT-141)

1. Basic Identification

• CAS No.: 189691-06-3 (free base); Acetate CAS: 1607799-13-2
• Product Name: Bremelanotide, PT-141
• IUPAC Name: (3S,6S,9R,12S,15S,23S)-9-benzyl-6-(3-carbamimidamidopropyl)-15-[(2S)-2-acetamidohexanamido]-12-(1H-imidazol-4-ylmethyl)-3-(1H-indol-3-ylmethyl)-2,5,8,11,14,17-hexaoxo-1,4,7,10,13,18-hexaazacyclotricosane-23-carboxylic acid
• Peptide Sequence: Ac-Nle-cyclo(-Asp-His-D-Phe-Arg-Trp-Lys)-OH
• Synonyms: PT141, Melanotan II derivative, Bremelanotide free base
• MDL Number: MFCD28971567
• InChIKey: UJOMLYQZGUYTKV-YICQRVHDSA-N

2. Chemical Data

• Molecular Formula: C??H??N??O??
• Molecular Weight: 1025.16 g/mol
• Exact Mass: 1024.5243
• Calculated LogP: -0.85
• TPSA: 370.70 ?2
• Hydrogen Bond Donors: 12
• Hydrogen Bond Acceptors: 24
• Rotatable Bonds: 22

3. Physical & Chemical Properties

• Appearance: White to off-white crystalline powder (free base); white lyophilized powder (acetate salt)
• Solubility: Acetate salt soluble in water ≥10 mg/mL; soluble in DMSO and methanol; poorly soluble in hexane, ether and chloroform; free base slightly soluble in water
• Melting Point: 220–230 °C (decomposes)
• Aqueous pH (1% acetate solution): 4.0–6.0
• Stability: Sensitive to light, heat and oxidation; hygroscopic; aqueous solution unstable, prepare fresh before use
• Storage Condition: Long-term storage at -20 °C; short-term storage at 2–8 °C; sealed, dry, light-proof, filled with inert gas

4. Product Specifications

• Purity: ≥98.0% by HPLC; ≥99.0% for pharmaceutical API grade
• Single maximum impurity: ≤1.0%
• Peptide content: ≥80.0%
• Acetate content: ≤10.0%
• Moisture: ≤8.0%
• Heavy metals total: ≤10 ppm; Pb ≤0.5 ppm, Cd ≤2.5 ppm, Hg ≤1.5 ppm, As ≤0.15 ppm
• Residue on ignition: ≤1.0%
• Product Grade: Research grade / Pharmaceutical API grade
• Standard Packing: 1 mg, 5 mg, 10 mg, 25 mg, 100 mg, 1 g (lyophilized, aluminum foil bag); bulk drum packaging

5. Biological Function & Applications

• Mechanism: Melanocortin receptor agonist (MC1R, MC3R, MC4R), mainly activates central MC4R to regulate sexual desire, dopamine release and energy metabolism
• Core Bioactivity: Approved by FDA for treating female hypoactive sexual desire disorder (HSDD); regulates food intake, body weight and energy balance; applied in neuroprotection, anti-inflammation and metabolic disorder research
• Applications: Commercial drug API (Vyleesi?); research reagent for sexual medicine, neuropeptide, obesity and metabolic disease study; intermediate for peptide drug structural modification

6. Safety & Handling Instructions

• GHS Hazard Classification: Non-hazardous chemical; no severe acute toxicity reported
• Operation Tips: Avoid inhalation, skin and eye contact; operate in well-ventilated fume hood with full protective equipment
• Waste Disposal: Dispose in accordance with local chemical waste regulations
• Reminder: Only for laboratory research and pharmaceutical development, unauthorized human administration is prohibited