| Target Molecule | Carbetocin |
| Synonyms | Duratocin, Pabal, Lonactene, Depotocin, d(COMOT) |
| CAS Number | 37025-55-1 (free base); 1631754-28-3, 1936459-26-5 (acetate salts) |
| Sequence (3-Letter) | But-Tyr(Me)-Ile-Gln-Asn-Cys-Pro-Leu-Gly-NH₂ (cyclic But1–Cys6 thioether) |
| Sequence (1-Letter) | But-Y(Me)IQNCPLG-NH₂ (thioether bridge But1–Cys6) |
| Molecular Formula | C₄₅H₆₉N₁₁O₁₂S (free base) |
| Molecular Weight | 988.16 (free base) |
| Service Category | Custom Peptide Synthesis / CDMO Manufacturing |
| Synthesis Purity | Customizable (e.g., ≥95%, ≥98% via HPLC) |
| Appearance | White to off-white lyophilized powder |
| Counter Ion | Acetate (standard pharmaceutical salt), TFA, or custom options |
| Synthesis Technology | Solid-Phase Peptide Synthesis (SPPS) and On-Resin Thioether (Carba) Cyclization |
| Modification Options | Thioether bridge formation, Tyr O-methylation, stable isotope labeling (13C, 15N), linear precursor impurity standards |
| Available Scale | Milligram (R&D) to Kilogram (Commercial CDMO) |
| Analytical Data | Comprehensive COA, HPLC, MS, and thioether connectivity verification provided per batch |
| Usage | Raw material synthesized strictly for laboratory research, analytical development, and industrial formulation. Not a finished medicine. |
Carbetocin (CAS 37025-55-1) is a synthetic oxytocin analogue featuring a rigid, enzyme-resistant thioether (carba) bridge between But1 and Cys6, alongside O-methylation of Tyr2. We target this sequence to supply high-purity reference materials and raw materials for obstetrics and uterine receptor research.
Forming the thioether bridge requires precise on-resin intramolecular nucleophilic substitution rather than standard disulfide oxidation. Our peptide synthesis platform utilizes optimized Solid-Phase Peptide Synthesis (SPPS) protocols and controlled base-catalyzed cyclization to ensure complete ring closure without polymeric side products.
Yes. We provide specialized peptide modification services for oxytocin analogues. Options include the synthesis of uncyclized linear precursors as critical impurity reference standards, site-specific stable isotope labeling (13C, 15N) for quantitative mass spectrometry (LC-MS/MS), and demethylated impurity controls.
Our manufacturing infrastructure scales production from milligram-level analytical batches to multigram and kilogram commercial quantities. We optimize preparative HPLC purification and controlled counter-ion exchange (ensuring acetate salt conversion) to guarantee strict batch-to-batch consistency.
We operate as an integrated technical partner providing complete peptide CDMO solutions. Our team manages sequence optimization, thioether verification, impurity profiling, analytical method validation, and regulatory documentation to support complex drug development pipelines.
Carbetocin (CAS 37025-55-1), commercialized under trade names such as Duratocin and Pabal, is a synthetic oxytocin analogue functioning as a long-acting uterotonic agent. Defined by the sequence But-Tyr(Me)-Ile-Gln-Asn-Cys-Pro-Leu-Gly-NH₂ with a But1–Cys6 thioether bridge, it exhibits enhanced metabolic stability compared to native oxytocin. Synpeptide delivers comprehensive custom synthesis solutions for this target molecule, demonstrating advanced technical expertise in carba-cyclization chemistries, non-standard amino acid assembly, and CDMO manufacturing.
Constructing Carbetocin presents distinct synthetic hurdles due to the substitution of the labile disulfide bond with a non-reducible thioether bridge. This requires an omega-halo-butyric acid coupled at the N-terminus followed by intramolecular nucleophilic attack by the Cys6 thiol. Our custom peptide synthesis platform resolves these hurdles using optimized Solid-Phase Peptide Synthesis (SPPS) protocols and precisely controlled base-catalyzed cyclization regimes. By regulating reaction kinetics, we suppress polymeric oligomers and deliver raw materials with rigorous purity specifications (typically ≥95% or ≥98% via HPLC).
Precise pharmacological profiling and method validation require distinct analytical controls. Through our peptide modification services, we synthesize uncyclized linear precursors and demethylated variants as essential reference standards for stability-indicating assays. We also incorporate heavy stable isotopes (13C, 15N) for quantitative bioanalysis and fluorescent labels for receptor localization studies.
Transitioning a carba-cyclic peptide from analytical scale to commercial volume demands robust downstream process engineering. We execute large-scale peptide synthesis for Carbetocin utilizing continuous-flow reactor systems and high-capacity preparative HPLC purification. Our facilities accommodate requirements from milligram research batches to kilogram commercial lots, ensuring uniform counter-ion exchange (consistently achieving the pharmaceutical acetate salt form) across all production volumes.
We deliver comprehensive technical support as a fully integrated peptide CDMO. Our development specialists assist pharmaceutical partners with process optimization, stability testing, impurity identification, and analytical method validation. Every batch is released with complete analytical documentation—including COA, HPLC purity traces, and exact mass confirmation—ensuring regulatory alignment for downstream therapeutic programs.
