| Product Name | Atosiban |
| Synonyms | [Mpa1, D-Tyr(Et)2, Thr4, Orn8]-oxytocin; RWJ-22164; ORF 22164; desamino-oxytocin analogue; Atosiban Impurity (catalogue name) |
| CAS Number | 90779-69-4 (free peptide); 914453-95-5 (acetate) |
| Sequence (3-Letter) | Mpa-D-Tyr(Et)-Ile-Thr-Asn-Cys-Pro-Orn-Gly-NH2 |
| Modified Residues | N-terminal 3-mercaptopropionic acid (Mpa, deamino-Cys); O-ethyl-D-tyrosine at position 2; L-ornithine at position 8; C-terminal amide |
| Disulfide Bridge | Mpa1–Cys6 (intramolecular) |
| Molecular Formula | C₄₃H₆₇N₁₁O₁₂S₂ |
| Molecular Weight | 994.2 |
| Category | Drug Peptide Impurity / Reference Standard – atosiban (oxytocin receptor antagonist) |
| Purity | ≥98% (by HPLC); reference-standard and pharmaceutical-grade specifications available |
| Appearance | White to off-white lyophilized powder |
| Counter Ion | Acetate (per specification) |
| Disulfide Bridge | Mpa1–Cys6 (intramolecular) |
| Water Content | Per specification (Karl Fischer) |
| Related Substances | Characterised per specification; named impurity / related-substance reference standards available |
| Storage | -20°C, desiccated, protected from light |
| Available Scale | mg quantities (reference-standard and research); larger scale on enquiry |
| QC Documentation | COA, HPLC, MS identity; extended characterisation (related substances, peptide content) on request |
| Usage | For research and pharmaceutical analytical / quality-control use only, including as a reference standard for identity and related-substance testing. Not for human or veterinary use; not for sale to patients or individuals. Customers are responsible for regulatory and intellectual-property compliance in their territory. |
Atosiban is a cyclic nine-residue oxytocin and vasopressin receptor antagonist with CAS 90779-69-4 and the molecular formula C43H67N11O12S2. It is a modified oxytocin, with the sequence Mpa-D-Tyr(Et)-Ile-Thr-Asn-Cys-Pro-Orn-Gly-NH2, a C-terminal amide, and an intramolecular disulfide bridge between the N-terminal mercaptopropionic acid and the cysteine at position six. We make it in-house and supply it as a synthetic lyophilized powder for research and analytical use, including as a reference standard.
Analytical and quality-control work needs a well-characterised reference standard of the active peptide to confirm identity, calibrate assays, and run system-suitability and related-substance tests. Atosiban reference material is used this way in the control of atosiban drug substances and products. We supply it with full identity and purity data so it can serve as the parent reference alongside named impurity standards.
Atosiban is a small, disulfide-bridged, amidated peptide with several modified residues, so it can form a defined set of related substances during synthesis and storage. Common ones include disulfide-bond isomers and the open-chain reduced form, diastereomers from racemisation, deamidation and truncated species, and dimers. These are controlled in pharmacopoeial and in-house methods, and we can prepare named impurity and related-substance reference standards alongside the parent peptide for method development and stability work.
We supply Atosiban as a synthetic peptide at high HPLC purity with a certificate of analysis, an HPLC chromatogram, and mass-spec identity confirmation. Reference-standard and pharmaceutical-grade specifications are available, including extended characterisation of related substances. Salt form, purity, and quantity can be set to your specification.
No. Atosiban supplied by SynPeptide is a raw material for research and pharmaceutical development, analysis, and manufacturing only. It is not a finished medicine, it is not for human or veterinary use, and it is not sold to patients or individuals for personal use. Any clinical or commercial medicinal use is the responsibility of an appropriately licensed party and is subject to the relevant regulatory approvals.
Atosiban (CAS 90779-69-4) is a cyclic nonapeptide antagonist of the oxytocin and vasopressin V1A receptors and a well-established peptide drug substance in obstetric research. In a peptide impurity and reference-standard programme it is the parent compound against which related substances are measured, and we supply it as a synthetic peptide for research, analytical, and quality-control use, including as a reference standard. It is not supplied as a finished medicine and not for human use.
Atosiban is a modified oxytocin with the sequence Mpa-D-Tyr(Et)-Ile-Thr-Asn-Cys-Pro-Orn-Gly-NH2, a C-terminal amide, and an intramolecular disulfide bridge between the N-terminal 3-mercaptopropionic acid and Cys6. It is the oxytocin sequence changed at four positions: a deamino N-terminus, an O-ethyl-D-tyrosine, a threonine at position 4, and an ornithine at position 8. These changes turn the agonist hormone into a receptor antagonist. Its molecular formula is C43H67N11O12S2 and its molecular weight is about 994.2.
Regulated peptide manufacturing needs reference standards to confirm identity, calibrate assays, and run system-suitability and related-substance tests. As a peptide drug substance with pharmacopoeial monographs, atosiban is routinely controlled this way. We supply well-characterised atosiban reference material with full identity and purity data, so it can serve as the parent reference alongside named impurity standards in method development, release testing, and stability studies.
Atosiban is a small, disulfide-bridged, amidated peptide with several modified residues, so it can form a characteristic set of related substances during synthesis, purification, and storage. Typical ones include disulfide-bond isomers and the reduced open-chain form, diastereomers from racemisation, deamidation products, truncated and deletion sequences, and dimers, along with closely related oxytocin-type sequences that analytical methods must resolve. These are the species that pharmacopoeial and in-house related-substance methods are designed to separate and limit, and we can prepare named impurity and related-substance reference standards to order.
Atosiban is a competitive antagonist at the oxytocin receptor and the vasopressin V1A receptor, both G-protein-coupled receptors. By blocking the oxytocin receptor in the uterus it reduces oxytocin-driven signalling and uterine contractions, which is the basis for its research and clinical use as a tocolytic in preterm labour. This is provided as factual background; the material we supply is for research and analytical use, not for human or veterinary use, not for sale to patients, and carries no health or therapeutic claims.
Store the lyophilized peptide at -20°C, kept dry and protected from light. Because the molecule depends on its Mpa1–Cys6 disulfide bridge, avoid reducing conditions and strong oxidants that could open or scramble the bond, and note that the asparagine residue and modified positions make controlled handling important to limit deamidation and epimerisation. Atosiban is water-soluble; reconstitute in a suitable aqueous buffer, aliquot stock solutions to avoid repeated freeze-thaw, and follow the certificate of analysis for lot-specific peptide and water content.
We make Atosiban and its related-substance reference standards by solid-phase synthesis with controlled disulfide formation, and release them with a certificate of analysis, HPLC purity data, and mass-spectrometry identity confirmation, with grade and salt form set to your specification. Impurity and related-substance reference standards are prepared through our peptide modification and custom peptide synthesis services, and this product sits in our drug peptide impurities reference-standard range. Material is supplied for research and pharmaceutical analytical or manufacturing use only; customers are responsible for the regulatory and intellectual-property requirements that apply in their territory.
