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- Brand：Knowlux
- Model：Bottle/Drum/Customized to your needs
- Purity：99%+
- Cas：90779-69-4
- Createtime： 2026-11-13
- Updatetime： 2026-11-03
| Sample availble | Yes |
| useage | Laboratory research，Food/nutraceutical industry (regulated forms only)，Cosmetics |
| deliveryInfo | |
| appearance | White powder |
| aliasen | |
| supplyCapacity | 10MT/Month |
| harbor | Hong Kong, Shanghai, Shenzhen |
| minorder | 1G |
| Molecular Formula: | C43H67N11O12S2 (free peptide); C45H71N11O14S2 (acetate salt) |
Atosiban Acetate | CAS 90779-69-4 / 914453-95-5 | Oxytocin Receptor Antagonist (Research Use Only) | Knowlux
Product Description
Atosiban Acetate, CAS 90779-69-4 (free peptide) / 914453-95-5 (acetate salt), is a synthetic cyclic nonapeptide oxytocin receptor antagonist supplied by Knowlux for laboratory research use. The sequence is Mpr-D-Tyr(Et)-Ile-Thr-Asn-Cys-Pro-Orn-Gly-NH2, with a disulfide bridge between Mpr1 and Cys6. The molecular formula is C43H67N11O12S2 and the molecular weight is 994.19 g/mol (free peptide basis). Each lot is released with a lot-specific COA, MSDS and analytical traceability.
CAS and Salt Form Clarification: CAS 90779-69-4 corresponds to the free peptide (Atosiban), while CAS 914453-95-5 corresponds to the acetate salt (Atosiban Acetate), as listed by Aladdin and ChemScene. Many ChemicalBook supplier listings use 90779-69-4 regardless of salt form, which creates ambiguity when comparing specifications or pricing. The acetate salt has a molecular weight of 1054.24 g/mol (C45H71N11O14S2), reflecting the addition of one acetate counter-ion. Knowlux declares the salt basis and acetate content per lot on the COA. Buyers should confirm whether the quoted material is free peptide or acetate salt before procurement.
Sequence Verification Note: The correct sequence, confirmed by ChemicalBook, R&D Systems, and KEGG, is Mpr-D-Tyr(Et)-Ile-Thr-Asn-Cys-Pro-Orn-Gly-NH2 with a disulfide bridge between Mpr1 and Cys6. The N-terminal residue is 3-mercaptopropionyl (Mpr), a non-natural group that contributes to receptor binding. The C-terminal glycine is amidated. The ornithine (Orn) residue at position 8 replaces the arginine found in native oxytocin.
Product Parameters
| Item | Specification |
|---|---|
| Product Name | Atosiban Acetate |
| Synonyms | RWJ-22164; Tractocile; Mpr-D-Tyr(Et)-Ile-Thr-Asn-Cys-Pro-Orn-Gly-NH2 (disulfide bridge) |
| CAS No. | 90779-69-4 (free peptide); 914453-95-5 (acetate salt) |
| Molecular Formula | C43H67N11O12S2 (free peptide); C45H71N11O14S2 (acetate salt) |
| Molecular Weight | 994.19 g/mol (free peptide); 1054.24 g/mol (acetate salt) |
| Sequence (1-letter) | Mpr-Y(Et)ITNCPOG-NH2 (disulfide bridge Mpr1-Cys6) |
| Sequence Length | 9 residues, cyclic (disulfide bridge Mpr1-Cys6) |
| Key Structural Features | 3-mercaptopropionyl (Mpr) N-terminal group; D-Tyr(Et) at position 2; ornithine at position 8; disulfide cyclisation; C-terminal amide |
| Appearance | White to off-white lyophilized powder |
| Solubility | Soluble in water (>=150 mg/mL); soluble in DMSO |
| Purity | >=98.0% (HPLC); >=99.0% available on request |
| Identity | Confirmed by LC-MS |
| Grade | Research grade |
| Counter-ion | Acetate (lot-specific, declared on COA) |
| Peptide Content | >=80.0% |
| Storage | -20C, desiccated, protected from light |
| Packaging | 1 mg / 5 mg / 10 mg / 50 mg / 100 mg vial; bulk on request |
| Application | Laboratory research use only |
| Origin | China |
Product Details
1. Overview
Atosiban is a synthetic cyclic nonapeptide that acts as a competitive antagonist at both oxytocin and vasopressin receptors. It is structurally derived from oxytocin through modifications including N-terminal mercaptopropionyl substitution, D-tyrosine ethylation, and ornithine replacement of arginine. In clinical medicine, atosiban acetate is approved in certain jurisdictions for the delay of imminent preterm birth. However, the material supplied under this specification is research-grade and is not intended for human administration. Knowlux supplies this compound strictly for laboratory investigation of oxytocin receptor signaling and related pharmacological pathways.
2. Structural Profile
The nonapeptide backbone comprises nine residues with a disulfide bridge cyclising Mpr1 and Cys6. The Mpr group replaces the native N-terminal cysteine-tyrosine sequence, contributing to antagonist activity rather than agonist activity. The D-Tyr(Et) substitution at position 2 enhances receptor binding affinity and metabolic stability. Ornithine at position 8 replaces the arginine found in oxytocin, a modification that affects receptor selectivity. The C-terminal glycinamide is amidated, protecting against carboxypeptidase degradation. These modifications collectively yield a peptide with antagonist activity at oxytocin receptors, distinguishing it from the agonist activity of native oxytocin.
3. Research Applications
Published pharmacological characterizations describe the following research applications:
-
Oxytocin receptor binding and functional antagonist assays
-
Vasopressin receptor cross-reactivity studies
-
Uterine myometrial contractility research models
-
Inhibition of oxytocin-mediated inositol triphosphate release
-
Reference standard development for HPLC and LC-MS analytical methods
These descriptions are derived from published research and are provided for scientific reference only. They do not constitute clinical guidance or dosing recommendations.
Quality Control
| Test Item | Method | Acceptance Criteria |
|---|---|---|
| Purity | RP-HPLC | >=98.0% |
| Identity & Molecular Mass | LC-MS (deconvoluted) | Consistent with structure |
| Single Impurity | RP-HPLC | <=2.0% |
| Peptide Content | Amino Acid Analysis | >=80.0% |
| Acetate Content | Ion chromatography or HPLC | Lot-specific (declared on COA) |
| Water Content | Karl Fischer | <=8.0% |
| Appearance | Visual | White to off-white powder |
| Bacterial Endotoxins | LAL or chromogenic | <=50 EU/mg (on request) |
Solubility and Handling
Solubility: Atosiban Acetate is highly soluble in water, with a reported solubility of >=150 mg/mL (150.88 mM) according to one supplier. R&D Systems lists solubility to 50 mg/mL in water for the free peptide. DMSO is also suitable for stock preparation. Prepare solutions fresh and aliquot to avoid repeated freeze-thaw cycles.
Handling Precautions: Use powder-handling containment (glove box or fume hood with particulate control). Avoid inhalation of fine powder. Wear nitrile gloves, lab coat, and eye protection. Follow institutional chemical hygiene plans for research peptides. The disulfide bridge is sensitive to reducing agents; avoid contact with dithiothreitol (DTT) or mercaptoethanol during handling. ChemScene lists GHS06 hazard classification (H301, H311, H331) for its Atosiban acetate catalog item; consult the lot-specific MSDS for applicable handling guidance.
Storage and Stability
| Format | Temperature | Shelf Life |
|---|---|---|
| Lyophilized Powder | -20C, sealed, desiccated, protected from light | 1 to 2 years (supplier-dependent) |
| Lyophilized Powder | 2C to 8C, sealed, desiccated | Short-term (weeks) |
| Reconstituted Solution | -20C, aliquoted | 6 months |
| Reconstituted Solution | 2C to 4C, aliquoted | 2 weeks |
Documentation Support
Per lot: COA, MSDS, certificate of origin, HPLC chromatogram, and mass spectrometry data. Sequence verification data and counter-ion specification available on request. Custom specifications and third-party inspection can be arranged on a project basis.
About Knowlux
Knowlux Biotechnology is a GMP-oriented manufacturer and supplier of peptides, APIs and fine-chemical research compounds, operating from Hubei, China. We serve research groups, CDMOs and distributors in more than 40 countries, and support contract synthesis, custom packaging and technical documentation requests.
Compliance Statement
FOR RESEARCH USE ONLY. NOT FOR HUMAN USE. NOT FOR DIAGNOSTIC OR THERAPEUTIC USE.
This product is supplied for laboratory research use only. It is not for human or animal administration, not for diagnostic or therapeutic use, not for retail sale, and not for personal use. Atosiban is an approved medicinal product in certain jurisdictions for specific clinical indications; however, the material offered under this specification is research-grade and is not intended for clinical use. The purchaser is responsible for verifying product specifications against their specific research requirements and for compliance with all applicable institutional, local, and national regulations governing research chemical acquisition, storage, and use. Research context statements are for scientific reference only and do not constitute medical advice, promotional claims, or dosing guidance.
