Cetrorelix Acetate | CAS 130143-01-0 / 20287-85-6 | GnRH Receptor Antagonist (Research Use Only) | Knowlux

Product Description

Cetrorelix Acetate, CAS 130143-01-0 (acetate salt) / 20287-85-6 (free peptide reference), is a synthetic decapeptide gonadotropin-releasing hormone (GnRH) receptor antagonist supplied by Knowlux for laboratory research use. The sequence is Ac-D-Nal(2)-D-Phe(4Cl)-D-Pal(3)-Ser-Tyr-D-Cit-Leu-Arg-Pro-D-Ala-NH2. The molecular formula is C70H92ClN17O14 and the molecular weight is 1431.06 g/mol (free peptide basis). Each lot is released with a lot-specific COA, MSDS and analytical traceability.

CAS and Salt Form Clarification: CAS 130143-01-0 corresponds to Cetrorelix Acetate, as confirmed by the National Cancer Institute and multiple ChemicalBook supplier listings. CAS 20287-85-6 appears in some supplier documentation alongside the free peptide basis. Note that the free peptide CAS is frequently listed as 120287-85-6 in PubChem and HMDB databases, not 20287-85-6. The acetate salt is the form most commonly supplied for research and clinical use. Knowlux declares the salt basis and acetate content per lot on the COA. Buyers should confirm the CAS number on the supplier COA matches the declared salt form before procurement.

Sequence Verification Note: The correct sequence, confirmed by PubChem and HMDB, is Ac-D-Nal(2)-D-Phe(4Cl)-D-Pal(3)-Ser-Tyr-D-Cit-Leu-Arg-Pro-D-Ala-NH2. The N-terminal residue is D-2-naphthylalanine (D-Nal(2)), a non-natural amino acid contributing to receptor binding. The C-terminal D-alaninamide is amidated. The citrulline (Cit) residue at position 6 replaces the glutamine found in native GnRH.

Product Parameters

Product Details

1. Overview

Cetrorelix is a synthetic decapeptide that acts as a competitive antagonist at gonadotropin-releasing hormone (GnRH) receptors. It is structurally distinguished from native GnRH by multiple non-natural amino acid substitutions, including D-naphthylalanine, D-4-chlorophenylalanine, and D-3-pyridylalanine, which confer antagonist activity and metabolic stability. In clinical medicine, cetrorelix acetate is approved for the inhibition of premature luteinizing hormone (LH) surges in controlled ovarian stimulation. 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 GnRH receptor signaling and related pharmacological pathways.

2. Structural Profile

The decapeptide backbone comprises ten residues with an acetylated N-terminus and an amidated C-terminus. The incorporation of three D-amino acids in the N-terminal region (positions 1, 2, and 3) is critical for antagonist activity, as these substitutions prevent receptor activation while maintaining high binding affinity. The D-citrulline residue at position 6 enhances stability against peptidase degradation. The C-terminal D-alaninamide protects against carboxypeptidase attack. These modifications collectively yield a peptide with high GnRH receptor affinity and prolonged activity relative to native GnRH.

3. Research Applications

Published pharmacological characterizations describe the following research applications:

• GnRH receptor binding and functional antagonist assays

• LH and FSH secretion inhibition studies in pituitary cell models

• Reproductive endocrinology research models

• 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

One supplier COA for Cetrorelix acetate reports HPLC purity of 98.2% and water content of 2.6% for a tested lot. Supplier specifications from ChemicalBook listings consistently report peptide content >=80.0%, acetate content <=12.0%, and endotoxin <=50 EU/mg. Buyers should request lot-specific HPLC chromatograms and mass spectra, and verify that the reported purity reflects peptide content on an anhydrous, acetate-free basis where assay performance is critical. Full COA, MSDS, and lot-specific chromatograms are issued with each shipment.

Solubility and Handling

Solubility: Cetrorelix Acetate is soluble in water with sonication at approximately 5 mg/mL according to one supplier COA. DMSO solubility is limited (slightly soluble) and should be confirmed on the lot-specific technical sheet. 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.

Storage and Stability

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. Cetrorelix 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.