| Target Molecule | Abarelix |
| Synonyms | Plenaxis, PPI-149, R-3827, Abarelix Acetate |
| CAS Number | 183552-38-7 (free base); 785804-17-3 (acetate salt) |
| Sequence (3-Letter) | Ac-D-Nal(2)-D-Phe(4-Cl)-D-Pal(3)-Ser-N-Me-Tyr-D-Asn-Leu-Lys(iPr)-Pro-D-Ala-NH₂ |
| Sequence (1-Letter) | Ac-[D-2Nal]-[D-4ClPhe]-[D-3Pal]-S-[NMe-Y]-[D-Asn]-L-[K(iPr)]-P-[D-Ala]-NH₂ |
| Molecular Formula | C₇₂H₉₅ClN₁₄O₁₄ (free base) |
| Molecular Weight | 1416.06 (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 salt options |
| Synthesis Technology | Solid-Phase Peptide Synthesis (SPPS) for N-Methylated and Unnatural Amino Acids |
| Modification Options | N-methylation, D-amino acid substitution, unnatural amino acid incorporation, C-terminal amidation, stable isotope labeling (13C, 15N), diastereomer impurity standards |
| Available Scale | Milligram (R&D) to Kilogram (Commercial CDMO) |
| Analytical Data | Comprehensive COA, HPLC, MS, and chiral purity confirmation provided per batch |
| Usage | Raw material synthesized strictly for laboratory research, analytical development, and industrial formulation. Not a finished medicine. |
Abarelix (CAS 183552-38-7) is a synthetic decapeptide functioning as a potent gonadotropin-releasing hormone (GnRH) receptor antagonist. Its sequence features extensive non-canonical modifications, including D-amino acids, N-methyl-tyrosine, and isopropyl-lysine, alongside N-terminal acetylation and C-terminal amidation. We target this sequence to supply high-purity reference materials and raw materials for oncology and reproductive endocrinology research.
The inclusion of sterically congested residues—specifically N-Me-Tyr5, D-Phe(4-Cl), D-Nal(2), and Lys(iPr)—substantially impedes coupling efficiency and elevates the risk of epimerization. Our peptide synthesis platform applies specialized coupling cocktails, elevated temperature protocols, and real-time monitoring to suppress deletion sequences and maintain chiral fidelity.
Yes. We provide specialized peptide modification services for GnRH antagonists. Capabilities include the deliberate synthesis of diastereomers and deletion sequences as critical impurity reference standards, site-specific stable isotope labeling (13C, 15N) for quantitative LC-MS/MS bioanalysis, and fluorescent or biotin tagging.
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, impurity profiling, analytical method validation, and regulatory documentation to accelerate complex preclinical and commercial pipelines.
Abarelix (CAS 183552-38-7), historically referenced under brand names such as Plenaxis, is a synthetic decapeptide operating as a competitive gonadotropin-releasing hormone (GnRH) receptor antagonist. Defined by the sequence Ac-[D-2Nal]-[D-4ClPhe]-[D-3Pal]-S-[NMe-Y]-[D-Asn]-L-[K(iPr)]-P-[D-Ala]-NH2, it features extensive structural engineering, including D-enantiomers, N-methylation, and halogenated aromatic residues. Synpeptide delivers comprehensive custom synthesis solutions for this target molecule, demonstrating advanced technical expertise in non-standard peptide chemistry, stereochemical control, and CDMO manufacturing.
Incorporating multiple bulky unnatural amino acids and an N-methylated peptide bond (N-Me-Tyr5) creates severe steric hindrance during chain elongation, lowering coupling efficiency and increasing the likelihood of truncated deletion sequences. Our custom peptide synthesis platform resolves these hurdles using optimized Solid-Phase Peptide Synthesis (SPPS) protocols on low-loading amide resins. By utilizing targeted coupling reagents, temperature control, and rigorous capping cycles, we suppress deletion fragments and epimerization, delivering raw materials with rigorous purity specifications (typically ≥95% or ≥98% via HPLC).
With multiple chiral centers and non-canonical amino acids, Abarelix demands stringent analytical validation. Partial racemization at stereocenters can yield diastereomeric impurities that compromise antagonistic activity. Through our peptide modification services, we synthesize deliberate diastereomers, unacetylated intermediates, and deletion variants as reference standards for stability-indicating assays. We also provide site-specific stable isotope labeling (13C, 15N) for pharmacokinetic bioanalysis and fluorescent probes for receptor-binding studies.
Moving a heavily modified decapeptide from laboratory-scale synthesis to commercial supply requires robust downstream chemical engineering. The combination of hydrophobic aromatic residues and basic isopropyl-lysine imparts a distinctive chromatographic profile during purification. We execute large-scale peptide synthesis for Abarelix by optimizing preparative HPLC purification and controlled lyophilization. Our facilities accommodate demands from milligram research batches to kilogram commercial lots, ensuring uniform counter-ion exchange (providing 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.
