Thymalfasin
CAS: 62304-98-7
Category: Peptides
| Purity | Reagent Grade ≥95%, Standard Grade ≥98%, High-Purity Grade ≥99%, Pharmaceutical Grade ≥97.0–103.0% ( |
| Molecular Formula | C129H215N33O55 |
| Molecular Weight | 3108.28 |
| Appearance | White to off-white powder |
| Packaging | 500 µg/glass vial, 1 mg/glass vial, 2 mg/lyophilized vial, 5 mg/lyophilized vial, 5 mg/glass vial, 10 mg/lyophilized vial, 10 mg/glass vial, 25 mg/glass vial, 50 mg/glass vial, 100 mg/glass vial, 250 mg/glass vial, 1 g/glass vial, or 1 g/lyophilized powder bottle |
| Testing Indicators | Appearance — Visual inspection (white to off-white powder); Purity — HPLC-UV (≥95–99.5%, C18 column, acetonitrile:buffer gradient, λ=220–254 nm); Related substances — HPLC (impurity profiling including deletion peptides, truncated sequences, oxidized methionine/cysteine analogs, and diastereomeric impurities); Assay — RP-HPLC (linearity validated, recovery 95.0–105.0%, mass balance 95.0–105.0%); Peptide content — Nitrogen determination (≥80.0% by N% analysis); Amino acid analysis — Ion-exchange chromatography or RP-HPLC (amino acid composition within ±10% of theoretical); Molecular weight confirmation — ESI-MS (m/z 3107 [M-H]⁻, m/z 3109 [M+H]⁺, exact mass 3106.504150); Sequence verification — Edman degradation or tandem MS (MS/MS); Acetate content — HPLC or titrimetric (≤12.0% w/w for acetate salt); Water content — Karl Fischer titration (GB/T 6283/EP 2.5.12, ≤10.0% for lyophilized powder); pH — Potentiometry (reconstituted solution, pH ~6.5–7.5); Specific optical rotation — Polarimetry ([α]D ~-30 to -40°, c=1 in water); Endotoxin — LAL test (≤50 EU/mg, pharmaceutical grade); Microbial limits — TAMC ≤100 CFU/g, TYMC ≤10 CFU/g (USP <61>); Residual solvents — GC-FID (acetonitrile ≤410 ppm, methanol ≤3000 ppm, ICH Q3C); Host cell proteins — ELISA (≤100 ppm for recombinant production); Host cell DNA — qPCR (≤10 ng/dose). |
| Storage Notes | Store in a cool, dry, well-ventilated area at -20°C or below. Protect from light, moisture, and air. Keep container tightly sealed. Store lyophilized powder at -20°C for long-term stability (up to 3 years); at 2–8°C for 2 years. Some suppliers recommend storage at -85 to -65°C for ultra-long-term stability. In solution, prepare fresh and use immediately; do not store aqueous solutions for extended periods. Light-sensitive and hygroscopic material; avoid prolonged exposure to light and humid conditions. The peptide is supplied as lyophilized powder to enhance stability. Store away from strong oxidizing agents and incompatible substances. Use inert atmosphere (nitrogen or argon) for long-term storage if available. |
| Lead Time | 10 days |
Thymalfasin (INN, also known as Thymosin α1, Thymosin alpha 1, Zadaxin, or Thymosin Alpha-1) is a 28-amino acid synthetic peptide corresponding to the N-terminal sequence of human prothymosin α. It functions as a potent immunomodulating agent that enhances the Th1 immune response, promotes T-cell differentiation, maturation and activation, enhances dendritic cell and antibody responses, and inhibits steroid-induced thymocyte apoptosis. It also modulates CD4+ CD25+ Foxp3+ Treg cells and pro-inflammatory cytokine levels, activates indoleamine 2,3-dioxygenase (IDO) during transplants to promote immune tolerance, and inhibits influenza A virus replication via TLR4 binding. Used as a pharmaceutical intermediate and active pharmaceutical ingredient (API) for the development and quality control of lyophilized powder for injection and subcutaneous injection formulations (e.g., Zadaxin 1.6 mg/vial). Approved for clinical use in the treatment of chronic hepatitis B (CHB), as a vaccine immune response enhancer for immunocompromised individuals (chronic hemodialysis, elderly), and as adjuvant therapy for anti-tumor treatment. Also employed in analytical method development, peptide synthesis quality control, and pharmacological research. ATC code: L03AX.