Description
Chemical Identity
Thymosin Alpha-1 is a naturally occurring 28-amino acid immunomodulatory peptide with the molecular formula C129H215N33O55 and a molecular weight of approximately 3108.3 Da. Originally isolated from thymic tissue by Allan Goldstein and colleagues in the 1970s, Thymosin Alpha-1 is the most biologically active component of Thymosin Fraction 5, a partially purified extract of the calf thymus gland. The peptide is N-terminally acetylated in its native form.
Thymosin Alpha-1 is also known by the following designations: Thymalfasin, Zadaxin, Thymosin α1.
| Property | Value |
|---|---|
| Molecular Formula | C129H215N33O55 |
| Molecular Weight | 3108.3 Da |
| CAS Number | 62304-98-7 |
| Sequence | Ac-Ser-Asp-Ala-Ala-Val-Asp-Thr-Ser-Ser-Glu-Ile-Thr-Thr-Lys-Asp-Leu-Lys-Glu-Lys-Lys-Glu-Val-Val-Glu-Glu-Ala-Glu-Asn |
| Research Status | Approved (35+ countries) |
Research Overview
Thymosin Alpha-1 has been investigated in controlled clinical trials and clinical practice spanning infectious disease, oncology, immunodeficiency, and critical care. The primary mechanism of action involves activation of Toll-like receptors (TLR9 and TLR2) on dendritic cells, promoting T-cell maturation and differentiation, enhancing NK cell cytotoxicity, and modulating cytokine production through context-dependent immune regulation.
Key areas of published research include:
- Chronic Hepatitis B: A meta-analysis of five randomized controlled trials enrolling 653 patients demonstrated that Thymosin Alpha-1 monotherapy produced significantly higher sustained virological response rates compared to untreated controls (relative risk 1.56, 95% CI 1.13-2.14). When combined with interferon-alpha, combination therapy achieved 40% sustained response rates versus 20% with interferon monotherapy, with no additional adverse effects.
- Sepsis and Critical Illness: The ETASS multicenter randomized trial enrolling 361 patients with severe sepsis demonstrated that Thymosin Alpha-1 reduced 28-day mortality (26.0% vs 35.0% in controls), with significant restoration of monocyte HLA-DR expression indicating reversal of sepsis-induced immunoparalysis and improved CD4+/CD8+ T-cell ratios.
- Cancer Immunotherapy: Multiple clinical trials have investigated Thymosin Alpha-1 as an adjunct to chemotherapy and transarterial chemoembolization (TACE). A meta-analysis of six trials in hepatocellular carcinoma reported improved 1-year and 2-year overall survival when Thymosin Alpha-1 was combined with TACE, with enhanced CD4+ T-cell counts and NK cell activity.
Thymosin Alpha-1 has received regulatory approval in over 35 countries (marketed as Zadaxin) for the treatment of chronic hepatitis B, hepatitis C, and as an immune adjuvant. It has not received FDA approval in the United States but holds orphan drug designation for certain indications. Over 4,400 patients have been studied in controlled clinical trials.
Specifications
All Thymosin Alpha-1 supplied by Prescott Bio Canada is manufactured to research-grade standards.
| Specification | Detail |
|---|---|
| Purity | >98% (HPLC) |
| Form | Lyophilized powder |
| Appearance | White to off-white powder |
| Storage (lyophilized) | -20°C, protected from light |
| Storage (reconstituted) | 2-8°C, use within 30 days |
| Solubility | Soluble in bacteriostatic water, sterile water, or normal saline |
Each vial is accompanied by a Certificate of Analysis (COA) documenting purity, identity, and endotoxin testing.
Research Applications
Thymosin Alpha-1 is supplied exclusively for in vitro and in vivo laboratory research. Published experimental applications include:
- Investigation of TLR9/TLR2-mediated dendritic cell activation and T-cell priming
- Assessment of immune reconstitution in immunosuppressed or immunosenescent models
- Study of vaccine adjuvancy and seroconversion enhancement in immunocompromised subjects
- Evaluation of anti-tumor immune surveillance in combination with cytotoxic agents
- Analysis of sepsis-induced immunoparalysis reversal and HLA-DR expression restoration
Researchers should consult the primary literature and institutional review protocols before designing experiments with Thymosin Alpha-1.
Storage and Handling
Lyophilized powder: Store at -20°C in the original sealed vial, protected from light and moisture. Under these conditions, Thymosin Alpha-1 maintains stability for up to 24 months.
Reconstituted solution: Reconstitute with bacteriostatic water or sterile water to the desired concentration. Store reconstituted Thymosin Alpha-1 at 2-8°C and use within 30 days. Avoid repeated freeze-thaw cycles.
Handling precautions: This product is intended for research use only (RUO). Not for human or veterinary diagnostic or therapeutic use. Handle using standard laboratory safety practices including appropriate PPE.