Thymalin

Thymalin is a polypeptide complex isolated from the thymus gland of calves, developed by the St. Petersburg Institute of Bioregulation and Gerontology. It is a peptide-based bioregulator that has been extensively studied for its immunomodulatory, geroprotective, and regenerative properties. Thymalin is often used interchangeably with Thymulin (also known as Serum Thymic Factor or Nonathymulin), a synthetic nonapeptide (Pyr-Ala-Lys-Ser-Gln-Gly-Gly-Ser-Asn-OH) that represents the active component of the thymic polypeptide complex. The compound has been approved as a medicinal drug in Russia (registration number LS-000267) since 2010 and has demonstrated efficacy in various infectious diseases, immunodeficiencies, and as an adjunct in cancer therapy.

Thymalin exerts its immunomodulatory effects through the actions of its active short peptide components—the dipeptides KE, EW, and the tripeptide EDP. These short peptides can specifically bind to double-stranded DNA and/or histone proteins, regulating gene expression and the synthesis of immune system proteins. This epigenetic regulatory mechanism influences the differentiation, proliferation, and apoptosis of immune cells. Thymalin enhances functional activity of T lymphocytes, stimulates cellular immunity, activates macrophages, and increases phagocytosis. It has been shown to reduce the synthesis of pro-inflammatory cytokines IL-1β, IL-6, and TNF-α in human peripheral blood mononuclear cells, while normalizing the number and ratio of T and B lymphocytes and their subpopulations.

• Immunodeficiency and Immunomodulation: Investigated for the treatment of primary and secondary immunodeficiencies, immune dysfunction-related diseases, and restoration of immune balance in immunocompromised states.
• Aging and Geroprotection: Studied for reversing age-related thymic atrophy, restoring T-cell output, and reducing mortality in elderly populations over long-term observation periods.
• Infectious Disease Research: Employed in studies on acute and chronic viral infections, including hepatitis, influenza, COVID-19, and pneumonia. In severe COVID-19 patients, Thymalin demonstrated reduced hospital mortality and faster clinical improvement.
• Cancer Adjuvant Therapy: Investigated as an adjunct in comprehensive cancer treatment, modulating immune responses against cancer cells and mitigating bone marrow suppression from chemo- or radiotherapy.
• Inflammatory and Autoimmune Conditions: Studied for its anti-inflammatory effects and potential applications in conditions involving immune dysregulation.

CAS Number: 63958-90-7 (Thymulin/nonapeptide); 79621-14-0 (alternative)
PubChem CID: 3085284
Molecular Formula: C₃₃H₅₄N₁₂O₁₅
Molecular Weight: 858.85–858.86 g/mol
Sequence: Pyr-Ala-Lys-Ser-Gln-Gly-Gly-Ser-Asn-OH
Purity: ≥ 99%
Form: Lyophilized powder
Storage: Store at ≤ -20°C in a cool, dry place, protected from light and moisture
Solubility: Soluble in sterile water; prepare working solutions per laboratory protocol