Short regulatory and thymic peptides
Thymosin alpha 1
Thymosin alpha 1 is a 28-residue, N-terminally acetylated peptide that was first isolated from the thymus; the synthetic form is also known as thymalfasin.
- TypePeptide
- FormulaC129H215N33O55
- Average mass3108.28 g/mol
- CAS62304-98-7
- Vesta listings2
Reference page for laboratory use · updated 2026-10-30
Overview
Thymosin alpha 1 at a glance
The sequence is Ac-SDAAVDTSSEITTKDLKEKKEVVEEAEN. It is derived from the precursor prothymosin alpha, and its chemistry and pharmacology are covered in drug-profile and review literature.
For analytical work, there is a published LC method that identifies and quantifies structurally related impurities in thymalfasin, which is a useful reference for what a thorough purity report should show.
Structure
The N-terminus is acetylated, so there is no free N-terminal amine. The calculated formula from the sequence matches PubChem exactly.
Identity
Identity data
| Name | Thymosin alpha 1 |
|---|---|
| Also written as | Thymalfasin, Tα1 |
| Type | Peptide |
| Research area | Short regulatory and thymic peptides |
| Molecular formula | C129H215N33O55 |
| Monoisotopic mass | 3106.5041 Da |
| Average molecular weight | 3108.28 g/mol |
| CAS number | 62304-98-7, 69521-94-4, 1337515-90-8 |
| Sequence | Ac-SDAAVDTSSEITTKDLKEKKEVVEEAEN |
| PubChem record | CID 16130571 |
The formula was calculated independently from the written sequence and matches the PubChem record exactly. Reference data retrieved on 2026-10-30. Compare these values with the batch certificate of analysis, using the compound identity file template.
Expected values
Mass spectrometry reference
Ions calculated from the monoisotopic mass 3106.5041 Da. Use them to check an LC-MS result; for larger peptides the instrument usually reports a deconvoluted mass close to 3108.3 Da instead.
| Ion | m/z |
|---|---|
| [M+3H]3+ | 1036.5086 |
| [M+4H]4+ | 777.6333 |
| [M+5H]5+ | 622.3081 |
| [M+6H]6+ | 518.7580 |
For molecules of this size the tallest isotope peak is one to two mass units above the monoisotopic peak. Read the guide to average and monoisotopic mass for how these values are calculated.
Quality
Analytical notes for batch documents
- Truncated and deletion sequences are the main process-related impurities in a 28-residue synthetic peptide; ask whether they were separated and identified.
- In electrospray MS expect a charge envelope from about 3+ to 5+; the deconvoluted mass should be close to the value in the table.
- Mass shifts to look for in this sequence: deamidation of Asn or Gln (+0.984 Da).
- The molecular weight of a vial of powder includes counter-ions and water; the share of the powder that is peptide is the net peptide content.
Terms used on this page: N-terminus, Peptide.
Vesta listings
Thymosin alpha 1 formats and prices
| Product | Per vial | SKU | Price per kit | Price per vial |
|---|---|---|---|---|
| Thymosin alpha 1 | 5 mg | TA5 | $126.87 | $12.69 |
| Thymosin alpha 1 | 10 mg | TA10 | $216.42 | $21.64 |
Prices are per kit of 10 vials in US dollars. Shipping is paid by the customer and is shown in the cart. Volume savings of 5 %, 8 % and 10 % apply from $350.00, $600.00 and $1,000.00. See the full price list.
Published literature
Selected scientific literature
Bibliographic details were read from PubMed on 2026-10-30. The papers are listed for scientific reference; Vesta makes no claim about the use of its research materials in people or animals.
- Identification and determination of structurally related peptide impurities in thymalfasin by liquid chromatography-high-resolution mass spectrometryCheng Y, Wu P, Kan Y et al. · Anal Bioanal Chem · 2022 · PMID 36207535
- Thymosin alpha-1Ancell CD, Phipps J, Young L et al. · Am J Health Syst Pharm · 2001 · PMID 11381492
Questions
Frequently asked questions
What is Thymosin alpha 1?
Thymosin alpha 1 is a 28-residue, N-terminally acetylated peptide that was first isolated from the thymus; the synthetic form is also known as thymalfasin.
What is the molecular weight of Thymosin alpha 1?
Thymosin alpha 1 has the formula C129H215N33O55, an average molecular weight of 3108.28 g/mol and a monoisotopic mass of 3106.5041 Da. A salt form, a different counter-ion or a metal complex changes the molecular weight printed on a certificate of analysis, so compare like with like.
How can I check the identity of a batch of Thymosin alpha 1?
Compare the intact mass measured by LC-MS with the expected values on this page, for example [M+4H]4+ at m/z 777.6333. Confirm that one main HPLC peak carries that mass and that the batch code on the report matches the vial. The guides on mass spectrometry and on certificates of analysis explain each step.
Which Thymosin alpha 1 products does Vesta list?
Vesta lists 2 products for Thymosin alpha 1: 5 mg, 10 mg per vial in kits of 10 vials. Prices are shown per kit in US dollars, and shipping is paid by the customer.