Thymosin Alpha-1

Thymosin alpha-1 is a 28-residue peptide originally isolated from thymic tissue, N-terminally acetylated, with a highly acidic character. Its research history is longer and better documented than most compounds in this catalogue — it has been through formal clinical investigation in several jurisdictions and the immunological mechanism is comparatively well mapped, centring on TLR signalling and dendritic cell maturation with downstream effects on T-cell differentiation.

Synthesis quality matters here because the sequence is long, acidic and contains multiple aspartate and glutamate residues prone to side reactions during chain assembly. Aspartimide formation is the specific failure mode: it produces a same-mass isomer that LC-MS alone will not catch. We use an orthogonal HPLC gradient specifically selected to resolve the aspartimide isomer, and the chromatogram is on the certificate.