Selank and Semax: tuftsin- and ACTH-derived heptapeptides

Sequences and parents

• Selank: Thr-Lys-Pro-Arg-Pro-Gly-Pro (TKPRPGP). Parent: tuftsin (Thr-Lys-Pro-Arg), a tetrapeptide fragment of immunoglobulin G heavy chain.
• Semax: Met-Glu-His-Phe-Pro-Gly-Pro (MEHFPGP). Parent: ACTH(4-7) (Met-Glu-His-Phe), part of adrenocorticotropic hormone; often described as an ACTH(4-10) analogue.
• Adamax, also listed by Sable, is a further modified Semax analogue; check its CoA for the exact structure of each lot.

PubChem data

• Selank: C33H57N11O9, 751.9 g/mol, monoisotopic 751.434 Da.
• Semax: C37H51N9O10S, 813.9 g/mol, monoisotopic 813.348 Da.

Source: PubChem CID 11765600: Selank; PubChem CID 9811102: Semax

Research background

Tuftsin and its analogues have a long literature, reviewed in 2017. Selank has been studied in rodent models and in gene-expression work on inflammation-related genes; Semax has been studied for effects on brain monoamine systems in rodents. Most of this work comes from a small number of Russian groups.

Source: Tuftsin: properties and analogs, Curr Med Chem 2017 (PubMed 28745220); Inflammation-related gene expression under the tuftsin analogue Selank, Mol Immunol 2014 (PubMed 24291245); Semax, an ACTH(4-10) analogue, and brain dopaminergic and serotoninergic systems, Neurochem Res 2005 (PubMed 16362768)

Analytical notes

• Selank is highly basic (Lys, Arg) and will carry several counter-ions; net peptide content is correspondingly lower than gross weight.
• Semax contains methionine, which can oxidise to the sulfoxide (+16 Da) in solution.
• Both have Pro-rich C-termini, which can show cis/trans isomer peak broadening on HPLC.

At Sable

Sable lists these compounds as lyophilised research materials. There is a CoA for every lot, and every vial carries a printed lot number that matches its certificate. A CoA is emailed within 2 hours of a request.

Frequently asked questions