Selank

Selank Research Background

Selank is a synthetic heptapeptide (sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro) supplied here as a reference material for in-vitro and preclinical laboratory work. Its structure is a synthetic analog of the endogenous immunomodulatory tetrapeptide tuftsin, extended with a C-terminal Pro-Gly-Pro tripeptide. That added tripeptide is a deliberate design feature: the terminal proline residues are associated with markedly greater resistance to enzymatic cleavage than the parent tetrapeptide, which is one reason the heptapeptide is frequently characterized in stability and metabolism assays. With a molecular formula of C33H57N11O9 (CAS 129954-34-3) and an average mass near 751 Da, Selank is produced entirely by solid-phase peptide synthesis and is not isolated from biological sources.

Interest in Selank as a research substance centers on how a short, proline-rich, sequence-defined peptide behaves across cell-culture and rodent-model systems. It appears in the literature as a tuftsin-derived peptide investigated for interactions with peptidergic and monoaminergic signaling pathways under controlled conditions. The compound has no established consumer application; the surrounding body of work is preliminary and ongoing, and observations from in-vitro or animal-model systems should not be extrapolated to human or veterinary outcomes.

What Has Been Studied in Preclinical Models

Published investigations of Selank are predominantly rodent-model and in-vitro in nature. Reported experimental lines of inquiry include its enzymatic-degradation profile in plasma and tissue homogenates, its association with expression of signaling-related genes in cultured and neural tissue, and observations reported in monoamine- and neuropeptide-related pathways within controlled animal-model paradigms. As a tuftsin analog, it has also been examined in assays probing immune-cell and cytokine-related endpoints. These are descriptions of experimental observations in laboratory systems only.

• Peptide-stability and metabolism assays characterizing degradation of the proline-rich sequence in vitro.
• Rodent-model paradigms measuring behavioral and neurochemical endpoints under controlled conditions.
• Gene- and protein-expression studies in neural and immune tissue, including cytokine-associated readouts.
• Receptor- and enzyme-interaction work used to characterize the heptapeptide in laboratory systems.

Analytical Characterization

Each research lot is supplied as a white lyophilized powder and characterized before release. Identity and purity are established using orthogonal methods so that the material described on the Certificate of Analysis (COA) matches the sequence and mass expected for the heptapeptide. This separates purity (how much of the sample is the target peptide) from identity (confirmation that the target is the correct molecule) rather than relying on a single measurement.

• HPLC-UV purity: quantified by reversed-phase peak-area integration, with lot purity reported on the COA (≥98%; representative lots have resolved at 99.9%). The chromatogram resolves the main Selank peak from process-related impurities and truncated sequences.
• LC-MS identity: mass spectrometry coupled to the HPLC confirms the observed mass against the theoretical value, with characteristic ions including the singly charged [M+H]+ near m/z 752, the sodiated [M+Na]+ near m/z 774, and the doubly charged [M+2H]2+ near m/z 376.
• Supporting data: appearance (white lyophilized powder) and net peptide content reported per vial (for example, ~10.7 mg net on a nominal 10 mg lot).

The COA accompanying each product is the definitive analytical record for that specific lot. Because purity and net content can vary slightly between synthesis batches, researchers should reference the COA tied to the lot number received — not generic specifications — when documenting experimental inputs, and retain it alongside experimental records to support reproducibility and traceability.

Laboratory Handling of Lyophilized Material

As a lyophilized peptide, Selank is hygroscopic and sensitive to repeated temperature cycling. Standard laboratory practice is to allow sealed vials to equilibrate to room temperature before opening to minimize condensation, then reconstitute with an appropriate research-grade solvent under aseptic technique. Aliquoting reconstituted stock into single-use portions limits freeze-thaw cycles that can compromise peptide integrity. Detailed temperature and stability windows for lyophilized, reconstituted, and working solutions appear in the storage table on this page.