Adalank (N-Acetyl Selank Amidate)

N-Acetyl Selank Amidate is a modified form of Selank, the synthetic heptapeptide Thr-Lys-Pro-Arg-Pro-Gly-Pro (Kost et al., 2001). As the name states, the N-terminus carries an acetyl group (N-acetylation) and the C-terminal carboxylic acid is replaced by an amide (C-terminal amidation), written Ac-Thr-Lys-Pro-Arg-Pro-Gly-Pro-NH2. The seven amino acids and their order are those of Selank.

PubMed indexes no study of the acetylated, amidated peptide and none comparing it with Selank. This guide sets out what is and is not on record, then summarizes Selank's own literature, labeled as Selank data throughout.

PubChem has no compound record for the acetylated, amidated peptide (name and structure searches, 13 October 2026), so the formula and weight above are calculated from the sequence. PubChem lists Selank (CID 11765600) as C₃₃H₅₇N₁₁O₉ at 751.9 g/mol, and the two caps add C₂H₃N in total. PubChem's record named N-acetyl Selank (CID 133082488, C₃₅H₅₉N₁₁O₁₀, 793.9 g/mol) carries the acetyl group but keeps a free C-terminal acid, so it is a different substance.

As of 13 October 2026, PubMed searches for "adalank", "N-acetyl selank", "acetyl selank" and "NA-Selank" return no records, and "selank amidate" returns two records about Selank itself. No cell, animal or human study of the capped peptide is on record. The summaries below cover those two records, then Selank and one acetylated relative, each with its model. None of them tested Adalank.

The two records for "selank amidate"

Both describe one rat study by Kozlovskii and Danchev, published in Russian in 2002 (Kozlovskii and Danchev, 2002) and in English translation in 2003 (Kozlovskii and Danchev, 2003). It compared unmodified Selank with piracetam in a conditioned active avoidance task over four daily sessions, counting correct responses and errors. Neither record mentions acetylation or amidation. PubMed returns them because it expands "amidate" to the MeSH heading Amides, which covers piracetam, a compound indexed on both records. Model: rats.

Selank, the parent sequence

Selank's first four residues, Thr-Lys-Pro-Arg, are tuftsin (PubChem CID 156080), first reported as a natural phagocytosis-stimulating peptide (Najjar and Nishioka, 1970), followed by Pro-Gly-Pro. Our Selank research guide covers its literature in depth, and Semax vs Selank compares it with Semax, which ends in the same tail.

Breakdown and peptidase assays (Selank)

Using uniformly tritium-labeled peptide, Zolotarev and colleagues identified Thr-Lys-Pro-Arg-Pro, Thr-Lys-Pro, Arg-Pro and Gly-Pro as the major products of Selank breakdown in blood plasma (Zolotarev et al., 2006). In human serum, Selank inhibited enkephalin-degrading enzymes with a half-maximal inhibitory concentration of 20 µM, and Semax at 10 µM; pentapeptide fragments of the two peptides kept that activity, while their tri-, tetra- and hexapeptide fragments did not (Kost et al., 2001). No study indexed in PubMed has reported whether the acetyl and amide caps change any of these findings. Models: plasma and serum in vitro.

Immune gene expression (Selank, mouse)

In mouse spleen, 34 of 84 inflammation-related genes changed expression 6 and 24 hours after a single Selank injection, and the immune regulator Bcl6 changed after Selank and after each of two Selank fragments (Kolomin et al., 2011). A follow-up found a 3-fold fall in complement C3 mRNA 30 minutes after Selank and a similar change after its Gly-Pro fragment (Kolomin et al., 2014). Model: mouse spleen.

Influenza infection model (Selank)

Against influenza A/Aichi/2/68 (H3N2), Selank added to cell cultures 24 hours before inoculation completely suppressed viral reproduction in the authors' assay, and in laboratory animals it induced interferon-alpha gene expression without changing IL-4, IL-10 or TNF-alpha (Ershov et al., 2009). The English abstract names neither the cell line nor the species. Models: cell culture and laboratory animals.

N-terminal acetylation in a related peptide (Semax)

A change at one end can alter a peptide's chemistry. In Semax (Met-Glu-His-Phe-Pro-Gly-Pro), N-terminal acetylation changed the copper(II) complex the peptide forms and its redox behavior, and the acetylated form did not protect SH-SY5Y neuroblastoma cells from copper(II) toxicity, which the authors tied to the loss of the free N-terminus; zinc(II) binding was of comparable strength (Magrì et al., 2016). That work used Semax, not Selank or Adalank. Models: solution chemistry and SH-SY5Y cells.