A practical reference on Selank: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
This page was last updated on 2026-03-06 and is reviewed periodically as new material appears.
Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro. It was designed as a stabilized analogue of tuftsin, a naturally occurring tetrapeptide fragment derived from the immunoglobulin heavy chain. The additional Pro-Gly-Pro segment at the carboxyl terminus is intended to slow enzymatic cleavage. The compound is usually described in the literature as a synthetic peptide with anxiolytic and cognitive-related activity, a label that reflects a research context rather than an approved therapeutic category.
Most published work on selank originates from a small number of research groups in the Russian Federation. A large share of that record appears in Russian-language journals, which limits access for readers who rely on English-indexed databases. Independent replication by laboratories outside the original research network is sparse in publicly available sources. This concentration of origin and language is a frequently noted feature when the compound is summarized in broader reviews of synthetic peptides.
Reported pharmacological effects center on reduced anxiety-like behavior in animal models and on measures of memory and learning. Proposed contributing mechanisms include modulation of GABAergic signaling, shifts in monoamine turnover, and changes in the activity of enzymes that degrade neuropeptides. Effects on the expression of genes linked to neuroplasticity have also been described. No single molecular target is widely accepted, and whether the behavioral findings arise from one pathway or several remains an open question.
Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro. It was designed at the Institute of Molecular Genetics of the Russian Academy of Sciences as a structural analogue of tuftsin, a naturally occurring tetrapeptide fragment of the immunoglobulin heavy chain. The added Pro-Gly-Pro tail was intended to slow enzymatic degradation and extend biological activity. In Russia it is registered as an anxiolytic nasal preparation, while regulators elsewhere have not approved it for clinical use.
Proposed mechanisms centre on modulation of the GABAergic system, with reports of altered expression of genes related to GABA-A receptor subunits and changed monoamine turnover. Some studies describe inhibition of enkephalinase, the enzyme that degrades endogenous enkephalins, which may prolong opioid peptide signalling. Effects on brain-derived neurotrophic factor and on cytokine expression have also been reported. These findings come largely from animal models and small human studies, and the precise primary target remains unresolved.
Published clinical evidence is limited. Most controlled trials were conducted in Russia, enrolled modest numbers of participants, and appeared in Russian-language journals, which restricts independent verification. Reported outcomes include lower anxiety scores, improved attention and memory measures, and changes in fatigue ratings. Reviews written in English note methodological limitations such as small samples and inconsistent endpoints. Whether the compound produces clinically meaningful benefit relative to established anxiolytics is therefore an open question rather than an established finding.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C33H57N11O9 | Derived from the seven-residue sequence |
| Molecular weight | About 751.9 g/mol | Average mass; the monoisotopic value is slightly lower |
| Residue count | Seven amino acids | Thr-Lys-Pro-Arg-Pro-Gly-Pro |
| Parent compound | Tuftsin (Thr-Lys-Pro-Arg) | Selank extends tuftsin at the C-terminus |
| Compound class | Synthetic short peptide | Studied in a research setting; not a licensed drug in most markets |
Animal studies have examined behaviour in tests of anxiety, memory retention and stress response, and several report changes in neurotrophic or neurotransmitter-related markers. The human evidence base is much smaller, consisting mainly of short trials conducted in Russia with limited reporting in English-language journals. Sample sizes are modest and outcome measures vary between studies, so the findings are best described as preliminary. Independent replication under modern trial standards has not been widely reported.
Outside its country of origin the compound is generally handled as a research chemical rather than an approved medicine. No regulatory approval from the United States Food and Drug Administration or the European Medicines Agency has been granted for human use. Identity and purity are normally checked by reverse-phase high-performance liquid chromatography, with mass spectrometry used to confirm the molecular mass. Lyophilised material is stored cold and desiccated, and repeated freeze-thaw cycles are avoided.
Selank is not a naturally occurring peptide and has no known endogenous counterpart in human physiology. Russian-language sources frequently call it TP-7, while English-language sources use the name Selank almost exclusively. Database indexing is uneven, partly because early reports appeared in regional journals that are not widely cataloged. Some summaries describe the material as a tuftsin analog and others as a synthetic heptapeptide; the labels overlap rather than conflict. Citing the primary sequence resolves ambiguity more reliably than the research or trade name alone.
Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro, written TKPRPGP in one-letter notation. Its structure consists of the immunomodulatory tetrapeptide tuftsin, Thr-Lys-Pro-Arg, extended at the carboxyl terminus by a Pro-Gly-Pro segment. The molecular formula is commonly given as C33H57N11O9, corresponding to a monoisotopic mass near 751.4 Da and an average molecular mass near 751.9 Da. All seven residues are proteinogenic amino acids, and the molecule carries no modified side chains or non-natural linkages.
The compound was designed at the Institute of Molecular Genetics of the Russian Academy of Sciences during the 1980s and 1990s. The stated design goal was to retain the immunomodulatory and central nervous system activity attributed to tuftsin while improving resistance to enzymatic breakdown. Adding a proline-rich tail to the short parent peptide was a deliberate strategy, because proline residues restrict the conformations available to many peptidases. The same laboratory produced Semax, an ACTH fragment analog, and both compounds were developed in parallel as short, enzymatically stabilized peptides intended for intranasal use.
Additionally, they were able to tune the retention factor for the analytes through isocratic temperature gradient elution. Ideal elutions occurred at 35 °C, but decreasing the temperature to 10 °C or raising it to 50 °C caused faster elutions either way. This is a strong indication that electrostatic and hydrophobic interactions can be similarly affected by changes in temperature. The major advantages from applying these success of this study include stationary phase versatility and maintaining bioactivity of the analytes. Ayano et al. modified PNIPAAm with cationic N,N-dimethylaminopropylacrylamide (DMAPAAm) and hydrophobic BMA and grafted it onto silica beads to form IDB. They used pH changes to adjust the LCST. The effect of pH on the LCST is as follows, from a plateau value between pH 4.5 and pH 6.0, the LCST decreased up to pH 9 and below pH 4.5. This can be interpreted as requiring slightly basic or moderately acidic conditions, as the 4.5–6.0 pH region holds a maximum value of the LCST, an unfavorable condition. They used these properties to separate several non-steroidal anti-inflammatory drugs (NSAIDs). The analysis of acidic drugs (salicylic acid: BA; SA; MS; and As) was performed below pH 4.5. MS is hydrophobic only its retention time was affected by an increase in temperature on the column without a terminally modified anion-exchanger (IB column). However, with an anion-exchanger present, dissociated acidic drugs were retained longer at temperatures below LCST, and shorter at temperatures above LCST.
== K == K-selection – Kary Mullis – karyoplasm – karyotype – keratin – keystone species – kidney – kinesiology – kinetic energy – Klinefelter syndrome – knock-out mouse – Konrad Lorenz – Krebs cycle (or citric acid cycle) – KSL cells - kwashiorkor
== Awards == Archer Martin shared the 1952 Nobel Prize in Chemistry for the invention of partition chromatography with Richard Synge. Archer Martin's 1954 paper with Anthony T. James, "Gas-Liquid Chromatography: A Technique for the Analysis and Identification of Volatile Materials" reported the discovery of gas-liquid chromatography. This was performed at the National Institute for Medical Research in Mill Hill, London, which became the Francis Crick Institute in 2016. It was honoured by a Citation for Chemical Breakthrough Award from the Division of History of Chemistry of the American Chemical Society presented in 2016 to the Francis Crick Institute. Martin was elected a Fellow of the Royal Society in 1950, and made a CBE in 1960.
Sources: en.wikipedia.org
=== Abiotic peptides === In contrast to DNA-encoded chemical libraries (DELS), abiotic peptide-encoded libraries (PELs) are emerging as an alternative in which synthetic peptide sequences are used as carriers of chemical information and small molecule discovery. Whereas DELs rely on nucleic acid tags and PCR amplification, PELs use non-natural amino acid sequences to store information which can be decoded by tandem mass spectrometry (MS/MS). In a protein-encoded library system, small molecules are synthesized using a split-and-pool strategy while being covalently linked to a peptide tag that is elongated orthogonally to encode each split step. This results in a peptide sequence that functions as a molecular barcode for information storage, similar to how DNA functions in DELs. The use of non-natural amino acids with distinct mass spectrometry signatures allows for the store of sequence-defined information that can be decoded after affinity selection against protein targets. The motivation behind the development of abiotic peptide encoding is the limited chemical reaction compatibility of DNA, which can degrade under various conditions. Since abiotic peptide encoding does not require DNA, these tags exhibit a greater library of molecules that can be synthesized and are also compatible with a broader range of chemical reactions. Despite this work, PELs still has its limitations, as PEL library sizes are orders of magnitude smaller than current DELs.
== Research == Sertraline may be useful to treat murine Zaire ebolavirus (murine EBOV). The World Health Organization (WHO) considers this a promising area of research. Lass-Flörl et al., 2003 finds it significantly inhibits phospholipase B in the fungal genus Candida, reducing virulence. Sertraline is also an effective leishmanicide. Specifically, Palit & Ali 2008 find that sertraline kills almost all promastigotes of Leishmania donovani. Sertraline is strongly antibacterial against some species. It is also known to act as a photosensitizer of bacterial surfaces. In combination with antibacterials its photosensitization effect reverses antibacterial resistance. As such sertraline shows promise for food preservation. Lass-Flörl et al., 2003 finds this compound acts as a fungicide against Candida parapsilosis. Its anti-Cp effect is indeed due to its serotonergic activity and not its other effects. Sertraline is a promising trypanocide. It acts at several different life stages and against several strains. Sertraline's trypanocidal mechanism of action is by way of interference with bioenergetics. When mothers take sertraline during pregnancy, there is research evidence that the newborn may experience sertraline withdrawal symptoms.
== History == 1919 F.D. Edwards establishes Edwards Equipment and Services in London, England. 1939 F.D. Edwards begins manufacturing vacuum equipment. 1955 The company acquires Alto Vuoto SpA, a freeze drying manufacturer in Italy. 1968 The company is acquired by BOC, after staying in private hands through the post-war period and until the 1960s when it went public. 1977 BOC Edwards acquire Kniese Apparatbau GmbH, a freeze drying manufacturer in Germany. 1992 Restructuring of Freeze Drying business resource centralised in Tonawanda (US). 1994 The company’s product portfolio is expanded with the acquisition of pharmaceutical filling systems from Calumatic in The Netherlands. 1995 The company’s portfolio is further expanded with loading systems introduced from the Dongen manufacturing site in The Netherlands. 2004 A joint venture is established with Tianli Cryogenic Company, a pharmaceutical freeze dryer manufacturer in Beijing, China. 2006 The BOC Group is acquired by Linde AG and together form The Linde Group. Linde sells the vacuum division of BOC Edwards. BOC Edwards Pharmaceutical Systems remains part of the Linde Group, as an independent division. 2008 IMA, Italy acquires the BOC Edwards Pharmaceutical Systems group creating IMA Edwards – a part of IMA Life division of the IMA group. 2010 Today the whole group has been renamed under the brand IMA LIFE - Aseptic Processing and Freeze Drying Solutions.
== Methods and practices == The term optical activity is derived from the interaction of chiral materials with polarized light. In a solution, the (−)-form, or levorotatory form, of an optical isomer rotates the plane of a beam of linearly polarized light counterclockwise. The (+)-form, or dextrorotatory form, of an optical isomer does the opposite. The rotation of light is measured using a polarimeter and is expressed as the optical rotation. The magnitudes of the optical rotations of both of the enantiomers are equal (but in opposite directions). Enantiomers can be separated by chiral resolution. This often involves forming crystals of a salt composed of one of the enantiomers and an acid or base from the so-called chiral pool of naturally occurring chiral compounds, such as malic acid or the amine brucine. Some racemic mixtures spontaneously crystallize into right-handed and left-handed crystals that can be separated by hand. Louis Pasteur used this method to separate left-handed and right-handed sodium ammonium tartrate crystals in 1849. Sometimes it is possible to seed a racemic solution with a right-handed and a left-handed crystal so that each will grow into a large crystal. Liquid chromatography (HPLC and TLC) may also be used as an analytical method for the direct separation of enantiomers and the control of enantiomeric purity, e.g. active pharmaceutical ingredients (APIs) which are chiral.
Sources: en.wikipedia.org
Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro, designed as a metabolically stabilized analogue of the endogenous tetrapeptide tuftsin. It has been studied mainly against anxiety-related and cognitive endpoints rather than as an approved medicine in most jurisdictions.
Tuftsin contains four residues, while selank carries an additional Pro-Gly-Pro segment at the carboxyl end. That extension is intended to reduce enzymatic cleavage. Comparative pharmacokinetic data in humans remain limited.
No single receptor target is widely accepted as the definitive mediator of the reported effects. Proposed contributors include GABAergic modulation, shifts in monoamine turnover, and altered neuropeptide degradation. The mechanism is treated in the literature as unresolved.
It is a seven-amino-acid peptide, Thr-Lys-Pro-Arg-Pro-Gly-Pro, produced by chemical synthesis rather than extracted from biological tissue. Its design is based on tuftsin, a natural immunomodulatory tetrapeptide. The C-terminal Pro-Gly-Pro segment is a common stabilising motif in short regulatory peptides.