If you have been reading about Selank and want a single page that covers the useful parts, this is it: definitions, context, how it is studied, and the questions that come up repeatedly.
Updated 2026-08-01. Numbers and descriptions here follow the published literature rather than marketing material.
Development work on the compound began in the 1980s and 1990s at the Institute of Molecular Genetics in Moscow, within the same research programme that produced the peptide Semax. Early investigators sought a tuftsin derivative with improved resistance to enzymatic breakdown and with activity in the central nervous system after peripheral administration. Most of the primary literature from this period was published in Russian, a factor that still shapes how easily the findings can be checked by outside groups.
Naming for this compound is not fully standardised in English sources. The spelling Selanc appears in some transliterations, and catalogue entries may instead list the peptide sequence itself as the identifier. Reference material sometimes groups it with other short synthetic peptides studied for behavioural effects, which can create confusion when citations are compared. Distinguishing the exact sequence from related tuftsin analogues is therefore a practical first step when reviewing any dataset or specification sheet.
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.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic heptapeptide | Tuftsin analogue |
| Sequence | Thr-Lys-Pro-Arg-Pro-Gly-Pro | Single-letter form: TKPRPGP |
| Molecular formula | C33H57N11O9 | Calculated for the free peptide |
| Molecular weight | About 751.9 g/mol | Derived from the sequence |
| Appearance | White to off-white powder | Typical lyophilised form |
The compound has a calculated molecular weight near 751.9 daltons and carries a net positive charge at physiological pH because of its arginine residue. It dissolves freely in water and in common aqueous buffers, and typically appears as a white or off-white lyophilized powder. The amide backbone makes the molecule susceptible to peptidases, which limits oral use and favors intranasal or parenteral routes. Nomenclature in the literature varies: the substance is also described by the sequence abbreviation TP-7 and by a Russian trade designation.
Regulatory status differs sharply by region. Selank holds a Russian marketing authorization, where it is supplied mainly as nasal drops, while authorities elsewhere have not approved it for medical use. Material sold internationally is therefore usually labeled as a research chemical rather than a medicine. Peer-reviewed publications come predominantly from Russian laboratories, and sample sizes are generally small. Whether the compound produces comparable effects under independent, well-controlled replication remains an open question that the broader literature has not settled.
Selank is a synthetic heptapeptide developed in Russia as a structural analogue of tuftsin, a naturally occurring immunomodulatory tetrapeptide. Its sequence, Thr-Lys-Pro-Arg-Pro-Gly-Pro, keeps the tuftsin core at the N-terminus and appends a Pro-Gly-Pro tail. Researchers at the Institute of Molecular Genetics in Moscow synthesized the compound during the 1990s while searching for peptides with combined anxiolytic and immunomodulatory activity. The added tail was intended to resist enzymatic cleavage and prolong the molecule's presence in circulation.
Lyophilized selank is normally supplied as a dry powder and is considered stable for extended periods when kept cold and dry. Moisture uptake is the main practical threat, because absorbed water promotes both hydrolysis and aggregation in the solid state. Vials are usually warmed to room temperature before opening so that condensation does not form on the powder. Supplier documentation commonly specifies -20 °C for routine storage, with -80 °C used for material intended to be archived for years.
Once dissolved, the peptide is markedly less stable than the dry powder. Aqueous solutions are subject to backbone hydrolysis and to microbial growth when they are handled without sterile technique. Buffered solutions near neutral pH are common for short-term laboratory work, while acidic conditions are sometimes used to improve solubility. Analytical laboratories generally prepare working solutions fresh rather than storing them, and a residual water film left in a reopened vial can seed degradation even when the container appears dry.
Reversed-phase high-performance liquid chromatography is the standard technique for estimating peptide purity. The result is a peak-area percentage, which describes how much of the detected material elutes as the main peak in one run. Mass spectrometry confirms the molecular mass and can reveal truncated, adducted, or otherwise modified species. Amino acid analysis or tandem mass spectrometry can address sequence fidelity when identity is in doubt. None of these measurements, taken alone, establishes that a sample is fit for any specific purpose.
Development took place at the Institute of Molecular Genetics of the Russian Academy of Sciences, where a series of short peptides were designed in the 1980s and 1990s. Selank was selected from variants of tuftsin that showed resistance to plasma peptidases. Russian regulatory approval covers it as an anxiolytic agent given intranasally. Outside that market the compound is normally handled as a research chemical rather than a medicine, and no widely recognised international pharmacopoeial monograph exists. The name Selank is a coined trade designation rather than a systematic chemical name.
Enzymatic stability motivates the extra three residues at the carboxyl end. Native tuftsin is cleaved quickly by circulating aminopeptidases and carboxypeptidases, which limits its duration of action and its usefulness as a tool compound. Extending the chain with proline-rich segments is a common design tactic because proline constrains the backbone and slows proteolysis. The same Pro-Gly-Pro motif appears in other Russian-developed peptides of the era. Whether the full seven-residue chain is required for activity, or whether it acts mainly as a prodrug releasing tuftsin, remains unresolved.
Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro. Its four N-terminal residues reproduce tuftsin, a tetrapeptide fragment of the immunoglobulin heavy chain, while the C-terminal Pro-Gly-Pro extension is a synthetic addition. The peptide has a molecular mass near 752 daltons and carries a net positive charge at physiological pH because of the arginine and lysine side chains. Published indexes list it under the name Selank and the sequence abbreviation TKPRPGP. Solid-phase peptide synthesis is the standard production route for research quantities.
Zinc is the fourth most common metal in use, trailing only iron, aluminium, and copper with an annual production of about 13 million tonnes. The world's largest zinc producer is Nyrstar, a merger of the Australian OZ Minerals and the Belgian Umicore. Nearly 70% of the world's zinc originates from mining, while over 30% comes from recycling secondary zinc. The proportion of recycled zinc is predicted to increase to over 50% by 2050.
Apart from the failed Third Period policy in the early 1930s, Marxist–Leninists played an important role in anti-fascist resistance movements, with the Soviet Union contributing to the Allied victory in World War II. In accordance with the three-power Yalta Agreement (4–11 February 1945), the Soviet Union purged native fascist collaborators and these in collaboration with the Axis Powers from the Eastern European countries occupied by the Axis Powers and installed native Marxist–Leninist governments.
=== Drug development === ITC can provide insights into drug development by charactering the affinity, selectivity, ligand-induced conformational changes, and drug partitioning into membranes. Binding affinity carries a huge importance in medicinal chemistry, as drugs need to bind to the protein effectively within a desired range. An exothermic binding process with a favorable enthalpy is considered a desirable characteristic for specific protein binders, as it indicates strong potential for optimization and high selectivity. However, determining enthalpy changes and optimization of thermodynamic parameters are hugely difficult when designing drugs. ITC troubleshoots this issue easily by deducing the binding affinity, enthalpic/entropic contributions and its binding stoichiometry.
Sources: en.wikipedia.org
On February 28, 2022, Pritzker lifted most of Illinois's COVID-19 restrictions, including the statewide mask mandate, which came just a few days after the CDC issued new, more relaxed masking guidance. On July 14, 2022, Pritzker announced the lifting of the COVID-19 vaccine mandate for college students.
=== Operation Inherent Resolve === On 19 December 2014, Stars & Stripes, a daily military newspaper, announced 1,000 soldiers from the 82nd Airborne's 3rd Brigade Combat Team would deploy to Iraq to train, advise, and assist Iraq's Security Forces. On 3 November 2016, it was reported that 1,700 soldiers from the 2d Brigade Combat Team will deploy to the US Central Command area of responsibility in Iraq, to take part in Operation Inherent Resolve. They will replace the 2d Brigade Combat Team, 101st Airborne Division and will advise and assist Iraqi Security Forces currently trying to retake Mosul from ISIS fighters. On 27 March 2017, it was reported that 300 paratroopers from the 82nd Airborne's 2nd Brigade Combat Team will temporarily deploy to northern Iraq to provide additional advise-and-assist combating ISIS, particularly to speed up the offensive against ISIS in Mosul. On 31 December 2019, approximately 750 soldiers from the 82nd Airborne's Immediate Response Force were authorized to be deployed to Iraq in response to events which saw the United States' embassy in the country stormed. From the start of January 2017 to September 2017, the division suffered the loss of five paratroopers killed in action.
==== Typical examples of patterns ==== For each of the functional entities (qi, xuĕ, zàng-fǔ, meridians etc.), typical disharmony patterns are recognized; for example: qi vacuity and qi stagnation in the case of qi; blood vacuity, blood stasis, and blood heat in the case of xuĕ; Spleen qi vacuity, Spleen yang vacuity, Spleen qi vacuity with down-bearing qi, Spleen qi vacuity with lack of blood containment, cold-damp invasion of the Spleen, damp-heat invasion of Spleen and Stomach in case of the Spleen zàng; wind/cold/damp invasion in the case of the meridians. TCM gives detailed prescriptions of these patterns regarding their typical symptoms, mostly including characteristic tongue and/or pulse findings. For example:
Latin and Greek were the primary languages of the late Roman Empire, with the former prevalent in the west and the latter in the east. Although Latin was historically important in the military, legal system, and government, its use declined in Byzantine territories from 400 AD. Greek had begun to replace it even in those functions by the time of Justinian I (r. 527–565), who may have tried to arrest Latin's decline. Its extinction in the east was thereafter inevitable. A similar process of linguistic Hellenization occurred in Asia Minor, whose inhabitants had mostly abandoned their indigenous languages for Greek by early Byzantine times. Still, much of the population of the early empire would have known neither Latin nor Greek, especially in rural areas—their languages included Armenian in Byzantine Armenia, Aramaic dialects such as Syriac in Mesopotamia and the Levant, Coptic in Egypt, Phoenician on the Levant coast and in Carthage, and Berber in rural North Africa. By the mid-6th century, Geoffrey Horrocks estimates that Greek was the native language of about one-third of the population, while it was spoken by 80% of the aristocracy. The empire lost its linguistic diversity in the wars of the 7th and 8th centuries, becoming overwhelmingly Greek-speaking. During this troubled period, classical Attic Greek—one of the linguistic registers the Byzantine Greeks inherited—fell out of use, while the everyday vernacular registers were still used.
Sources: en.wikipedia.org
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Sources: en.wikipedia.org
The sequence is Thr-Lys-Pro-Arg-Pro-Gly-Pro, commonly written as TKPRPGP. It shares the first four residues with tuftsin and carries three prolines in the chain. The proline-rich tail is the main structural feature that separates it from the parent tetrapeptide.
Selank is a synthetic analogue built on the tuftsin tetrapeptide Thr-Lys-Pro-Arg. Extra proline residues were added to the C-terminus during design work. That modification is intended to make the peptide less vulnerable to rapid enzymatic degradation.
Transliteration from Russian produces variant spellings such as Selanc. Many suppliers avoid the trade-style name entirely and list the peptide sequence. Comparing sequences rather than names is the reliable way to confirm two entries describe the same molecule.
The sequence is Thr-Lys-Pro-Arg-Pro-Gly-Pro, written TKPRPGP in one-letter code. It combines the tetrapeptide tuftsin with a carboxyl-terminal Pro-Gly-Pro extension. This full sequence identifies the molecule more precisely than the research name.