en · de · es · fr · pt
selank-notes.peptides9002.com › Topic › Selank Background And Chemical Identity — What the Evidence Shows

Selank Background And Chemical Identity — What the Evidence Shows

By Editorial Desk · published 2025-12-23 · last reviewed 2026-01-23 · Topic

This is a working overview of Selank, written for readers who want more than a one-paragraph summary but less than a textbook.

This page was last updated on 2026-01-23 and is reviewed periodically as new material appears.

Selank Background And Chemical Identity

Selank is a synthetic heptapeptide developed in Russia during the 1990s. Researchers at the Institute of Molecular Genetics of the Russian Academy of Sciences designed it as a stabilized analog of tuftsin, a naturally occurring immunomodulatory tetrapeptide. The compound has been studied primarily for its reported anxiolytic and nootropic effects. It remains largely unknown in Western pharmacology and is not approved as a medicine by major regulators such as the FDA or the EMA.

The primary structure of Selank is Thr-Lys-Pro-Arg-Pro-Gly-Pro, corresponding to the molecular formula C33H57N11O9 and a monoisotopic mass of roughly 751.9 daltons. The N-terminal threonine and the arginine residue in the fourth position are shared with tuftsin, which carries the sequence Thr-Lys-Pro-Arg. The three additional residues at the C-terminus, Pro-Gly-Pro, extend the chain and are associated with greater resistance to enzymatic degradation. This extension also separates Selank from the shorter parent peptide.

Naming conventions place Selank in the same research family as Semax, another Russian-developed peptide investigated for cognitive effects. The two compounds share a lineage but differ in sequence and in the biological systems proposed as their targets. Semax descends from ACTH fragments, whereas Selank descends from tuftsin. Publications sometimes identify Selank by its full peptide sequence or by laboratory codes rather than one uniform trade name. Because replication outside Russia is limited, reports on its properties are best read alongside the study design and the purity of the material tested.

Peptide Identity and Structure

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.

Selank at a glance

PropertyValueNotes
Molecular classSynthetic heptapeptideStabilized analog of tuftsin
SequenceThr-Lys-Pro-Arg-Pro-Gly-ProSingle-letter form: TKPRPGP
Molecular formulaC33H57N11O9Monoisotopic mass about 751.9 Da
AppearanceWhite to off-white powderTypically supplied as lyophilized solid
SolubilityFreely soluble in waterAlso soluble in common polar solvents

Background and Peptide Identity

Selank is a synthetic heptapeptide developed in Russia. Its sequence is Thr-Lys-Pro-Arg-Pro-Gly-Pro, a seven-residue chain built around the natural tetrapeptide tuftsin. Researchers at the Institute of Molecular Genetics of the Russian Academy of Sciences first described the compound in the mid-1990s. The design combined the tuftsin core with an added Pro-Gly-Pro tail, a modification intended to extend the molecule's stability in biological fluids. Published work on the peptide has appeared mainly in Russian-language journals.

Reported activity for Selank centers on anxiolytic and nootropic effects. Russian clinical reports describe use in anxiety and in cognitive or attention-related complaints. Most of this evidence comes from studies conducted by the same research groups that developed the peptide. Independent replication in other countries remains limited, and no major Western regulatory agency has approved the compound for any indication. The gap between local reports and external verification is a recurring point in discussions of the peptide.

Related pages on this site

Background and Molecular Identity

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.

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.

Analytical Methods And Storage Stability

Characterization of Selank in laboratory settings relies on standard peptide analytical techniques. Reverse-phase high-performance liquid chromatography separates the peptide from related impurities and degradation products, while mass spectrometry confirms molecular identity through accurate mass measurement. Amino acid analysis and peptide sequencing verify the primary structure when reference material is unavailable. Because Selank is a short chain, fragmentation-based analysis produces a diagnostic ion pattern that supports confident identification.

Peptide stability depends strongly on temperature, moisture, and pH. Lyophilized Selank is generally most stable when stored cold and dry, with freezer temperatures commonly used for long-term storage. In solution, the compound is susceptible to hydrolysis and to microbial growth if it is not handled aseptically. The C-terminal proline-rich extension appears to slow enzymatic cleavage relative to tuftsin, though quantitative degradation rates vary with the matrix and the conditions tested. Published stability data specific to Selank remain sparse.

Notes from published material

Calcium isotope fractionation during mineral formation has led to several applications of calcium isotopes. In particular, the 1997 observation by Skulan and DePaolo that calcium minerals are isotopically lighter than the solutions from which the minerals precipitate is the basis of analogous applications in medicine and in paleoceanography. In animals with skeletons mineralised with calcium, the calcium isotopic composition of soft tissues reflects the relative rate of formation and dissolution of skeletal mineral. In humans, changes in the calcium isotopic composition of urine have been shown to be related to changes in bone mineral balance. When the rate of bone formation exceeds the rate of bone resorption, the 44Ca/40Ca ratio in soft tissue rises and vice versa. Because of this relationship, calcium isotopic measurements of urine or blood may be useful in the early detection of metabolic bone diseases like osteoporosis. A similar system exists in seawater, where 44Ca/40Ca tends to rise when the rate of removal of Ca2+ by mineral precipitation exceeds the input of new calcium into the ocean. In 1997, Skulan and DePaolo presented the first evidence of change in seawater 44Ca/40Ca over geologic time, along with a theoretical explanation of these changes. More recent papers have confirmed this observation, demonstrating that seawater Ca2+ concentration is not constant, and that the ocean is never in a "steady state" with respect to calcium input and output. This has important climatological implications, as the marine calcium cycle is closely tied to the carbon cycle.

== Mechanism of action == Gliclazide selectively binds to sulfonylurea receptors (SUR-1) on the surface of the pancreatic beta-cells. It was shown to provide cardiovascular protection as it does not bind to sulfonylurea receptors (SUR-2A) in the heart. This binding effectively closes these K+ ion channels. This decreases the efflux of potassium from the cell which leads to the depolarization of the cell. This causes voltage dependent Ca2+ ion channels to open increasing the Ca2+ influx. The calcium can then bind to and activate calmodulin which in turn leads to exocytosis of insulin vesicles leading to insulin release. The mouse model of Maturity-onset diabetes of the young (MODY) diabetes suggested that the reduced gliclazide clearance stands behind their therapeutic success in human MODY patients, but Urbanova et al. found that human MODY patients respond differently and that there was no consistent decrease in gliclazide clearance in randomly selected HNF1A-MODY and HNF4A-MODY patients. Its classification has been ambiguous, as literature uses it as both a first-generation and second-generation sulfonylurea.

=== 13-31 August 2008 === An anonymous U.S. functionary said: "Saakashvili had always told us he could not stand by while Georgian villages were being shelled, and we always knew this was a point of pressure. We always told him that he should not give in to the kind of provocations we knew the Russians were capable of." In August 2008, Modest Kolerov, former head of the Department for international and cultural ties with foreign countries of the President's Office, admitted that the Kremlin had "a clear plan of action in the case of a conflict", and "the expediency with which the military operation was executed confirms that." Robert Gates, United States Secretary of Defense, said on August 14 that there had been clashes with the South Ossetian forces each August since 2004, but "This year it escalated very quickly and it seemed to me that Russians were prepared to take advantage of an opportunity and did so very aggressively." Zbigniew Brzezinski compared Russia's attack on Georgia to the Soviet attack on Finland and wrote that "Moscow was waiting for such an act to provide a pretext for the use of force." He suggested that Russia could attack Ukraine and other post-Soviet countries were not safe. Ralph Peters, a former military intelligence analyst, and several western diplomats (a western diplomat with contacts with the Georgians and a western mediator acquainted with Saakashvili) said that it was Russia who was provoking Georgia. It was reported that the United States had prevented Saakashvili from taking military action in Abkhazia in early May 2008.

Sources: en.wikipedia.org

Background from the literature

=== Oncolytic virus === An oncolytic virus is a virus that preferentially infects and kills cancer cells. As the infected cancer cells are destroyed by oncolysis, they release new infectious virus particles or virions to help destroy the remaining tumour. Oncolytic viruses are thought not only to cause direct destruction of the tumour cells, but also to stimulate host anti-tumour immune responses for long-term immunotherapy. The potential of viruses as anti-cancer agents was first realized in the early twentieth century, although coordinated research efforts did not begin until the 1960s. A number of viruses including adenovirus, reovirus, measles, herpes simplex, Newcastle disease virus and vaccinia have now been clinically tested as oncolytic agents. T-Vec is the first FDA-approved oncolytic virus for the treatment of melanoma. A number of other oncolytic viruses are in Phase II-III development.

=== Silica gel drying === Another trend is silica gel. Its initial cost is greater than that of borax-sand or borax-cornmeal combinations, but silica gel can be used over and over for many years. Silica gel dries flowers quickly, so it can be used to dry more flowers during a single season than the same quantity of a borax mixture. Silica gel is available under a number of trade names. It is white, but some types contain blue crystals that act as an indicator of the amount of moisture that has been absorbed. When these crystals are clear blue, the material is dry. As moisture is absorbed from the flowers, the crystals gradually turn pink. At that point, it is time to re-dry the crystals before using them again. To dry the material, silica gel is spread on open pans or cookie sheets in a layer 10–20 mm (1⁄2–3⁄4 in) thick. Materials to be preserved are then baked in an oven at 250˚Celsius for about an hour, or until the moisture-indicating crystals, if present, are blue again. Material is then stirred several times while drying. Flowers dried in silica gel must be placed in airtight containers. If a container is not sealed tightly, the silica gel absorbs moisture from the air, and flowers dry too slowly or not at all. A candy tin, plastic container, coffee can, large-mouth jar or any other container with a tight-fitting lid may be used. If no containers with tight lids are available, loose tops should be sealed with tape. Silica gel is especially useful for drying fragile plants and flowers with delicate colors.

== External South African operations (1978–1984) == Access to Angola provided PLAN with limitless opportunities to train its forces in secure sanctuaries and infiltrate insurgents and supplies across South West Africa's northern border. The guerrillas gained a great deal of leeway to manage their logistical operations through Angola's Moçâmedes District, using the ports, roads, and railways from the sea to supply their forward operating bases. Soviet vessels offloaded arms at the port of Moçâmedes, which were then transshipped by rail to Lubango and from there through a chain of PLAN supply routes snaking their way south towards the border. "Our geographic isolation was over," Nujoma commented in his memoirs. "It was as if a locked door had suddenly swung open...we could at last make direct attacks across our northern frontier and send in our forces and weapons on a large scale." In the territories of Ovamboland, Kaokoland, Kavangoland and East Caprivi after 1976, the SADF installed fixed defences against infiltration, employing two parallel electrified fences and motion sensors. The system was backed by roving patrols drawn from Eland armoured car squadrons, motorised infantry, canine units, horsemen and scrambler motorcycles for mobility and speed over rough terrain; local San trackers, Ovambo paramilitaries, and South African special forces. PLAN attempted hit-and-run raids across the border but, in what was characterised as the "corporal's war", SADF sections largely intercepted them in the Cutline before they could get any further into South West Africa itself.

Sources: en.wikipedia.org

Frequently asked questions

What is Selank?

Selank is a synthetic heptapeptide designed as a stabilized analog of the natural tetrapeptide tuftsin. It has been investigated mainly for anxiolytic and cognitive effects. It is not an approved pharmaceutical in most countries.

Where was Selank developed?

It was developed in Russia, at the Institute of Molecular Genetics of the Russian Academy of Sciences, during the 1990s. Most published research originates from Russian institutions. Independent international replication remains limited.

How does Selank differ from tuftsin?

Tuftsin is a natural tetrapeptide with the sequence Thr-Lys-Pro-Arg that participates in immune signaling. Selank extends that sequence with Pro-Gly-Pro at the C-terminus. The added residues are linked to greater resistance to enzymatic breakdown.

What is the primary sequence of Selank?

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.

Network