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Background And Molecular Identity — Questions and Answers

By Editorial Desk · published 2026-03-25 · last reviewed 2026-04-22 · Wiki

The short version of Research chemical fits in a sentence. The long version — which is the one that helps — is below.

This page was last updated on 2026-04-22 and is reviewed periodically as new material appears.

Background and Molecular Identity

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 Origin and Chemical Identity

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.

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 at a glance

PropertyValueNotes
Chemical classSynthetic heptapeptideTuftsin analogue with a C-terminal Pro-Gly-Pro tail
Amino acid sequenceThr-Lys-Pro-Arg-Pro-Gly-ProAbbreviated TKPRPGP in most catalogues
Molecular massAbout 752 DaValue for the free peptide
SolubilityFreely soluble in waterAqueous solutions are kept cold and used promptly
Typical storage-20 °C, dry, protected from lightApplies to the lyophilised powder before reconstitution

Identity and Structural Background

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, frequently abbreviated as TKPRPGP. It was designed as a structural analogue of tuftsin, a naturally occurring tetrapeptide released by enzymatic cleavage of the immunoglobulin heavy chain. The two additional proline residues at the C-terminal end extend the parent chain and change how the molecule behaves in solution. The free peptide has a calculated molecular mass of approximately 751.9 g/mol and is generally supplied as a lyophilised white to off-white powder.

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Storage, Analysis, and Regulatory Status

Selank is a hydrophilic peptide and dissolves readily in water and in aqueous buffers. The lyophilised powder is typically a white to off-white solid. Because short peptides are prone to hydrolysis and oxidation, handling benefits from limiting exposure to heat, moisture and strong light. Working solutions are commonly prepared in sterile water or saline, and repeated freeze-thaw cycles are avoided to reduce aggregation and loss of activity. These practices reflect general laboratory convention rather than published stability specifications.

Dry powder is normally held at -20 degrees Celsius or lower, in a sealed container with desiccant and protection from light. Reconstituted solutions are usually kept at 2 to 8 degrees Celsius for short periods and frozen for longer ones. Proline residues at several positions are generally associated with some resistance to peptidase attack, but chemical stability still declines at neutral to alkaline pH and at elevated temperature. Exact shelf-life figures are product-specific and are not standardised across suppliers.

Identity and purity are usually assessed by reversed-phase high-performance liquid chromatography, with mass spectrometry used to confirm molecular mass and sequence information. Amino acid analysis and peptide mapping may supplement these methods. Certified reference standards are scarce, and many commercial lots are sold as research chemicals without a pharmacopoeial monograph. Regulatory treatment differs by country: Selank is a registered prescription medicine in Russia, while in the European Union and the United States it is not an approved drug and may fall under research-chemical or unapproved-product frameworks.

Supporting material

=== Diplomatic espionage === French diplomat Talleyrand served as a source of intelligence for the Coalition powers against Napoleon. At the Congress of Erfurt in September–October 1808, Talleyrand secretly counseled Tsar Alexander. Alexander's attitude towards Napoleon was one of apprehensive opposition. Talleyrand believed Napoleon would eventually destroy the empire he had worked to build across multiple rulers. After his resignation in 1807 from the ministry, Talleyrand began to accept bribes from hostile powers (mainly Austria, but also Russia), to betray Napoleon's secrets. Various agents of Napoleon were known such as Madame d'Oettlinger.

== External links == The Encyclopaedia of Actin-Binding Proteins (and Drugs)– alphabetical list, sourced profile for each Maciver, Sutherland (ed.). "The Encyclopaedia of Actin-Binding Proteins (and Drugs)". Maciver Lab Web Page (online ed.). School of Biomedical Sciences, University of Edinburgh. Archived from the original on 2005-11-24. Actin-Binding+Proteins at the U.S. National Library of Medicine Medical Subject Headings (MeSH)

Mirodenafil is a PDE5 inhibitor used to treat erectile dysfunction. Developed by SK Chemicals Life Science, mirodenafil is marketed in Korea under the brand name Mvix, offered both as tablets (50 mg and 100 mg) and as orally dissolving films (50 mg). Despite several clinical trials having been conducted, mirodenafil has not been approved for use in the United States by the US Food and Drug Administration.

Sources: en.wikipedia.org

Supporting material

=== Fluid replacement === The amount of fluid replaced depends on the estimated degree of dehydration. If dehydration is so severe as to cause shock (severely decreased blood pressure with insufficient blood supply to the body's organs), or a depressed level of consciousness, rapid infusion of saline (1 liter for adults, 10 mL/kg in repeated doses for children) is recommended to restore circulating volume. Slower rehydration based on calculated water and sodium shortage may be possible if the dehydration is moderate, and again saline is the recommended fluid. Very mild ketoacidosis with no associated vomiting and mild dehydration may be treated with oral rehydration and subcutaneous rather than intravenous insulin under observation for signs of deterioration. Normal saline (0.9% saline) has generally been the fluid of choice. There have been a few small trials looking at balanced fluids with few differences. A special but unusual consideration is cardiogenic shock, where the blood pressure is decreased not due to dehydration but due to the inability of the heart to pump blood through the blood vessels. This situation requires ICU admission, monitoring of the central venous pressure (which requires the insertion of a central venous catheter in a large upper body vein), and the administration of medication that increases the heart pumping action and blood pressure.

== Revival of fine teas == Yellow and white teas became difficult to find in the United States and even green tea had become uncommon because of the People's Republic of China's ban on exports to the U.S. After the ban was lifted in 1971, these teas typical to China re-entered the American market for the first time since the first two decades of the 20th century. In the early 1980s, a mini-revival of demand for better quality teas from all origins occurred in the United States. Prior to this time, much of the tea available in 20th century U.S. was blended specifically for gallon and half-gallon sized iced tea bags, with the quality of not "creaming down" (a creamy looking color that imparts to some teas after cooling down) when iced as a needed aspect; "clear-liquoring" teas were required. Most iced tea blends in the U.S. have traditionally been made from the teas of Indonesia, Sri Lanka, Kenya, Argentina and Malawi. A recent rise in the demand for orthodox tea in both gallon and half-gallon iced tea bags, as well as 500 and 1,000 gram loose tea packs has caused manufacturers to reinstate orthodox manufacturing methods. This is a departure from the more common Sri Lankan, Indonesian, Argentinian and other nations' orthodox rotorvane tea-making method which has limitations and can not produce whole leaf black tea. The rotorvane method was adopted primarily to satisfy the demand for the smaller leaf sizes that fit into small (1-2 gram) tea bag blends worldwide starting in the early 20th century.}

Kahala Brands is a wholly owned subsidiary of Canada-based MTY Food Group Inc. of Montreal, Quebec. Based in Scottsdale, Arizona, Kahala is one of North America's largest holding company of franchise fast food restaurant companies. In May 2016, the publicly traded Canadian MTY Food Group announced a friendly takeover deal with the Kahala Brands. MTY agreed to pay about US$300 million to acquire Kahala. The two companies generated nearly $2 billion in revenues in the previous year. Jeff Smit was chosen to lead the US operations of MTY.

=== Stress/ Hypothalamic-pituitary-adrenal (HPA) axis === GHSR1A, Ghrelin's endogenous receptor, is expressed within the hypothalamus including the arcuate nucleus, but not in the paraventricular nucleus (PVN) where ghrelin has been found to indirectly affect HPA axis function via neighboring corticotropin releasing hormone (CRH) neurons. Studies regarding how ghrelin affects cortisol and adrenocorticotropic hormone (ACTH) secretion along with how cortisol and ACTH levels affect ghrelin are inconsistent as different psychological and physical stressors within in-vivo studies have produced a myriad of results as the underlying mechanisms are still not understood well.

Sources: en.wikipedia.org

Frequently asked questions

What is Selank chemically?

Selank is a seven-amino-acid peptide built from the tuftsin sequence plus a Pro-Gly-Pro tail. It is produced by chemical synthesis rather than extracted from a natural source. The free peptide is usually supplied as a lyophilised powder or in an aqueous formulation.

How does Selank relate to tuftsin?

Tuftsin is a natural tetrapeptide derived from the Fc portion of immunoglobulin G. Selank retains that tetrapeptide at its N-terminus and adds three residues to improve resistance to enzymatic breakdown. The relationship is structural, and the two molecules are not interchangeable in experimental work.

Is Selank an approved medicine?

It holds a product registration in Russia for intranasal use as an anxiolytic. Registrations of that kind are not automatically accepted by regulators elsewhere. In most other countries it is treated as an unapproved substance or a research material.

What is Selank?

Selank is a synthetic seven-amino-acid peptide modeled on tuftsin, a fragment of the immunoglobulin G heavy chain. It was designed in Russia to combine anxiolytic and immunomodulatory properties in one molecule.

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