Selank comes up often in conversation and rarely with the context attached. Here we lay out the basics in order, then work through the practical considerations.
Last reviewed on 2025-12-17. Where a claim depends on a specific study, the study is described rather than over-claimed.
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 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.
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.
| Property | Value | Notes |
|---|---|---|
| Peptide sequence | Thr-Lys-Pro-Arg-Pro-Gly-Pro | Seven residues; tuftsin plus a Pro-Gly-Pro tail |
| Molecular formula | C33H57N11O9 | Commonly reported value for the free peptide |
| Monoisotopic mass | Roughly 751.4 Da | Average molecular mass near 751.9 Da |
| Appearance | White to off-white powder | Typically supplied as a lyophilized solid |
| Solubility class | Freely soluble in water | Also dissolves in saline and other polar solvents |
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.
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.
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.
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.
Quantification in biological matrices relies on liquid chromatography coupled to tandem mass spectrometry with stable-isotope internal standards. Low plasma concentrations and adsorption to container surfaces both complicate measurement. Solid-phase extraction is often needed to reduce matrix interference before injection. Reported limits of quantification differ widely between laboratories, which makes direct comparison of pharmacokinetic results difficult and limits meta-analysis.
Peptide bonds are vulnerable to protease attack, and Selank is no exception. Measured half-life in serum is short, on the order of minutes in several reports, which explains why intranasal administration is the common route described in the literature. Absorption across the nasal mucosa partially bypasses first-pass hepatic metabolism. Quantitative data on human bioavailability remain limited and are difficult to compare across studies.
Lyophilised material kept dry at minus 20 degrees Celsius or colder is the most stable form, and suppliers commonly state a shelf life of two years or more under those conditions. Once dissolved, degradation accelerates through hydrolysis and deamidation, particularly at alkaline pH or elevated temperature. Working solutions are usually divided into single-use aliquots to avoid repeated freeze-thaw cycles. The choice of reconstitution solvent affects both stability and the ionic strength of the final preparation.
Published work on this peptide almost always uses intranasal delivery, with drops or a spray applied to the nasal mucosa. Some animal experiments have used subcutaneous or intraperitoneal injection, and a smaller number have compared routes directly. Oral administration is not a focus of the literature, because short peptides of this size are broken down by digestive enzymes and cross intestinal barriers poorly. How much of an intranasal dose reaches the bloodstream intact in humans remains an open question.
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.
=== Brad Scott Era (2023–2026) === In 2023, reports emerged claiming that the club was reconsidering its logo. These included rumours that the bomber logo was insensitive due to the operation of bomber jets in conflict. These reports were denied by then-captain Zach Merrett. At the end of the 2023 season, it was announced that former West Coast and Gold Coast player Matt Rosa would join Essendon as Talent & Operations Manager and that Adrian Dodoro would step back from his position of recruiting manager after the upcoming trade and draft periods. In Brad Scott's first season as coach, Essendon sat in fifth position after round 17, but their form fell off later in the season to finish 11th with 11 wins and 12 losses. In Brad Scott's second season as coach, Essendon finished with a win–draw–loss record of 11–1–11. On 13 August 2024 club champion Dyson Heppell announced he would retire at the end of the season after playing 253 games for the club. Heppell was the final player of the Essendon 34 still playing at the club. Brad Scott’s third season as coach was less successful, with Essendon finishing the season with just 6 wins and 17 losses, failing to win a game after Round 11. The season was marked by injury, resulting in the bombers breaking the record for the most players debuted in a season at 15, surpassing Fitzroy who previously held the record with 13 debutants. Essendon announced part way through the season that head of high performance Suan Murphy and the club would part ways. Mathew Inness was announced as his replacement in September after the end of the season.
Racial disparities have been a prominent and contentious aspect of the war on drugs in the US. In 1957, a belief at the time about drug use was summarized by journalist Max Lerner in his work, America as a Civilization: "As a case in point we may take the known fact of the prevalence of reefer and dope addiction in Negro areas. This is essentially explained in terms of poverty, slum living, and broken families, yet it would be easy to show the lack of drug addiction among other ethnic groups where the same conditions apply." The Anti-Drug Abuse Act of 1986 created a 100:1 sentencing disparity in the US for the trafficking or possession of crack when compared to penalties for trafficking of powder cocaine. The bill had been widely criticized as discriminatory against minorities, mostly blacks, who were more likely to use crack than powder cocaine. In 1994, studying the effects of the 100:1 sentencing ratio, the United States Sentencing Commission (USSC) found that nearly two-thirds of crack users were white or Hispanic, while nearly 85% of those convicted for possession were black, with similar numbers for trafficking. Powder cocaine offenders were more equally divided across race. The USSC noted that these disparities resulted in African Americans serving longer prison sentences than other ethnicities. In a 1995 report to Congress, the USSC recommended against the 100:1 sentencing ratio. In 2010, the 100:1 sentencing ratio was reduced to 18:1. Other studies indicated similarly dramatic racial differences in enforcement and sentencing.
=== Metabolic dysfunction–associated steatotic liver disease === A 2023 systematic review reported that GLP-1 agonists are as effective a treatment for metabolic dysfunction–associated steatotic liver disease (MASLD) as the medications in current use, pioglitazone and vitamin E. It noted a reduction in steatosis, ballooning necrosis, lobular inflammation, and fibrosis. Wegovy (semaglutide) is approved by the FDA to treat MASH (metabolic dysfunction-associated steatohepatitis) with stage 2 or stage 3 liver fibrosis. The mechanism of action for this treatment is under investigation, but part 1 of its stage 3 clinical trials saw a 60% reduction in liver inflammation. Clinical trials are ongoing.
Dihydrocodeine products which can be purchased over the counter in many European and Pacific Rim countries generally contain from 2 to 20 mg of dihydrocodeine per dosing unit combined with one or more other active ingredients such as paracetamol (acetaminophen), aspirin, ibuprofen, antihistamines, decongestants, vitamins, medicinal herb preparations, and other such ingredients. In a subset of these countries and foreign possessions, 30 mg tablets and 60 mg controlled-release tablets are available over the counter and chemists may very well be able to dispense the 90 and 120 mg strengths at their discretion. In the United States, the most common analgesic brands with dihydrocodeine are: DHC Plus (16 and 32 mg), Panlor SS (32 mg), ZerLor (32 mg), Panlor DC (16 mg) and Synalgos DC (16 mg). These combination products also include paracetamol (acetaminophen) and caffeine. Aspirin is used in the case of Synalgos DC. Dihydrocodeine is sometimes marketed in combination preparations with paracetamol as co-dydramol (BAN) to provide greater pain relief than either agent used singly (see Synergy § Drug synergy). In the UK and other countries, 30 mg tablets containing only dihydrocodeine as the active ingredient are available, also a 40 mg Dihydrocodeine tablet is available in the UK as DF-118 Forte. The original dihydrocodeine product, Paracodin, is an elixir of dihydrocodeine hydroiodide also available as a Tussionex-style suspension in many European countries.
=== Artificial synthesis === Prostacyclin can be synthesized from the methyl ester of prostaglandin F2α. After its synthesis, the drug is reconstituted in saline and glycerin. Because prostacyclin is so chemically labile, quantitation of their inactive metabolites, rather than the active compounds, is used to assess their rate of synthesis.
Sources: en.wikipedia.org
The glycolytic end-product, pyruvate (plus NAD+) is converted to acetyl-CoA, CO2 and NADH + H+ within the mitochondria in a process called pyruvate decarboxylation. The resulting acetyl-CoA enters the citric acid cycle (or Krebs Cycle), where the acetyl group of the acetyl-CoA is converted into carbon dioxide by two decarboxylation reactions with the formation of yet more intra-mitochondrial NADH + H+. The intra-mitochondrial NADH + H+ is oxidized to NAD+ by the electron transport chain, using oxygen as the final electron acceptor to form water. The energy released during this process is used to create a hydrogen ion (or proton) gradient across the inner membrane of the mitochondrion. Finally, the proton gradient is used to produce about 2.5 ATP for every NADH + H+ oxidized in a process called oxidative phosphorylation.
==== Second state of emergency: June 1986 ==== The partial emergency was lifted on 7 March 1986, only to be replaced on 12 June – in the run-up to the tenth anniversary of the Soweto uprising on 16 June – by a second, far more stringent state of emergency, now applying across the country. Among other things, the new order empowered any member of the police or army to use any kind of force deemed necessary to clear an area. With the death toll by then "far in excess of 1,600", Botha told Parliament, "I am of the opinion that the ordinary laws of the land at present on the statute book are inadequate to enable the government to insure the security of the public and to maintain public order". The government said that it detained more than 1,000 people on the first day of the emergency; 30,000 were detained by August 1987. Indeed, the primary use of the emergency orders was to enable mass and indefinite detention of those viewed by the government as the ringleaders or instigators of the unrest. Critics of the government argued that this was deeply counterproductive, as the putative ringleaders were generally "simply the most articulate and experienced activists", the removal of whom "created a political vacuum into which unruly, undisciplined elements surged". In the phrase of the UDF's Murphy Morobe (speaking to press while in hiding to evade arrest), "Removing responsible leaders of the people has effectively paved the way for a blood bath". Desmond Tutu lamented as early as May 1986 that the government "have arrested the very people they should be talking to...
===== Mechanism of a single selectin binding ===== A single PSGL-1 and selectin binding is similar to conventional protein binding when the force is kept constant, with a dissociation constant. As the force exerted starts to increase, the dissociation constant decreases, causing binding to become stronger. As the force reach a threshold level of 11 pN, the dissociation constant starts to increase again, weakening the bond, causing the bond to exhibit a slip bond property.
Melamine is used to manufacture melamine-formaldehyde resin, a type of plastic known for its flame-retardant properties and commonly employed in countertops, dry-erase boards, etc. It has also been employed as a non-protein nitrogen, appearing in soy meal, corn gluten meal and cottonseed meal used in cattle feed. Melamine is known to cause kidney failure and kidney stones in humans and animals when it reacts with cyanuric acid inside the body. The use of melamine in food production is not approved by the World Health Organization (WHO) or national authorities. Melamine is nitrogen-rich, so it is sometimes illegally added to food products to increase their apparent protein content. The Kjeldahl and Dumas methods used to test for protein levels fail to distinguish between nitrogen in melamine and naturally occurring nitrogen in amino acids, allowing the protein levels to be falsified. Introduced into milk, it can help conceal fraudulent dilution with water. Melamine adulteration of food products also made headlines when pet food was recalled in Europe and the U.S. in 2007.
The mevalonate pathway (also called HMG-CoA reductase pathway) begins with acetyl-CoA and ends with dimethylallyl diphosphate (DMAPP) and isopentenyl diphosphate (IPP). DMAPP and IPP donate isoprene units, which are assembled and modified to form terpenes and isoprenoids (a large class of lipids, which include the carotenoids and form the largest class of plant natural products). Here, the activated isoprene units are joined to make squalene and folded into a set of rings to make lanosterol. Lanosterol can then be converted into other steroids, such as cholesterol and ergosterol.
Sources: en.wikipedia.org
Neo and Trinity try to jack out, but Cypher threatens to unplug them too; however, he is thwarted when Tank recovers, killing Cypher and helping Neo and Trinity jack out. Neo learns that the Agents seek to hack into Morpheus's brain in order to force him to tell them the access codes to the mainframe computer within humanity's last refuge, the city of Zion. After refusing to sacrifice Morpheus to prevent this, Neo decides to jack in and attack the building where he is being held. He and Trinity proceed to fight their way to the roof level of the building, where they are confronted by agent Jones. Neo unloads two entire magazines on Jones as he dodges each bullet effortlessly. When Jones returns fire, Neo proves capable of dodging bullets himself, fluidly moving in a way only an agent was thought to be capable of, although he is not yet as fast as them, as his leg is grazed by a bullet. Trinity then shoots Jones at point-blank range. Using an armed chopper, Neo and Trinity successfully rescue Morpheus. As Neo has just successfully rescued comrades from a building protected by heavily armed guards and agents (thought to be an unprecedented feat), Tank and Morpheus both believe that Neo is indeed the One. Neo tries to tell Morpheus what the Oracle told him, but Morpheus explains that she merely told Neo what he needed to hear; had he believed himself to be the One, he would likely not have attempted the rescue, which was a necessary step to his emergence as the One. Reaching the landline phone, Morpheus and Trinity return to the real world, but Neo is trapped by agent Smith.
Maggot debridement therapy (also known as MDT, larval therapy, or simply maggot therapy) is a type of biotherapy involving the introduction of live, disinfected maggots into non-healing skin and soft-tissue wounds of a human or other animal for the purpose of cleaning out the necrotic tissue within a wound (debridement), and disinfection. There is evidence that maggot therapy may help with wound healing.
== Cells in APUD system == Anterior pituitary Neurons of hypothalamus Chief cells of parathyroid Adrenal medullary cells Glomus cells in carotid body Melanocytes of skin Cells of pineal gland Renin producing cells in the kidney
=== October === 1 October – A ban on single-use plastic cutlery, plates and polystyrene trays comes into force in England. 2 October – NHS doctors in England begin a 72-hour strike as their dispute over pay and conditions continues. Education Secretary Gillian Keegan announces plans to ban pupils from using mobile phones at schools, both in lessons and during breaktime. A gas tank explodes at the Severn Trent Green Power site in Cassington, Oxfordshire, after it is struck by lightning. A boy is taken to hospital in a critical condition along with a man in his 50s after both are hit by lightning during a football match at The Sele School in Hertford. 3 October – Appearing at Sheffield Crown Court, a 13-year-old boy admits causing the death of Marcia Grant, 60, by running her over with her own car in the Greenhill area of Sheffield in April 2023. Following a trial at Worcester Crown Court, food processing factory worker Garry Jones, who contaminated food destined for Nando's with plastic gloves, plastic bags and metal ring pulls is sentenced to three years in prison. 4 October – Sunak confirms plans to replace A Levels and T Levels in England with a new qualification called the Advanced British Standard. 5 October – Historic England says it has discovered damage to Hadrian's Wall next to the felled Sycamore Gap Tree. An inquest is opened and adjourned into the M53 motorway coach crash. 8 October – Part of the Grade II listed Old Courthouse in Cockermouth, Cumbria, collapses into the River Cocker.
1787–1797: Self-taught Chinese astronomer Wang Zhenyi published at least twelve books and multiple articles on astronomy and mathematics. Using a lamp, a mirror and a table, she once created a famous scientific exhibit designed to accurately simulate a lunar eclipse. 1786–1797: German astronomer Caroline Herschel discovered eight new comets, along with numerous other discoveries. 1789: French astronomer Louise du Pierry, the first Parisian woman to become an astronomy professor, taught the first astronomy courses specifically open to female students. 1794: British chemist Elizabeth Fulhame invented the concept of catalysis and published a book on her findings. c. 1796–1820: During the reign of the Jiaqing Emperor, astronomer Huang Lü became the first Chinese woman to work with optics and photographic images. She developed a telescope that could take simple photographic images using photosensitive paper. 1797: English science writer and schoolmistress Margaret Bryan published A Compendious System of Astronomy, including an engraving of herself and her two daughters. She dedicated the book to her students.
Sources: en.wikipedia.org
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.
No peptide with this exact sequence has been identified as an endogenous substance. It is a laboratory-designed analog of tuftsin, a naturally occurring immunomodulatory tetrapeptide. The Pro-Gly-Pro extension has no known natural source.
Proline introduces conformational constraints that make a peptide less accessible to common peptidases. This is a standard stabilization strategy in peptide design. The added residues also increase the distance between the active tuftsin portion and typical cleavage sites.
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.