A practical reference on Regulatory peptide: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
This page was last updated on 2025-09-12 and is reviewed periodically as new material appears.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Molecular class | Synthetic heptapeptide | Stabilized analog of tuftsin |
| Sequence | Thr-Lys-Pro-Arg-Pro-Gly-Pro | Single-letter form: TKPRPGP |
| Molecular formula | C33H57N11O9 | Monoisotopic mass about 751.9 Da |
| Appearance | White to off-white powder | Typically supplied as lyophilized solid |
| Solubility | Freely soluble in water | Also soluble in common polar solvents |
Proposed mechanisms centre on the GABAergic system. Animal and tissue studies report changes in GABA-A receptor expression and reduced activity of GABA transaminase, the enzyme that degrades GABA. Effects on monoamine turnover, including serotonin and dopamine pathways, are also described, and a separate line of work links the peptide to increased expression of brain-derived neurotrophic factor in hippocampal tissue. Most of these findings come from rodent models and cell preparations. How the individual observations combine into a single coherent mode of action is not settled.
Pharmacokinetic data are sparse and largely derived from animal work. After intranasal administration the peptide appears in plasma within minutes, and reported half-lives are short, on the order of minutes to tens of minutes. Degradation proceeds through ordinary proteolytic cleavage into constituent amino acids and smaller fragments. Direct evidence that intact Selank reaches brain tissue in meaningful amounts is limited, and the extent of blood-brain barrier penetration is debated. Some authors argue that fragments, not the parent peptide, carry much of the observed activity.
Published clinical work is concentrated in Russian-language journals and generally involves small samples without independent replication. Systematic reviews in English note the shortage of randomised, placebo-controlled trials and the difficulty of verifying methods from translated reports. Outcome measures vary between studies, which complicates pooling of results. Interest in the compound as a cognitive or anxiolytic agent therefore rests on a thinner evidence base than the volume of citations suggests. Replication in well-powered trials with preregistered endpoints would be needed before firm conclusions about efficacy can be drawn.
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 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. 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.
== Experimental chemistry == In 1995, the first report on attempted isolation of the element was unsuccessful, prompting new theoretical studies to investigate how best to investigate bohrium (using its lighter homologs technetium and rhenium for comparison) and removing unwanted contaminating elements such as the trivalent actinides, the group 5 elements, and polonium. In 2000, it was confirmed that although relativistic effects are important, bohrium behaves like a typical group 7 element. A team at the Paul Scherrer Institute (PSI) conducted a chemistry reaction using six atoms of 267Bh produced in the reaction between 249Bk and 22Ne ions. The resulting atoms were thermalised and reacted with a HCl/O2 mixture to form a volatile oxychloride. The reaction also produced isotopes of its lighter homologues, technetium (as 108Tc) and rhenium (as 169Re). The isothermal adsorption curves were measured and gave strong evidence for the formation of a volatile oxychloride with properties similar to that of rhenium oxychloride. This placed bohrium as a typical member of group 7. The adsorption enthalpies of the oxychlorides of technetium, rhenium, and bohrium were measured in this experiment, agreeing very well with the theoretical predictions and implying a sequence of decreasing oxychloride volatility down group 7 of TcO3Cl > ReO3Cl > BhO3Cl.
== Medical uses == Insulin degludec is indicated to improve glycemic control in people with diabetes. In a meta-analysis involving data from 3 randomized controlled trials having 1171 patients, thrice weekly insulin degludec had similar efficacy as daily insulin glargine injections with regards to the fasting blood glucose reduction, having similar safety and risk of low blood glucose (hypoglycaemia) profile. However the overall HbA1c reduction with thrice weekly insulin degludec injection was marginally lower than that of daily insulin glargine injections. Hence thrice weekly degludec injections can be considered in extremely needle prick phobic patients as a choice for basal insulin therapy.
Latynina noted that while Kokoity and Russia had been preparing to defend from the Georgian attack for 4 years, there was no bomb shelter in the headquarters of Russian peacekeepers. Latynina finally concluded that by the time when Russia formally declared that it had entered the war against Georgia, the Russian 58th army (not the peacekeepers), had already been engaged in military clashes: "It is obvious that [on August 8] at 3 pm Russia decided not to start the war but to acknowledge it." In December 2008, Pavel Baev named Sergei Makarov, Commander of the North Caucasus Military District, and Anatoly Khrulyov, Commander of the 58th Army, as persons to have possibly given orders for deployment in August 2008. In 2009, Andrey Illarionov in the book 'The Guns of August 2008' authored the chapter The Russian Leadership's Preparation for War, 1999-2008. He wrote that the decisions were made by the Russian authorities between September 1999 and June 2003 that caused the Russo-Georgian war. When Vladimir Putin became Prime Minister of Russia in August 1999, the Russian government changed its policy regarding Georgia, even before Saakashvili came to power in Georgia in November 2003 and could play a part in the deterioration of the relations between two countries.
In the early stages after the procedure, the use of interdental brushes is strongly advised against due to the potential damage to interdental tissues in the operated area, toothpicks are recommended as an alternative. The patient is asked to visit every two weeks for monitoring of their plaque levels. The time between visits will gradually increase if the patients’ plaque control is up to standard.
Sources: en.wikipedia.org
=== Chemical lysis === This method uses chemical disruption. It is the most popular and simple approach. Chemical lysis chemically deteriorates/solubilizes the proteins and lipids present within the membrane of targeted cells. Common lysis buffers contain sodium hydroxide (NaOH) and sodium dodecyl sulfate (SDS). Cell lysis is best done at a pH range of 11.5–12.5. Although simple, it is a slow process, taking anywhere from 6 to 12 hours.
The Green Revolution was possible in Asia because of existing infrastructure and institutions, such as a system of roads and public seed companies that made seeds available. These resources were in short supply in Africa, decreasing the Green Revolution's impact on the continent. For example, almost five million of the 13 million people in Malawi used to need emergency food aid. However, in the early 2000s, the Malawian government changed its agricultural policies, and implemented subsidies for fertilizer and seed introduced against World Bank strictures. By 2007, farmers were producing record-breaking corn harvests. Corn production leaped to 3.4 million in 2007 compared to 1.2 million in 2005, making Malawi a major food exporter. Consequently, food prices lowered and wages for farmworkers rose. Such investments in agriculture are still needed in other African countries like the Democratic Republic of the Congo (DRC). Despite the country's great agricultural potential, the prevalence of malnutrition in the DRC is among the highest in the world. Proponents for investing in agriculture include Jeffrey Sachs, who argues that wealthy countries should invest in fertilizer and seed for Africa's farmers. Imported Ready to Use Therapeutic Food (RUTF) has been used to treat malnutrition in northern Nigeria. Some Nigerians also use soy kunu, a locally sourced and prepared blend consisting of peanut, millet and soybeans. New technology in agricultural production has great potential to combat undernutrition. It makes farming easier, thus improving agricultural yields.
When Norse Vikings from Scandinavia arrived in the then-province of Neustria and settled the land that became known as Normandy, they originally spoke Old Norse, a North Germanic language. Over time, they came to live among the local Gallo-Romance-speaking population, with the two communities converging to the point that the original Norsemen largely assimilated and adopted the local dialect of Old French while contributing some elements from the Old Norse language. This Norse-influenced dialect which then arose was known as Old Norman, and it is the ancestor of both the modern Norman language still spoken today in the Channel Islands and parts of mainland Normandy, as well as the historical Anglo-Norman language in England. Old Norman was also an important language of the Principality of Antioch during Crusader rule in the Levant. Old Norman and Anglo-Norman literature was quite extensive during the Middle Ages, with records existing from notable Norman poets such as Wace, who was born on the island of Jersey and raised in mainland Normandy.
Sources: en.wikipedia.org
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.
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.
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.
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.