Selank raises a handful of sensible questions. This page answers them in order, starting with the fundamentals and moving to applications.
Reviewed 2026-07-03. Anything still debated is marked as such rather than presented as settled.
Peptide bonds in selank are susceptible to hydrolysis under strongly acidic or basic conditions, and the terminal proline residues are vulnerable to exopeptidase activity in biological samples. Lyophilized powder stored dry at -20 °C typically remains stable for extended periods, whereas aqueous solutions degrade faster and may lose measurable purity within days to weeks depending on pH, temperature, and microbial load. Repeated freeze-thaw cycles promote aggregation and adsorption to container surfaces. For analytical work, solutions are usually prepared fresh, kept cold, and used within a single working day.
Handling follows standard practice for research peptides. Material is weighed in a low-humidity environment because the powder absorbs atmospheric moisture. Purity is reported as the percentage area of the main peak in a chromatogram, with specifications commonly set at 95 percent or higher; values below that threshold indicate the presence of truncated or modified species. Residual trifluoroacetate from purification is often present and may affect mass balance. Certificates of analysis should state the analytical method, the column and gradient used, and the lot-specific retention time so that results can be compared across suppliers.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Identity confirmation | Reversed-phase HPLC retention time versus reference standard | Retention depends on column, gradient, and ion-pairing agent |
| Mass confirmation | Electrospray or MALDI mass spectrometry | Doubly protonated ion near m/z 377 is consistent with about 752 Da |
| Typical purity specification | 95 percent or higher by chromatographic peak area | Lower values suggest truncated or modified peptide species |
| Storage of lyophilized powder | -20 °C, desiccated, protected from light | Powder tolerates long storage better than solution |
| Storage of solution | 2-8 °C for short periods | Freeze-thaw cycling promotes aggregation and surface adsorption |
Reverse-phase high-performance liquid chromatography with ultraviolet detection near 214 nanometres is the standard purity method. Mass spectrometry, typically electrospray ionisation, confirms identity through the expected mass-to-charge pattern. Amino acid analysis can verify composition independently. Chiral purity requires separate techniques such as derivatisation followed by chromatographic separation, and such data are rarely reported for research-grade material.
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.
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.
Reported pharmacological effects center on reduced anxiety-like behavior in animal models and on measures of memory and learning. Proposed contributing mechanisms include modulation of GABAergic signaling, shifts in monoamine turnover, and changes in the activity of enzymes that degrade neuropeptides. Effects on the expression of genes linked to neuroplasticity have also been described. No single molecular target is widely accepted, and whether the behavioral findings arise from one pathway or several remains an open question.
Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro. It was designed as a stabilized analogue of tuftsin, a naturally occurring tetrapeptide fragment derived from the immunoglobulin heavy chain. The additional Pro-Gly-Pro segment at the carboxyl terminus is intended to slow enzymatic cleavage. The compound is usually described in the literature as a synthetic peptide with anxiolytic and cognitive-related activity, a label that reflects a research context rather than an approved therapeutic category.
This reaction is part of biochemical pathway called the hydantoinase process which converts 5-substituted hydantoins into optically pure D- or L-amino acids. This enzyme is a hydrolase which act on carbon-nitrogen bonds other than peptide bonds, specifically in linear amides. The systematic name of this enzyme class is N-carbamoyl-L-amino acid amidohydrolase.
=== Informants and holdouts === Also targeted were civilians suspected of being informants of the apartheid police. Alongside petrol bombs, necklacing became a favoured method of executing such suspects. In one early example known nationwide, a young woman in Duduza, Maki Skosana, was necklaced on 20 July 1985 at a funeral for a local activist; a television crew filmed a crowd of young men kicking and beating her, tearing her clothes off, dousing her in petrol, and then setting her alight while one man rammed a glass bottle into her vagina. Skosana was rumoured to be the girlfriend and co-conspirator of Joe Mamasela, a notorious askari who had killed several Duduza youths by hand grenade in an entrapment operation in June. In addition, though mass action had broad support during this period, there were frequently complaints that the reluctant were compelled to participate in stay-aways or boycotts by force or intimidation. Groups of COSAS supports were accused of "erecting barricades to prevent residents from going to work; attacking those who tried to do so; moving from school to school ordering students out of class; hurling stones and petrol bombs at policemen; attacking buses and taxis; digging trenches in the streets; destroying buildings; and assaulting members of rival organisations". There was also evidence that vigilante attacks were sometimes perpetrated on the basis of mere political or personal "grudges".
In 2021 a 5Å CryoEM analysis revealed the relationship between the catalytic domains and the intact TPR regions confirming the dimer arrangement first seen in the TPR alone X ray structure. This structure supports an ordered sequential bi-bi mechanism that matches the fact that “at saturating peptide concentrations, a competitive inhibition pattern was obtained for UDP with respect to UDP-GlcNAc.”
Prominent Romanian painters include: Nicolae Grigorescu, Ștefan Luchian, Ion Andreescu Nicolae Tonitza, and Theodor Aman. Notable Romanian classical composers of the 19th and 20th centuries include: Ciprian Porumbescu, Anton Pann, Eduard Caudella, Mihail Jora, Dinu Lipatti, and especially George Enescu. The annual George Enescu Festival is held in Bucharest in honour of the 20th-century composer. Contemporary musicians like Angela Gheorghiu, Gheorghe Zamfir, Inna, Alexandra Stan, and many others have achieved various levels of international acclaim. From the late 2000s through the early 2010s, the Romanian popcorn music style had established itself in the international mainstream. At the Eurovision Song Contest Romanian singers achieved third place in 2005 and 2010. In cinema, several movies of the Romanian New Wave have achieved international acclaim. At the Cannes Film Festival, The Death of Mr. Lazarescu by Cristi Puiu won the Prix Un Certain Regard in 2005, while 4 Months, 3 Weeks and 2 Days by Cristian Mungiu won the festival's top prize, the Palme d'Or, in 2007. At the Berlin International Film Festival, Child's Pose by Călin Peter Netzer won the Golden Bear in 2013. The list of World Heritage Sites includes six cultural sites located within Romania, including eight painted churches of northern Moldavia, eight wooden churches of Maramureș, seven villages with fortified churches in Transylvania, the Horezu Monastery, and the Historic Centre of Sighișoara.
In Costa Rica, public universities include the University of Costa Rica, the National University, the Distance State University, National Technical University and the Costa Rica Institute of Technology.
Sources: en.wikipedia.org
=== Genome === As of early 2022, about 7 million SARS-CoV-2 genomes had been sequenced and deposited into public databases and another 800,000 or so were added each month. By September 2023, the GISAID EpiCoV database contained more than 16 million genome sequences. SARS-CoV-2 has a linear, positive-sense, single-stranded RNA genome about 30,000 bases long. Its genome has a bias against cytosine (C) and guanine (G) nucleotides, like other coronaviruses. The genome has the highest composition of U (uracil) (32.2%), followed by A (adenine) (29.9%), and a similar composition of G (19.6%) and C (18.3%). The nucleotide bias arises from the mutation of guanines and cytosines to adenines and uracils, respectively. The mutation of CG dinucleotides is thought to arise to avoid the zinc finger antiviral protein related defence mechanism of cells, and to lower the energy to unbind the genome during replication and translation (adenine and uracil base pair via two hydrogen bonds, cytosine and guanine via three). The depletion of CG dinucleotides in its genome has led the virus to have a noticeable codon usage bias. For instance, arginine's six different codons have a relative synonymous codon usage of AGA (2.67), CGU (1.46), AGG (.81), CGC (.58), CGA (.29), and CGG (.19). A similar codon usage bias trend is seen in other SARS–related coronaviruses.
== Signs and symptoms == The clinical presentation of IRIS is variable and typically depends on the underlying OI. Common features that may be present include clinical worsening after starting ART and localized tissue inflammation. A systemic inflammatory response may or may not be present. The majority of IRIS cases occur within 4 to 8 weeks of ART initiation or change. However, there have been reported cases from 3 days to several months or even years after ART initiation. The following table describes the major and minor presentations in reported underlying OIs.
Stanton, along with 33 other Essendon players, was found guilty of using a banned performance-enhancing substance, thymosin beta-4, as part of Essendon's sports supplements program during the 2012 season. He and his team-mates were initially found not guilty in March 2015 by the AFL Anti-Doping Tribunal, but a guilty verdict was returned in January 2016 after an appeal by the World Anti-Doping Agency. He was suspended for two years which, with backdating, ended in November 2016; as a result, he served approximately fourteen months of his suspension and missed the entire 2016 AFL season. On 10 August 2016 Stanton re-committed to the Bombers on a one-year deal. Early in the 2017 season, Stanton played his 250th AFL game against the Brisbane Lions at the Gabba. On 24 August 2017, Stanton announced that he would retire at the end of the 2017 season.
Designer drugs are structural or functional analogues of controlled substances that are designed to mimic the pharmacological effects of the parent drug while avoiding detection or classification as illegal. Many of the older designer drugs (research chemicals) are structural analogues of psychoactive tryptamines or phenethylamines but there are many other chemically unrelated new psychoactive substances that can be considered part of the designer drug group. Designer drugs can also include substances that are not psychoactive in effect, such as analogues of controlled anabolic steroids and other performance and image enhancing drugs (PIEDs), including nootropics, weight loss drugs and erectile dysfunction medications. The pharmaceutical activities of these compounds might not be predictable based strictly upon structural examination. Many of the substances have common effects while structurally different or different effects while structurally similar due to SAR paradox. As a result of no real official naming for some of these compounds, as well as regional naming, this can all lead to potentially hazardous mix ups for users. The following list is not exhaustive.
Sources: en.wikipedia.org
Identity is confirmed by matching the retention time in reversed-phase chromatography against a reference standard and by measuring the molecular mass with mass spectrometry. Tandem mass spectrometry or amino acid analysis can verify the sequence of the seven residues. Because the peptide contains no aromatic amino acids, detection at 280 nm is not useful.
Lyophilized powder is normally stored desiccated at -20 °C, protected from light and moisture. Powder kept under these conditions is generally stable for long periods. Solutions are less stable and are usually prepared immediately before use.
A purity value from one chromatographic method does not capture every possible impurity. Related peptides with similar retention behavior, counterions, and residual solvents may not appear in the same analysis. Independent testing with an orthogonal method provides stronger assurance of identity and content.
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.