If you have been reading about Selank and want a single page that covers the useful parts, this is it: definitions, context, how it is studied, and the questions that come up repeatedly.
Updated 2025-11-23. Numbers and descriptions here follow the published literature rather than marketing material.
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.
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.
Published clinical evidence is limited. Most controlled trials were conducted in Russia, enrolled modest numbers of participants, and appeared in Russian-language journals, which restricts independent verification. Reported outcomes include lower anxiety scores, improved attention and memory measures, and changes in fatigue ratings. Reviews written in English note methodological limitations such as small samples and inconsistent endpoints. Whether the compound produces clinically meaningful benefit relative to established anxiolytics is therefore an open question rather than an established finding.
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.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic heptapeptide | Analog of the tetrapeptide tuftsin |
| Sequence | Thr-Lys-Pro-Arg-Pro-Gly-Pro | Reported consistently across pharmacopoeial descriptions |
| Appearance | White to off-white lyophilized powder | Typical form of research-grade material |
| Solubility | Freely soluble in water | Aqueous buffers; poor in nonpolar solvents |
| Typical storage temperature | -20 degrees Celsius | Lyophilized powder; protect from moisture |
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.
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.
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.
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.
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.
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.
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.
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 incompressible Navier–Stokes equations with uniform density and viscosity and conservative external field is the fundamental equation of hydraulics. The domain for these equations is commonly a 3 or fewer dimensional Euclidean space, for which an orthogonal coordinate reference frame is usually set to explicit the system of scalar partial differential equations to be solved. In 3-dimensional orthogonal coordinate systems are 3: Cartesian, cylindrical, and spherical. Expressing the Navier–Stokes vector equation in Cartesian coordinates is quite straightforward and not much influenced by the number of dimensions of the euclidean space employed, and this is the case also for the first-order terms (like the variation and convection ones) also in non-cartesian orthogonal coordinate systems. But for the higher order terms (the two coming from the divergence of the deviatoric stress that distinguish Navier–Stokes equations from Euler equations) some tensor calculus is required for deducing an expression in non-cartesian orthogonal coordinate systems. A special case of the fundamental equation of hydraulics is the Bernoulli's equation. The incompressible Navier–Stokes equation is composite, the sum of two orthogonal equations,
=== Preservation === Archaeological work at Flag Fen is ongoing. Extensive drainage of the surrounding area, which benefits agriculture, means that many of the timbers are drying out and are threatened with destruction by such exposure. One section of poles is being preserved by replacing the cellulose in the wood with water-carried wax, impregnating the wood over the years. This technique is also being used to preserve Seahenge and the Hassholme Boat. Another preservation technique used for timbers found at the site is freeze drying. A well-organised visitor centre, the Flag Fen Bronze and Iron Age Centre, has been constructed there with a museum and exhibitions. In the preservation hall one section of the timbers is preserved in situ and prevented from drying out by misting with water. Also at the site are reconstructions of two Bronze Age roundhouses and one from the Iron Age. A section of the Roman road known as the Fen Causeway has been exposed and crosses the site. In addition there is a reconstruction of a prehistoric droveway used for moving livestock.
OD600 (Also written as O.D. 600, D600, o.d. 600, OD600) is an abbreviation indicating the optical density of a sample measured at a wavelength of 600 nm in 1 cm light path (unless otherwise stated). It is a commonly used in microbiology for estimating the concentration of bacteria or other cells in a liquid as the 600 nm wavelength does little to damage or hinder their growth. OD600 is a type of turbidity measurement. Since optical density in case of OD600 measurements results from light scattering by particles (cells) rather than absorption, size and shape as well as dead cells and debris of a cell may add to light dissipating. Distinctive cell types that are at densities of the same level (eg. cell/mL), may, therefore, show varying values OD600, when estimated on a similar instrument. For turbid samples such as cell cultures, the major contributor for the optical density measured is light scattering and not the result of molecular absorption following the Beer-Lambert Law. The measurements are therefore depending on the optical setup of the spectrophotometer (distance between the cell holder and instrument exit slit, monochromator optics, slit geometry, etc.), different instrument types will most likely tend to give different OD600 readings for the same turbid sample. Measuring the change of the OD600 as a function of time (e.g. measuring of the growth curve) may indicate the growth phase of cultured cell population, i.e. whether it is in the lag phase, log phase, or stationary phase.
== Rieske protein family == The homologues of the Rieske proteins include ISP components of cytochrome b6f complex, aromatic-ring-hydroxylating dioxygenases (phthalate dioxygenase, benzene, naphthalene and toluene 1,2-dioxygenases) and arsenite oxidase (EC 1.20.98.1). Comparison of amino acid sequences has revealed the following consensus sequence:
=== Atomic === A mendelevium atom has 101 electrons. They are expected to be arranged in the configuration [Rn]5f137s2 (ground state term symbol 2F7/2), although experimental verification of this electron configuration had not yet been made as of 2006. The fifteen electrons in the 5f and 7s subshells are valence electrons. In forming compounds, three valence electrons may be lost, leaving behind a [Rn]5f12 core: this conforms to the trend set by the other actinides with their [Rn] 5fn electron configurations in the tripositive state. The first ionization potential of mendelevium was measured to be at most (6.58 ± 0.07) eV in 1974, based on the assumption that the 7s electrons would ionise before the 5f ones; this value has not yet been refined further due to the lack to larger samples of mendelevium. The ionic radius of hexacoordinate Md3+ had been preliminarily estimated in 1978 to be around 91.2 pm; 1988 calculations based on the logarithmic trend between distribution coefficients and ionic radius produced a value of 89.6 pm, as well as an enthalpy of hydration of −3654±12 kJ/mol. Md2+ should have an ionic radius of 115 pm and hydration enthalpy −1413 kJ/mol; Md+ should have ionic radius 117 pm.
Sources: en.wikipedia.org
Alexander McLeish. For services to Charity. Martin Gerard McTague. Low Pay Commissioner and National Chair, UK Federation of Small Businesses. For services to Small Businesses. Thomas Anthony Meadows. Lead Operations Manager, Security Services Group, Defence Infrastructure Organisation. For services to Defence. Dr. Teame Mebrahtu. For services to Education, to Refugees and to the community in Bristol. Dr. Nicholas John Merriman. Chief Executive, The Horniman Museum and Gardens. For services to the Arts and to Heritage. Gillian Jayne Millane. Co-Founder, Love Grace. For services to Charitable Fundraising and Tackling Violence Against Women. Dr. Jane Patricia Monckton-Smith. Professor of Public Protection, University of Gloucestershire. For services to Criminal Justice. Keith Morgan. Coach, Crystal Palace Weightlifting Club. For services to Sport. Andrew David Murphy. Lately Chief Operating Officer, John Lewis Partnership. For services to the British Retail Industry. Professor James Michael Olu N'Dow, DL. Professor of Urological Surgery, University of Aberdeen. For services to Cancer and Urology, and to Voluntary Work. Professor Kimberley Anne-Isola Nekaris. Head, Nocturnal Primate Research Group, Oxford Brookes University. For services to Conservation. Kenneth Paul Newton. Governing Governor, HM Prison Birmingham. For Public Service. Robert Stewart Nicol. Lately Chief Executive, Inverness Chambers of Commerce. For services to the Economy of the Highlands of Scotland. Beryce Amy Nixon. Chief Executive Officer, Exceed Learning Partnership Trust. For services to Education.
== History == The origins of CLIA can be traced back to the late 1960s, when cytology laboratories faced issues due to overworked personnel and a high incidence of errors in reading PAP smears. In response to these concerns, the Clinical Laboratory Improvement Amendment was introduced in 1967, which laid down the first set of regulations for laboratory standards, focusing mainly on independent and hospital laboratories. The Clinical Laboratory Improvement Act of 1988 (CLIA 88) was passed in the USA after the publication of an article in November 1987 in The Wall Street Journal entitled "Lax Laboratories: The Pap Test Misses Much Cervical Cancer Through Labs Errors", which alerted the public to the fact that a pap smear may be falsely negative. The article implied that false negative tests were largely due to carelessness among doctors. After this, claims involving pap smears showed an alarming growth. The Act aimed at a comprehensive regulation of gynecologic cytology laboratories.
In solid phase peptide synthesis, a linker is a molecule that connects the solid phase (a beaded resin support) to the growing peptide chain. The linker is often permanently attached to the solid phase, but carries a transient covalent bond to the peptide (typically its C-terminus) that can be cleaved after completion of the synthesis to release the peptide. Cleavage can take place under various conditions depending on the linker type and result in different C-terminal functionalities of the released peptide, e.g. amides, carboxylic acids, esters, lactams, etc. Linkers that do not attach via the C-terminus do also exist.
Eutyrannosaurs have a rough texture on their nasal bones and their mandibular fenestra is reduced externally. Tyrannosaurids lack kinetic skulls or special crests on their nasal bones, and have a lacrimal with a distinctive process on it. Tyrannosaurids also have an interfenestral strut that is less than half as big as the maxillary fenestra. Many phylogenetic analyses have found Tarbosaurus bataar to be the sister taxon of T. rex. The discovery of the tyrannosaurid Lythronax further indicates that Tarbosaurus and Tyrannosaurus are closely related, forming a clade with fellow Asian tyrannosaurid Zhuchengtyrannus, with Lythronax being their sister taxon. A further study from 2016 by Steve Brusatte, Thomas Carr and colleagues, also indicates that Tyrannosaurus may have been an immigrant from Asia, as well as a possible descendant of Tarbosaurus. This cladogram of Tyrannosauridae is based on the phylogenetic analysis conducted by Loewen and colleagues in 2013.
Disulfur decafluoride is a chemical compound with the formula S2F10. It was discovered in 1934 by Denbigh and Whytlaw-Gray. Each sulfur atom of the S2F10 molecule is octahedral, and surrounded by five fluorine atoms and one sulfur atom. The two sulfur atoms are connected by a single bond. In the S2F10 molecule, the oxidation state of each sulfur atoms is +5, but their valency is 6 (they are hexavalent). It is a colorless liquid with a burnt match smell similar to sulfur dioxide.
Sources: en.wikipedia.org
After fascism came to power with the March on Rome on 28 October 1922, a centralized dictatorial regime began in the southern region, strengthened after the assassination of socialist deputy Giacomo Matteotti in 1924 and formalized with the Leggi fascistissime of 1925–1926, which outlawed all political parties except the fascist party, censored the press, and banned trade unions and strikes. In addition, mayoral elections were abolished, replaced by podestà, appointed by the prefect, with absolute powers in political and economic management. During this period, the most representative Calabrian political personality was Michele Bianchi, a native of Belmonte Calabro, who was a close associate of Mussolini and quadrumviral of the 1922 March on Rome, in addition to holding the posts of deputy, undersecretary at the Ministry of the Interior and, finally, minister of Public Works. In this capacity, which he held until his death in 1930, he had a number of infrastructures built in Calabria, such as the Camigliatello Silano ski resort (initially called Camigliatello Bianchi), as well as promoting public works in Cosenza while Tommaso Arnoni was mayor (1925–1934). In December 1924 a false rumor spread in Reggio Calabria that Benito Mussolini had resigned as Prime Minister because of the Matteotti affair, leading to joyous all-night celebrations. In the morning, the people learned that Mussolini was still prime minister. Several Fascist officials were dismissed for not suppressing the celebrations.
As the Pizarro approached the Canary Islands, it passed Lanzarote on 16 June 1799, where Humboldt and Bonpland observed volcanic landscapes, including the Timanfaya volcano, which had last erupted in the 1730s. Navigation among the islands was challenging due to fog and unpredictable winds. The crew mistook a rock formation on Graciosa for a coastal castle, and the ship narrowly avoided being driven onto rocks by strong currents during the night. On 19 June 1799, the Pizarro arrived near Grand Canary. Dense fog delayed progress, but as it cleared, the ship’s company saw Pico del Teide, the volcanic peak of Tenerife, which Humboldt and Bonpland intended to ascend. British warships were observed nearby, but the Pizarro was protected by the guns of a Spanish fort and continued safely.
== Absorption == Azinphos-methyl can enter the body via inhalation, ingestion and dermal contact. Ingestion of azinphos-methyl is responsible for the low-dose exposure to a large part of the population, due to their presence as residues in food and drinking water. After ingestion it can be absorbed from the digestive tract. By skin contact, AzM can also enter the body through dermal cells. Absorption through the skin is responsible for the occupational exposure to relatively high doses, mainly in agriculture workers.
According to Democracy Now!, "[r]esearchers did not obtain signed consent forms, and medical personnel said Pfizer did not tell parents their children were getting the experimental drug." The lawsuits also accused Pfizer of using the outbreak to perform unapproved human testing, as well as allegedly under-dosing a control group being treated with traditional antibiotics in order to skew the results of the trial in favor of Trovan. Nigerian medical personnel as well as at least one Pfizer physician said the trial was conducted without regulatory approval. In 2007, Pfizer published a Statement of Defense letter, claiming that Trozan was safely tested in five thousand patients prior to the Nigerian children clinical trial, and mortality in the patients treated by Pfizer was lower than that observed historically in African meningitis epidemics. They claim that the effects suffered by the victims were due to meningitis and not Trovan. Pfizer states that its actions did not violate any law, as there was no law in Nigeria that requires ethical committee approval prior to conducting a clinical trial. However, the drug was never tested in children before. Pfizer claims that no unusual side effects, unrelated to meningitis, were observed after four weeks in the Nigerian children clinical study, though an investigation by The Washington Post revealed that one of the children continued to have the drug administered to them until their death despite their condition worsening, which violated ethical guidelines.
Sources: en.wikipedia.org
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.
The first four residues of Selank reproduce the tuftsin sequence Thr-Lys-Pro-Arg. A Pro-Gly-Pro extension at the C-terminus was added to slow enzymatic breakdown and extend residence time.
It holds marketing authorization in Russia, where nasal drop formulations are sold. No equivalent approval exists in the European Union, the United States, or most other countries.
It is a seven-amino-acid peptide, Thr-Lys-Pro-Arg-Pro-Gly-Pro, produced by chemical synthesis rather than extracted from biological tissue. Its design is based on tuftsin, a natural immunomodulatory tetrapeptide. The C-terminal Pro-Gly-Pro segment is a common stabilising motif in short regulatory peptides.