tuftsin 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 2026-03-15. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
Most published work on selank originates from a small number of research groups in the Russian Federation. A large share of that record appears in Russian-language journals, which limits access for readers who rely on English-indexed databases. Independent replication by laboratories outside the original research network is sparse in publicly available sources. This concentration of origin and language is a frequently noted feature when the compound is summarized in broader reviews of synthetic peptides.
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.
| 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 |
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.
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.
Outside its country of origin the compound is generally handled as a research chemical rather than an approved medicine. No regulatory approval from the United States Food and Drug Administration or the European Medicines Agency has been granted for human use. Identity and purity are normally checked by reverse-phase high-performance liquid chromatography, with mass spectrometry used to confirm the molecular mass. Lyophilised material is stored cold and desiccated, and repeated freeze-thaw cycles are avoided.
==== Metabolism ==== Atenolol undergoes minimal or negligible metabolism by the liver. It has been estimated that about 5% of atenolol is metabolized. This is in contrast to other beta blockers like propranolol and metoprolol, but is similar to nadolol. In accordance with its lack of hepatic metabolism, the pharmacokinetics of atenolol are not altered in hepatic impairment, unlike the case of propranolol. Two metabolites of atenolol have been identified: hydroxyatenolol and atenolol glucuronide. It has been said that it is unknown if these metabolites are active. However, another source stated that hydroxyatenolol has one-tenth the beta-blocking activity of atenolol.
The core macrocycle, prerapamycin (figure 2), is then modified (figure 3) by an additional five enzymes, which lead to the final product, rapamycin. First, the core macrocycle is modified by RapI, SAM-dependent O-methyltransferase (MTase), which O-methylates at C39. Next, a carbonyl is installed at C9 by RapJ, a cytochrome P-450 monooxygenases (P-450). Then, RapM, another MTase, O-methylates at C16. Finally, RapN, another P-450, installs a hydroxyl at C27 immediately followed by O-methylation by Rap Q, a distinct MTase, at C27 to yield rapamycin. The biosynthetic genes responsible for rapamycin synthesis have been identified. As expected, three extremely large open reading frames (ORF's) designated as rapA, rapB, and rapC encode for three extremely large and complex multienzymes, RapA, RapB, and RapC, respectively. The gene rapL has been established to code for a NAD+-dependent lysine cycloamidase, which converts L-lysine to L-pipecolic acid (figure 4) for incorporation at the end of the polyketide. The gene rapP, which is embedded between the PKS genes and translationally coupled to rapC, encodes for an additional enzyme, an NPRS responsible for incorporating L-pipecolic acid, chain termination and cyclization of prerapamycin. In addition, genes rapI, rapJ, rapM, rapN, rapO, and rapQ have been identified as coding for tailoring enzymes that modify the macrocyclic core to give rapamycin (figure 3).
Iron–sulfur clusters occur in many biological systems, often as components of electron transfer proteins. The ferredoxin proteins are the most common Fe–S proteins in nature. They feature either 2Fe–2S or 4Fe–4S centers. They occur in all branches of life. Fe–S clusters can be classified according to their Fe:S stoichiometry [2Fe–2S], [4Fe–3S], [3Fe–4S], and [4Fe–4S]. The [4Fe–4S] clusters occur in two forms: normal ferredoxins and high potential iron proteins (HiPIP). Both adopt cuboidal structures, but they utilize different oxidation states. They are found in all forms of life. The relevant redox couple in all Fe–S proteins is Fe(II)/Fe(III). Many clusters have been synthesized in the laboratory with the formula [Fe4S4(SR)4]2−, which are known for many R substituents, and with many cations. Variations have been prepared including the incomplete cubanes [Fe3S4(SR)3]3−.
Among prokaryotes, five major groups of bacteria have evolved the ability to photosynthesize, including heliobacteria, green sulfur and nonsulfur bacteria and proteobacteria. However, the only lineage where oxygenic photosynthesis has evolved is in the cyanobacteria, often known as blue-green algae for their blue-green (cyan) coloration. They are classified as the phylum Cyanobacteriota or Cyanophyta. However, this phylum also includes two classes of non-photosynthetic bacteria: Melainabacteria (also called Vampirovibrionia or Vampirovibrionophyceae) and Sericytochromatia (also known as Blackallbacteria). A third class contains the photosynthetic ones, known as Cyanophyceae (also called Cyanobacteriia or Oxyphotobacteria). As bacteria, their cells lack membrane-bound organelles, with the exception of thylakoids. Like other algae, cyanobacteria have chlorophyll a as their primary photosynthetic pigment. Their accessory pigments include phycobilins (phycoerythrobilin and phycocyanobilin), carotenoids and, in some cases, b, d, or f chlorophylls, generally distributed in phycobilisomes found in the surface of thylakoids. They display a variety of body forms, such as single cells, colonies, and unbranched or branched filaments. Their cells are commonly covered in a sheath of mucilage, and they also have a typical gram-negative bacterial cell wall composed largely of peptidoglycan. They have various storage particles, including cyanophycin as aminoacid and nitrogen reserves, "cyanophycean starch" (similar to plant amylose) for carbohydrates, and lipid droplets.
Sources: en.wikipedia.org
=== Lactation === The IGFR signalling pathway is of critical importance during normal development of mammary gland tissue during pregnancy and lactation. During pregnancy, there is intense proliferation of epithelial cells which form the duct and gland tissue. Following weaning, the cells undergo apoptosis and all the tissue is destroyed. Several growth factors and hormones are involved in this overall process, and IGF-1R is believed to have roles in the differentiation of the cells and a key role in inhibiting apoptosis until weaning is complete.
=== Aldoses and ketoses === Monosaccharides which contain an aldehyde group are known as aldoses, and those with a ketone group are known as ketoses. The aldehyde can be oxidized via a redox reaction in which another compound is reduced. Thus, aldoses are reducing sugars. Sugars with ketone groups in their open chain form are capable of isomerizing via a series of tautomeric shifts to produce an aldehyde group in solution. Therefore, ketones like fructose are considered reducing sugars but it is the isomer containing an aldehyde group which is reducing since ketones cannot be oxidized without decomposition of the sugar backbone. This type of isomerization is catalyzed by the base present in solutions which test for the presence of reducing sugars.
During embryogenesis and early development, cells switch back and forth between different cellular phenotypes via MET and its reverse process, epithelial–mesenchymal transition (EMT). Developmental METs have been studied most extensively in embryogenesis during somitogenesis and nephrogenesis and carcinogenesis during metastasis, but it also occurs in cardiogenesis or foregut development. MET is an essential process in embryogenesis to gather mesenchymal-like cells into cohesive structures. Although the mechanism of MET during various organs morphogenesis is quite similar, each process has a unique signaling pathway to induce changes in gene expression profiles.
=== Indirect discrimination === Although the Fair Work Act 2009 does not expressly distinguish direct and indirect discrimination as other federal legislation does, and state legislation does, if a rule that is neutral on its face has a disparate impact on one group, this will also be unlawful. For example, in Australian Iron & Steel Pty Ltd v Banovic an employer’s policy for redundancy based on “last in, first off” was held to be indirect discrimination against women, who at that mining workplace has mostly only been recently employed. Similarly in Song v Ainsworth Game Technology Pty Ltd a woman won a claim for indirect discrimination, after she was told she could not work full time, and also use her break time to transfer her child from school to after school care. Such a rule disparately impacted women, especially since it was found that other staff could take cigarette breaks without reducing their work hours.
=== Transportation === Steel belts may be used to move the finished product or raw material or in parcel sorting systems, transporting of bottles, bulk loads, bricks, machinery parts and the like. Straight tracking, high abrasion resistance, and dynamic fatigue strength are crucial when transporting bulky material or unit load. Extremely high operating speeds cause a high number of load cycles and create severe operating conditions. Steel belts can be made to suit these extreme requirements.
Sources: en.wikipedia.org
Energy column The column labeled "energy" denotes the energy equivalent of (the mass of a neutron minus the mass per nucleon), that is of the mass defect with respect to the neutron, in MeV. Use of the neutron as reference guarantees all nuclides will have a positive value. Mathematically: mn − mnuclide / A. Note that this means that a higher "energy" value actually means that the nuclide has a lower energy. Inversely the mass is A (mn − E / k) where E is the energy, mn is 1.0086649159 and k = 931.4941037 MeV (energy equivalent of the dalton). Omitted if there is no experimental mass determination within 0.0001.
Delta-sleep-inducing peptide (DSIP) is a neuropeptide that when infused into the mesodiencephalic ventricle of recipient rabbits induces spindle and delta EEG activity and reduced motor activities. Its amino acid sequence is Trp-Ala-Gly-Gly-Asp-Ala-Ser-Gly-Glu (WAGGDASGE). The gene has yet to be found in rabbits, along with any receptors or precursor peptides. However, searches through BLAST have found that it aligns with a hypothetical Amycolatopsis coloradensis protein. This could indicate that DSIP has a bacterial origin.
Otto Hahn – winner of the Enrico Fermi Award 1966 U.S Government, Department of Energy Otto Hahn on Nobelprize.org including the Nobel Lecture on 13 December 1946 From the Natural Transmutations of Uranium to Its Artificial Fission Award Ceremony Speech honoring Otto Hahn by Professor Arne Westgren, Stockholm. Otto Hahn and the Discovery of Nuclear Fission Archived 1 February 2014 at the Wayback Machine BR, 2008 Otto Hahn – Discoverer of Nuclear Fission Author: Dr. Anne Hardy (Pro-Physik, 2004) Otto Hahn (1879–1968) – The discovery of fission Visit Berlin, 2011. Otto Hahn – Discoverer of nuclear fission Otto Hahn – Founder of the Atomic Age Author: Dr Edmund Neubauer (Translation: Brigitte Hippmann) – Website of the Otto Hahn Gymnasium (OHG), 2007. Otto Hahn Award Otto Hahn Peace Medal in Gold Website of the United Nations Association of Germany (DGVN) in Berlin Otto Hahn Medal The history of the Hahn Meitner Institute (HMI) Helmholtz-Zentrum, Berlin 2011. Otto Hahn heads a delegation to Israel 1959 Website of the Max Planck Society, 2011. Biography Otto Hahn 1879–1968 Otto Hahn – A Life for Science, Humanity and Peace Archived 24 September 2015 at the Wayback Machine Hiroshima University Peace Lecture, held by Dietrich Hahn, 2 October 2013. Otto Hahn – Discoverer of nuclear fission, grandfather of the Atombomb GMX, Switzerland, 17 December 2013. Author: Marinus Brandl. Newspaper clippings about Otto Hahn in the 20th Century Press Archives of the ZBW
== Biological functions == (Z)-9-Tricosene is a sex pheromone produced by female house flies (Musca domestica) to attract males. In bees, it is one of the communication pheromones released during the waggle dance.
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.
Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro, designed as a metabolically stabilized analogue of the endogenous tetrapeptide tuftsin. It has been studied mainly against anxiety-related and cognitive endpoints rather than as an approved medicine in most jurisdictions.