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.
Updated 2025-09-05. Numbers and descriptions here follow the published literature rather than marketing material.
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.
Quality assessment of Selank samples typically combines purity determination with identity confirmation and counter-ion analysis. Purity is usually reported as a percentage by chromatographic area, with values above 95 percent often quoted for research-grade material. Water content and residual solvents are checked in lyophilized batches because they affect both stability and accurate mass determination. A reported purity figure does not by itself establish that a sample is the intended sequence, so orthogonal methods are needed to rule out sequence isomers or truncation products.
Characterization of Selank in laboratory settings relies on standard peptide analytical techniques. Reverse-phase high-performance liquid chromatography separates the peptide from related impurities and degradation products, while mass spectrometry confirms molecular identity through accurate mass measurement. Amino acid analysis and peptide sequencing verify the primary structure when reference material is unavailable. Because Selank is a short chain, fragmentation-based analysis produces a diagnostic ion pattern that supports confident identification.
| 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 |
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.
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.
Measuring peptide exposure inside the brain is technically difficult. Selank is degraded rapidly in plasma, and assays must separate intact peptide from fragments, which favors targeted mass spectrometry over immunoassays alone. Reported half-lives are short, on the order of minutes, so effects observed hours later are attributed to downstream signaling rather than to the parent compound. Blood-brain barrier permeability is debated and rarely quantified directly. Gaps include absent dose-response characterization, inconsistent reporting of purity, and almost no pharmacokinetic data from human participants.
Selank is studied chiefly as an animal-model anxiolytic with proposed secondary effects on memory and immune signaling. Reported mechanisms include modulation of the GABA-A receptor complex, inhibition of enkephalin-degrading enzymes, and shifts in monoamine turnover within limbic structures. Some experiments describe increased expression of brain-derived neurotrophic factor in the hippocampus after repeated dosing. No single molecular target has been confirmed, and the peptide does not bind any receptor with the selectivity typical of a conventional small-molecule drug. Mechanism therefore remains a set of hypotheses rather than an established pathway.
Lyophilized material is generally stable for extended periods when kept dry at or below minus twenty degrees Celsius. Working solutions are less stable, and common practice is to aliquot and freeze them so that repeated freeze-thaw cycles are avoided. Aqueous solutions are sensitive to pH extremes and to microbial growth, so short-term storage at refrigerator temperature is typical. Oxidation and hydrolysis are the principal degradation routes. Reconstitution with sterile water or a mild buffer is standard, and solutions should be protected from light.
Regulatory treatment varies by jurisdiction. In Russia the compound is a registered prescription product, while in the European Union and the United States it is generally handled as a research chemical without a marketing authorization. Suppliers therefore operate outside pharmaceutical oversight, and buyers rely on supplier documentation for purity and identity claims. Chain of custody and third-party testing are the main verification tools. Analysts note that the absence of a pharmacopoeial monograph for research-grade material limits standardization across vendors.
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.
Profile at Parliament of the United Kingdom Contributions in Parliament at Hansard Voting record at Public Whip Record in Parliament at TheyWorkForYou Profile on OpenSanctions, an open database of sanctions and persons of interest HAND ID – Their entry in the HAND (Human and Digital) Talent ID registry of real people and fictional characters George Galloway Contributor page, The Guardian website George Galloway Contributor page, The Independent website Hansard 1803–2005: contributions in Parliament by George Galloway George Galloway at IMDb
== English translations == Robert Potter, 1781 - verse: full text Michael Wodhull, 1782 – verse Edward P. Coleridge, 1891 – prose: full text Theodore Alois Buckley, 1892 – prose: full text Gilbert Murray, 1912 – verse: full text Arthur S. Way, 1912 – verse F. L. Lucas, 1924 – verse Augustus T. Murray, 1931 – prose Countee Cullen, 1935 Moses Hadas and John McLean, 1936 – prose R. C. Trevelyan, 1939 – verse Rex Warner, 1944 – verse Robinson Jeffers, 1946 – verse Ray Mathew, 1953 – verse Peter D. Arnott, 1961 – verse Philip Vellacott, 1963 Rush Rehm, 1973 - prose John Davie, 1996 James Morwood, 1997 – prose Paul Roche, 1998 – verse Ruby Blondell, 1999 – verse George Theodoridis, 2004 – prose: full text Stephen Esposito, 2004 – verse Joseph Goodrich, 2005 – verse: full text Graham Kirby, 2006 – verse (The Bloomsbury Theatre) Diane Arnson Svarlien, 2008 – verse Robin Robertson, 2008 – verse J. Michael Walton, 2008 – prose Ian C. Johnston, 2008 – verse: full text Tom Paulin, 2010 - full text Judith Mossman (classicist), 2011 – prose Brian Vinero, 2012 – rhymed verse: full text Mike Bartlett, 2012 – play Diane Rayor, 2013 David Stuttard, 2014 – prose Alan Chriztopher R. Aranza, 2015 – prose Rachel Kitzinger, 2016 – verse Charles Martin, 2019 Dr. Richard W. Swanson, 2020 – prose Michael Ewans, 2022 – verse
==== Intramuscular injection ==== In contrast to oral administration, which is associated with very low bioavailability (<10%), the bioavailability of both estradiol and estradiol esters like estradiol valerate is complete (i.e., 100%) via intramuscular injection. In addition, estradiol esters like estradiol cypionate and estradiol valerate when given as an injection of oil solution or microcrystalline aqueous suspension have a relatively long duration due to the formation of an intramuscular depot from which they are slowly released and absorbed. Upon intramuscular injection of estradiol cypionate in an oil solution, the solvent (i.e., oil) is absorbed, and a primary microcrystalline depot is formed within the muscle at the site of injection. In addition, a secondary depot may be formed in adipose tissue. The slow release of estradiol cypionate from the tissue depot is caused by the high lipophilicity of the estradiol ester, which in turn is due to its long fatty acid cypionic acid ester moiety. Estradiol cypionate is formulated for use alone and in combination with testosterone cypionate as an oil solution, and for use in combination with medroxyprogesterone acetate as a microcrystalline aqueous suspension. Aqueous suspensions of steroid esters generally have longer durations by intramuscular injection than oil solutions. A single intramuscular injection of 5 mg estradiol cypionate has been found to result in peak circulating concentrations of 338 pg/mL estradiol and 145 pg/mL estrone, which occurred at about 4 and 5 days post-injection, respectively (see right table).
There have been several structures solved for this class of enzymes, given PDB accession codes, and published in peer-reviewed journals. At least 4 such structures have been solved using pig enzymes: PDB: 1OHV, PDB: 1OHW, PDB: 1OHY, PDB: 1SF2, and at least 4 such structures have been solved in Escherichia coli: PDB: 1SFF, PDB: 1SZK, PDB: 1SZS, PDB: 1SZU. There are actually some differences between the enzyme structure for these organisms. E. coli enzymes of GABA-T lack an iron-sulfur cluster that is found in the pig model. Amino acid residues found in the active site of 4-aminobutyrate transaminase include Lys-329, which are found on each of the two subunits of the enzyme. This site will also bind with a pyridoxal 5'- phosphate co-enzyme. Aminooxyacetic acid Gabaculine Phenelzine Phenylethylidenehydrazine (PEH) Rosmarinic acid Valproic acid Vigabatrin 4-Aminobutyrate+Transaminase at the U.S. National Library of Medicine Medical Subject Headings (MeSH) Pearl PL, Parviz M, Hodgeman R, Gibson KM, Reimschisel T (2015). "GABA-transaminase deficiency". MedLink Neurology.
Wide range of genomic applications and scientific questions, including de novo genome assembly, haplotype phasing, structural variant analysis, and transcriptome and epigenetic analysis. Accuracy and scalability. Method requires small quantities of input DNA, which can be beneficial for small samples or single cell studies. More cost effective per sample in comparison with long-read technologies such as Oxford Nanopore sequencing. Libraries produced by linked-read can be processed using Illumina short read sequencing, increasing accessibility. Complexity of library construction - this technology requires high molecular DNA preparation in order to produce long enough DNA molecules for sequencing. Limitations in read length may result in limited haplotype resolution, which could reduce the efficacy of this technology in highly complex genomic regions.
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Boron (5B) naturally occurs as isotopes 10B and 11B, the latter of which makes up about 80% of natural boron. There are 13 radioisotopes that have been discovered, with mass numbers from 7 to 21, all with short half-lives, the longest being that of 8B, with a half-life of only 771.9(9) ms and 12B with a half-life of 20.20(2) ms. All other isotopes have half-lives shorter than 17.35 ms. Those isotopes with mass below 10 decay into helium via short-lived isotopes of beryllium while those with mass above 11 mostly become carbon.
A memorandum to end the war was signed on 17 June by the presidents of the US and Iran, lifting the dual blockade. Tensions again escalated, but on 28 June, the US and Iran agreed to cease their exchange of attacks. On 8 July, the ceasefire deal between the US and Iran collapsed after Iran initiated attacks on commercial vessels in the Strait of Hormuz to assert sovereignty over the strait, which interrupted a brief diplomatic lull.
Top-grain leather includes the outer layer of the hide, known as the grain, which features finer, more densely packed fibers, resulting in strength and durability. Depending on thickness, it may also contain some of the more fibrous under layer, known as the corium. Types of top-grain leather include: Full-grain leather contains the entire grain layer, without any removal of the surface. Rather than wearing out, it develops a patina during its useful lifetime. It is usually considered the highest quality leather. Furniture and footwear are often made from full-grain leather. Full-grain leather is typically finished with a soluble aniline dye. Russia leather is a form of full-grain leather. Corrected grain leather has the surface subjected to finishing treatments to create a more uniform appearance. This usually involves buffing or sanding away flaws in the grain, then dyeing and embossing the surface. Nubuck is top-grain leather that has been sanded or buffed on the grain side to give a slight nap of short protein fibers, producing a velvet-like surface. Split leather is created from the corium left once the top-grain has been separated from the hide, known as the drop split. In thicker hides, the drop split can be further split into a middle split and a flesh split. Bicast leather is split leather that is coated with a layer of polyurethane or vinyl with an embossed texture. This gives it the appearance of a grain. It is slightly stiffer than top-grain leather but has a more consistent texture.
Calcium sulfate (or calcium sulphate) is an inorganic salt with the chemical formula CaSO4. It occurs in several hydrated forms; the anhydrous state (known as anhydrite) is a white crystalline solid often found in evaporite deposits. Its dihydrate form is the mineral gypsum, which may be dehydrated to produce bassanite, the hemihydrate state. Gypsum occurs in nature as crystals (selenite) or fibrous masses (satin spar), typically colorless to white, though impurities can impart other hues. All forms of calcium sulfate are sparingly soluble in water and cause permanent hardness when dissolved therein.
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== Interactions == Patiromer was tested for drug-drug interactions with 28 drugs and showed binding or interaction with 14 of these drugs. This could reduce their availability and thus effectiveness, wherefore patiromer has received a boxed warning by the US Food and Drug Administration (FDA), telling patients to wait for at least six hours between taking patiromer and any other oral drugs. Of the 14 drugs that did show an interaction in vitro, 12 were selected for further testing in phase 1 studies in healthy volunteers to assess whether the results seen in vitro translated into an effect in people. These studies showed patiromer did not alter the absorption of nine of the 12 drugs when co-administered. Patiromer reduced absorption of three drugs when co-administered, however, there was no interaction when patiromer and these three drugs were taken 3 hours apart. This information was submitted to the FDA in the form of a supplemental New Drug Application (sNDA) and as a result, in November 2016 the FDA approved the removal of the boxed warning regarding the separation of patiromer and other oral medications. The updated label recommends patients take patiromer at least three hours before or three hours after other oral medications.
A milestone in that process was the work of Linus Pauling in 1949, which for the first time linked the specific genetic mutation in patients with sickle cell disease to a demonstrated change in an individual protein, the hemoglobin in the erythrocytes of heterozygous or homozygous individuals.
NPR also noted that polls underestimated Trump's level of support in battleground states and across the nation. The New York Times asserted that "[Trump] made one essential bet: that his grievances would become the grievances of the MAGA movement, and then the G.O.P., and then more than half the country. It paid off." The Times added that Trump's several setbacks actually benefited his public image and approval, as "his mug shot became a best-selling shirt. His criminal conviction inspired $100 million in donations in one day. The images of him bleeding after a failed assassination attempt became the symbol of what supporters saw as a campaign of destiny." NBC noted a Democratic strategist's contention that male voters' belief that they were "being left behind, that society doesn't have a place for them" was a major factor in men's support for Trump. The network contended that Trump's approval ratings among non-college-educated and middle-income voters, especially among Latinos and young men, showed that he had made strides in his promise to assemble a multiracial, working-class coalition. Trump increased his support from Hispanics from 2020 to 2024, especially near the Mexican–American border and in areas impacted by recent immigration. Several observers pointed to shifting habits in how Americans consume media and a growing lack of trust in mainstream news outlets. Trump embraced alternative media through podcasts and online streamers such as Joe Rogan, Adin Ross, Theo Von, Sneako and the Nelk Boys. The New York Times reported that such avenues "presented a way for Mr.
Don Cossacks (Russian: Донские казаки, romanized: Donskiye kazaki, Ukrainian: Донські козаки, romanized: Donski kozaky) or Donians (Russian: донцы, romanized: dontsy, Ukrainian: донці, romanized: dontsi), are Cossacks who settled along the middle and lower Don. Historically, they lived within the former Don Cossack Host (Russian: Донское казачье войско, romanized: Donskoe kazache voysko, Ukrainian: Головне Донське військо, romanized: Holovne Dons'ke viis'ko), which was either an independent or an autonomous democratic polity in present-day Southern Russia and parts of the Donbas region of Ukraine, from the end of the 16th century until 1918. As of 1992, by presidential decree of the Russian Federation, Cossacks can be enrolled on a special register. A number of Cossack communities have been reconstituted to further Cossack cultural traditions, including those of the Don Cossack Host. Don Cossacks have had a rich military tradition—they played an important part in the historical development of the Russian Empire and participated in most of its major wars.
Organic cofactors, such as ATP and NADH, are present in all known forms of life and form a core part of metabolism. Such universal conservation indicates that these molecules evolved very early in the development of living things. At least some of the current set of cofactors may, therefore, have been present in the last universal ancestor, which lived about 4 billion years ago. Organic cofactors may have been present even earlier in the history of life on Earth. The nucleotide adenosine is a cofactor for many basic metabolic enzymes such as transferases. It may be a remnant of the RNA world. Adenosine-based cofactors may have acted as adaptors that allowed enzymes and ribozymes to bind new cofactors through small modifications in existing adenosine-binding domains, which had originally evolved to bind a different cofactor. This process of adapting a pre-evolved structure for a novel use is known as exaptation. Prebiotic origin of coenzymes. Like amino acids and nucleotides, certain vitamins and thus coenzymes can be created under early earth conditions. For instance, vitamin B3 can be synthesized with electric discharges applied to ethylene and ammonia. Similarly, pantetheine (a vitamin B5 derivative), a precursor of coenzyme A and thioester-dependent synthesis, can be formed spontaneously under evaporative conditions. Other coenzymes may have existed early on Earth, such as pterins (a derivative of vitamin B9), flavins (FAD, flavin mononucleotide = FMN), and riboflavin (vitamin B2). Changes in coenzymes.
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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 most common approach combines reverse-phase liquid chromatography with mass spectrometry. Chromatography separates the components while mass spectrometry confirms the molecular mass. Peptide sequencing or tandem mass analysis can further verify the amino acid order.