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 2025-10-09. Where a claim depends on a specific study, the study is described rather than over-claimed.
Reversed-phase high-performance liquid chromatography is the standard technique for estimating peptide purity. The result is a peak-area percentage, which describes how much of the detected material elutes as the main peak in one run. Mass spectrometry confirms the molecular mass and can reveal truncated, adducted, or otherwise modified species. Amino acid analysis or tandem mass spectrometry can address sequence fidelity when identity is in doubt. None of these measurements, taken alone, establishes that a sample is fit for any specific purpose.
Lyophilized selank is normally supplied as a dry powder and is considered stable for extended periods when kept cold and dry. Moisture uptake is the main practical threat, because absorbed water promotes both hydrolysis and aggregation in the solid state. Vials are usually warmed to room temperature before opening so that condensation does not form on the powder. Supplier documentation commonly specifies -20 °C for routine storage, with -80 °C used for material intended to be archived for years.
Once dissolved, the peptide is markedly less stable than the dry powder. Aqueous solutions are subject to backbone hydrolysis and to microbial growth when they are handled without sterile technique. Buffered solutions near neutral pH are common for short-term laboratory work, while acidic conditions are sometimes used to improve solubility. Analytical laboratories generally prepare working solutions fresh rather than storing them, and a residual water film left in a reopened vial can seed degradation even when the container appears dry.
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.
| Property | Value | Notes |
|---|---|---|
| Typical purity specification | 95 percent or higher by RP-HPLC | Area percentage of the main peak |
| Identity confirmation | Electrospray ionization mass spectrometry | Observed mass compared with the theoretical value near 751.9 Da |
| Recommended dry storage | -20 °C, desiccated | -80 °C for multi-year archival material |
| Solution handling | Prepare fresh; avoid long storage | Sterile filtration reduces microbial load |
| Common synonyms | TKPRPGP; TP-7 | Sequence code and laboratory designation used interchangeably |
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.
Peptide stability depends strongly on temperature, moisture, and pH. Lyophilized Selank is generally most stable when stored cold and dry, with freezer temperatures commonly used for long-term storage. In solution, the compound is susceptible to hydrolysis and to microbial growth if it is not handled aseptically. The C-terminal proline-rich extension appears to slow enzymatic cleavage relative to tuftsin, though quantitative degradation rates vary with the matrix and the conditions tested. Published stability data specific to Selank remain sparse.
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.
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.
Laboratory work relies on standard behavioral paradigms. Rodents are tested in the elevated plus maze, open field, and passive avoidance tasks, with outcomes compared against diazepam or vehicle controls. Intranasal dosing is used most often because it bypasses first-pass metabolism, though intraperitoneal and intravenous routes also appear in published protocols. Biochemical endpoints include tissue BDNF concentrations, cytokine levels, and monoamine metabolites. Human data are limited to small Russian trials reporting reduced anxiety scores; most were not prospectively registered, and few employed independent outcome assessment.
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.
Purity assessment relies mainly on reverse-phase high-performance liquid chromatography with ultraviolet detection. Because the peptide lacks a strong chromophore, detection often uses backbone absorbance near 214 nm. Identity is confirmed by mass spectrometry, typically electrospray ionization or matrix-assisted laser desorption, comparing the measured mass against the expected value. Amino acid analysis can verify composition after acid hydrolysis. Diastereomer content and residual counterions are reported less often, although both can influence biological assays.
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.
=== Taste === Salts can elicit all five basic tastes, e.g., salty (sodium chloride), sweet (lead diacetate, which will cause lead poisoning if ingested), sour (potassium bitartrate), bitter (magnesium sulfate), and umami or savory (monosodium glutamate).
Cases were reported where mental symptoms were alleviated following the surgical removal of diseased or damaged brain tissue. The accumulation of medical case studies on behavioural changes following damage to the frontal lobes led to the formulation of the concept of Witzelsucht, which designated a neurological condition characterised by a certain hilarity and childishness in those with the condition. The picture of frontal lobe function that emerged from these studies was complicated by the observation that neurological deficits attendant on damage to a single lobe might be compensated for if the opposite lobe remained intact. In 1922, the Italian neurologist Leonardo Bianchi published a detailed report on the results of bilateral lobectomies in animals that supported the contention that the frontal lobes were both integral to intellectual function and that their removal led to the disintegration of the subject's personality. This work, while influential, was not without its critics due to deficiencies in experimental design. The first bilateral lobectomy of a human subject was performed by the American neurosurgeon Walter Dandy in 1930. The neurologist Richard Brickner reported on this case in 1932, relating that the recipient, known as "Patient A", while experiencing a blunting of affect, had no apparent decrease in intellectual function and seemed, at least to the casual observer, perfectly normal. Brickner concluded from this evidence that "the frontal lobes are not 'centers' for the intellect".
Most venous diseases involve obstruction such as a thrombus or insufficiency of the valves, or both of these. Other conditions may be due to inflammation, or compression. Ageing is a major independent risk factor for venous disorders. The medical speciality involved with the diagnosis and treatment of venous disorders is known as phlebology (also venology), and the specialist concerned is a phlebologist. There are a number of vascular surgeries and endovascular surgeries carried out by vascular surgeons to treat many venous diseases.
== Reproduction == Zearalenone structure is similar to estrogens and α-zearalenol binds with an even greater affinity estrogen receptors, while β-zearalenol's affinity is lower than both the parent compound's and α-Zel's binding affinity. This identifies ZEN and its metabolites as xenoestrogens. The human and livestock exposure to ZEN through the diet poses health concern due to the onset of several sexual disorders and alterations in the development of sexual organs. There are reliable case reports of early puberty in girls chronically exposed to ZEN in various regions of the world. In mice, ZEN consumption was linked to a decline of potent sperm and egg cells, an increase to double-stranded breaks in DNA and activation of DNA repair mechanisms, followed by embryonic development challenges that reduced the viability of offspring.
Sources: en.wikipedia.org
=== Proteomics === ETD is widely used in the analysis of protein and large peptides. Important post translational modifications including phosphorylation, glycosylation and disulfide linkages are all analyzed using ETD.
Mary Osborn and Klaus Weber wrote a classic paper in biochemistry on determination of the molecular weight of a protein via SDS polyacrylamide gel electrophoresis, published in 1969 in Journal of Biological Chemistry. They knew that in 1967 Shapiro, Vinuela, and Maisel had shown that electrophoresis of proteins along with Sodium Dodecyl Sulfate (SDS) in polyacrylamide gels (PAGE) could separate the tested polypeptide chains by molecular weight. To see if this method applied to proteins of various sizes and shapes, Osborn and Weber took 40 known proteins, including globular and filamentous proteins, analyzed them via SDS PAGE, and plotted the logarithms of their molecular weights against their electrophoretic mobilities. The results showed convincingly that "the good resolution and the fact that an estimate of the molecular weight can be obtained within a day, together with the small amount of protein needed, makes the method strongly competitive with others commonly employed." This method has been used extensively by biochemists in all kinds of studies involving protein purification and identification as part of the process.
When the body has ample carbohydrates available as energy source, glucose is completely oxidized to CO2; acetyl-CoA is formed as an intermediate in this process, first entering the citric acid cycle followed by complete conversion of its chemical energy to ATP in oxidative phosphorylation. When the body has excess carbohydrates available, some glucose is fully metabolized, and some of it is stored in the form of glycogen or, upon citrate excess, as fatty acids (see lipogenesis). Coenzyme A is recycled at this step. When the body has no free carbohydrates available, fat must be broken down into acetyl-CoA in order to get energy. Under these conditions, acetyl-CoA cannot be metabolized through the citric acid cycle because the citric acid cycle intermediates (mainly oxaloacetate) have been depleted to feed the gluconeogenesis pathway. The resulting accumulation of acetyl-CoA activates ketogenesis. Insulin and glucagon are key regulating hormones of ketogenesis, with insulin being the primary regulator. Both hormones regulate hormone-sensitive lipase and acetyl-CoA carboxylase. Hormone-sensitive lipase produces diglycerides from triglycerides, freeing a fatty acid molecule for oxidation. Acetyl-CoA carboxylase catalyzes the production of malonyl-CoA from acetyl-CoA. Malonyl-CoA reduces the activity of carnitine palmitoyltransferase I, an enzyme that brings fatty acids into the mitochondria for β-oxidation.
Sources: en.wikipedia.org
Sealed, desiccated storage at -20 °C or colder is the standard recommendation for research-grade material. Vials should reach room temperature before they are opened, which limits condensation. Repeated temperature cycling is discouraged.
A reported purity value reflects the share of the main peak in one chromatographic run and says nothing about identity. Confirming that the expected sequence is present requires a separate measurement such as mass spectrometry. Purity and identity are distinct questions.
A mass spectrum reports the molecular masses present in a sample and shows whether they match the value expected for selank, near 751.9 Da. It also flags common artifacts such as truncation or adduct formation. It does not establish correct stereochemistry or complete sequence order on its own.
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.