If you have been reading about tuftsin 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.
Last reviewed on 2025-10-28. Where a claim depends on a specific study, the study is described rather than over-claimed.
Lyophilized Selank, the dry powder form, is generally stored frozen at minus 20 degrees Celsius or colder for long-term keeping. The solid is hygroscopic and should stay sealed, dry, and protected from light. Once dissolved, the peptide is less stable and is usually held refrigerated at 2 to 8 degrees Celsius for short periods. Repeated freezing and thawing is avoided because it can promote aggregation and loss of activity. Buffers and pH choice also affect how long a solution remains usable.
Solubility behavior is a practical concern for handling. Selank dissolves readily in water and in common aqueous buffers, which simplifies preparation of working solutions. The choice of solvent, ionic strength, and pH can influence aggregation over time, particularly at higher concentrations. Aqueous solutions are typically sterile-filtered before use. Because stability depends on several variables, storage and handling notes should be treated as general guidance rather than fixed rules, and specific values are best confirmed against a certificate of analysis for each batch.
Characterization of Selank in a laboratory setting relies on standard peptide methods. Reverse-phase high-performance liquid chromatography separates the target from related impurities and provides a purity figure, commonly reported as 95 percent or higher. Mass spectrometry, typically electrospray ionization or matrix-assisted laser desorption, confirms the molecular mass and helps detect truncation or modification. Amino acid analysis can verify composition when a sequence-level check is needed. These techniques together establish identity and purity for a given lot.
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 |
|---|---|---|
| Solubility | Freely soluble in water | Also in aqueous buffers |
| Typical purity (HPLC) | 95 percent or higher | Lot-dependent |
| Dry powder storage | Minus 20 degrees Celsius | Sealed, dry, protected from light |
| Solution storage | 2 to 8 degrees Celsius | Short-term use |
| Identity confirmation | Mass spectrometry | ESI or MALDI-TOF |
Enzymatic stability motivates the extra three residues at the carboxyl end. Native tuftsin is cleaved quickly by circulating aminopeptidases and carboxypeptidases, which limits its duration of action and its usefulness as a tool compound. Extending the chain with proline-rich segments is a common design tactic because proline constrains the backbone and slows proteolysis. The same Pro-Gly-Pro motif appears in other Russian-developed peptides of the era. Whether the full seven-residue chain is required for activity, or whether it acts mainly as a prodrug releasing tuftsin, remains unresolved.
Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro. Its four N-terminal residues reproduce tuftsin, a tetrapeptide fragment of the immunoglobulin heavy chain, while the C-terminal Pro-Gly-Pro extension is a synthetic addition. The peptide has a molecular mass near 752 daltons and carries a net positive charge at physiological pH because of the arginine and lysine side chains. Published indexes list it under the name Selank and the sequence abbreviation TKPRPGP. Solid-phase peptide synthesis is the standard production route for research quantities.
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.
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.
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 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.
Bicalutamide produces abnormal liver changes necessitating discontinuation in around 1% of people. Rarely, it has been associated with cases of serious liver damage, serious lung toxicity, and sensitivity to light. Although the risk of adverse liver changes is small, monitoring of liver function is recommended during treatment. Bicalutamide is a member of the nonsteroidal antiandrogen (NSAA) group of medications. It works by selectively blocking the androgen receptor (AR), the biological target of the androgen sex hormones testosterone and dihydrotestosterone (DHT). It does not lower androgen levels. The medication can have some estrogen-like effects in men when used as a monotherapy due to increased estradiol levels. Bicalutamide is well-absorbed, and its absorption is not affected by food. The elimination half-life of the medication is around one week. It shows peripheral selectivity in animals, but crosses the blood–brain barrier and affects both the body and brain in humans. Bicalutamide was patented in 1982 and approved for medical use in 1995. It is on the World Health Organization's List of Essential Medicines. Bicalutamide is available as a generic medication. The drug is sold in more than 80 countries, including most developed countries. It was at one time the most widely used antiandrogen in the treatment of prostate cancer, with millions of men with the disease having been prescribed it. Although bicalutamide is also used for other indications besides prostate cancer, the vast majority of prescriptions appear to be for treatment of prostate cancer.
=== Diagnostic uses === The transaminase enzymes are important in the production of various amino acids, and measuring the concentrations of various transaminases in the blood is important in the diagnosing and tracking many diseases. For example, the presence of elevated transaminases can be an indicator of liver and cardiac damage. Two important transaminase enzymes are aspartate transaminase (AST), also known as serum glutamic oxaloacetic transaminase (SGOT); and alanine transaminase (ALT), also called alanine aminotransferase (ALAT) or serum glutamate-pyruvate transaminase (SGPT). These transaminases were discovered in 1954 and their clinical importance was described in 1955.
=== Business career: expansion and near disaster === By now the property boom was in full swing. Heseltine and Labovitch established first one, then a group of companies under the name "Bastion Properties". Heseltine later recorded that he and Labovitch bought at least three properties in W1 and W2 which they were able to sell at a profit before they had completed the original purchases. They also built eight small houses in Queensborough Mews, Bayswater. They bought a 58-year lease on a block of seven properties at Stafford Terrace, off Kensington High Street, which they converted into flats and built houses for Stepney Borough Council. Bastion also planned to build an estate of up to 126 houses at Tenterden, Kent, which failed to sell. In order to attract other buyers to the empty estate Heseltine had to accept an offer of £4,000 for the first house, which had been valued at £7,250. The estate was beset with repair problems until after Heseltine's election to Parliament. Heseltine and Labovitch also founded the magazine publishing company Cornmarket, and brought out Directory of Opportunities for School Leavers and Directory of Opportunities for Qualified Men, which earned a steady income from advertising. Canadian, French and German versions were also launched, although these were less profitable. In late 1959, using £10,000 of a £30,000 profit on selling a freehold site off Regents Park, they acquired the famous (but unprofitable) magazine Man About Town whose title was shortened to About Town then simply Town.
It has been well demonstrated that regions of tau six-residue segments, namely PHF6 (VQIVYK) and PHF6* (VQIINK), can form tau PHF aggregation in AD. Apart from the PHF6, some other residue sites like Ser285, Ser289, Ser293, Ser305 and Tyr310, located near the C-terminal of the PHF6 sequences, play key roles in the phosphorylation of tau. Hyperphosphorylated tau differs in its sensitivity and its kinase as well as alkaline phosphatase activity and is, along with beta-amyloid, a component of the pathologic lesion seen in Alzheimer disease. Soluble oligomeric tau species have been linked to more aggressive clinical progression in Alzheimer’s disease. In 2025, patient-derived high-molecular-weight tau was reported to impair complex spike bursting in hippocampal CA1 neurons and to be associated with reduced neuronal CaV2.3 expression in mouse and ex vivo models, providing a possible cellular mechanism for tau-related cognitive decline. A recent hypothesis identifies the decrease of reelin signaling as the primary change in Alzheimer's disease that leads to the hyperphosphorylation of tau via a decrease in GSK3β inhibition. A68 is a name sometimes given (mostly in older publications) to the hyperphosphorylated form of tau protein found in the brains of individuals with Alzheimer's disease. In 2020, researchers from two groups published studies indicating that an immunoassay blood test for the phospho-tau-217 (p-tau-217) form of the protein could diagnose Alzheimer's up to decades before dementia symptoms were evident.
A Pew Research Center post-election analysis of voters who are listed as having voted in their state's voter turnout records who have also reported voting in a survey after the election similarly found a "more racially and ethnically diverse" electorate, one that was less engaged politically than in the four previous federal elections. More 2020 Trump voters (89%) than 2020 Biden voters (85%) also voted in 2024. 15% of those who voted for Biden in 2020 did not vote in the 2024 election. 78% of White voters supported Trump in 2024, a lower level of support for him among this group than in 2020 and 2016. Fewer Black voters supported Harris in 2024 than they did the Democratic candidates in the 2020 and 2016 elections.
Sources: en.wikipedia.org
The PLA began as an all-volunteer force. In 1955, as part of an effort to modernize the PLA, the first Military Service Law created a system of compulsory military service. Since the late 1970s, the PLA has been a hybrid force that combines conscripts and volunteers. Conscripts who fulfilled their service obligation can stay in the military as volunteer soldiers for a total of 16 years. De jure, military service with the PLA is obligatory for all Chinese citizens. However, mandatory military service has not been enacted in China since 1949. Due to the effect of the one-child policy, over 70 percent of the PLA and 80 percent of its combat troops come from one-child households, according to Liu Mingfu of the National Defense University.
The global moisture budget is primarily being influenced by tropical sea surface temperatures from the position of the Intertropical Convergence Zone (ITCZ). The Southern Hemisphere has a unique meteorological feature positioned in the southwestern Pacific Basin called the South Pacific Convergence Zone (SPCZ), which contains a perennial position within the Southern Hemisphere. During ENSO warm periods, the SPCZ reverses orientation extending from the equator down south through Solomon Islands, Vanuatu, Fiji and towards the French Polynesian Islands; and due east towards South America affecting geochemistry of corals in tropical regions. Geochemical analysis of skeletal coral can be linked to sea surface salinity (SSS) and sea surface temperature (SST), from El Nino 3.4 SSTA data, of tropical oceans to seawater δ18O ratio anomalies from corals. ENSO phenomenon can be related to variations in sea surface salinity (SSS) and sea surface temperature (SST) that can help model tropical climate activities.
== Other effects == In concert with the primary surface forces described above, there are several circumstantial effects in play. While the forces themselves each contribute to the magnitude of the adhesion between the surfaces, the following play a crucial role in the overall strength and reliability of an adhesive device.
=== Toxins === The leaves, stem, and green unripe fruit of the tomato plant contain small amounts of the alkaloid tomatine. They contain small amounts of solanine, a toxic alkaloid found in larger amounts in potato leaves and other members of the nightshade family. Tomato plants can be toxic to dogs if they eat large amounts of the fruit, or chew plant material. Small amounts of tomato foliage are sometimes used for flavoring, and the green fruit of unripe red tomato varieties is sometimes used for cooking, particularly as fried green tomatoes.
, where distance is the direct (not logarithmic) distance in number of decades or "octaves" to the right the mass concentration is found. To translate from mass to molar concentration, the dividend (molar mass and the divisor (1000) in the division change places, or, alternatively, distance to right is changed to distance to left. Substances with a molar mass around 1000g/mol (e.g. thyroxine) are almost vertically aligned in the mass and molar images. Adrenocorticotropic hormone, on the other hand, with a molar mass of 4540, is 0.7 decades to the right in the mass image. Substances with molar mass below 1000g/mol (e.g. electrolytes and metabolites) would have "negative" distance, that is, masses deviating to the left. Many substances given in mass concentration are not given in molar amount because they haven't been added to the article. The diagram above can also be used as an alternative way to convert any substance concentration (not only the normal or optimal ones) from molar to mass units and vice versa for those substances appearing in both scales, by measuring how much they are horizontally displaced from one another (representing the molar mass for that substance), and using the same distance from the concentration to be converted to determine the equivalent concentration in terms of the other unit. For example, on a certain monitor, the horizontal distance between the upper limits for parathyroid hormone in pmol/L and pg/mL may be 7 cm, with the mass concentration to the right.
Sources: en.wikipedia.org
=== Use as forage === In former times, Jerusalem artichoke was used as forage for domesticated cattle, horses, and pigs. The plant has valuable nutrient contents and various bioactive compounds, and so is used today as an animal feed source or for the health of several animal species. Pigs, for example, can eat the tuber either dried or directly from the ground or the green plant biomass (stalks and leaves) from the pasture. Washed Jerusalem artichoke tubers can be fed to many animals, and silage produced from the harvested stalks and leaves. The silage has high nutrient values and satisfactory digestion performance for ruminants. Its high inulin content beneficially affects the rumen metabolism and microflora. However, cutting the tops to produce silage greatly reduces the harvest of the tubers. There are also many other Jerusalem artichoke products on the market, such as supplementary feed for horses, dogs, and small animals.
Most studies agree on a Cretaceous age for the most recent common ancestor of modern birds but estimates range from the Early Cretaceous to the latest Cretaceous. Similarly, there is no agreement on whether most of the early diversification of modern birds occurred in the Cretaceous and associated with breakup of the supercontinent Gondwana or occurred later and potentially as a consequence of the Cretaceous–Palaeogene extinction event. This disagreement is in part caused by a divergence in the evidence. Most molecular dating studies suggests a Cretaceous evolutionary radiation, while fossil evidence points to a Cenozoic radiation (the so-called 'rocks' versus 'clocks' controversy). The discovery in 2005 of Vegavis from the Maastrichtian, the last stage of the Late Cretaceous, proved that the diversification of modern birds started before the Cenozoic era. The affinities of an earlier fossil, the possible galliform Austinornis lentus, dated to about 85 million years ago, are still too controversial to provide a fossil evidence of modern bird diversification. In 2020, Asteriornis from the Maastrichtian was described, it appears to be a close relative of Galloanserae, the earliest diverging lineage within Neognathae. Attempts to reconcile molecular and fossil evidence using genomic-scale DNA data and comprehensive fossil information have not resolved the controversy.
It is a situation similar to lipocalins (from Greek lipos=fat and Greek kalyx=cup), where the name designates a superfamily of widely distributed and heterogenous proteins, which transport small hydrophobic molecules including steroids and lipids. However, in contrast to lipocalins, the “CSP” family refers to homogenous evolutionary-well conserved proteins with characteristic sequence (4 cysteines), tissue profiling (ubiquitously expressed), and rather highly diverse binding properties (not only to long fatty acids (FAs) and straight lipid chains, but also to cyclic compounds such as cinnamaldehyde) [34]. Therefore, it is rather difficult to name groups and sub-groups within the CSP family, although numerous CSP proteins are mainly produced in the gut and the fat body that are considered as the insect body’s principle storage organs for energy in the forms of FAs and lipids, which are mobilized through lipolysis process to provide fuel to other organs to develop, regenerate or grow and/or to respond to an infectious agent [4, 14, 50]. In moths, specific lipid chains are mobilized for pheromone synthesis [9-14].
Diagnosis is by measuring growth hormone after a person has consumed a glucose solution, or by measuring insulin-like growth factor I in the blood. After diagnosis, medical imaging of the pituitary is carried out to determine if an adenoma is present. If excess growth hormone is produced during childhood, the result is the condition gigantism rather than acromegaly, and it is characterized by excessive height.
==== Biomarkers of cereal presence in archaeological pottery ==== Recently, alkylresorcinols have been widely recognised as a biomarker for the presence of cereals in archaeological pottery. They were previously found in a well-preserved Bronze Age wooden container from Switzerland, and coarse ware vessels from a Roman cavalry barrack at Vindolanda. A study demonstrated that the survival of ARs is highly dependent on the cooking procedures and burial conditions. However, if recoverable, analysis of these phenolic lipids in archaeological contexts is valuable as it can help explain the uptake and spread of cereal processing of past communities in particular regions.
Sources: en.wikipedia.org
Reverse-phase HPLC is the usual method and gives a percentage purity value. Mass spectrometry then confirms the molecular mass. Together they provide a basic identity and purity profile for a lot.
Freeze-dried material is kept frozen, often at minus 20 degrees Celsius, and protected from light and moisture. Dissolved peptide is refrigerated for short-term use. Repeated freeze-thaw cycles are avoided.
A certificate of analysis typically lists purity by HPLC, the confirmed mass, appearance, and sometimes water or counter-ion content. It documents results for a specific batch. Details vary by supplier.
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.