A practical reference on Tuftsin: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
Reviewed 2026-08-01. Anything still debated is marked as such rather than presented as settled.
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.
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.
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 |
|---|---|---|
| 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 |
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.
Naming for this compound is not fully standardised in English sources. The spelling Selanc appears in some transliterations, and catalogue entries may instead list the peptide sequence itself as the identifier. Reference material sometimes groups it with other short synthetic peptides studied for behavioural effects, which can create confusion when citations are compared. Distinguishing the exact sequence from related tuftsin analogues is therefore a practical first step when reviewing any dataset or specification sheet.
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.
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.
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.
Quantification in biological matrices relies on liquid chromatography coupled to tandem mass spectrometry with stable-isotope internal standards. Low plasma concentrations and adsorption to container surfaces both complicate measurement. Solid-phase extraction is often needed to reduce matrix interference before injection. Reported limits of quantification differ widely between laboratories, which makes direct comparison of pharmacokinetic results difficult and limits meta-analysis.
Peptide bonds are vulnerable to protease attack, and Selank is no exception. Measured half-life in serum is short, on the order of minutes in several reports, which explains why intranasal administration is the common route described in the literature. Absorption across the nasal mucosa partially bypasses first-pass hepatic metabolism. Quantitative data on human bioavailability remain limited and are difficult to compare across studies.
Lyophilised material kept dry at minus 20 degrees Celsius or colder is the most stable form, and suppliers commonly state a shelf life of two years or more under those conditions. Once dissolved, degradation accelerates through hydrolysis and deamidation, particularly at alkaline pH or elevated temperature. Working solutions are usually divided into single-use aliquots to avoid repeated freeze-thaw cycles. The choice of reconstitution solvent affects both stability and the ionic strength of the final preparation.
== Contraindications == Like other AASs, oxandrolone may worsen hypercalcemia by increasing osteolytic bone resorption. When taken by pregnant women, oxandrolone may have unintended effects such as masculinization on the fetus.
=== Reaction to Harry Potter partnership === In August 2026, Tim Horton announced its “Back to Hogwarts with Harry Potter” campaign, with a series of themed products released to mark the 25th anniversary of the release of the first film of the Harry Potter movie franchise. The campaign received criticism from the 2SLGBTQ+ community, with Tim Horton being rebranded by online activists as "TERF-Hortons" for being perceived to be aligning themselves with J.K. Rowling's "anti-trans" views. Advocacy group Egale Canada argued that "as a brand that is synonymous with Canada, Tim Hortons and their partnerships should reflect Canada — a country that is inclusive and proud of its diversity".
== History == Waterlogged wood is a wooden object that has been submerged or partially submerged in water and has affected the original intended purpose or look of the object. Waterlogged wood objects can also include wood found within moist soil from archaeological sites, underwater archaeology, maritime debris, or damaged wood objects. Conservation of waterlogged wood has changed throughout time. Due to the delicate structure of this organic material, conservators and museum professionals alike have struggled with finding a textbook method. An example of the conservation of wood and how it has changed over time can be illustrated by the conservation treatments of a Kefermarkt altar. The earliest attempt at wood conservation is recorded as late as 1852–1855, A. Stifter treated the Kefermarkt altar in Austria with table salt in an attempt to protect the wood against pests. In around 1916-1918 Councillor Bolle attempted to protect the wood altar from pests included brushing the wood with petroleum and hexachloroethane. Finally, in 1929 the use of hydrogen cyanide relieved the pest problem and preserve the woods longevity. From a conservation standpoint, waterlogged or not, wood has been difficult to preserve because it is an organic material.
Sources: en.wikipedia.org
Globally, about 98 percent of soybean meal is used as animal feed. Of the US soybean production magnitude from 2010 through 2012, about 44 percent was exported as soybeans, and 53 percent was crushed in the US. Of the crushed tonnage, 19 percent was recovered as soybean oil and the remainder was recovered as soybean meal. Of the total US soybean tonnage produced, about 35 percent was fed to US livestock and poultry as soybean meal. Most of the remaining soybean meal produced in the US was exported. It has been estimated that, of soybean meal fed to animals in the US, 48 percent is fed to poultry, 26 percent to swine, 12 percent to beef cattle, 9 percent to dairy cattle, 3 percent is used in fish feed and about 2 percent in pet food. Although this implies that the tonnage of soybean meal fed to other species is relatively minor, such use is not unimportant. For example, for rapidly growing lambs on low-protein feeds, soybean meal can be an important supplement to ensure adequate protein intake, and partly because of its palatability, soybean meal is often recommended for use in starter rations when creep feeding lambs.
As part of their viral marketing campaign, Amazon also started to promote the faux in-universe fictional film Dawn of the Seven which led to the release of a faux trailer in the Vought International YouTube channel named the Bourke Cut that makes reference to Zack Snyder's Justice League, a viral marketing website dawnoftheseven.com which gives users the details for the fictional film such as faux interviews, and a series of faux posters which included a promotional one and individuals for each member of the Seven designed by Kyle Lambert who also worked for the posters of Stranger Things. On May 30, 2022, on YouTube it was posted a 1980s themed anti-drug campaign short video with Ackles portraying Soldier Boy making reference at the Just Say No campaign. The following day, the in-universe outtakes of Soldier Boy were published revealing the true colors of the character as a hypocritical short-tempered, foul-mouthed, alcoholic, and drug-addicted superhero.
=== Journal articles === Bridge, D; Cunningham, C W; Schierwater, B; DeSalle, R; Buss, L W (15 September 1992). "Class-level relationships in the phylum Cnidaria: evidence from mitochondrial genome structure". Proceedings of the National Academy of Sciences. 89 (18): 8750–8753. Bibcode:1992PNAS...89.8750B. doi:10.1073/pnas.89.18.8750. PMC 49998. PMID 1356268. Bridge, D; Cunningham, CW; DeSalle, R; Buss, LW (July 1995). "Class-level relationships in the phylum Cnidaria: molecular and morphological evidence". Molecular Biology and Evolution. 12 (4): 679–689. doi:10.1093/oxfordjournals.molbev.a040246. PMID 7659022. Fautin, Daphne Gail (October 2002). "Reproduction of Cnidaria". Canadian Journal of Zoology. 80 (10): 1735–1754. Bibcode:2002CaJZ...80.1735F. doi:10.1139/z02-133. hdl:1808/5373. Mackie, G O (October 2002). "What's new in cnidarian biology?". Canadian Journal of Zoology. 80 (10): 1649–1653. Bibcode:2002CaJZ...80.1649M. doi:10.1139/z02-138. Schuchert, P. (27 April 2009). "Phylogenetic analysis of the Cnidaria". Journal of Zoological Systematics and Evolutionary Research. 31 (3): 161–173. doi:10.1111/j.1439-0469.1993.tb00187.x. Kass-Simon, G; Scappaticci, Jr., A A (October 2002). "The behavioral and developmental physiology of nematocysts". Canadian Journal of Zoology. 80 (10): 1772–1794. Bibcode:2002CaJZ...80.1772K. doi:10.1139/z02-135. J. Zrzavý (2001). "The interrelationships of metazoan parasites: a review of phylum- and higher-level hypotheses from recent morphological and molecular phylogenetic analyses". Folia Parasitologica. 48 (2): 81–103.
Sources: en.wikipedia.org
== Genetics == The gene for G-CSF is located on chromosome 17, locus q11.2-q12. Nagata et al. found that the GCSF gene has four introns, and that two different polypeptides are synthesized from the same gene by differential splicing of mRNA. The two polypeptides differ by the presence or absence of three amino acids. Expression studies indicate that both have authentic GCSF activity. It is thought that stability of the G-CSF mRNA is regulated by an RNA element called the G-CSF factor stem-loop destabilising element.
== Function == Neurotransmitter transport systems are responsible for the release, re-uptake and recycling of neurotransmitters at synapses. High affinity transport proteins found in the plasma membrane of presynaptic nerve terminals and glial cells are responsible for the removal, from the extracellular space, of released-transmitters, thereby terminating their actions. The majority of the transporters constitute an extensive family of homologous proteins that derive energy from the co-transport of Na+ and Cl−, in order to transport neurotransmitter molecules into the cell against their concentration gradient. Neurotransmitter sodium symporters (NSS) are targets for anti-depressants, psychostimulants and other drugs.
Basic stocks are usually named for the primary meat type. A distinction is usually made between fond blanc, or white stock, made by using raw bones and mirepoix, and fond brun, or brown stock, which gets its color by roasting the bones and mirepoix before boiling; the bones may also be coated in tomato paste before roasting. Chicken is most commonly used for fond blanc, while beef or veal are most commonly used in fond brun. Other regional varieties include:
Countercurrent exchange is used extensively in biological systems for a wide variety of purposes. For example, fish use it in their gills to transfer oxygen from the surrounding water into their blood, and birds use a countercurrent heat exchanger between blood vessels in their legs to keep heat concentrated within their bodies. In vertebrates, this type of organ is referred to as a rete mirabile (originally the name of the organ in the fish gills). Mammalian kidneys use countercurrent exchange to remove water from urine so the body can retain water used to move the nitrogenous waste products (see countercurrent multiplier).
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.
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.