Everything below concerns elevated plus maze. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Last reviewed on 2025-10-27. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
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.
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.
Hard ionization techniques are those that impart high quantities of residual internal energy in the subject molecule, even after ionization. Part of the energy would be dissipated by rupturing chemical bonds within the ion, producing many fragmentary radical cations. The resultant ions tend to have m/z lower than the molecular ion (other than in the case of proton transfer and not including isotope peaks). The most common example of hard ionization is electron ionization (EI). The radical ions produced after the first ionization are called second-generation product ions. The products are then directed towards the mass analyzer by a repeller electrode. The ionization process often follows predictable cleavage reactions that give rise to fragment ions which, following detection and signal processing, convey structural information about the analyte. Conversely, soft ionization techniques are those that impart little residual energy onto the subject molecule and as such result in little fragmentation. Examples include fast atom bombardment (FAB), chemical ionization (CI), atmospheric-pressure chemical ionization (APCI), atmospheric-pressure photoionization (APPI), electrospray ionization (ESI), desorption electrospray ionization (DESI), and matrix-assisted laser desorption/ionization (MALDI).
=== Interactions with Dictyostelium === The slime mold Dictyostelium discoideum contains "farmer" individuals that live in association with Pseudomonas fluorescens. Two strains of the bacterium are associated with the farmer. One strain serves as a food source and the other strain serves as a symbiont that produces beneficial secondary metabolites. The main genetic difference between these two strains is a mutation of the global activator gene called gacA. This gene plays a key role in gene regulation; when this gene is knocked out in the nonfood bacterial strain, it loses its special secondary metabolites and, independently, is transformed into a food strain.
== Biography == Peter Joseph Moloney and his three sisters, whose father died in 1897, were raised in Powassan by their widowed mother. The four siblings were the grandchildren of Irish Catholics who left Ireland during the Great Famine of Ireland and settled in Warminster, Southern Ontario. He received secondary education at the preparatory school of St. Michael's College, Toronto. He earned a bachelor's degree from the University of Toronto in 1912 and a master's degree with thesis Rate of Solution and Precipitation of Gypsum in chemistry in 1915. During a stay at the University of California at Berkeley for the academic year 1915–1916, he met Angelina Cecilia Chapman. They married in Berkeley on July 6, 1916. Moloney worked between 1917 and 1919 at the Department of Agriculture in Ottawa in food chemistry. From 1919 Moloney worked as a research assistant for Connaught Laboratories, a vaccine manufacturer that emerged from the University of Toronto and now belongs to Sanofi. While working for Connaught Laboratories he studied at the University of Toronto, where his mentor was John G. FitzGerald. After acquiring a Ph.D. with thesis On the Purification of Insulin in 1924 from the University of Toronto, Moloney was in the working group of Charles Best and Frederick Banting from 1921 with the purification of insulin to make it clinically usable, which was achieved for the first time in 1922.
== Non-enzymatic processes == Protein backbones are very stable in water at neutral pH and room temperature, although the rate of hydrolysis of different peptide bonds can vary. The half-life of a peptide bond under normal conditions can range from 7 years to 350 years, even higher for peptides protected by modified terminus or within the protein interior. The rate of hydrolysis however can be significantly increased by extremes of pH and heat. Spontaneous cleavage of proteins may also involve catalysis by zinc on serine and threonine. Strong mineral acids can readily hydrolyse the peptide bonds in a protein (acid hydrolysis). The standard way to hydrolyze a protein or peptide into its constituent amino acids for analysis is to heat it to 105 °C for around 24 hours in 6M hydrochloric acid. However, some proteins are resistant to acid hydrolysis. One well-known example is ribonuclease A, which can be purified by treating crude extracts with hot sulfuric acid so that other proteins become degraded while ribonuclease A is left intact. Certain chemicals cause proteolysis only after specific residues, and these can be used to selectively break down a protein into smaller polypeptides for laboratory analysis. For example, cyanogen bromide cleaves the peptide bond after a methionine. Similar methods may be used to specifically cleave tryptophanyl, aspartyl, cysteinyl, and asparaginyl peptide bonds. Acids such as trifluoroacetic acid and formic acid may be used for cleavage. Like other biomolecules, proteins can also be broken down by high heat alone.
Sources: en.wikipedia.org
A tactic in which security forces pose as 'pseudo' insurgents to gather intelligence was developed prior to the Rhodesian Bush War, and had also been used by police forces. Pseudo operations involve security force personnel being trained to closely imitate insurgents. Teams of these personnel then enter regions where insurgents are active and portray themselves as insurgents. After establishing credibility, the team collects intelligence on actual insurgents and their sources of support. These tactics can be most necessary in regions where the insurgents have eliminated the government's sources of intelligence, as was the case in north-eastern Rhodesia in 1973. In general, 'pseudo' teams undertake only intelligence collection work, and do not attack insurgents themselves. 'Pseudo' tactics are generally most effective when the teams include former insurgents who have been 'turned' to side with the government. The effectiveness of these tactics is partially dependent on their use not becoming known, as this will lead to insurgents improving their security processes. Internationally, there has also been a risk of pseudo units breaking the law. If local civilians learn that the security forces are posing as insurgents and using this as cover to break the law, the tactics can be counter-productive as they will erode support for the government. The British authorities used pseudo tactics during the Malayan Emergency, with this coming to the attention of the Rhodesians who took part in that conflict.
Early cephalopods are thought to have produced jets by drawing their body into their shells, as Nautilus does today. Nautilus is also capable of creating a jet by undulations of its funnel; this slower flow of water is more suited to the extraction of oxygen from the water. When motionless, Nautilus can only extract 20% of oxygen from the water. The jet velocity in Nautilus is much slower than in coleoids, but less musculature and energy is involved in its production. Jet thrust in cephalopods is controlled primarily by the maximum diameter of the funnel orifice (or, perhaps, the average diameter of the funnel) and the diameter of the mantle cavity. Changes in the size of the orifice are used most at intermediate velocities. The absolute velocity achieved is limited by the cephalopod's requirement to inhale water for expulsion; this intake limits the maximum velocity to eight body-lengths per second, a speed which most cephalopods can attain after two funnel-blows. Water refills the cavity by entering not only through the orifices, but also through the funnel. Squid can expel up to 94% of the fluid within their cavity in a single jet thrust. To accommodate the rapid changes in water intake and expulsion, the orifices are highly flexible and can change their size by a factor of 20; the funnel radius, conversely, changes only by a factor of around 1.5. Some octopus species are also able to walk along the seabed. Squids and cuttlefish can move short distances in any direction by rippling of a flap of muscle around the mantle. While most cephalopods float (i.e.
One-place studies are a branch of family history and/or local history with a focus on the entire population of a single road, village or community, not just a single, geographically dispersed family line.
Sources: en.wikipedia.org
In its wild-type form, the IDH1 enzyme is active in the cytoplasm and peroxisomes, where it catalyzes the conversion of isocitrate into α-ketoglutarate (α-KG) as part of the citric acid cycle. This process generates NADPH, a vital molecule that supports antioxidant defenses and biosynthetic processes. When mutated, IDH1 undergoes a neomorphic transformation, shifting its function. The altered enzyme converts α-KG into D-2-hydroxyglutarate (D-2HG), an oncometabolite. Elevated D-2HG levels disrupt normal cellular processes by inhibiting α-KG–dependent dioxygenases, leading to epigenetic changes, DNA hypermethylation, and impaired differentiation. Moreover, the mutation redirects NADPH consumption, increasing oxidative stress, which further drives tumor development. The accumulation of D-2HG and elevated oxidative stress play a critical role in reshaping the tumor microenvironment, positioning the R132H mutation as a prime target for IDH inhibitors. These therapies aim to restore regular metabolic functions and reduce tumor aggressiveness, offering a promising avenue for glioma treatment. In addition to being mutated in diffuse gliomas, IDH1 has also been shown to harbor mutations in human acute myeloid leukemia. The IDH1 mutation is considered a driver alteration and occurs early during tumorigenesis, in specific in glioma and glioblastoma multiforme, its possible use as a new tumour-specific antigen to induce antitumor immunity for the cancer treatment has recently been prompted.
Democratic Left was a post-communist political organisation that operated in the United Kingdom from 1991 to 1998. It emerged from the Eurocommunist faction within the Communist Party of Great Britain (CPGB) and was closely associated with the magazine Marxism Today, which ceased publication around the same period. The organisation was founded on 11 November 1991 following the CPGB's decision to dissolve and reconstitute itself as a left-wing reformist think tank and grassroots campaign group. This transformation was guided by the party's Manifesto for New Times, which outlined a vision for post-communist politics in Britain. Nina Temple, who had served as the final general secretary of the CPGB, became the organisation's secretary. Temple, who had been Press and Publicity Officer of the CPGB from 1983 to 1989 before becoming general secretary in 1990 at age 33, was one of the leading proponents of the CPGB's dissolution. The CPGB's transformation into Democratic Left proved controversial within the party. Many members rejected this reformist direction and instead affiliated with the Communist Party of Britain, which had split from the CPGB in 1988, while others in Scotland established the Communist Party of Scotland.
Capsaicin (8-methyl-N-vanillyl-6-nonenamide) (, commonly ) is a toxin that is the main active component of chili peppers and gives them their distinct pungent, "spicy" or "hot" taste. It is a potent irritant for mammals for which it produces a sensation of burning in any tissue with which it comes into contact. Capsaicin and several related amides (capsaicinoids) are produced as secondary metabolites by chili peppers, likely as deterrents against eating by mammals and against the growth of fungi. Pure capsaicin is a hydrophobic, highly pungent (i.e., spicy) crystalline solid.
The Office of the Inspector General also found that because the EPA's perchlorate reference dose is conservative and protective of human health further reducing perchlorate exposure below the reference dose does not effectively lower risk. Because of ammonium perchlorate's adverse effects upon children, Massachusetts set its maximum allowed limit of ammonium perchlorate in drinking water at 2 parts per billion (2 ppb = 2 micrograms per liter). Perchlorate affects only thyroid hormone. Because it is neither stored nor metabolized, effects of perchlorate on the thyroid gland are reversible, though effects on brain development from lack of thyroid hormone in fetuses, newborns, and children are not. Toxic effects of perchlorate have been studied in a survey of industrial plant workers who had been exposed to perchlorate, compared to a control group of other industrial plant workers who had no known exposure to perchlorate. After undergoing multiple tests, workers exposed to perchlorate were found to have a significant systolic blood pressure rise compared to the workers who were not exposed to perchlorate, as well as a significant decreased thyroid function compared to the control workers. A study involving healthy adult volunteers determined that at levels above 0.007 milligrams per kilogram per day (mg/(kg·d)), perchlorate can temporarily inhibit the thyroid gland's ability to absorb iodine from the bloodstream ("iodide uptake inhibition", thus perchlorate is a known goitrogen).
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.