Everything below concerns GABA-A receptor. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Updated 2026-03-13. Numbers and descriptions here follow the published literature rather than marketing material.
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.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Typical purity report | 95% or higher by HPLC | Area percentage at 214 nm |
| Identity confirmation | Mass spectrometry | Electrospray or MALDI |
| Powder storage | -20 C, desiccated | Protect from light |
| Solution storage | 2-8 C short term | Freeze aliquots for longer |
| Quality document | Certificate of analysis | States method and value |
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.
Reverse-phase high-performance liquid chromatography with ultraviolet detection near 214 nanometres is the standard purity method. Mass spectrometry, typically electrospray ionisation, confirms identity through the expected mass-to-charge pattern. Amino acid analysis can verify composition independently. Chiral purity requires separate techniques such as derivatisation followed by chromatographic separation, and such data are rarely reported for research-grade material.
Proposed mechanisms centre on the GABAergic system. Animal and tissue studies report changes in GABA-A receptor expression and reduced activity of GABA transaminase, the enzyme that degrades GABA. Effects on monoamine turnover, including serotonin and dopamine pathways, are also described, and a separate line of work links the peptide to increased expression of brain-derived neurotrophic factor in hippocampal tissue. Most of these findings come from rodent models and cell preparations. How the individual observations combine into a single coherent mode of action is not settled.
Pharmacokinetic data are sparse and largely derived from animal work. After intranasal administration the peptide appears in plasma within minutes, and reported half-lives are short, on the order of minutes to tens of minutes. Degradation proceeds through ordinary proteolytic cleavage into constituent amino acids and smaller fragments. Direct evidence that intact Selank reaches brain tissue in meaningful amounts is limited, and the extent of blood-brain barrier penetration is debated. Some authors argue that fragments, not the parent peptide, carry much of the observed activity.
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.
Proteomics: Large-scale study of proteins, particularly their structures and functions. Mass spectrometry techniques are used. Chemoproteomics: An array of techniques used to study protein-small molecule interactions Immunoproteomics: Study of large sets of proteins (proteomics) involved in the immune response Nutriproteomics: Identifying the molecular targets of nutritive and non-nutritive components of the diet. Uses proteomics mass spectrometry data for protein expression studies Proteogenomics: An emerging field of biological research at the intersection of proteomics and genomics. Proteomics data used for gene annotations. Structural genomics: Study of the three-dimensional structure of every protein encoded by a given genome using a combination of experimental and modeling approaches.
McKew said that "Putin and his minions have spent the past 15 years ranting about how the West (specifically NATO) wants a new Cold War". She suggested that "fighting a new Cold War would be in America's interest", adding "We won the last Cold War. We will win the next one too". The New Republic editor Jeet Heer criticised McKew's suggestion as "troubling" and for "wildly overstating the extent of Russian ambitions and power". Heer said that unlike the old Cold War, "Current U.S. troubles with Russia aren't the result of ideological differences ... and are intensely localized along Russia's borders, in countries like the Ukraine and Georgia". Jeremy Shapiro, a senior fellow in the Brookings Institution, wrote in his blog post at RealClearPolitics, referring to the US–Russia relations: "A drift into a new Cold War has seemed the inevitable result" of "Russian–Western confrontation" over Eastern European counties such as Ukraine, Moldova and Georgia. In August 2017, Russian Deputy Foreign Minister Sergei Ryabkov denied claims that the US and Russia were having another cold war, despite ongoing tensions between the two countries over Ukraine and Syria, and newer US sanctions against Russia. The University of East Anglia graduate student Oliver Steward, as well as the Casimir Pulaski Foundation senior fellow Stanisław Koziej, attributed the Russia's Zapad 2017 exercise in Belarus as part of the new Cold War between Russia and the West.
== Food Packet, Long Range Patrol == A freeze-dried, dehydrated ration, the FPIC required 1+1⁄2 U.S. pints (700 milliliters) of water to cook and reconstitute it. This was not a problem where water supplies were plentiful. However, the water sources in Vietnam were usually teeming with parasites such as blood flukes and tapeworms, as well as viruses, so the water had to be boiled or mixed with iodine tablets, the latter leaving an unwanted taste in a ration. Fresh water could also be collected from rainwater or, in an emergency, a LRP ration could be consumed 'dry', but the soldier doing so had to consume extra water to prevent dehydration. Some soldiers mixed its contents with MCI rations to reduce monotony and to supply extra dietary energy, as the ration was insufficient for an active soldier. However, this defeated the purpose of deploying the LRP ration in the first place. Another complaint was the absence of cigarettes found in C-rations. Due to these drawbacks, the original concept of its wide adoption was shelved in favor of its limited use by Special Operations units like the Long Range Patrols, Special Forces, and Navy SEALs. It then acquired the new designation of Food Packet, Long Range Patrol (LRP), also known as "Lurp meals" or "long rats". Production was limited to five million units in 1967, rising to just nine million in 1968. It was considered a novelty by line soldiers, who usually "acquired" as many as they could before going on field operations.
Sources: en.wikipedia.org
S. mutilans, like other centipedes, is a predator that kills by injecting venom into its prey. Venom is injected to immobilize and break down internal tissues. Venoms of Scolopendridae, including Scolopendra mutilans, contain neurotoxins, which are suspected to be a significant fast-acting component in venoms of many centipedes. This species mainly feeds on live animals; plant materials are occasionally consumed but its consumption is considered negligible. To get hold of the prey, this centipede grabs prey with its anterior legs, and typically envenomates prey by stabbing it using its forcipules. Little quantitative ecological and behavioural work was done for centipedes. Some studies, however, have found that centipedes are highly selective and tend to strike at the head or thorax instead of the abdomen. If the bite was made on the abdomen, the centipede would usually reposition the prey and strike again on the head or thorax. Venom availability has a significant effect on predatory response. Returning to their normal attack rate after venom extraction takes more time when facing larger prey. Research on these behaviours has suggested that the reason for centipedes to reposition their prey is to enhance the speed where neurotoxins in the venom arrive at the thoracic ganglia, where it controls limb movement or the brain. This explanation was based on the position of such ganglia locating on the abdominal side (i.e.
== Treatment == There is no cure for VERBAS. In almost all cases, people with VERBAS are able to attend mainstream school with or without supports. Due to the lack of research and rareness of the disorder, there are no developed treatments for it and all treatments are symptomatic.
The evidence suggests "consumers pay lower electricity net-of-tax prices in countries where there are still incumbents owned by national governments." With the sharp rise in fossil fuel prices that came from the 2022 Russian invasion of Ukraine and the fossil fuel cartel OPEC deciding to restrict supply, the EU Commission proposed a windfall fossil fuel tax. There are not yet common standards on energy enterprise governance, although a number of member states ensure that workers and energy bill payers have the right to vote for directors.
Sources: en.wikipedia.org
Purity is usually reported as an HPLC area percentage, most often measured at 214 nm. Identity is confirmed separately by mass spectrometry. A certificate of analysis should state both the method and the observed value.
Dry powder is kept frozen, desiccated, and shielded from light. Dissolved material is aliquoted and frozen to limit freeze-thaw cycles. Short-term refrigerated storage is common for working solutions.
Russia registers it as a prescription nasal product. Most other markets classify it as a research chemical with no approved medical use. Oversight of purity and labeling is consequently minimal in those markets.
The sequence is Thr-Lys-Pro-Arg-Pro-Gly-Pro, commonly written as TKPRPGP. It shares the first four residues with tuftsin and carries three prolines in the chain. The proline-rich tail is the main structural feature that separates it from the parent tetrapeptide.