Everything below concerns Heptapeptide. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Last reviewed on 2026-06-19. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C33H57N11O9 | Free peptide form |
| Molecular mass | About 751.9 Da | Calculated average mass |
| Amino acid sequence | Thr-Lys-Pro-Arg-Pro-Gly-Pro | Single-letter form TKPRPGP |
| Structural basis | Tuftsin analogue | Extended version of a natural tetrapeptide |
| Development origin | Russian Academy of Sciences | Work carried out from the 1980s onward |
Dry powder is normally held at -20 degrees Celsius or lower, in a sealed container with desiccant and protection from light. Reconstituted solutions are usually kept at 2 to 8 degrees Celsius for short periods and frozen for longer ones. Proline residues at several positions are generally associated with some resistance to peptidase attack, but chemical stability still declines at neutral to alkaline pH and at elevated temperature. Exact shelf-life figures are product-specific and are not standardised across suppliers.
Identity and purity are usually assessed by reversed-phase high-performance liquid chromatography, with mass spectrometry used to confirm molecular mass and sequence information. Amino acid analysis and peptide mapping may supplement these methods. Certified reference standards are scarce, and many commercial lots are sold as research chemicals without a pharmacopoeial monograph. Regulatory treatment differs by country: Selank is a registered prescription medicine in Russia, while in the European Union and the United States it is not an approved drug and may fall under research-chemical or unapproved-product frameworks.
Selank is a hydrophilic peptide and dissolves readily in water and in aqueous buffers. The lyophilised powder is typically a white to off-white solid. Because short peptides are prone to hydrolysis and oxidation, handling benefits from limiting exposure to heat, moisture and strong light. Working solutions are commonly prepared in sterile water or saline, and repeated freeze-thaw cycles are avoided to reduce aggregation and loss of activity. These practices reflect general laboratory convention rather than published stability specifications.
Selank is not a naturally occurring peptide and has no known endogenous counterpart in human physiology. Russian-language sources frequently call it TP-7, while English-language sources use the name Selank almost exclusively. Database indexing is uneven, partly because early reports appeared in regional journals that are not widely cataloged. Some summaries describe the material as a tuftsin analog and others as a synthetic heptapeptide; the labels overlap rather than conflict. Citing the primary sequence resolves ambiguity more reliably than the research or trade name alone.
Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro, written TKPRPGP in one-letter notation. Its structure consists of the immunomodulatory tetrapeptide tuftsin, Thr-Lys-Pro-Arg, extended at the carboxyl terminus by a Pro-Gly-Pro segment. The molecular formula is commonly given as C33H57N11O9, corresponding to a monoisotopic mass near 751.4 Da and an average molecular mass near 751.9 Da. All seven residues are proteinogenic amino acids, and the molecule carries no modified side chains or non-natural linkages.
Development took place at the Institute of Molecular Genetics of the Russian Academy of Sciences, where a series of short peptides were designed in the 1980s and 1990s. Selank was selected from variants of tuftsin that showed resistance to plasma peptidases. Russian regulatory approval covers it as an anxiolytic agent given intranasally. Outside that market the compound is normally handled as a research chemical rather than a medicine, and no widely recognised international pharmacopoeial monograph exists. The name Selank is a coined trade designation rather than a systematic chemical name.
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.
Diaphoresis due to ectopic catecholamine is a classic symptom of a pheochromocytoma, a rare tumor of the adrenal gland. Acetylcholinesterase inhibitors (e.g. some insecticides) also cause contraction of sweat gland smooth muscle leading to diaphoresis. Mercury is well known for its use as a diaphoretic, and was widely used in the 19th and early 20th century by physicians to "purge" the body of an illness. However, due to the high toxicity of mercury, secondary symptoms would manifest, which were erroneously attributed to the former disease that was being treated with mercurials. Infantile acrodynia (childhood mercury poisoning) is characterized by excessive perspiration. A clinician should immediately consider acrodynia in an afebrile child who is sweating profusely. Some people can develop a sweat allergy. The allergy is not due to the sweat itself but instead to an allergy-producing protein secreted by bacteria found on the skin. Tannic-acid has been found to suppress the allergic response along with showering.
Following the deaths of children in China from powdered milk in 2008, the Joint Research Centre (JRC) of the European Commission in Belgium set up a website about methods to detect melamine. In May 2009, the JRC published the results of a study that benchmarked the ability of labs around the world to accurately measure melamine in food. The study concluded that the majority of labs can effectively detect melamine in food. In October 2008, the U.S. Food and Drug Administration (FDA) issued new methods for the analysis of melamine and cyanuric acid in infant formulations in the Laboratory Information Bulletin No 4421. Similar recommendations have been issued by other authorities, like the Japanese Ministry of Health, Labor and Welfare, both based on liquid chromatography – mass spectrometry (LC/MS) detection after hydrophilic interaction liquid chromatography (HILIC) separation. The existing methods for melamine determination using a triple quadrupole liquid chromatography – mass spectrometry (LC/MS) after solid phase extraction (SPE) are often complex and time-consuming. However, electrospray ionization methods coupled with mass spectrometry allow a rapid and direct analysis of samples with complex matrices: the native liquid samples are directly ionized under ambient conditions in their original solution. In December 2008, two new fast and inexpensive methods for detecting melamine in liquids have been published.
An antimicrobial is an agent that kills microorganisms (microbicide) or stops their growth (bacteriostatic agent). Antimicrobial medicines can be grouped according to the microorganisms they are used to treat. For example, antibiotics are used against bacteria, and antifungals are used against fungi. They can also be classified according to their function. Antimicrobial medicines to treat infection are known as antimicrobial chemotherapy, while antimicrobial drugs are used to prevent infection, which known as antimicrobial prophylaxis. The main classes of antimicrobial agents are disinfectants (non-selective agents, such as bleach), which kill a wide range of microbes on surfaces to prevent the spread of illness, antiseptics which are applied to living tissue and help reduce infection during surgery, and antibiotics which destroy microorganisms within the body. The term antibiotic originally described only those formulations derived from living microorganisms but is now also applied to synthetic agents, such as sulfonamides or fluoroquinolones. Though the term used to be restricted to antibacterials, its context has broadened to include all antimicrobials. In response, further advancements in antimicrobial technologies have resulted in solutions that can go beyond simply inhibiting microbial growth. Instead, certain types of porous media have been developed to kill microbes on contact. The misuse and overuse of antimicrobials in humans, animals and plants are the main drivers in the development of drug-resistant pathogens.
In the 1920s there was an outbreak of a mysterious haemorrhagic cattle disease in Canada and the northern United States. The disease was named sweet clover disease because the cattle had grazed on sweet clover hay. It wasn't until ten years after the outbreak, that a local investigator, Karl P. Link and his student Wilhelm Schoeffel started an intense investigation to find the substance causing the internal bleeding. It took them 6 years to discover dicoumarol, the causing agent. They patented the right for the substance and in 1945 Link started selling a coumarin derivative as a rodenticide. He and his colleagues worked on several variations and ended up with a substance they named warfarin in 1948. It wasn't until 1954 that it was approved for medicinal use in humans making warfarin the first oral anticoagulant drug.
The right to take collective action, including the "right to strike" within "the laws of the particular country" is a universal right in international law. However, Australian law is one of the most restrictive on unions' freedom to take action to protect members' interests, and progressive restrictions on voice at work have matched a stagnation of wages. Before 1993, the law formally did not allow strike action at all, although in practice many strikes took place. Disputes were meant to be solved by compulsory arbitration, leading to notable instances of union officers being sued in tort for millions in damages where they took action. This is because under old common law, a strike that breaks a contract may lead to the imposition of industrial torts. Under the Fair Work Act 2009 section 19, industrial action is performing work "in a manner different from that in which it is customarily performed" or "a restriction or limitation on, or a delay in, the performance of work". It is not clear whether picketing is always industrial action, given a Federal Court case before the FWA 2009 doubting that it was, leading to the result that picketing would not be protected action, but also that the FWC could not issue stop orders against pickets.
Sources: en.wikipedia.org
=== Unknown blood type === Because blood type O negative is compatible with anyone, it is often overused and in short supply. According to the Association for the Advancement of Blood and Biotherapies, the use of this blood should be restricted to persons with O negative blood, as nothing else is compatible with them, and women who might be pregnant and for whom it would be impossible to do blood group testing before giving them emergency treatment. Whenever possible, the AABB recommends that O negative blood be conserved by using blood type testing to identify a less scarce alternative.
Charcot–Marie–Tooth (CMT) disease is a genetically heterogeneous disorder, meaning that it can be caused by mutations in many different genes. To date, dozens of genes have been linked to various forms of CMT, reflecting the complexity of its molecular basis. As a result, CMT is classified into several major types, such as CMT1, CMT2, CMT4, CMTX, and intermediate forms, based on the pattern of inheritance and whether the primary defect affects the myelin sheath or the axon. CMT1 involves demyelination and is most caused by duplication of the PMP22 gene, while CMT2 is primarily axonal and frequently linked to mutations in genes such as MFN2 or NEFL. X-linked and autosomal recessive forms, like CMTX and CMT4, are also recognized and often associated with more severe or early-onset symptoms. Each type is further divided into subtypes, defined by the specific gene that is mutated. This genetic classification helps guide diagnosis, prognosis, and, potentially, the development of targeted therapies.
Dried and salted cod, sometimes referred to as salt cod or saltfish or salt dolly, is cod which has been preserved by drying after salting. Cod which has been dried without the addition of salt is stockfish. Salt cod was long a major export of the North Atlantic region, and has become an ingredient of many cuisines around the Atlantic and in the Mediterranean. Dried and salted cod has been produced for over 500 years in Newfoundland, Iceland, and the Faroe Islands. It is also produced in Norway, where it is called klippfisk, literally "cliff-fish". Traditionally, it was dried outdoors by the wind and sun, often on cliffs and other bare rock-faces. Today, klippfisk is usually dried indoors with the aid of electric heaters. But in western and northern Norway fish is still dried outdoors, mainly for export to southern Europe markets.
The most common first symptom of all snakebites is an overwhelming fear, which may contribute to other symptoms, and may include nausea and vomiting, diarrhea, vertigo, fainting, tachycardia, and cold, clammy skin. Snake bites can have a variety of different signs and symptoms depending on their species. Dry snakebites and those inflicted by a non-venomous species may still cause severe injury. The bite may become infected from the snake's saliva. The fangs sometimes harbor pathogenic microbial organisms, including Clostridium tetani, and may require an updated tetanus immunization. Most snakebites, from either a venomous or a non-venomous snake, will have some type of local effect. Minor pain and redness occur in over 90 percent of cases, although this varies depending on the site. Bites by vipers and some cobras may be extremely painful, with the local tissue sometimes becoming tender and severely swollen within five minutes. This area may also bleed and blister and may lead to tissue necrosis. Other common initial symptoms of pit viper and viper bites include lethargy, bleeding, weakness, nausea, and vomiting. Symptoms may become more life-threatening over time, developing into hypotension, tachypnea, severe tachycardia, severe internal bleeding, altered sensorium, kidney failure, and respiratory failure. Bites by some snakes, such as the kraits, coral snake, Mojave rattlesnake, and the speckled rattlesnake, may cause little or no pain, despite their serious and potentially life-threatening venom.
Sources: en.wikipedia.org
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.
The core four residues correspond to tuftsin, which occurs naturally as part of immunoglobulin G. The full seven-residue sequence, however, is not a known endogenous peptide. It is a laboratory-designed analogue intended to combine tuftsin-like activity with greater resistance to breakdown.
No single receptor has been confirmed as the primary target. Reports describe involvement of the GABAergic system, interference with enkephalin degradation, and shifts in neurotrophic factor expression. Because these observations come from different models and assays, they have not yet been integrated into one accepted mechanism.
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.