Everything below concerns mass spectrometry. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Updated 2026-01-28. Numbers and descriptions here follow the published literature rather than marketing material.
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.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic heptapeptide | Tuftsin analogue |
| Sequence | Thr-Lys-Pro-Arg-Pro-Gly-Pro | Single-letter form: TKPRPGP |
| Molecular formula | C33H57N11O9 | Calculated for the free peptide |
| Molecular weight | About 751.9 g/mol | Derived from the sequence |
| Appearance | White to off-white powder | Typical lyophilised form |
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.
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.
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.
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.
A vein () is a blood vessel in the circulatory system of humans and most other animals that carries blood towards the heart. Most veins carry deoxygenated blood from the tissues back to the heart; exceptions are those of the pulmonary and fetal circulations which carry oxygenated blood to the heart. In the systemic circulation, arteries carry oxygenated blood away from the heart, and veins return deoxygenated blood to the heart, in the deep veins. There are three sizes of veins: large, medium, and small. Smaller veins are called venules, the smallest of which are called post-capillary venules – microscopic veins that play a major role in microcirculation. Veins are often closer to the skin than arteries. Veins have less smooth muscle and connective tissue and wider internal diameters than arteries. Because of their thinner walls and wider lumens they are able to expand and hold more blood. This greater capacity gives them the term of capacitance vessels. At any time, nearly 70% of the total volume of blood in the human body is in the veins. In medium and large sized veins the flow of blood is maintained by one-way (unidirectional) venous valves to prevent backflow. In the lower limbs this is also aided by muscle pumps, also known as venous pumps that exert pressure on intramuscular veins when they contract and drive blood back to the heart.
Breteni was upset over this interaction because it took them two years to be able to come out with her daughter’s results and only after an interaction with Dr. Lisa Sanders. Dr. Sanders believed this was because they might have initially forgotten to share the results and didn't want to ligate any misinterpretations. Once Breteni received the results it was shown that Kamiyah had a break in a gene that wasn't inherited from her mother or father, it created itself. Specifically a break within the KCNMA1 gene, and she was the first patient of her kind, she's “groundbreaking”. The NIH said that it would take more patients with the same illness and a doctor to “peg” it to be able to create a disease grouping for diagnosis. When Dr. Lisa Sanders created the column for Kamiyah, instead of asking for the readers to chime in for their diagnosis, she went out looking for readers who would have the same symptoms/gene break as her. From the publication of the column, Breteni was able to find dozens of people who themselves or their children had the same KCNMA1 gene mutation. There was also a scientist who reached out to Dr. Lisa Sanders, who had based the last 20 years of her career on researching the specific ion pathway for the KCNMA1 gene. The scientist goes into detail about the gene and how it regulates the amount of potassium that enters the cells and as a result this affects the brain wave levels corresponding to movement and in theory would create the fainting episodes.
The compromises contained in the agreement caused the civil war in the 26 counties in June 1922 – April 1923, in which the pro-Treaty Provisional Government defeated the anti-Treaty Republican forces. The latter were led, nominally, by Éamon de Valera, who had resigned as President of the Republic on the treaty's ratification. His resignation outraged some of his own supporters, notably Seán T. O'Kelly, the main Sinn Féin organiser. On resigning, he then sought re-election but was defeated two days later on a vote of 60–58. The pro-Treaty Arthur Griffith followed as President of the Irish Republic. Michael Collins was chosen at a meeting of the members elected to sit in the House of Commons of Southern Ireland (a body set up under the Government of Ireland Act 1920) to become Chairman of the Provisional Government of the Irish Free State in accordance with the Treaty. The general election in June gave overwhelming support for the pro-Treaty parties. W. T. Cosgrave's Crown-appointed Provisional Government effectively subsumed Griffith's republican administration with the death of both Collins and Griffith in August 1922. The day after the founding of the Irish Free State, anti-Treaty IRA men shot and killed Seán Hales an elected member of the lower house of Parliament (Dáil Éireann). The next day (8 December 1922), four imprisoned leaders of the anti-Treaty IRA (Liam Mellows, Rory O'Connor, Joe McKelvey and Dick Barrett) were executed in retaliation for the killing of Hales.
Benzalkonium chloride – "quat" disinfectant that attacks membranes Bethoxazin – "new broad spectrum industrial microbicide" in 2012, noted as "Canceled in U.S." in 2022 PubChem-EPA query Cybutryne – banned since 2023 in ship paint Dichlone – quinone fungicide/algaecide, not persistent in soil Dichlorophen – also kills invertebrate animals and bacteria Diuron – herbicide/algaecide, inhibits photosynthesis Endothal – herbicide/algaecide, inhibits protein phosphatase 2A Fentin – quinone fungicide/algaecide, discontinued Isoproturon – selective substituted urea herbicide, discontinued Methabenzthiazuron – substituted urea herbicide, discontinued Nabam – fungicide/algicide discontinued in the EU over cancer Oxyfluorfen – herbicide, "very toxic to aquatic life with long lasting effects" Pentachlorophenyl laurate Quinoclamine – herbicide/algicide, not used in most of the EU Quinonamid Simazine – herbicide/algaecide, inhibits photosynthesis Terbutryn Tiodonium
One contemporary news article claimed the murder was related to "the demoniac rites of West African savages, from whom Voodoo practices were transferred to West Indian Negroes, and from them to the United States."
Sources: en.wikipedia.org
All living organisms produce substances to defend themselves from being eaten. However, the term "poison" typically refers to substances that are toxic to humans. Substances that are toxic primarily to pathogens and not to humans are generally classified as antibiotics. For instance, Penicillium chrysogenum produces compounds toxic to bacteria, but not to humans, making them effective as antibacterial drugs. Similarly, human antimicrobial peptides, which are toxic to viruses, fungi, bacteria, and cancerous cells; are considered part of the innate immune system. In nuclear physics, the term nuclear poison refers to a substance that absorbs neutrons and interferes with a nuclear reaction. Substances classified as environmentally hazardous are not always poisonous, and vice versa. For example, wastewater from food processing, such as potato juice or milk; can be environmentally damaging by depleting oxygen in aquatic ecosystems (leading to eutrophication), but it poses no direct toxic threat to humans and is not considered a poison. From a biological standpoint, virtually any substance can be toxic in sufficient quantity. Even something as essential as water can be fatal when consumed in excessive amounts; a condition known as water intoxication. Many drugs used in medicine, such as fentanyl, have a median lethal dose (LD50) only slightly higher than their effective dose (ED50), highlighting the thin margin between therapeutic benefit and toxicity. Some classification systems differentiate between lethal substances with therapeutic value and those without.
Conversely if the temperature falls the controller acts to close the TCV which reduces the heat transfer increasing the temperature of the first fluid. In the case of heating medium with the falling temperature of the first fluid the controller would act to open the TCV to increase the flow of heating medium thereby raising the temperature of the first fluid. The controller (TIC) may also generate high (TAH) and low temperature (TAL) alarms to warn operating personnel of a potential problem. Fin fan coolers use air to cool gases and liquids. The temperature of fluid is controlled (TIC) by opening or closing dampers on the cooler or adjusting the speed of the fan or the pitch angle of the fan blades thereby increasing or decreasing the flow of air. Temperature monitoring and control instrumentation is used in fired heaters and furnaces to adjust the fuel flow valve (FCV) to maintain a desired thermal output. Waste heat recovery units (WHRU) are used to extract heat from the flow of hot exhaust gases from a gas turbine to heat a fluid (heating medium). Instrumentation includes controllers to maintain a desired temperature of the heating medium by closing or opening dampers in the exhaust gas flow. Low temperature alarms (TSL) are used where cold fluids could be routed to pipework which is not suitable for cold service. Instrumentation may include an initial alarm (TAL) and then a shutdown action (TSLL) to close a shutdown valve (XV).
The original parlor (a remodeled grocery store) at 57th and J Streets in Sacramento remained in business until the mid-1990s. The second Shakey's Pizza Parlor opened in Portland, Oregon, in 1956. Shakey's opened their third parlor in Albany, Oregon, in 1959, which was the first building Shakey's actually owned and the first building to be built in the distinct building style for which Shakey's is known. It now operates as a used bookstore. According to Johnson, Shakey's Pizza engaged in little market research and made most of its decisions on where to locate stores by going where Kinney Shoes opened stores. By the time Johnson sold his interest in 1967, there were 272 Shakey's Pizza Parlors in the United States. The first international store opened in Winnipeg, Manitoba, Canada, in 1968. By 1975, the company had expanded to the Pacific Rim, including Japan (in 1973) and the Philippines (in 1975). By the early 1970s, Shakey's had become popular with families and youth sports groups in Southern California. The long rows of picnic tables end-on-end facilitated large groups. Youth sports teams would go to Shakey's after their weekend games, where the kids could eat pizza and have fun, and the parents could drink beer and socialize. In fact, the advertising motto for Shakey's was "We serve fun at Shakey's... also pizza". One of the features of Shakey's was its large windows between the dining hall and the kitchen. One could order pizza and then watch as the dough was prepared, sauce and toppings added, and then pizza slid into the oven.
In 1991, Glaxo received approval for sumatriptan, which was the first available triptan. In July 2009, the US Food and Drug Administration (FDA) approved a single-use jet injector formulation of sumatriptan. The device delivers a subcutaneous injection of sumatriptan, without the use of a needle. Autoinjectors with needles have been previously available in Europe and North America. Phase III studies with an iontophoretic transdermal patch (Zelrix/Zecuity) started in July 2008. This patch uses low voltage controlled by a pre-programmed microchip to deliver a single dose of sumatriptan through the skin within 30 minutes. Zecuity was approved by the FDA in January 2013. Sales of Zecuity have been stopped following reports of skin burns and irritation.
Sources: en.wikipedia.org
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.
Selank is a synthetic analogue built on the tuftsin tetrapeptide Thr-Lys-Pro-Arg. Extra proline residues were added to the C-terminus during design work. That modification is intended to make the peptide less vulnerable to rapid enzymatic degradation.
Transliteration from Russian produces variant spellings such as Selanc. Many suppliers avoid the trade-style name entirely and list the peptide sequence. Comparing sequences rather than names is the reliable way to confirm two entries describe the same molecule.
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.