The short version of TKPRPGP fits in a sentence. The long version — which is the one that helps — is below.
Reviewed 2026-04-19. Anything still debated is marked as such rather than presented as settled.
The compound was designed at the Institute of Molecular Genetics of the Russian Academy of Sciences during the 1980s and 1990s. The stated design goal was to retain the immunomodulatory and central nervous system activity attributed to tuftsin while improving resistance to enzymatic breakdown. Adding a proline-rich tail to the short parent peptide was a deliberate strategy, because proline residues restrict the conformations available to many peptidases. The same laboratory produced Semax, an ACTH fragment analog, and both compounds were developed in parallel as short, enzymatically stabilized peptides intended for intranasal use.
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.
Published clinical work is concentrated in Russian-language journals and generally involves small samples without independent replication. Systematic reviews in English note the shortage of randomised, placebo-controlled trials and the difficulty of verifying methods from translated reports. Outcome measures vary between studies, which complicates pooling of results. Interest in the compound as a cognitive or anxiolytic agent therefore rests on a thinner evidence base than the volume of citations suggests. Replication in well-powered trials with preregistered endpoints would be needed before firm conclusions about efficacy can be drawn.
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.
| Property | Value | Notes |
|---|---|---|
| Peptide sequence | Thr-Lys-Pro-Arg-Pro-Gly-Pro | Seven residues; tuftsin plus a Pro-Gly-Pro tail |
| Molecular formula | C33H57N11O9 | Commonly reported value for the free peptide |
| Monoisotopic mass | Roughly 751.4 Da | Average molecular mass near 751.9 Da |
| Appearance | White to off-white powder | Typically supplied as a lyophilized solid |
| Solubility class | Freely soluble in water | Also dissolves in saline and other polar solvents |
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.
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.
== Solution concentration and purification == After leaching, the leach liquor must normally undergo concentration of the metal ions that are to be recovered. Additionally, undesirable metal ions sometimes require removal.
== Other uses == Caffeic acid may be the active ingredient in caffenol, a do-it-yourself black-and-white photographic developer made from instant coffee. The developing chemistry is similar to that of catechol or pyrogallol. It is also used as a matrix in MALDI mass spectrometry analyses.
=== Immigration === In April 2022, Schmitt repeated a Great Replacement–derived claim on Glenn Beck's program that the Democratic Party seeks to "fundamentally" change the country through illegal immigration to the United States. In a September 2025 speech, Schmitt criticized both legal and illegal immigration to the United States.
elegans.Similar effects have been observed in other invertebrate excitable cells, including Drosophila melanogaster neurons and crayfish muscle. Since GluCl does not exist in vertebrates, it has become a valuable target for anti-parasitic drugs such as Avermectin and Ivermectin.
=== Fasting blood sugar === A level below 5.6 mmol/L (100 mg/dL) after 10–16 hours without eating is normal. 5.6–6 mmol/L (100–109 mg/dL) may indicate prediabetes and an oral glucose tolerance test (OGTT) should be offered to high-risk individuals (old people, those with high blood pressure etc.). 6.1–6.9 mmol/L (110–125 mg/dL) means an OGTT should be offered even if other indicators of diabetes are not present. 7 mmol/L (126 mg/dL) and above indicate diabetes and the fasting test should be repeated.
Sources: en.wikipedia.org
ALK-negative ALCL tumor cells show products made by chimeric genes: DUSP22-IRF4 (many of which are fused at particular site and termed DUSP22-FRA7H) in 30% of the cases; TP63-TBL1XR1 in 8% of cases; and NFKB2-ROS1, NCOR2-ROS1, NFKB2-TYK2, or PABPC4-TYK2 in rare cases. They also show mutations in the JAK1 and/or STAT3 genes in 18% of cases; the MSC gene in 15% of cases, and the NOTCH1 gene in 15% of cases. About 24% of cases have a truncated ERBB4 gene. DUSP22 gene rearrangements have been associated with favorable outcomes in ALK-negative ALCL while TP63 gene arrangements are often associated with a poorer prognosis in various cancers. ALK-negative ALCL cells overexpress overactive STAT3 in 47% of cases and JAK1 in many cases. Many of these gene abnormalities appear to contribute to the development of ALK-negative ALCL.
However, in the event of a radioiodine release too massive and widespread to be controlled by the limited stock of iodide and iodate prophylaxis drugs, then the addition of perchlorate ions to the water supply, or distribution of perchlorate tablets would serve as a cheap, efficacious, second line of defense against carcinogenic radioiodine bioaccumulation. The ingestion of goitrogen drugs is, much like potassium iodide also not without its dangers, such as hypothyroidism. In all these cases however, despite the risks, the prophylaxis benefits of intervention with iodide, iodate, or perchlorate outweigh the serious cancer risk from radioiodine bioaccumulation in regions where radioiodine has sufficiently contaminated the environment.
== Intellectual property == After several attempts to file for U.S. patent protection, a filing was made in March 1990 which eventually became U.S. Patents 5,216,167 (June 1993), 5,312,924 (May 1994) and 6,143,769 (November 2000). After filing its NDA for repaglinide in 1997, Novo Nordisk applied for patent extension under the Hatch-Waxman Act. This process, called patent term restoration, allows drug patents to be extended based on the time that a drug spent in clinical trials and in the approval process. Previously it had been decided by the U.S. Patent and Trademark Office that the expiration date of U.S. Patents 5,216,167 and 5,312,924 would be 5 September 2006. In February 2001 Prandin's patent life was extended to 14 March 2009 in response to Novo Nordisk's patent term restoration application, with U.S. Patent 5,216,167 having been reissued as RE37035. Prior to the end of repaglinide's patent term, Novo Nordisk obtained a new patent, U.S. Patent 6,677,358 (January 2004), covering the combination therapy of repaglinide together with the generic anti-diabetic drug metformin. This new patent was due to expire June 2018. In January 2011, a federal court ruled Novo Nordisk's new patent invalid on the grounds of obviousness, and unenforceable on the grounds of inequitable conduct on the part of Novo Nordisk's patent attorneys.
This information is saved and analyzed in the last step, data analysis, using bioinformatics software. This compares the sequences to a reference genome to align the fragments and show mutations in the targeted area of the sequence.
Sources: en.wikipedia.org
Additional endogenous trigger pathways have been explored through the exploitation of inner and outer tumor environments, such as reactive oxygen species, glutathione, enzymes, hypoxia, and adenosine-5'- triphosphate (ATP), all of which are generally highly present in and around tumors. External triggers are also used, such as light, low frequency ultrasound (LFUS), electrical fields, and magnetic fields. In specific, LFUS has demonstrated high efficacy in the controlled trigger of various drugs in mice, such as cisplatin and calcein.
Amnesty International stated the following month that the Salvadoran government had committed "massive human rights violations", including torture, against prisoners. In June 2024, Bukele told Time that the security situation in El Salvador had become sustainable and that he and his government hoped to end the state of emergency "in the near future". By 4 March 2025, the state of exception had been extended 36 times by the Legislative Assembly. By that same date, over 85,000 suspected gang members had been arrested, 3,319 of whom were minors according to Human Rights Watch. The large-scale arrests increased El Salvador's prison population from 37,190 in 2020 to over 105,000 by December 2023. With 1.7 percent of its population in prison, El Salvador has the highest incarceration rate in the world. By November 2024, more than 8,000 people had been released after the government determined that they were innocent. According to human rights organizations, at least 367 people had died in custody by March 2025. A number of opinion polls between May 2022 and June 2023 indicated that 80 to 90 percent of Salvadorans approved of the gang crackdown and measures taken by the government against the gangs.
I am weary tonight and low in spirits. I cannot but think of Lucy, and how different things might have been. If I don't sleep at once, chloral, the modern Morpheus—C2HCl3O·H2O! I must be careful not to let it grow into a habit. No, I shall take none tonight! I have thought of Lucy, and I shall not dishonour her by mixing the two. In the conclusion of Edith Wharton's 1905 novel The House of Mirth, Lily Bart, the novel's heroine, becomes addicted to chloral hydrate and overdoses on the substance:
=== Portal: Companion Collection === Portal: Companion Collection is a compilation of both games and Still Alive content released for Nintendo Switch on June 28, 2022. The port was developed in collaboration with Nvidia Lightspeed Studios.
As it is now accepted that not only transition metals, but also anions in cathodes participate in redox activity necessary for lithium insertion and removal, the design of cathode materials with diverse transition metal cations increasingly consider also oxygen redox reactions in lithium-ion battery cathodes and how these may enhance capacity beyond transition metal limitations, with computational studies using density functional theory helping to optimize materials while minimizing structural degradation. Advances in anionic redox understanding have led to stabilization strategies like surface fluorination, improving cycling stability and safety.
Sources: en.wikipedia.org
The sequence is Thr-Lys-Pro-Arg-Pro-Gly-Pro, written TKPRPGP in one-letter code. It combines the tetrapeptide tuftsin with a carboxyl-terminal Pro-Gly-Pro extension. This full sequence identifies the molecule more precisely than the research name.
No peptide with this exact sequence has been identified as an endogenous substance. It is a laboratory-designed analog of tuftsin, a naturally occurring immunomodulatory tetrapeptide. The Pro-Gly-Pro extension has no known natural source.
Proline introduces conformational constraints that make a peptide less accessible to common peptidases. This is a standard stabilization strategy in peptide design. The added residues also increase the distance between the active tuftsin portion and typical cleavage sites.
Reports describe modulation of GABA signalling, changes in monoamine turnover and effects on neurotrophic factor expression. These observations come mainly from animal and cell studies. A single unifying mechanism has not been demonstrated.