A practical reference on Heptapeptide: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
Reviewed 2026-03-25. Anything still debated is marked as such rather than presented as settled.
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.
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.
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.
| 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 |
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.
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.
Proposed mechanisms centre on modulation of the GABAergic system, with reports of altered expression of genes related to GABA-A receptor subunits and changed monoamine turnover. Some studies describe inhibition of enkephalinase, the enzyme that degrades endogenous enkephalins, which may prolong opioid peptide signalling. Effects on brain-derived neurotrophic factor and on cytokine expression have also been reported. These findings come largely from animal models and small human studies, and the precise primary target remains unresolved.
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.
=== Promotions === Vkusno i tochka has repeatedly held collaborations featuring Om Nom from the Cut the Rope game franchise, with promotional items included with in the kids menu in January 2025, December 2025 and January 2026. In July 2025, a Hello Kitty themed menu was released by the restaurant. The centrepiece of the campaign was a pink coloured burger and sauce, as well as themed packaging. For the 65th anniversary of Yuri Gagarin's flight, the first human orbital spaceflight in history, special collectibles were included with the Kids Combo included nine spacecraft models of Vostok, Soyuz-2, Buran, Angara-A5, Arktika-M, Lunokhod-1, Marfa Robot, cosmonauts, and 'Tastemen'. Each set would include historical information relating to it, as well as a link to an asteroids style mobile game. The promotion was launched on 7 April 2026, ready for Cosmonautics Day. In August 2026, Vkusno i tochka partnered with miHoYo, creators of the action role-playing video game Genshin Impact. Branding and characters from the game were placed across food packaging, promotional materials and collectible merchandise. Customers would purchase special meal options named Super Boxes, which included a physical collectible as well as an activation code which would be activated within the Vkusno i tochka app. The promotion ran from 17 August to 13 September 2026. In September 2026, a collaboration with banking and financial services company Sberbank was announced, with marketing based on the companies "SberKot" mascot for the promotion of the companies SberPrime subscription services.
2C-B acts as a potent partial agonist of the serotonin 5-HT2 receptors, including of the serotonin 5-HT2A and 5-HT2C receptors and to a lesser extent of the serotonin 5-HT2B receptor. In one study, it had EC50Tooltip half-maximal effective concentration (EmaxTooltip maximal efficacy) values of 1.2 nM (101%) at the serotonin 5-HT2A receptor, 13 nM (97%) at the serotonin 5-HT2B receptor, and 0.63 nM (98%) at the serotonin 5-HT2C receptor. In earlier studies, 2C-B was found to be a low-efficacy serotonin 5-HT2A and 5-HT2C receptor partial agonist or even antagonist. However, subsequent studies have consistently found higher efficacy of 2C-B at these receptors. In addition to the serotonin 5-HT2 receptors, 2C-B also shows lower affinity for other serotonin receptors, such as the serotonin 5-HT1A and 5-HT1B receptors among others. However, while 2C-B itself was not assessed, other 2C derivatives showed little activity as serotonin 5-HT1A receptor agonists (EC50 = >3,000 nM). At the serotonin 5-HT2A receptor, 2C-B has subsequently been identified as a biased agonist, acting as a near-full agonist of receptor in terms of Ca2+ mobilization (EC50 = 1.64 nM; Emax = 92.6%) but with 6-fold lower potency as a moderate-efficacy partial agonist in terms of β-arrestin2 recruitment (EC50 = 10.0 nM; Emax = 60.1%). However, serotonin itself showed about 42-fold greater potency in activating Ca2+ mobilization than β-arrestin2 signaling in the study. The implications of the preceding findings are not fully clear.
An alpha helix (or α-helix) is a sequence of amino acids in a protein that are twisted into a coil (a helix). The alpha helix is the most common structural arrangement in the secondary structure of proteins. It is also the most extreme type of local structure, and it is the local structure that is most easily predicted from a sequence of amino acids. The alpha helix has a right-handed helix conformation in which every backbone N−H group hydrogen bonds to the backbone C=O group of the amino acid that is four residues earlier in the protein sequence. The alpha helix is also commonly called a: Pauling–Corey–Branson α-helix (from the names of three scientists who described its structure) 3.613-helix because there are 3.6 amino acids in one ring, with 13 atoms being involved in the ring formed by the hydrogen bond (starting with amidic hydrogen and ending with carbonyl oxygen)
Np(III) or Np3+ exists as hydrated complexes in acidic solutions, Np(H2O)3+n. It is a dark blue-purple and is analogous to its lighter congener, the pink rare-earth ion Pm3+. In the presence of oxygen, it is quickly oxidized to Np(IV) unless strong reducing agents are also present. Nevertheless, it is the second-least easily hydrolyzed neptunium ion in water, forming the NpOH2+ ion. Np3+ is the predominant neptunium ion in solutions of pH 4–5.
Pioglitazone (Actos), France and Germany have suspended its sale after a study suggested the drug could raise the risk of bladder cancer. Rosiglitazone (Avandia), which was put under selling restrictions in the US and withdrawn from the market in Europe due to some studies suggesting an increased risk of cardiovascular events. Upon re-evaluation of new data in 2013, the FDA lifted the restrictions. Lobeglitazone (Duvie), approved for use in South Korea Experimental, failed and non-marketed agents include:
Sources: en.wikipedia.org
=== Allosteric site transporter substrates === Alternatively, some reuptake inhibitors bind to allosteric sites and inhibit reuptake indirectly and noncompetitively. Phencyclidine and related drugs such as benocyclidine, tenocyclidine, ketamine, and dizocilpine (MK-801), have been shown to inhibit the reuptake of the monoamine neurotransmitters. They appear to exert their reuptake inhibition by binding to vaguely characterized allosteric sites on each of the respective monoamine transporters. Benztropine, mazindol, and vanoxerine also bind to these sites and have similar properties. In addition to their high affinity for the main site of the monoamine transporters, several competitive transporter substrates such as cocaine and indatraline have lower affinity for these allosteric sites as well. A few of the selective serotonin reuptake inhibitors (SSRIs) such as the dextro-enantiomer of citalopram appear to be allosteric reuptake inhibitors of serotonin. Instead of binding to the active site on the serotonin transporter, they bind to an allosteric site, which exerts its effects by causing conformational changes in the transporter protein and thereby modulating the affinity of substrates for the active site. As a result, escitalopram has been marketed as an allosteric serotonin reuptake inhibitor. Notably, this allosteric site may be directly related to the above-mentioned PCP binding sites.
Potash is primarily a mixture of potassium salts because plants have little or no sodium content, and the rest of a plant's major mineral content consists of calcium salts of relatively low solubility in water. While potash has been used since ancient times, its composition was not understood. Georg Ernst Stahl obtained experimental evidence that led him to suggest the fundamental difference of sodium and potassium salts in 1702, and Henri Louis Duhamel du Monceau was able to prove this difference in 1736. The exact chemical composition of potassium and sodium compounds, and the status as chemical element of potassium and sodium, was not known then, and thus Antoine Lavoisier did not include the alkali in his list of chemical elements in 1789. For a long time the only significant applications for potash were the production of glass, bleach, soap and gunpowder as potassium nitrate. Potassium soaps from animal fats and vegetable oils were especially prized because they tend to be more water-soluble and of softer texture, and are therefore known as soft soaps. The discovery by Justus Liebig in 1840 that potassium is a necessary element for plants and that most types of soil lack potassium caused a steep rise in demand for potassium salts. Wood-ash from fir trees was initially used as a potassium salt source for fertilizer, but, with the discovery in 1868 of mineral deposits containing potassium chloride near Staßfurt, Germany, the production of potassium-containing fertilizers began at an industrial scale.
Spy&Go purification of proteins with either N-terminal, internal or C-terminal SpyTag have all been reported. SpyDock resin is compatible with all SpyTag generations (SpyTag, SpyTag002, SpyTag003) and it does not interfere with the later covalent conjugation of the purified proteins with SpyCatcher.
=== Blocking of L-type calcium channels === Because the presence of calcium in the cytosol is required for muscle contraction, blockers of calcium channels prevent the muscles from building tension. Blockers of the L-type calcium channels, which occur in cardiac and smooth muscles, thus act as smooth muscle relaxants and inhibitors of cardiac contractions. Common blockers of L-type calcium channels are 1,4-dihydropyridines, which are used in treatment of cardiovascular diseases. Because of their activity as a relaxant, they can relax smooth muscles surrounding blood vessels, thus widening them and lowering the blood pressure.
With the encouragement of Ollendorff (promising that a US organization called "The Friends of the Technion" would support Feher's studies), he applied for 50 universities in the US, and only two were willing to accept him. He could not afford the voyage to US so he started a small production line for devices with piezoelectric crystals, mainly microphones. In December 1946 he arrived to New York, where he realized that "Friends of the Technion" would not fund his degree. With poor means he attended the University of California, Berkeley, where he received his bachelor's degree in engineering physics (1950), master's degree in electrical engineering (1951) and doctorate (1954).
Sources: en.wikipedia.org
Events in 1958 – notably a riot during Vice President Nixon's visit to Caracas, Venezuela, in May 1958 – resulted in a reversal of the U.S. position in August 1958. With U.S. support, in April 1959 the Organization of American States created the Inter-American Development Bank, most of whose capital was contributed by the borrowing countries. To further engage other wealthy countries in development assistance, the United States supported the creation of the Aid India Consortium in August 1958. This was the first of several informal groupings of donors focussing on particular countries. The United States also encouraged Western Europe and Japan to increase their development assistance by building on the European Marshall Plan organization, the Organization of European Economic Cooperation (OEEC). The OEEC had been created in 1948 by recipients of Marshall Plan aid, at the request of the United States government, to decide on allocation of that aid within Europe, and by the late 1950s it had fulfilled its original mandate. In January 1960, Eisenhower and Under Secretary of State C. Douglas Dillon got agreement from OEEC members to create a Development Assistance Group composed of the OEEC members who were the main sources of development assistance, along with non-members who were major donors – the U.S., Canada, and Japan. In 1961, the OEEC itself was restructured to become the Organisation for Economic Co-operation and Development, which established a Development Assistance Committee (DAC) as a restructured DAG that was brought under the OECD.
== Pharmacokinetics == Phenobarbital has an oral bioavailability of about 90%. Peak plasma concentrations (Cmax) are reached eight to 12 hours after oral administration. It is one of the longest-acting barbiturates available – it remains in the body for a very long time (half-life of two to seven days) and has very low protein binding (20 to 45%). Phenobarbital is metabolized by the liver, mainly through hydroxylation and glucuronidation and induces many isozymes of the cytochrome P450 system. Cytochrome P450 2B6 (CYP2B6) is specifically induced by phenobarbital via the CAR/RXR nuclear receptor heterodimer. It is excreted primarily by the kidneys.
Breast milk contains several anti-infective factors such as bile salt stimulated lipase (protecting against amoebic infections) and lactoferrin (which binds to iron and inhibits the growth of intestinal bacteria). Exclusive breastfeeding until six months of age helps to protect an infant from gastrointestinal infections in both developing and industrialized countries. The risk of death due to diarrhea and other infections increases when babies are either partially breastfed or not breastfed at all. Infants who are exclusively breastfed for the first six months are less likely to die of gastrointestinal infections than infants who switched from exclusive to partial breastfeeding at three to four months. During breastfeeding, approximately 0.25–0.5 grams per day of secretory IgA antibodies pass to the baby via milk. This is one of the important features of colostrum. The main target for these antibodies are probably microorganisms in the baby's intestine. The rest of the body displays some uptake of IgA, but this amount is relatively small. Maternal vaccinations while breastfeeding are safe for almost all vaccines. Additionally, the mother's immunity obtained by vaccination against tetanus, diphtheria, whooping cough, and influenza can protect the baby from these diseases, and breastfeeding can reduce the fever rate after infant immunization. However, smallpox and yellow fever vaccines increase the risk of infants developing vaccinia and encephalitis.
PFOA and PFOS are extremely persistent in the environment and resistant to typical environmental degradation processes. [They] are widely distributed across the higher trophic levels and are found in soil, air and groundwater at sites across the United States. The toxicity, mobility and bioaccumulation potential of PFOS and PFOA pose potential adverse effects for the environment and human health. In 2024 EPA published drinking water regulations for PFOA and five other PFAS.
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.
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.