A practical reference on selank: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
Reviewed 2025-11-30. Anything still debated is marked as such rather than presented as settled.
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.
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 work on this peptide almost always uses intranasal delivery, with drops or a spray applied to the nasal mucosa. Some animal experiments have used subcutaneous or intraperitoneal injection, and a smaller number have compared routes directly. Oral administration is not a focus of the literature, because short peptides of this size are broken down by digestive enzymes and cross intestinal barriers poorly. How much of an intranasal dose reaches the bloodstream intact in humans remains an open question.
Animal studies have examined behaviour in tests of anxiety, memory retention and stress response, and several report changes in neurotrophic or neurotransmitter-related markers. The human evidence base is much smaller, consisting mainly of short trials conducted in Russia with limited reporting in English-language journals. Sample sizes are modest and outcome measures vary between studies, so the findings are best described as preliminary. Independent replication under modern trial standards has not been widely reported.
| 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 |
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.
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.
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.
Most published work on selank originates from a small number of research groups in the Russian Federation. A large share of that record appears in Russian-language journals, which limits access for readers who rely on English-indexed databases. Independent replication by laboratories outside the original research network is sparse in publicly available sources. This concentration of origin and language is a frequently noted feature when the compound is summarized in broader reviews of synthetic peptides.
Selank is a synthetic heptapeptide developed in Russia as a structural analogue of tuftsin, a naturally occurring immunomodulatory tetrapeptide. Its sequence, Thr-Lys-Pro-Arg-Pro-Gly-Pro, keeps the tuftsin core at the N-terminus and appends a Pro-Gly-Pro tail. Researchers at the Institute of Molecular Genetics in Moscow synthesized the compound during the 1990s while searching for peptides with combined anxiolytic and immunomodulatory activity. The added tail was intended to resist enzymatic cleavage and prolong the molecule's presence in circulation.
The compound has a calculated molecular weight near 751.9 daltons and carries a net positive charge at physiological pH because of its arginine residue. It dissolves freely in water and in common aqueous buffers, and typically appears as a white or off-white lyophilized powder. The amide backbone makes the molecule susceptible to peptidases, which limits oral use and favors intranasal or parenteral routes. Nomenclature in the literature varies: the substance is also described by the sequence abbreviation TP-7 and by a Russian trade designation.
20 February Reg Douglas, Olympic rower (1956), British Empire and Commonwealth Games gold (1954, 1958) and silver medallist (1954) (born 1930). Sir Peter Trapski, lawyer and judge, chief District Court judge (1985–1989) (born 1935). Maata Wharehoka, weaver, Māori arts advocate, community leader (Parihaka), Ngā Tohu ā Tā Kīngi Īhaka (2015) (born 1950). 21 February – John Anderson, businessman, founder of Contiki Tours (1962) (born 1938). 24 February – Khalid Sandhu, Muslim community leader and physician, president of the Federation of Islamic Associations of New Zealand (1986–1988, 1989–1990) (born 1942). 27 February Dave Gillespie, rugby union player (Otago, Wellington, national team) (born 1934). Michael Moroney, Hall of Fame Thoroughbred racehorse trainer (Brew, Tofane, Xcellent) (born 1958).
=== Chiral crown ether === Chiral crown stationary phases consist Crown ethers, immobilized or bonded to the support particles, are polyethers with a macrocyclic structure that can create host-guest complexes with alkali, earth-alkali metal ions, and ammonium cations. The skeleton of the cyclic structure is composed of oxygen and methylene groups arranged alternately. The electron-donating ether oxygens are positioned within the inner wall of the crown cavity, and are encircled by methylene groups in a collar-like arrangement. The chiral recognition is based on two distinct diastereomeric inclusion complexes that can be generated. The primary interactions facilitating complexation involve hydrogen bonds, formed between the three amine hydrogens and the oxygens of the macrocyclic ether, arranged in a tripod configuration. Additionally, ionic interactions, dipole-dipole interactions, or hydrogen bonds can occur between the carbocyclic groups and polar groups of the analytes, providing further support for the complexes.
The Japanese Hisatugu Numata developed the first panoramic radiograph in 1933/34. This was followed by the development of intraoral panoramic X-ray units, in which the X-ray tube is placed intraorally (inside the mouth) and the X-ray film extraorally (outside the mouth). At the same time, Horst Beger from Dresden in 1943 and the Swiss dentist Walter Ott in 1946 worked on the Panoramix (Koch & Sterzel), Status X (Siemens) and Oralix (Philips). Intraoral panoramic devices were discontinued at the end of the 1980s because the radiation exposure was too high in direct contact with the tongue and oral mucosa due to the intraoral tube.
Sources: en.wikipedia.org
== Treatment == The mainstay of treatment for GPS is plasmapheresis, a procedure in which the affected person's blood is sent through a centrifuge and the various components are separated based on weight. The plasma contains the anti-GBM antibodies that attack the affected person's lungs and kidneys, and is filtered out. The other parts of the blood (the red blood cells, white blood cells, and platelets) are recycled and intravenously reinfused. Most individuals affected by the disease also need to be treated with immunosuppressant drugs, especially cyclophosphamide, prednisone, and rituximab, to prevent the formation of new anti-GBM antibodies to prevent further damage to the kidneys and lungs. Other, less toxic immunosuppressants such as azathioprine may be used to maintain remission.
=== Polypeptides === The convention for a polypeptide is to list its constituent amino acid residues as they occur from the amino terminus to the carboxylic acid terminus. The amino acid residues are always joined by peptide bonds. Protein, though used colloquially to refer to any polypeptide, refers to larger or fully functional forms and can consist of several polypeptide chains as well as single chains. Proteins can also be modified to include non-peptide components, such as saccharide chains and lipids.
Space Invaders, originally released for arcades in 1978, became a killer app when it was ported to the Atari VCS console in 1980, quadrupling sales of the three-year-old console. Star Raiders, released in 1980, was the first killer app computer game. BYTE named it the single most important reason for sales of Atari 400 and 800 computers. Another was Eastern Front (1941), released in 1981. In 1996, Computer Gaming World wrote that Wizardry: Proving Grounds of the Mad Overlord (1981) "sent AD&D fans scrambling to buy Apple IIs". The Famicom home port of Xevious is considered the console's first killer app, which caused system sales to jump by nearly 2 million units. Computer Gaming World stated that The Legend of Zelda on the Nintendo Entertainment System, Phantasy Star II on the Sega Genesis, and Far East of Eden for the NEC TurboGrafx-16 were killer apps for their consoles. The Super Mario, Final Fantasy, and Dragon Quest series were killer apps for Nintendo's Famicom and Super Famicom consoles in Japan. John Madden Football's popularity in 1990 helped the Genesis gain market share against the Super NES in North America. Sonic the Hedgehog, released in 1991, was hailed as a killer app as it revived sales of the three-year-old Genesis. Mortal Kombat helped pushed the sales of the Genesis due to being uncensored unlike the Nintendo version. Streets of Rage became a system seller for the Mega Drive/Genesis in the UK. Street Fighter II, originally released for arcades in 1991, became a system-seller for the Super NES when it was ported to the platform in 1992.
Sources: en.wikipedia.org
Cyanobacteria, the only prokaryotes performing oxygenic photosynthesis and the only prokaryotes that contain two types of photosystems (type I (RCI), also known as Fe-S type, and type II (RCII), also known as quinone type). The seven remaining prokaryotes have anoxygenic photosynthesis and use versions of either type I or type II. Chlorobi (green sulfur bacteria) Type I Heliobacteria Type I Chloracidobacterium Type I Proteobacteria (purple sulfur bacteria and purple non-sulfur bacteria) Type II (see: Purple bacteria) Chloroflexota (green non-sulfur bacteria) Type II Gemmatimonadota Type II Eremiobacterota Type II
Following the season, the club's annual report noted the need for a spearhead full-forward, stating: "It is very apparent that no team is complete without a spearhead and your committee has high hopes of rectifying that fault this coming season". The 1949 season marked the debut of John Coleman. In his first appearance against Hawthorn in Round 1, 1949, he kicked 12 goals, establishing a round one record that stood for forty-five years. Coleman maintained this form throughout the season, kicking exactly 100 goals to become the first player to kick 100 goals in a season since Richmond's Jack Titus in 1940, and the first to do so in a debut season. Essendon qualified for the finals in 4th place and went on to win the premiership.
Known in antiquity to such medical doctors as Hippocrates and Galen, noma was once reported around the world, including in Europe and the United States. The disease was well-known in the Netherlands in the 1500s and 1600s. The first clinical description of noma was in 1595 by a Dutch man, Carolus Battus. Dutch surgeon Cornelis van de Voorde first used the term "noma" to describe the disease in 1680. A European scientist, Gabriel Lund, attributed noma to poverty, cramped living conditions, and malnutrition in 1765. English medical doctor John Addington Symmonds linked the disease to previous infection with measles. The first surgical treatment for noma sequelae was performed in 1781. Surgical treatments for sequelae developed throughout the 1800s. In the late 1800s, scientists suspected that noma was caused by bacteria. With improvements in hygiene and nutrition, noma has disappeared from industrialized countries since the 20th century, except during World War II when it was endemic to the Auschwitz and Belsen concentration camps. The disease and treatments were studied by Berthold Epstein, a Czech medical doctor and forced-labor prisoner who had recommended the study under Josef Mengele's direction. Since 1970, there has been little research done on noma, with few exceptions. One such exception is Cyril Enwonwu, a Nigerian scientist focusing on noma.
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.
Most published work uses intranasal application, either as drops or as a nasal spray. Injection routes appear in a smaller set of animal experiments. Oral use is uncommon in the literature because peptide breakdown and poor absorption limit this route.