If you have been reading about tuftsin and want a single page that covers the useful parts, this is it: definitions, context, how it is studied, and the questions that come up repeatedly.
Updated 2026-07-04. Numbers and descriptions here follow the published literature rather than marketing material.
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.
Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro. Its four N-terminal residues reproduce tuftsin, a tetrapeptide fragment of the immunoglobulin heavy chain, while the C-terminal Pro-Gly-Pro extension is a synthetic addition. The peptide has a molecular mass near 752 daltons and carries a net positive charge at physiological pH because of the arginine and lysine side chains. Published indexes list it under the name Selank and the sequence abbreviation TKPRPGP. Solid-phase peptide synthesis is the standard production route for research quantities.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic heptapeptide | Tuftsin analogue with a C-terminal Pro-Gly-Pro tail |
| Amino acid sequence | Thr-Lys-Pro-Arg-Pro-Gly-Pro | Abbreviated TKPRPGP in most catalogues |
| Molecular mass | About 752 Da | Value for the free peptide |
| Solubility | Freely soluble in water | Aqueous solutions are kept cold and used promptly |
| Typical storage | -20 °C, dry, protected from light | Applies to the lyophilised powder before reconstitution |
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.
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.
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.
On 4 April, explosions were reported at an auxiliary building of the Bushehr Nuclear Power Plant as well as the Mahshahr Special Petrochemical Zone in Mahshahr, Iran. The airstrikes in Mahshahr killed at least five and injured 170 others. An Iranian missile strike hit in the vicinity of the IDF's HaKirya headquarters in Tel Aviv. On 5 April, after heavy fighting, the second stranded crew member from the F-15E downed on 3 April was recovered by US forces in a rescue operation, which resulted in damage to helicopters, the shooting down of an A-10 Thunderbolt II, and the destruction of two C-130 Hercules, three IRGC members killed, and several American service members injured. On 6 April, the IRGC announced that the head of the IRGC's intelligence organization, Major General Majid Khademi, had been killed in a joint US-Israeli airstrike. Their statement claimed that Khademi had "played a major role in Iran's intelligence and security apparatus over nearly five decades". Israel said that Yazdan Mir, a high-ranking commander of the IRGC Quds Force, had also been killed in the attacks. On the same day, before Trump's deadline for targeting Iranian infrastructure, Israel carried out strikes on the South Pars Petrochemical facility in Asaluyeh, Iran. The IAF said that "85% of Iran's petrochemical exports" had been taken offline by now. At least 34 people, including six children, were killed in US-Israeli airstrikes across Iran, including against Sharif University of Technology and residential areas.
FK Ibar Leposavić FK Kopaonik Lešak FK Moša Banje FK Rudar Kosovska Mitrovica FK Zvečan FK Radnik Prilužje (until 2013) FK Sočanica (until 2014) There are two other clubs from North Kosovo, which compete in different leagues:
Many substances regarded as poisons are toxic only indirectly, by toxication. An example is "wood alcohol" or methanol, which is not poisonous itself, but is chemically converted to toxic formaldehyde and formic acid in the liver. Many drug molecules are made toxic in the liver, and the genetic variability of certain liver enzymes makes the toxicity of many compounds differ between individuals. Exposure to radioactive substances can produce radiation poisoning, an unrelated phenomenon. Two common cases of acute natural poisoning are theobromine poisoning of dogs and cats, and mushroom poisoning in humans. Dogs and cats are not natural herbivores, but a chemical defense developed by Theobroma cacao can be incidentally fatal nevertheless. Many omnivores, including humans, readily consume edible fungi, and thus many fungi have evolved to become decisively inedible, in this case as a direct defense.
Another art museum in Moscow is the Pushkin Museum of Fine Arts, which was founded by (among others) the father of poet Marina Tsvetaeva. The Pushkin Museum resembles the British Museum in London in having halls that offer a cross-section of exhibits on world civilizations, with many copies of ancient sculptures. However, the Pushkin Museum also houses paintings from major European eras; works by Claude Monet, Paul Cézanne, and Pablo Picasso are included in the museum's collection. In addition, Moscow contains museums of history, technology, military history, and space exploration. The State Historical Museum of Russia (Russian: Государственный Исторический музей) is located between Red Square and Manege Square in Moscow. The museum's exhibitions range from relics of prehistoric tribes in the area of present-day Russia to valuable artworks acquired by the Romanov dynasty. The number of objects in the museum's collection totals several million. The Polytechnical Museum, founded in 1872, is the largest technical museum in Russia, offering an array of historical inventions and technological achievements—including humanoid automata from the 18th century and the earliest Soviet computers. The museum's collection contains more than 160,000 items. The Borodino Panorama museum, located on Kutuzov Avenue, provides an opportunity for visitors to simulate the experience of a battlefield with a 360° diorama.
==== Gomori-positive astrocytes and brain dysfunction ==== A type of astrocyte with an aging-related pathology has been described over the last fifty years. Astrocytes of this subtype possess prominent cytoplasmic granules that are intensely stained by Gomori's chrome alum hematoxylin stain, and hence are termed Gomori-positive (GP) astrocytes. They can be found throughout the brain, but are by far the most abundant in the olfactory bulbs, medial habenula, dentate gyrus of the hippocampus, arcuate nucleus of the hypothalamus, and in the dorsal medulla, just beneath the area postrema. Gomori-positive cytoplasmic granules are derived from damaged mitochondria engulfed within lysosomes. Cytoplasmic granules contain undigested remnants of mitochondrial structures. These contents include heme-linked copper and iron atoms remaining from mitochondrial enzymes. These chemical substances account for the pseudoperoxidase activity of Gomori-positive granules that can utilized to stain for these granules. Oxidative stress is believed to be cause of damage to these astrocytes. However, the exact nature of this stress is uncertain. Brain regions enriched in Gomori-positive astrocytes also contain a sub-population of specialized astrocytes that synthesize Fatty Acid Binding Protein 7 (FABP7). Indeed, astrocytes in the hypothalamus that synthesize FABP7 have also been shown to possess Gomori-positive granules. Thus, a connection between these two glial features is apparent.
Sources: en.wikipedia.org
=== Oman === In Dhofar, Oman, frankincense species grow north of Salalah. It was traded in the ancient coastal city of Sumhuram, now Khor Rori, and Al-Baleed, an ancient port. In 2000, UNESCO inscribed the sites as a World Heritage Site Land of Frankincense.
=== Activin === As with other members of the superfamily, activins interact with two types of cell surface transmembrane receptors (Types I and II) which have intrinsic serine/threonine kinase activities in their cytoplasmic domains:
=== Preclinical === Acne vaccine – immunostimulant ADA-308 – antiandrogen (androgen receptor antagonist) Research programme: acne vulgaris therapeutics - Attillaps Pharmaceuticals – acetylcholinesterase inhibitors
== Chemical changes == As ionising radiation passes through food, it creates a trail of chemical transformations due to radiolysis effects. Irradiation does not make foods radioactive, change food chemistry, compromise nutrient contents, or change the taste, texture, or appearance of food.
Sources: en.wikipedia.org
Selank is a seven-amino-acid peptide built from the tuftsin sequence plus a Pro-Gly-Pro tail. It is produced by chemical synthesis rather than extracted from a natural source. The free peptide is usually supplied as a lyophilised powder or in an aqueous formulation.
Tuftsin is a natural tetrapeptide derived from the Fc portion of immunoglobulin G. Selank retains that tetrapeptide at its N-terminus and adds three residues to improve resistance to enzymatic breakdown. The relationship is structural, and the two molecules are not interchangeable in experimental work.
It holds a product registration in Russia for intranasal use as an anxiolytic. Registrations of that kind are not automatically accepted by regulators elsewhere. In most other countries it is treated as an unapproved substance or a research material.
Selank is a synthetic heptapeptide designed as a stabilized analog of the natural tetrapeptide tuftsin. It has been investigated mainly for anxiolytic and cognitive effects. It is not an approved pharmaceutical in most countries.