The short version of amino acid sequence fits in a sentence. The long version — which is the one that helps — is below.
This page was last updated on 2025-09-25 and is reviewed periodically as new material appears.
The primary structure of Selank is Thr-Lys-Pro-Arg-Pro-Gly-Pro, corresponding to the molecular formula C33H57N11O9 and a monoisotopic mass of roughly 751.9 daltons. The N-terminal threonine and the arginine residue in the fourth position are shared with tuftsin, which carries the sequence Thr-Lys-Pro-Arg. The three additional residues at the C-terminus, Pro-Gly-Pro, extend the chain and are associated with greater resistance to enzymatic degradation. This extension also separates Selank from the shorter parent peptide.
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.
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.
Selank is a hydrophilic peptide and dissolves readily in water and in aqueous buffers. The lyophilised powder is typically a white to off-white solid. Because short peptides are prone to hydrolysis and oxidation, handling benefits from limiting exposure to heat, moisture and strong light. Working solutions are commonly prepared in sterile water or saline, and repeated freeze-thaw cycles are avoided to reduce aggregation and loss of activity. These practices reflect general laboratory convention rather than published stability specifications.
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.
| Property | Value | Notes |
|---|---|---|
| Molecular class | Synthetic heptapeptide | Stabilized analog of tuftsin |
| Sequence | Thr-Lys-Pro-Arg-Pro-Gly-Pro | Single-letter form: TKPRPGP |
| Molecular formula | C33H57N11O9 | Monoisotopic mass about 751.9 Da |
| Appearance | White to off-white powder | Typically supplied as lyophilized solid |
| Solubility | Freely soluble in water | Also soluble in common polar solvents |
Outside its country of origin the compound is generally handled as a research chemical rather than an approved medicine. No regulatory approval from the United States Food and Drug Administration or the European Medicines Agency has been granted for human use. Identity and purity are normally checked by reverse-phase high-performance liquid chromatography, with mass spectrometry used to confirm the molecular mass. Lyophilised material is stored cold and desiccated, and repeated freeze-thaw cycles are avoided.
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.
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.
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.
=== Collaborative history with Pharrell Williams === As a teenage rapper, Malice met music producers Chad Hugo and Pharrell Williams in 1988 and 1990, respectively. Hugo and Williams knew each other and would go on to form the production duo the Neptunes. One day, Pusha T was at Hugo's house and started rapping. Impressed, Williams convinced the brothers to form a rap duo. Clipse's intended debut album, Exclusive Audio Footage (1999), was shelved by Elektra Records; their actual debut Lord Willin' was released by the Neptunes' record label Star Trak Entertainment in 2002. The Neptunes would go on to have production credits on every commercially released studio album by Clipse until the latter's disbandment. Williams claimed to not be on speaking terms with Hugo in 2024 in light of a lawsuit from the latter against him over claims that he was monopolizing the Neptunes name. When asked in 2024 if Clipse worked with Hugo on Let God Sort Em Out, Pusha T denied it. He also responded not being "familiar with" the lawsuit. Clipse stated in 2025 that they still have a strong personal relationship with Hugo, although they differed on whether they missed working with him musically; Pusha T stated that his favorite Clipse album Hell Hath No Fury (2006) was produced entirely by Williams. Malice references the breakup on promotional single "So Be It"—"Ain't no more Neptunes, so P's Saturn."
On Valve's official website circa 2010, his function was described as follows: "Kelly is Valve's senior audio producer, responsible for creating sound effects & music." Around March 2011, Kelly Bailey left Valve with colleague Mike Dussault to work on their project Sunspark Labs LLC, launched in December 2010, developing iOS applications, their first being "Morfo", released in June 2011. The news caused some concern and displeasure from the Steam community due to the lack of any public farewell or notification regarding Bailey's departure. However, at a press conference in February 2014, Mike Morasky (the current composer at Valve), stated that Kelly Bailey was working with Valve again. On 24 September 2015, a collection of new music composed by Bailey was released as a custom music kit in Counter-Strike: Global Offensive titled Hazardous Environments. The music kit's description states that it was "inspired by the darker side of the Half-Life universe". On 18 March 2016, Forbes wrote that Bailey is no longer with Valve but that he has created his own video game company, IndiMo Labs, and that he had been spending sixteen hours a day for the previous seven months as the sole developer behind Vanishing Realms: Rite of Steel, a virtual reality video game with RPG elements for the HTC Vive. The game released as an early access title on Steam on 5 April 2016, the same day the HTC Vive was launched.
Reform UK's Mick Barton, the leader of Nottinghamshire County Council, has banned journalists from the Nottingham Post and its online version, Nottingham Live, from speaking to him or any of his councillors following a dispute over a story the newspaper printed about reorganising local government. A few days later Barton says that his councillors are not banned from speaking to journalists from the newspaper. 29 August – The UK government says that an Israeli delegation will not be invited to a global defence exhibition in London in September because of the Gaza war. 2025 Scottish Greens co-leadership election: Ross Greer and Gillian Mackay are elected as co-leaders of the Scottish Greens. 31 August – Conservative Party leader Kemi Badenoch says her party would remove all net zero requirements on oil and gas companies drilling in the North Sea if they win the next general election. Derek Thomson is suspended as Secretary-General of the Scottish branch of Unite the union pending an internal investigation.
In July 2015, Allergan agreed to sell its generic drug business (Actavis Generics) to Teva for $40.5 billion ($33.75 billion in cash and $6.75 billion worth of shares). As a result, Teva dropped its pursuit of Mylan. In order for the deal to gain regulatory approval, Teva sold off a number of assets, including a portfolio of five generic drugs to Sagent Pharmaceuticals for $40 million, as well as a further eight medicines to Dr. Reddy's in a $350 million deal. Teva also sold a further 15 marketed generics, as well as three others that were close to market, for $586 million to Impax Laboratories. In July, Teva sold off a further 42 products to Australian generics company, Mayne Pharma, for $652 million; the deal moved Mayne up 50 spots, into the top-25 companies of US generic companies. As part of the deal Teva will seek to raise $20 to $25 billion through a bond sale. After completing the $39 billion acquisition of Actavis Generics, Teva announced another, smaller, deal with Allergan, agreeing to acquire its generic distribution business Anda for $500 million.
The Randle cycle, also known as the glucose fatty-acid cycle, is a metabolic process involving the cross inhibition of glucose and fatty acids for substrates. It is theorized to play a role in explaining type 2 diabetes and insulin resistance. It was named for Philip Randle, who described it in 1963.
Sources: en.wikipedia.org
Hypothesis of the non-Slavic origin of the Zaporozhian, Don and Kuban Cossacks is problematised by the minimal levels of Circassian and Asian components in the Y-chromosomal gene pool of these groups, with exception of the Terek Cossacks who have historically been aligned with North Circassian groups, likely as a result of the assimilation of such populations into the Terek Host. As the grand duchies of Moscow and Lithuania grew in power, new political entities appeared in the region. These included Moldavia and the Crimean Khanate. In 1261, Slavic people living in the area between the Dniester and the Volga were mentioned in Ruthenian chronicles. As early as the 15th century, a few individuals ventured into the Wild Fields, the southern frontier regions of Ukraine separating Poland-Lithuania from the Crimean Khanate. These were short-term expeditions, to acquire the information regarding the naturally rich and fertile region teeming with horses, cattle, wild animals, and fish. The Cossack lifestyle was based on subsistence agriculture, nomadic hunting, then returning home in the winter. They settled tightly knit communities and practiced advanced horse training methods, a type of communal living that came to be known as the Cossack way of life. Crimean–Nogai slave raids in Eastern Europe caused terror, considerable devastation, and depopulation to those thriving communities. The Crimean Tatar raids played a role in the evolution of the war like attitudes of the Cossacks and their subsequent reprisals.
== Biochemistry == In prokaryotes and eukaryotes, GGT consists of two polypeptide chains, a heavy and a light subunit, processed from a single chain precursor by an autocatalytic cleavage. The active site of GGT is known to be located in the light subunit. Co-translational N-glycosylation serves a significant role in the proper autocatalytic cleavage and proper folding of GGT. Single site mutations at asparagine residues were shown to result in a functionally active yet slightly less thermally stable version of the enzyme in vitro, while knockout of all asparagine residues resulted in an accumulation of the uncleaved, propeptide form of the enzyme.
Counterfeit drugs are a serious problem. People can potentially ingest useless or dangerous drugs without their knowledge. Custom package seals, authentication labels, holograms, and security printing can be valued parts of an entire security system. They help verify that enclosed drugs are what the package says they are. Drug counterfeiters, however, often work with package counterfeiters, some of whom can be sophisticated. No packaging system is completely secure.
The highest-volume chemicals made by biocatalysis are bio-ethanol (70 million metric tons), high-fructose corn syrup (2 million metric tons), acrylamide, 6-aminopenicillanic acid (APA), L-lysine and other amino acids, citric acid and niacinamide (all more than 10,000 metric tons). Biosynthesis, the conversion of organic materials into fine chemicals by microorganisms, is used for the production of both small molecules (using enzymes in whole cell systems) and less complex, non-glycosylated big molecules, including peptides and simpler proteins. The technology has been used for 10,000 years to produce food products, like alcoholic beverages, cheese, yogurt, and vinegar. In contrast to biocatalysis, a biosynthetic process does not depend on chemicals as starting materials, but only on cheap natural feedstock, such as glucose, to serve as nutrient for the cells. The enzyme systems triggered in the particular microorganism strain lead to the excretion of the desired product into the medium, or, in the case of HMW peptides and proteins, to the accumulation within so-called inclusion bodies in the cells. The key elements of fermentation development are strain selection and optimization, as well as media and process development. Dedicated plants are used for large-scale industrial production. As the volume productivity is low, the bioreactors, called fermenters, are large, with volumes that can exceed 250 m3 (8,828.67 cubic feet). Product isolation was previously based on large-volume extraction of the medium containing the product.
Endothelial cell loss may be aggravated or accelerated by intraocular trauma or surgery. A common scenario involves prolonged corneal swelling or edema following cataract surgery or other types of ocular surgery. Hence, patients with a history of Fuchs' dystrophy may be at a greater risk of corneal edema after ocular surgery as they have fewer functioning endothelial cells. FECD is classified into 4 stages, from early signs of guttae formation to end-stage subepithelial scarring. Diagnosis is made by biomicroscopic examination in the clinic. Other modalities, such as corneal thickness measurement (pachymetry), in-vivo confocal biomicroscopy, and specular microscopy can be used in conjunction. The exact pathogenesis is unknown but factors include endothelial cell apoptosis, sex hormones, inflammation, and aqueous humor flow and composition. Mutations in collagen VIII, a major component of Descemet's membrane secreted by endothelial cells, have been linked to the early-onset FECD. As a genetically heterogeneous disease, the phenotype, or clinical experience of patients with Fuchs dystrophy may reflect the combination of genetic contributors to the disease. Some genetic lesions correlate with more severe disease and earlier onset. Therefore, some individuals may experience symptoms of the disease at a much earlier age, while others may not experience symptoms until late in life. Genes include:
Sources: en.wikipedia.org
=== Sexual deviance === CPA is used as an antiandrogen and form of chemical castration in the treatment of paraphilias and hypersexuality in men. It is used to treat sex offenders. The medication is approved in more than 20 countries for this indication and is predominantly employed in Canada, Europe, and the Middle East. CPA works by decreasing sex drive and sexual arousal and producing sexual dysfunction. CPA can also be used to reduce sex drive in individuals with inappropriate sexual behaviors, such as people with intellectual disability and dementia. The medication is also used to reduce sexual behavior diagnosed as self-harmful, such as masochism. CPA has comparable effectiveness to medroxyprogesterone acetate in suppressing sexual urges and function but appears to be less effective than GnRH modulators like leuprorelin and has more side effects. High-dose CPA significantly decreases sexual fantasies and sexual activity in 80 to 90% of men with paraphilias. In addition, it has been found to decrease the rate of reoffending in sex offenders from 85% to 6%, with most of the reoffenses being committed by individuals who did not follow their CPA treatment prescription. It has been reported that in 80% of cases, 100 mg/day CPA is adequate to achieve the desired reduction of sexuality, whereas in the remaining 20% of cases, 200 mg/day is sufficient. When only a partial reduction in sexuality is desired, 50 mg/day CPA can be useful.
Monosaccharides are also called "simple sugars", the most important being glucose. Most monosaccharides have a formula that conforms to CnH2nOn with n between 3 and 7 (deoxyribose being an exception). Glucose has the molecular formula C6H12O6. The names of typical sugars end with -ose, as in "glucose" and "fructose". Such labels may also refer to any types of these compounds. Fructose, galactose and glucose are all simple sugars, monosaccharides, with the general formula C6H12O6. They have five hydroxyl groups (−OH) and a carbonyl group (C=O) and are cyclic when dissolved in water. They each exist as several isomers with dextro- and laevo-rotatory forms that cause polarised light to diverge to the right or the left.
==== MeSH D12.125.481 – glycine ==== MeSH D12.125.481.100 – allylglycine MeSH D12.125.481.700 – n-substituted glycines MeSH D12.125.481.700.249 – glycocholic acid MeSH D12.125.481.700.249.420 – glycodeoxycholic acid MeSH D12.125.481.700.249.420.400 – glycochenodeoxycholic acid MeSH D12.125.481.700.374 – sarcosine MeSH D12.125.481.700.500 – thiopronine MeSH D12.125.481.700.750 – thiorphan
== Chemistry == Dezocine has a structure similar to the benzomorphan group of opioids. Dezocine is unusual among opioids as it is one of the only primary amines known to be active as an opioid (along with bisnortilidine, an active metabolite of tilidine).
László Bíró, a Hungarian newspaper editor (later a naturalized Argentine) frustrated by the amount of time that he wasted filling up fountain pens and cleaning up smudged pages, noticed that inks used in newspaper printing dried quickly, leaving the paper dry and smudge-free. He decided to create a pen using the same type of ink. Bíró enlisted the help of his brother György, a dentist with useful knowledge of chemistry, to develop viscous ink formulae for new ballpoint designs. Bíró's innovation successfully coupled viscous ink with a ball-and-socket mechanism that allowed controlled flow while preventing ink from drying inside the reservoir. Bíró filed for a British patent on 15 June 1938. In 1941, the Bíró brothers and a friend, Juan Jorge Meyne, fled Germany and moved to Argentina, where they formed "Bíró Pens of Argentina" and filed a new patent in 1943. Their pen was sold in Argentina as the "Birome", from the names Bíró and Meyne, which is how ballpoint pens are still known in that country. This new design was licensed by the British engineer Frederick George Miles and manufactured by his company Miles Aircraft, to be used by Royal Air Force aircrew as the "Biro". Ballpoint pens were found to be more versatile than fountain pens, especially in airplanes, where fountain pens were prone to leak. Bíró's patent, and other early patents on ballpoint pens, often used the term "ball-point fountain pen".
Sources: en.wikipedia.org
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.
It was developed in Russia, at the Institute of Molecular Genetics of the Russian Academy of Sciences, during the 1990s. Most published research originates from Russian institutions. Independent international replication remains limited.
Tuftsin is a natural tetrapeptide with the sequence Thr-Lys-Pro-Arg that participates in immune signaling. Selank extends that sequence with Pro-Gly-Pro at the C-terminus. The added residues are linked to greater resistance to enzymatic breakdown.
Dry powder is normally held at -20 degrees Celsius or below in a sealed, light-protected container with desiccant. Brief room-temperature handling during weighing is generally tolerated. Storage instructions vary between suppliers, so the accompanying certificate of analysis should be followed.