Everything below concerns heptapeptide. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Last reviewed on 2025-11-13. Where a claim depends on a specific study, the study is described rather than over-claimed.
Tuftsin, the parent structure, is a naturally occurring immunomodulatory tetrapeptide released from the Fc region of immunoglobulin G by spleen enzymes. Selank extends this four-residue sequence with three additional amino acids. The stated rationale is that the added tail slows enzymatic breakdown and may influence receptor interactions. How the full heptapeptide behaves at the molecular level is not firmly established, and proposed mechanisms often involve indirect modulation of neurotransmitter or immune signaling rather than a single defined target.
Selank is a synthetic heptapeptide developed in Russia. Its sequence is Thr-Lys-Pro-Arg-Pro-Gly-Pro, a seven-residue chain built around the natural tetrapeptide tuftsin. Researchers at the Institute of Molecular Genetics of the Russian Academy of Sciences first described the compound in the mid-1990s. The design combined the tuftsin core with an added Pro-Gly-Pro tail, a modification intended to extend the molecule's stability in biological fluids. Published work on the peptide has appeared mainly in Russian-language journals.
Reported activity for Selank centers on anxiolytic and nootropic effects. Russian clinical reports describe use in anxiety and in cognitive or attention-related complaints. Most of this evidence comes from studies conducted by the same research groups that developed the peptide. Independent replication in other countries remains limited, and no major Western regulatory agency has approved the compound for any indication. The gap between local reports and external verification is a recurring point in discussions of the 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.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic heptapeptide | Modeled on tuftsin |
| Amino acid sequence | Thr-Lys-Pro-Arg-Pro-Gly-Pro | Seven residues |
| Approximate molecular mass | Around 750 Da | Depends on counter-ion and hydration |
| Common forms | Lyophilized powder | Also described as aqueous solution |
| Primary origin of research | Russian laboratories | Mid-1990s onward |
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.
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.
Once dissolved, the peptide is markedly less stable than the dry powder. Aqueous solutions are subject to backbone hydrolysis and to microbial growth when they are handled without sterile technique. Buffered solutions near neutral pH are common for short-term laboratory work, while acidic conditions are sometimes used to improve solubility. Analytical laboratories generally prepare working solutions fresh rather than storing them, and a residual water film left in a reopened vial can seed degradation even when the container appears dry.
Reversed-phase high-performance liquid chromatography is the standard technique for estimating peptide purity. The result is a peak-area percentage, which describes how much of the detected material elutes as the main peak in one run. Mass spectrometry confirms the molecular mass and can reveal truncated, adducted, or otherwise modified species. Amino acid analysis or tandem mass spectrometry can address sequence fidelity when identity is in doubt. None of these measurements, taken alone, establishes that a sample is fit for any specific purpose.
Lyophilized selank is normally supplied as a dry powder and is considered stable for extended periods when kept cold and dry. Moisture uptake is the main practical threat, because absorbed water promotes both hydrolysis and aggregation in the solid state. Vials are usually warmed to room temperature before opening so that condensation does not form on the powder. Supplier documentation commonly specifies -20 °C for routine storage, with -80 °C used for material intended to be archived for years.
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.
Reported pharmacological effects center on reduced anxiety-like behavior in animal models and on measures of memory and learning. Proposed contributing mechanisms include modulation of GABAergic signaling, shifts in monoamine turnover, and changes in the activity of enzymes that degrade neuropeptides. Effects on the expression of genes linked to neuroplasticity have also been described. No single molecular target is widely accepted, and whether the behavioral findings arise from one pathway or several remains an open question.
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.
=== Murder of Catherine "Rena" West === Rena maintained sporadic contact with her children on each occasion she and Fred separated. She is also known to have visited Fred's family in Much Marcle, Herefordshire, to enquire as to her children's whereabouts and welfare in the latter half of August 1971. Fred's sister-in-law, Christine, later recollected Rena was depressed and extremely anxious about her children. Being provided with Fred's Midland Road address, Rena sought to confront him—likely to discuss or demand custody of her daughters. This was the last time Rena was seen alive. She is believed to have been murdered by strangulation, possibly in the back seat of Fred's Ford Popular and likely while intoxicated. When Rena's body was discovered, a short length of metal tubing was found with her remains, leaving open a possibility she had been restrained and subjected to a sexual assault prior to her murder. The body was extensively dismembered, placed into plastic bags and buried close to a cluster of trees, known as Yewtree Coppice, at Letterbox Field.
Forensic science, often known as criminalistics, is the application of science principles and methods to support decision-making related to rules or law, generally criminal and civil law. During criminal investigation in particular, it is governed by the legal standards of admissible evidence and criminal procedure. It is a broad field utilizing numerous practices such as the analysis of DNA, fingerprints, bloodstain patterns, firearms, ballistics, toxicology, microscopy, and fire debris analysis. Modern forensic analysis is also conducted on cybersecurity related incidents where major breach has occurred leading to substantial financial loss. Forensic scientists collect, preserve, and analyze evidence during the course of an investigation. While some forensic scientists travel to the scene of the crime to collect the evidence themselves, others occupy a laboratory role, performing analysis on objects brought to them by other individuals. Others are involved in analysis of financial, banking, or other numerical data for use in financial crime investigation, and can be employed as consultants from private firms, academia, or as government employees. In addition to their laboratory role, forensic scientists testify as expert witnesses in both criminal and civil cases and can work for either the prosecution or the defense. While any field could technically be forensic, certain sections have developed over time to encompass the majority of forensically related cases.
Viktor Antonov (Bulgarian: Виктор Антонов; 5 February 1972 – 7 February 2025) was a Bulgarian artist, video game designer, writer, and worldbuilder who worked on numerous first-person shooter (FPS) games. In 2017, Blake Hester wrote for Vice that Antonov "has created disturbing, memorable, and unique worlds" which "conjure images of cyberpunk metropolises and grim London alleyways." Antonov's first game credits were at Xatrix Entertainment, for Redneck Rampage (1997), Redneck Deer Huntin' (1998), Redneck Rampage Rides Again (1998), and Kingpin: Life of Crime (1999). At Valve, he worked on Counter-Strike: Source (2004), Half-Life 2 (2004), and Half-Life 2: Lost Coast (2005). As art director of Half-Life 2, he principally designed its dystopian setting of City 17: a decaying Eastern European city occupied by the Combine alien empire, featuring Soviet-era Brutalist buildings and alien structures similar to panopticons which constitute the Combine's surveillance state. Antonov was temporarily art director of Valve's Team Fortress 2 (2007). While developing Dark Messiah of Might and Magic (2006) and Dishonored (2012) at Arkane Studios, Antonov worked on films and wrote a graphic novel. He principally designed Dishonored's setting of Dunwall, a labyrinthine dystopian city with steampunk Victorian and Gothic buildings; it and City 17 are often considered some of the best worlds ever made for video games.
==== Illicit drugs ==== The sources and production mechanisms of illegal drugs has been another area that has seen successful application of hydrogen isotope characterization. Usually, as with other applications of stable isotope techniques, results are best when data for multiple stable isotopes are compared with one another. δ2H, δ13C and δ15N have been used together to analyze tablets of MDA and MDMA and has successfully identified differences which could be used to differentiate between different sources or production mechanisms. The same combination of stable isotopes with the addition of δ18O was applied to heroin and associated packaging and could successfully distinguish between different samples. Analysis using deuterium NMR was also able to shed light on the origin and processing of both cocaine and heroin. In the case of heroin this site-specific natural isotopic fraction measured by deuterium NMR (SNIF-NMR) method could be used for determining the geographic origin of the molecule by analyzing so-called natural sites (which were present in the morphine from which heroin is made), as well as gaining information on the synthesis process by analyzing the artificial sites (added during drug processing).
== Structure == Most sv-LAAOs are reported as being homodimers with multiple subunits that have molecular weights around 50–70 kDa and the interaction between the subunits occurs via non-covalent interactions. Sv-LAAOs are present in the acidic, basic, and neutral forms of the protein. Studies that look at x-ray crystal structures have confirmed that sv-LAAOs are often found as functional dimers, with each dimer having three domains. The three domains are the substrate-binding site, FAD-binding site, and a helical domain. The substrate-binding site lies at the bottom of a funnel-shaped cavity approximately 25 Å deep, enabling substrate specificity among sv-LAAOs. Structural differences in active site topology likely account for species-dependent substrate preferences. Additionally, LAAOs are thermolabile, with cold inactivation and heat reactivation properties, necessitating specific storage and pre-activation conditions to preserve enzymatic activity. It has also been determined that the FAD prosthetic group becomes deeply entrenched in the enzyme structure, which allows for pervasive interactions with both neighboring atoms and conserved water molecules. Additionally, this flavin-containing prosthetic group has been classified as providing snake venom with its quintessential dark yellow coloration, which is shown in Figure 2. One unusual characteristic reported for sv-LAAOs regards the cold inactivation and heat reactivation properties of the protein. Thereby, most sv-LAAOs are considered to be thermolabile enzymes.
Sources: en.wikipedia.org
=== World War I === During the mobilization when Bulgaria entered World War I, Kimon Georgiev became a company commander in the newly formed Forty-fourth Infantry Tundzhan Regiment and shortly after was appointed commander of its 2nd Troop. The regiment was part of the Second Infantry Thracian Division under the command of General Dimitar Geshov and fought on the Salonika front. Georgiev distinguished himself in the fighting at Kayali, where he would capture 316 British soldiers, in which became a major in 1916. He participated in the Battle of the Crna Bend, where his detachment was in key positions at the village of Brod and the mouth of the Sakuleva River, which it occupied on 8 October. During the following days it was subjected to intense artillery shelling and repeated attacks by Entente forces, with Georgiev proving to be an effective field officer, holding off the enemy on the opposite bank of the Cherna. On 19 October, he lost one eye and severely wounded. After recovering from his wound, Kimon Georgiev was appointed as an instructor and then as a member of the Ordnance Council at the headquarters of the army. On 27 February 1918, he was promoted to lieutenant-colonel. During demobilization after the Armistice of Salonica, he was transferred to the War Ministry, and from 26 October 1918 was head of the Inspectorate Section. Kimon Georgiev became a member of the Military Union after the returning of headquarters of the army in Sofia and headed its organization for the Sofia garrison.
== Post-retirement == De retired in 1973 from the Calcutta Medical College at the age of 58. After his retirement, he showed no interest in higher positions but continued his research at the Bose Institute, Calcutta. De's desire to purify the cholera toxin did not progress any further as the protein purification technology was not well established in his research settings. During his time of research, De worked with hypertoxin-producing classical strains of V. cholerae O1, which was abruptly replaced by El Tor biotype [producing less cholera toxin] in Calcutta from 1963. This new development was another reason why De could not continue his research on purification of cholera toxin. In 1978, the Nobel Foundation invited De to participate in the 43rd Nobel Symposium on Cholera and Related Diarrhoeas. De died on 15 April 1985 at the age of 70.
=== Ending manufacture === Citing health concerns, several manufacturing companies have ended or stated that they plan to end the sale of PFAS or products that contain them. These companies include W. L. Gore & Associates (the maker of Gore-Tex), Patagonia, REI, H&M, and 3M. An alternative for some companies may have been to move production to countries such as Thailand and India, where there is less regulation.
MHC class I molecules are one of two primary classes of major histocompatibility complex (MHC) molecules (the other being MHC class II) and are found on the cell surface of all nucleated cells in the bodies of vertebrates. They also occur on platelets, but not on red blood cells. Their function is to display peptide fragments of proteins from within the cell to cytotoxic T cells; this will trigger an immediate response from the immune system against a particular non-self antigen displayed with the help of an MHC class I protein. Because MHC class I molecules present peptides derived from cytosolic proteins, the pathway of MHC class I presentation is often called cytosolic or endogenous pathway. In humans, the HLAs corresponding to MHC class I are HLA-A, HLA-B, and HLA-C.
== Chromatography == Mikhail Tsvet invented chromatography in 1900 during his research on plant pigments. He used liquid-adsorption column chromatography with calcium carbonate as adsorbent and petrol ether/ethanol mixtures as eluent to separate chlorophylls and carotenoids. The method was described on 30 December 1901 at the XI Congress of Naturalists and Physicians (XI съезд естествоиспытателей и врачей) in St. Petersburg. The first printed description was in 1905, in the Proceedings of the Warsaw Society of Naturalists, biology section. He first used the term "chromatography" in print in 1906 in his two papers about chlorophyll in the German botanical journal, Berichte der Deutschen botanischen Gesellschaft. In 1907, he demonstrated his chromatograph for the German Botanical Society. For several reasons, Tsvet's work was long ignored: the violent political upheaval in Russia at the beginning of the 20th century, the fact that Tsvet originally published only in Russian (making his results largely inaccessible to western scientists), and an article denying Tsvet's findings. Richard Willstätter and Arthur Stoll tried to repeat Tsvet's experiments, but because they used an overly aggressive adsorbent (destroying the chlorophyll), they were not able to do so. They published their results, and Tsvet's chromatography method fell into obscurity. It was revived 10 years after his death thanks to Austrian biochemist Richard Kuhn and his student, German scientist Edgar Lederer as well as the work of A. J. Martin and R. L. Synge.
Sources: en.wikipedia.org
Quotations related to Mental health at Wikiquote Media related to Mental health at Wikimedia Commons Mental Health by WHO The Public Health Agency of Canada "Mental health and substance abuse". WHO Regional Office for the Eastern Mediterranean. National Institute of Mental Health (United States) Health-EU Portal Mental Health in the EU Mental Health Department of Health (United Kingdom)
==== Generic drugs ==== Generic drugs are chemical and therapeutic equivalents of name-brand drugs, normally whose patents have expired. Approved generic drugs should have the same dosage, safety, effectiveness, strength, stability, and quality, as well as route of administration. In general, they are less expensive than their name brand counterparts, are manufactured and marketed by rival companies and, in the 1990s, accounted for about a third of all prescriptions written in the United States. For a pharmaceutical company to gain approval to produce a generic drug, the FDA requires scientific evidence that the generic drug is interchangeable with or therapeutically equivalent to the originally approved drug. This is called an Abbreviated New Drug Application (ANDA). 80% of prescription drugs sold in the United States are generic brands.
While supporters of the aetherial theory accepted the possibility that negatively charged particles are produced in Crookes tubes, they believed that they are a mere by-product and that the cathode rays themselves are immaterial. Thomson set out to investigate whether or not he could actually separate the charge from the rays. Thomson constructed a Crookes tube with an electrometer set to one side, out of the direct path of the cathode rays. Thomson could trace the path of the ray by observing the phosphorescent patch it created where it hit the surface of the tube. Thomson observed that the electrometer registered a charge only when he deflected the cathode ray to it with a magnet. He concluded that the negative charge and the rays were one and the same.
In the United States, shipments larger than about 7,000 kg (15,432 lb) are typically classified as truckload (TL) freight. This is because it is more efficient and economical for a large shipment to have exclusive use of one larger trailer rather than share space on a smaller LTL trailer. By the Federal Bridge Gross Weight Formula the total weight of a loaded truck (tractor and trailer, 5-axle rig) cannot exceed 80,000 lb (36,287 kg) in the United States. In ordinary circumstances, long-haul equipment will weigh about 15,000 kg (33,069 lb), leaving about 20,000 kg (44,092 lb) of freight capacity. Similarly a load is limited to the space available in the trailer, normally 48 ft (14.63 m) or 53 ft (16.15 m) long, 2.6 m (102+3⁄8 in) wide, 9 ft 0 in (2.74 m) high and 13 ft 6 in or 4.11 m high overall. While express, parcel and LTL shipments are always intermingled with other shipments on a single piece of equipment and are typically reloaded across multiple pieces of equipment during their transport, TL shipments usually travel as the only shipment on a trailer. In fact, TL shipments usually deliver on exactly the same trailer as they are picked up on.
Sources: en.wikipedia.org
Selank is a synthetic peptide made of seven amino acids. It is modeled on tuftsin, a natural tetrapeptide, with an added three-residue tail. It is not a small-molecule drug.
It originates from research in Russia, associated with the Institute of Molecular Genetics of the Russian Academy of Sciences. The first descriptions date to the mid-1990s. Most published studies come from Russian laboratories.
No, Selank itself does not occur naturally. Its backbone is based on tuftsin, which is produced in the body, but the seven-residue version is a synthetic construct. It is supplied as a manufactured peptide.
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.