Everything below concerns mass spectrometry. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Updated 2026-05-05. Numbers and descriptions here follow the published literature rather than marketing material.
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.
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.
Measuring peptide exposure inside the brain is technically difficult. Selank is degraded rapidly in plasma, and assays must separate intact peptide from fragments, which favors targeted mass spectrometry over immunoassays alone. Reported half-lives are short, on the order of minutes, so effects observed hours later are attributed to downstream signaling rather than to the parent compound. Blood-brain barrier permeability is debated and rarely quantified directly. Gaps include absent dose-response characterization, inconsistent reporting of purity, and almost no pharmacokinetic data from human participants.
Selank is studied chiefly as an animal-model anxiolytic with proposed secondary effects on memory and immune signaling. Reported mechanisms include modulation of the GABA-A receptor complex, inhibition of enkephalin-degrading enzymes, and shifts in monoamine turnover within limbic structures. Some experiments describe increased expression of brain-derived neurotrophic factor in the hippocampus after repeated dosing. No single molecular target has been confirmed, and the peptide does not bind any receptor with the selectivity typical of a conventional small-molecule drug. Mechanism therefore remains a set of hypotheses rather than an established pathway.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C33H57N11O9 | Derived from the seven-residue sequence |
| Molecular weight | About 751.9 g/mol | Average mass; the monoisotopic value is slightly lower |
| Residue count | Seven amino acids | Thr-Lys-Pro-Arg-Pro-Gly-Pro |
| Parent compound | Tuftsin (Thr-Lys-Pro-Arg) | Selank extends tuftsin at the C-terminus |
| Compound class | Synthetic short peptide | Studied in a research setting; not a licensed drug in most markets |
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.
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.
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.
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.
== Current status == The primary goal of MMP inhibitor design is selectivity. The targeting of specific MMPs is expected to improve efficacy and prevent side effects like musculoskeletal syndrome (MSS). 3D structures of MMP inhibitors provide a source of insight of the structural relationships for selectivity. High throughput screening can as well increase the chances of discovering inhibitors with high selectivity.
The U.S. Army has commissioned ongoing research into potential risks of depleted uranium and other projectile weapon materials like tungsten, which the U.S. Navy has used in place of DU since 1993. Studies by the U.S. Armed Forces Radiobiology Research Institute conclude that moderate exposures to either depleted uranium or uranium present a significant toxicological threat. In 2003, Professor Brian Spratt FRS, chairman of the Royal Society's working group on depleted uranium, said: "The question of who carries out the initial monitoring and clean-up is a political rather than scientific question," and "the coalition needs to acknowledge that depleted uranium is a potential hazard and make in-roads into tackling it by being open about where and how much depleted uranium has been deployed." A 2008 review of all relevant articles appearing in the peer-reviewed journals on MEDLINE through to the end of 2007, including multiple cohort studies of veterans, found no consistent evidence of excess risks of neoplasms that could have some link to DU, and that "[t]he overall incidence of cancers is not increased in the cohort studies of Gulf war and Balkans veterans". One particular subgroup of veterans that may be at higher risk comprises those who have internally retained fragments of DU from shrapnel wounds.
=== Emerging technologies === Many different forms of human enhancing technologies are either on the way or are currently being tested and trialed. A few of these emerging technologies include human genetic engineering (gene therapy), neurotechnology (neural implants and brain–computer interfaces), cyberware, strategies for engineered negligible senescence, nanomedicine, and 3D bioprinting. Variants of human genetic engineering with so far limited usage include the artificial creation of human-animal hybrids (where each cell has partly human and partly animal genetic contents) and human-animal chimeras (where some cells are human and some cells are animal in origin).
Mark Cassell, How Governments Privatize: the Politics of Divestment in the United States and Germany, Georgetown University Press, 2002. Vladimiro Giacché, Anschluss: Die deutsche Vereinigung und die Zukunft Europas, Laika-Verlag, Hamburg 2014, German Edition, ISBN 978-3-9442-3326-0.
British Post Office scandal: Court documents reveal that Fujitsu, the company at the centre of the Post Office scandal, won a £184m contract by the Foreign and Commonwealth Office in 2021, despite concerns the system it was offering was "unfit for purpose". Court documents show that former prime minister Sir Tony Blair was warned the Horizon IT system could be "possibly unreliable" before it was rolled out, and raised concerns about it, but gave it the green light after receiving reassurance from others, including his Secretary of State for Trade and Industry Peter Mandelson. 13 January – Yvonne Tracey, a former deputy postmistress from New Malden, south London, announces her intention to stand in the Parliamentary constituency of Kingston and Surbiton, Sir Ed Davey's seat, at the next general election. 14 January – Foreign Secretary David Cameron tells the BBC that military action was taken against Houthi rebels because the strikes were needed after months of attacks against cargo ships, and that the UK is "prepared to back our words with actions". 15 January – Sunak tells Parliament that air strikes against Houthi targets were meant as a "limited, single action" but that the UK "will not hesitate to protect our security, our people and our interests where required". James Stockan announces he is stepping down from the post of leader of Orkney Islands Council, as well as relinquishing his council seat, after six years in the role.
Sources: en.wikipedia.org
== Format == Each episode is adapted from a corresponding story by fan fiction author Squirrelking that was posted on the website FanFiction.net. The original text of the story is narrated over video captured in the game Garry's Mod, often with accompanying music and sound effects. Each episode is voiced by a different narrator, each credited by an online handle.
Dehydrogenation by 17β-hydroxysteroid dehydrogenase (17β-HSD) into estrone Conjugation by estrogen sulfotransferases and UDP-glucuronyltransferases into C3 and/or C17β estrogen conjugates like estrone sulfate and estradiol glucuronide Hydroxylation by cytochrome P450 enzymes such as CYP1A1 and CYP3A4 into catechol estrogens like 2-hydroxyestrone and 2-hydroxyestradiol as well as 16-hydroxylated estrogens like 16α-hydroxyestrone and estriol (16α-hydroxyestradiol) The liver is almost entirely responsible for metabolism of estradiol. Both dehydrogenation of estradiol by 17β-HSD into estrone and conjugation into estrogen conjugates are reversible transformations. However, in regards to sulfation and desulfation, transformation of estrone into estrone sulfate is predominant relative to the reverse reaction. Estradiol can also be reversibly converted into long-lived lipoidal estradiol forms like estradiol palmitate and estradiol stearate as a minor route of metabolism. The elimination half-life of estradiol administered via intravenous injection has been found to be 2 hours in men and 27 to 50 minutes in women. Other routes of administration of estradiol like oral administration or intramuscular injection have far longer elimination half-lives and durations of action due to (1) the formation of a large circulating reservoir of metabolism-resistant estrogen conjugates that can be reconverted back into estradiol and/or (2) the formation of slowly-releasing depots.
Preservatives have been used since prehistoric times. Smoked meat for example has phenols and other chemicals that delay spoilage. The preservation of foods has evolved greatly over the centuries and has been instrumental in increasing food security. Historically foods were preserved using traditional oils, salting, drying, smoking methods. The use of chemical preservatives in food began in the late 19th century, but was not widespread until the 20th century. The use of food preservatives varies greatly depending on the country. Many developing countries that do not have strong governments to regulate food additives face either harmful levels of preservatives in foods or a complete avoidance of foods that are considered unnatural or foreign. These countries have also proven useful in case studies surrounding chemical preservatives, as they have been only recently introduced. In urban slums of highly populated countries, the knowledge about contents of food tends to be extremely low, despite consumption of these imported foods.
== Further reading == Jackie Y. Ying (2001). Nanostructured Materials. Academic Press. pp. 5–. ISBN 978-0-12-744451-2. Nanoparticles Used in Solar Energy Conversion (ScienceDaily). "Nanoparticles: An occupational hygiene review" Archived 24 September 2015 at the Wayback Machine by RJ Aitken and others. Health and Safety Executive Research Report 274/2004 "EMERGNANO: A review of completed and near completed environment, health and safety research on nanomaterials and nanotechnology" by RJ Aitken and others. High transmission Tandem DMA for nanoparticle studies by SEADM, 2014.
=== 35 kDa Protein === The lesser known component of the OpLuc enzyme has 320 amino acids with 11 cysteine and 5 leucine molecules. The amino terminus of the protein was experimentally concluded to begin at 39 amino acids. It is thought to stabilize 19 kDa and is not thought to be affect by substrate specificity, however its exact function is not known.
Sources: en.wikipedia.org
=== Eosinophilic asthma === Reslizumab was first used for eosinophilic asthma in 2008. In a 106-patient, phase II clinical trial, the researchers showed reslizumab was effective in reducing sputum eosinophils. Furthermore, the patients receiving reslizumab showed improvements in airway function, and a general trend toward greater asthma control than those receiving placebo was observed. A large, 981-patient, phase III clinical trial showed that reslizumab was effective at improving lung function, asthma control, and quality of life in comparison to placebo. These results led to the FDA approval for the maintenance treatment of severe asthma in patients aged 18 years and older, with an eosinophilic phenotype on March 23, 2016.
=== Death === Rockefeller was killed in an automobile accident in Mount Pleasant, New York (near the Rockefeller family estate in Pocantico), on July 10, 1978, at the age of 72. He is buried at the Rockefeller Family Cemetery in Sleepy Hollow, New York.
CH3CH2Br + SC(NH2)2 → [CH3CH2SC(NH2)2]Br [CH3CH2SC(NH2)2]Br + NaOH → CH3CH2SH + OC(NH2)2 + NaBr The thiourea route works well with primary halides, especially activated ones. Secondary and tertiary thiols are less easily prepared. Secondary thiols can be prepared from the ketone via the corresponding dithioketals. A related two-step process involves alkylation of thiosulfate to give the thiosulfonate ("Bunte salt"), followed by hydrolysis. The method is illustrated by one synthesis of thioglycolic acid:
Preotact is delivered in a two chamber, glass ampoule. One chamber contains the active substance in the form of a white powder (with excipients: mannitol, citric acid monohydrate, NaCl, NaOH, HCl). And the other contains the solvent; water for injection. The powder is mixed with the solvent when the ampoule is inserted into the injection device.
Sources: en.wikipedia.org
Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro, designed as a metabolically stabilized analogue of the endogenous tetrapeptide tuftsin. It has been studied mainly against anxiety-related and cognitive endpoints rather than as an approved medicine in most jurisdictions.
Tuftsin contains four residues, while selank carries an additional Pro-Gly-Pro segment at the carboxyl end. That extension is intended to reduce enzymatic cleavage. Comparative pharmacokinetic data in humans remain limited.
No single receptor target is widely accepted as the definitive mediator of the reported effects. Proposed contributors include GABAergic modulation, shifts in monoamine turnover, and altered neuropeptide degradation. The mechanism is treated in the literature as unresolved.
Intranasal administration predominates in both animal and human research because it avoids hepatic first-pass metabolism. Injectable and intraperitoneal routes appear in animal work mainly for comparison.