Everything below concerns Certificate of analysis. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Updated 2025-09-26. Numbers and descriptions here follow the published literature rather than marketing material.
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.
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.
Characterization of Selank in a laboratory setting relies on standard peptide methods. Reverse-phase high-performance liquid chromatography separates the target from related impurities and provides a purity figure, commonly reported as 95 percent or higher. Mass spectrometry, typically electrospray ionization or matrix-assisted laser desorption, confirms the molecular mass and helps detect truncation or modification. Amino acid analysis can verify composition when a sequence-level check is needed. These techniques together establish identity and purity for a given lot.
Lyophilized Selank, the dry powder form, is generally stored frozen at minus 20 degrees Celsius or colder for long-term keeping. The solid is hygroscopic and should stay sealed, dry, and protected from light. Once dissolved, the peptide is less stable and is usually held refrigerated at 2 to 8 degrees Celsius for short periods. Repeated freezing and thawing is avoided because it can promote aggregation and loss of activity. Buffers and pH choice also affect how long a solution remains usable.
| 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 |
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.
Laboratory work relies on standard behavioral paradigms. Rodents are tested in the elevated plus maze, open field, and passive avoidance tasks, with outcomes compared against diazepam or vehicle controls. Intranasal dosing is used most often because it bypasses first-pass metabolism, though intraperitoneal and intravenous routes also appear in published protocols. Biochemical endpoints include tissue BDNF concentrations, cytokine levels, and monoamine metabolites. Human data are limited to small Russian trials reporting reduced anxiety scores; most were not prospectively registered, and few employed independent outcome assessment.
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.
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.
Clinical evidence comes mainly from small studies conducted in Russia, several of which were open-label or lacked robust blinding. Reported outcomes include lower anxiety scores, changes in attention measures, and effects on asthenic states following illness. Sample sizes are typically in the tens of participants, and independent replication outside the region is scarce. Reviews published in English generally note the limited methodological quality of the underlying trials. Whether the compound produces clinically meaningful effects under rigorous conditions remains unresolved.
Proposed mechanisms center on modulation of the GABA system, but no single molecular target has been confirmed. Rodent studies report changes in GABA-A receptor expression and in the turnover of serotonin, dopamine, and norepinephrine in several brain regions. Increases in brain-derived neurotrophic factor and its receptor have also been described after repeated administration. These findings come largely from animal models, and the degree to which they describe human neurochemistry remains an open question. The mechanism is best characterized as multi-system and not fully resolved.
Pharmacokinetic data are limited. Like most short peptides, Selank is vulnerable to plasma and tissue peptidases, and its measured half-life in circulation is short, on a minutes scale. The Pro-Gly-Pro tail slows this degradation but does not eliminate it. Intranasal administration is the route described in most reports, with absorption through the nasal mucosa and a hypothesized path into the central nervous system that avoids the blood-brain barrier. Direct measurements of human brain exposure are unavailable, so distribution claims rest on inference from animal work.
== Medical uses == Pivekimab sunirine is indicated for the treatment of adults with blastic plasmacytoid dendritic cell neoplasm. Blastic plasmacytoid dendritic cell neoplasm is an ultra-rare and fast-growing cancer of the bone marrow and blood that can affect multiple organs, including the skin, lymph nodes, spleen, and liver.
== Concerns == Since microbes, namely Salmonella and Bacillus cereus, can persist in IMFs, other hurdles including reduction in pH and the use of preservatives is not unusual. However, additives such as nitrites and sulfites are associated with health concerns. Nitrites have a negative connotation in the food industry since they can combine with secondary amines to form nitrosamines, which are carcinogenic. Nitrites are linked to an increase risk in cancer and heart disease. Sulfite is another additive that is commonly avoided due to people having a sensitivity to sulfites. Yeast and mold are not fully inhibited by IMF processing because these microorganisms can tolerate water activity as low as 0.80. Browning can occur during storage of Intermediate moisture fruits and vegetables. Finally, sugar used commonly added as a humectant increases the caloric value of the food.
Proof of concept trials have indicated that Ebola-targeted siRNAs may be effective as post-exposure prophylaxis in humans, with 100% of non-human primates surviving a lethal dose of Zaire Ebolavirus, the most lethal strain.
Sources: en.wikipedia.org
CD98 is a glycoprotein that is a heterodimer composed of SLC3A2 and SLC7A5 that forms the large neutral amino acid transporter (LAT1). LAT1 is a heterodimeric membrane transport protein that preferentially transports branched-chain (valine, leucine, isoleucine) and aromatic (tryptophan, tyrosine, phenylalanine) amino acids. LAT is highly expressed in brain capillaries (which form the blood–brain barrier) relative to other tissues. A functional LAT1 transporter is composed of two proteins encoded by two distinct genes:
== Works == Newsom, Gavin; Dickey, Lisa (February 7, 2013). Citizenville: How to Take the Town Square Digital and Reinvent Government. Penguin. ISBN 978-1101605813. Newsom, Gavin (February 24, 2026). Young Man in a Hurry: A Memoir of Discovery. Penguin. ISBN 978-1984881939.
== Surface properties == It is also possible to modify the surface of graphene oxide to change its properties. Graphene oxide has unique surface properties which make it a very good surfactant material stabilizing various emulsion systems. Graphene oxide remains at the interface of the emulsions systems due to the difference in surface energy of the two phases separated by the interface.
Sources: en.wikipedia.org
Penetrating abdominal trauma (PAT) typically arises from stabbings, ballistic injuries (shootings), or industrial accidents. PAT can be life-threatening because abdominal organs, especially those in the retroperitoneal space, can bleed profusely, and the space can hold a large volume of blood. If the pancreas is injured, it may be further injured by its own secretions, in a process called autodigestion. Injuries of the liver, common because of the size and location of the organ, present a serious risk for shock because the liver tissue is delicate and has a large blood supply and capacity. The intestines, taking a large part of the lower abdomen, are also at risk of perforation. People with penetrating abdominal trauma may have signs of hypovolemic shock (insufficient blood in the circulatory system) and peritonitis (an inflammation of the peritoneum, the membrane that lines the abdominal cavity). Penetration may abolish or diminish bowel sounds due to bleeding, infection, and irritation, and injuries to arteries may cause bruits (a distinctive sound similar to heart murmurs) to be audible. Percussion of the abdomen may reveal hyperresonance (indicating air in the abdominal cavity) or dullness (indicating a buildup of blood). The abdomen may be distended or tender, signs which indicate an urgent need for surgery. The standard management of penetrating abdominal trauma was for many years mandatory laparotomy.
=== Pharmacokinetics === The pharmacokinetics of honokiol have been explored in rats and mice; however, further research must be done in humans. Intravenous delivery of 5–10 mg/kg in rodent models has shown a plasma half-life of around 40–60 minutes while intraperitoneal injections of 250 mg/kg had a plasma half-life around 4–6 hours with maximum plasma concentration occurring between 20 and 30 minutes.
=== Video games === John Stewart appears in Justice League: Injustice for All. John Stewart appears in Justice League: Chronicles. John Stewart appears as a playable character in Justice League Heroes, voiced by Michael Jai White. John Stewart appears in DC Universe Online, voiced by Ken Thomas. Since 2012, he has been voiced by George Washington III. John Stewart appears as a downloadable alternate skin for Hal Jordan in Injustice: Gods Among Us, voiced again by Phil LaMarr. John Stewart as a Green and Indigo Lantern appears as a character summon in Scribblenauts Unmasked: A DC Comics Adventure. John Stewart appears as a NPC in Young Justice: Legacy, voiced again by Kevin Michael Richardson. John Stewart appears as a playable character in Lego Batman 3: Beyond Gotham, voiced by Ike Amadi. John Stewart appears as a "premier skin" for Hal Jordan in Injustice 2, voiced again by Phil LaMarr. John Stewart appears as a playable character in Lego DC Super-Villains, voiced by Nyambi Nyambi. John Stewart appears as a playable character in Teen Titans Go! Figure. John Stewart appears in Justice League: Cosmic Chaos, voiced by Terrence C. Carson. John Stewart appears as a boss in Suicide Squad: Kill the Justice League, voiced by Dan White. This version is a member of the Justice League.
The most common method for alkylation of the lactam nitrogen of 2,5-diketopiperazines is based on the use of sodium hydride as base. However epimerisation can occur especially with proline-fused 2,5-diketopiperazines, even with milder methods such as under phase-transfer catalyst conditions for example 1 to 2. Reduction of the carbonyl groups of chiral 2,5-diketopiperazine with lithium aluminium hydride (LiAlH4) cleanly gives the corresponding chiral piperazines. For example, cyclo(L-Phe-L-Phe) 1 gives the chiral piperazine (2S,5S)-dibenzylpiperazine 2. Reaction of the lactam-derived enol phosphates 4 of 2,5-diketopiperazines with palladium catalyzed reactions (reduction, Suzuki and Stille cross-coupling reactions) enables the synthesis of a range of functionalised 1,4-dihydropyrazines 5 which can be aromatized to 1,4-pyrazines 6 in the presence of acid.
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.
Reverse-phase HPLC is the usual method and gives a percentage purity value. Mass spectrometry then confirms the molecular mass. Together they provide a basic identity and purity profile for a lot.