Everything below concerns Selank. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Last reviewed on 2026-05-19. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
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 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.
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.
| 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 |
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.
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.
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.
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.
== History == The Code for Intact Stability was first issued in 1993 under IMO resolution A.749(18)). In 2008, the Code was updated by the IMO. In December 2019, amendments to the Code were adopted that entered into force on 1 January 2020. These amendments related to ships engaged in anchor handling operations and to ships carrying out lifting and towing operations.
is unstable. Starting from almost everywhere in the concentration space, the system evolves to a homochiral state. It is generally understood that autocatalysis alone does not yield homochirality, and the presence of the mutually antagonistic relationship between the two enantiomers is necessary for the instability of the racemic mixture. Homochirality could be achieved from autocatalysis in the absence of the mutually antagonistic relationship, but the underlying mechanism for symmetry-breaking is different.
These grafts were synthesized as a graft copolymer of microfibrillar type I collagen and a glycosaminoglycan, chondroitin-6-sulfate, fabricated into porous sheets by freeze-drying, and then cross-linked by dehydrothermal treatment. Control of the structural features of the collagen scaffold (average pore size, degradation rate and surface chemistry) was eventually found to be a critical prerequisite for its unusual biological activity. In 1981 Burke and Yannas proved that their artificial skin worked on patients with 50 to 90 percent burns, vastly improving the chances of recovery and improved quality of life. John F. Burke also claimed, in 1981, "[The Artificial skin] is soft and pliable, not stiff and hard, unlike other substances used to cover burned-off skin." Several patents were granted to MIT for the creation of collagen-based grafts that can induce dermis regeneration. U.S. Patent 4,418,691 (December 6, 1983) was cited by the National Inventors Hall of Fame as the key patent describing the invention of a process for regenerated skin (Inductees Natl. Inventors Hall of Fame, 2015). These patents were later translated into a commercial product by Integra LifeSciences Corp., a company founded in 1989. Integra Dermal Regeneration Template received FDA approval in 1996, and the FDA listed it as a "Significant Medical Device Breakthrough" in the same year.
Sources: en.wikipedia.org
== Gene == The COL2A1 gene is located on the long (q) arm of chromosome 12 between positions 13.11 and 13.2, from base pair 46,653,017 to base pair 46,684,527. The expression of COL2A1 is regulated by SOX-9 and retrotransposon gag-like-3 gene RTL3 in chondrocytes. There are two transcripts identified for this gene.
=== Physical properties === A promethium atom has 61 electrons, arranged in the configuration [Xe] 4f5 6s2. The seven 4f and 6s electrons are valence electrons. In forming compounds, the atom loses its two outermost electrons and one 4f-electron, which belongs to an open subshell. The element's atomic radius is the second largest among all the lanthanides but is only slightly greater than those of the neighboring elements. It is the most notable exception to the general trend of the contraction of lanthanide atoms with the increase of their atomic numbers (lanthanide contraction). Many properties of promethium rely on its position among lanthanides and are intermediate between those of neodymium and samarium. For example, the melting point, the first three ionization energies, and the hydration energy are greater than those of neodymium and lower than those of samarium; similarly, the estimate for the boiling point, ionic (Pm3+) radius, and standard heat of formation of monatomic gas are greater than those of samarium and less than those of neodymium. Promethium has a double hexagonal close packed (dhcp) structure and a hardness of 63 kg/mm2. This low-temperature alpha form converts into a beta, body-centered cubic (bcc) phase upon heating to 890 °C.
doi:10.1353/sor.2006.0010. S2CID 143149001. Andrew D. Black (Fall 2007). ""The War on People": Reframing "The War on Drugs" by Addressing Racism Within American Drug Policy Through Restorative Justice and Community Collaboration". University of Louisville Law Review. 46 (1): 177–197. Veda Kunins, Hillary; Bellin, Eran; Chazotte, Cynthia; Du, Evelyn; Hope Arnsten, Julia (March 2007). "The effect of race on provider decisions to test for illicit drug use in the peripartum setting". Journal of Women's Health. 16 (2): 245–355. doi:10.1089/jwh.2006.0070. PMC 2859171. PMID 17388741. Beckett, Katherine (June 2008). "Drugs, Data, Race and Reaction: A Field Report". Antipode. 40 (3): 442–447. Bibcode:2008Antip..40..442B. doi:10.1111/j.1467-8330.2008.00612.x. Fellner, Jamie (2009). "Race, Drugs, and Law Enforcement in the United States". Stanford Law & Policy Review. 20 (2): 257–291.
Patent leather is leather that has been given a high-gloss finish by the addition of a coating. Dating to the late 1700s, it became widely popular after inventor Seth Boyden developed the first mass-production process, using a linseed-oil-based lacquer, in 1818. Modern versions are usually a form of bicast leather. Suede is made from the underside of a split to create a soft, napped finish. It is often made from younger or smaller animals, as the skins of adults often result in a coarse, shaggy nap. Bonded leather, also called reconstituted leather, is a material that uses leather scraps that are shredded and bonded together with polyurethane or latex onto a fiber mesh. The amount of leather fibers in the mix varies from 10% to 90%, affecting the properties of the product. The term "genuine leather" does not describe a specific grade. The term often indicates split leather that has been extensively processed, and some sources describe it as synonymous with bicast leather, or made from multiple splits glued together and coated. In some countries, when it is the description on a product label the term means nothing more than "contains leather"; depending on jurisdiction, regulations limit the term's use in product labelling.
Sources: en.wikipedia.org
Pauling had been practically apolitical until World War II. At the beginning of the Manhattan Project, Robert Oppenheimer invited him to be in charge of the Chemistry division of the project. He declined, not wanting to uproot his family.
== Pathophysiology == The recognised forms of MODY are all due to ineffective insulin production or release by pancreatic beta cells. Several of the defects are mutations of transcription factor genes. One form is due to mutations of the glucokinase gene. For each form of MODY, multiple specific mutations involving different amino acid substitutions have been discovered. In some cases, there are significant differences in the activity of the mutant gene product that contribute to variations in the clinical features of the diabetes (such as degree of insulin deficiency or age of onset).
clinafloxacin gatifloxacin moxifloxacin sitafloxacin prulifloxacin besifloxacin delafloxacin Two structurally related fourth-generation drugs, but formally not 4-quinolones, are gemifloxacin and trovafloxacin (removed from clinical use). In development:
=== Hematopoietic stem cell transplantation === Hematopoietic stem cell transplantation (HSCT) is a potentially curative treatment for both alpha and beta thalassemia. It involves replacing the dysfunctional stem cells in the bone marrow with healthy cells from a well-matched donor. Cells are ideally sourced from human leukocyte antigen matched relatives; the procedure is more likely to succeed in children rather than adults. The first HSC transplant for thalassemia was carried out in 1981 on a patient with beta thalassemia major. Since then, a number of patients have received bone marrow transplants from healthy matched donors, although this procedure has a high level of risk. In 2018 an unborn child with hydrops fetalis, a potentially fatal complication of alpha thalassemia, was successfully transfused in utero with her mother's stem cells. HSCT is a dangerous procedure with many possible complications; it is reserved for patients with life-threatening diseases. Risks associated with HSCT can include graft-versus host disease, failure of the graft, and other toxicity related to the transplant. In one study of 31 people, the procedure was successful for 22 whose hemoglobin levels improved to the normal range, in seven the graft failed and they continued to live with thalassemia, and two died of transplantation-related causes.
Neurons that produce GABA as their output are called GABAergic neurons. In adult vertebrates, GABA is usually considered as the major inhibitory neurotransmitter. It also exhibits excitatory effect via GABAB receptor via activation of a specific type of voltage dependent calcium channel. Medium spiny cells are a typical example of inhibitory central nervous system GABAergic cells. In contrast, GABA exhibits both excitatory and inhibitory actions in insects, mediating muscle activation at synapses between nerves and muscle cells, and also the stimulation of certain glands. In mammals, some GABAergic neurons, such as chandelier cells, are also able to excite their glutamatergic counterparts. In addition to fast-acting phasic inhibition, small amounts of extracellular GABA can induce slow timescale tonic inhibition on neurons. GABAA receptors are ligand-activated chloride channels: when activated by GABA, they allow the flow of chloride ions across the membrane of the cell. Whether this chloride flow is depolarizing (makes the voltage across the cell's membrane less negative), shunting (has no effect on the cell's membrane potential), or inhibitory/hyperpolarizing (makes the cell's membrane more negative) depends on the direction of the flow of chloride. When net chloride flows out of the cell, GABA is depolarising; when chloride flows into the cell, GABA is inhibitory or hyperpolarizing. When the net flow of chloride is close to zero, the action of GABA is shunting.
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.
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.