A practical reference on tuftsin: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
Reviewed 2026-08-01. Anything still debated is marked as such rather than presented as settled.
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.
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.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Appearance | White to off-white powder | Lyophilised solid form |
| Solubility class | Freely soluble in water | Hydrophilic heptapeptide |
| Dry storage temperature | -20 degrees Celsius or lower | Sealed, desiccated, protected from light |
| Solution storage | 2 to 8 degrees Celsius short term | Avoid repeated freeze-thaw cycles |
| Common identification method | Reversed-phase HPLC with mass spectrometry | Confirms purity and molecular mass |
Regulatory status differs sharply by region. Selank holds a Russian marketing authorization, where it is supplied mainly as nasal drops, while authorities elsewhere have not approved it for medical use. Material sold internationally is therefore usually labeled as a research chemical rather than a medicine. Peer-reviewed publications come predominantly from Russian laboratories, and sample sizes are generally small. Whether the compound produces comparable effects under independent, well-controlled replication remains an open question that the broader literature has not settled.
Selank is a synthetic heptapeptide developed in Russia as a structural analogue of tuftsin, a naturally occurring immunomodulatory tetrapeptide. Its sequence, Thr-Lys-Pro-Arg-Pro-Gly-Pro, keeps the tuftsin core at the N-terminus and appends a Pro-Gly-Pro tail. Researchers at the Institute of Molecular Genetics in Moscow synthesized the compound during the 1990s while searching for peptides with combined anxiolytic and immunomodulatory activity. The added tail was intended to resist enzymatic cleavage and prolong the molecule's presence in circulation.
The compound has a calculated molecular weight near 751.9 daltons and carries a net positive charge at physiological pH because of its arginine residue. It dissolves freely in water and in common aqueous buffers, and typically appears as a white or off-white lyophilized powder. The amide backbone makes the molecule susceptible to peptidases, which limits oral use and favors intranasal or parenteral routes. Nomenclature in the literature varies: the substance is also described by the sequence abbreviation TP-7 and by a Russian trade designation.
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.
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.
A keystone species is a singular species within an ecosystem that others within the same ecosystem, or the entire ecosystem itself, rely upon. Keystone species' are so vital for an ecosystem that without their presence, an ecosystem could transform or stop existing entirely. One way keystone species impact an ecosystem is through their presence in an ecosystem's food web and, by extension, a food chain within said ecosystem. Sea otters, a keystone species in Pacific coastal regions, prey on sea urchins. Without the presence of sea otters, sea urchins practice destructive grazing on kelp populations which contributes to declines in coastal ecosystems within the northern pacific regions. The presence of sea otters controls sea urchin populations and helps maintain kelp forests, which are vital for other species within the ecosystem.
=== AZFb === The AZFb subregion is located in the middle region of Yq11. Genes in this region have been found to support the growth and maturity of sperm and are critical for efficient progression of spermatogenesis. Common phenotypic manifestations of deletions in this region are spermatogenic arrest and azoospermia. There are multiple candidate genes in the AZFb region that have been shown to cause infertility in males: RNA Binding Motif Protein, Y-linked (RBMY), PTPN13-like, Y-linked (PRY), Chromosome Y Open Reading Frame 15 (CYorf15), Ribosomal Protein S4, Y-linked (RPS4Y1), Eukaryotic Translation Initiation Factor 1A, Y-linked (EIF1AY), Lysine Demethylase 5D (KDM5D), X Linked Kell Blood Group Precursor, Y-linked (XKRY), and Heat Shock Transcription Factor, Y-linked (HSFY).
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Although both ribosome display and mRNA display are in vitro selection methods, mRNA display has some advantage over the ribosome display technology. mRNA display utilizes covalent mRNA-peptide complexes linked through puromycin; whereas, ribosome display utilizes stalled, noncovalent ribosome-mRNA-peptide complexes. For ribosome display, selection stringency is limited to keep ribosome-mRNA-peptide in a complex because of the noncovalent ribosome-mRNA-peptide complexes. This may cause difficulties in reducing background binding during the selection cycle. Also, the peptides under selection in a ribosome display system are attached to an enormous rRNA-protein complex, a ribosome, which has a molecular weight of more than 2,000,000 Da. There might be some unpredictable interaction between the selection target and the ribosome, and this may lead to a loss of potential binders during the selection cycle. In contrast, the puromycin DNA spacer linker used in mRNA display technology is much smaller comparing to a ribosome. This linker may have less chance to interact with an immobilized selection target. Thus, mRNA display technology is more likely to give less biased results.
Sources: en.wikipedia.org
He acknowledged that up to 200 Americans who wanted to leave did not, despite his August 18 pledge to keep troops in Afghanistan until all Americans who wanted to leave had left. After the withdrawal, the U.S. continued to send aid to Afghanistan, remaining its biggest aid donor as of August 2024 and spending at least $20.7 billion post-withdrawal. U.S. funding has helped support the Taliban government and stabilize Afghanistan's economy. On September 25, 2024, the United States House of Representatives passed a resolution condemning the Biden administration for the U.S. withdrawal from Afghanistan, with ten Democrats and all Republicans voting in favor.
During an exclusive interview with El Mundo on 5 June 2023, Kaili said, "I was not spied on with Pegasus, but for Pegasus, we believe Morocco, Spain, France and Belgium spied on the European Parliament's committee." In a statement to Politico, she said that Belgian secret services monitored her due to her work on the parliament's committee investigating the use of Pegasus spyware in Europe, claiming that this was the "real scandal". Revealed in Euro News article, it was mentioned that Belgian authorities tried to force her to name people in the case in exchange for "a deal". Furthermore, according to the Spanish activist and politician Miguel Urbán statement, the Qatargate scandal points to an even deeper Moroccogate affair. The European Parliament should take the same precautionary measures with Morocco as it did with Qatar. Every European Parliament legislative activity in recent years involving Moroccan interests should be retrospectively reviewed to ensure that it has not been influenced by foreign interference.
=== Recreational use === Methylergometrine is a synthetic analogue of ergometrine, a psychedelic alkaloid found in ergot, and many species of morning glory. Methylergometrine is a member of the ergoline family and chemically similar to LSD, ergine, ergometrine, and lysergic acid. According to Jonathan Ott, methylergometrine produces LSD-like psychedelic effects at doses of 2 mg and above. Clinical effectiveness of methylergometrine as a medication occurs around 200 μg, which is 10 times lower than the hallucinogenic threshold.
The northernmost, Atlasov Island (Araido in Japanese), is an almost-perfect volcanic cone rising sheer out of the sea; it has been depicted by Japanese artists in haiku, wood-block prints, and other forms, in much the same way as the better-known Mount Fuji. Its summit is the highest point in Sakhalin Oblast.
The European Bioinformatics Institute (EMBL-EBI) is an intergovernmental organization (IGO) which, as part of the European Molecular Biology Laboratory (EMBL) family, focuses on research and services in bioinformatics. It is located on the Wellcome Genome Campus in Hinxton near Cambridge, and employs over 600 full-time equivalent (FTE) staff. Further, the EMBL-EBI hosts training programs that teach scientists the fundamentals of the work with biological data and promote the plethora of bioinformatic tools available for their research, both EMBL-EBI-based and not so. One of the roles of the EMBL-EBI is to index and maintain biological data in a set of databases, including Ensembl (housing whole genome sequence data), UniProt (protein sequence and annotation database) and Protein Data Bank (protein and nucleic acid tertiary structure database). A variety of online services and tools is provided, such as Basic Local Alignment Search Tool (BLAST) or Clustal Omega sequence alignment tool, enabling further data analysis.
Sources: en.wikipedia.org
Catherine E. Costello is the William Fairfield Warren distinguished professor in the department of biochemistry, Cell Biology and Genomics, and the director of the Center for Biomedical Mass Spectrometry at the Boston University School of Medicine. Catherine E. Costello attended the Emmanuel College in Boston for her undergraduate studies in chemistry, and minors in mathematics and physics. She received a Master of Science (1967) and a PhD from Georgetown University (1971). After graduation, she did post-doctoral research with Klaus Biemann at Massachusetts Institute of Technology.
Each fission of a parent atom produces a different set of fission product atoms. However, while an individual fission is not predictable, the fission products are statistically predictable. The amount of any particular isotope produced per fission is called its yield, typically expressed as percent per parent fission; therefore, yields total to 200%, not 100%. (The true total is in fact slightly greater than 200%, owing to rare cases of ternary fission.) While fission products include every element from zinc through the lanthanides, the majority of the fission products occur in two peaks. One peak occurs at about (expressed by atomic masses 85 through 105) strontium to ruthenium while the other peak is at about tellurium to neodymium (expressed by atomic masses 130 through 145). The yield is somewhat dependent on the parent atom and also on the energy of the initiating neutron. In general the higher the energy of the state that undergoes nuclear fission, the more likely that the two fission products have similar mass. Hence, as the neutron energy increases and/or the energy of the fissile atom increases, the valley between the two peaks becomes more shallow. For instance, the curve of yield against mass for 239Pu has a more shallow valley than that observed for 235U when the neutrons are thermal neutrons. The curves for the fission of the later actinides tend to make even more shallow valleys. In extreme cases such as 259Fm, only one peak is seen; this is a consequence of symmetric fission becoming dominant due to shell effects.
21% of all participants were children. No studies directly compared insulin degludec with NPH insulin. In the studies comparing insulin degludec to insulin detemir (2 RCTs) and insulin degludec to insulin glargine (4 RCTs), no clinically relevant difference was found for the outcomes of all-cause mortality, health-related quality of life (QoL), severe hypoglycemia, non-fatal myocardial infarction/stroke (NFMI/NFS), severe nocturnal hypoglycaemia, serious adverse effects (SAE) and Glycated haemoglobin A1c (HbA1c).
== Adulteration, contamination and mislabeling == Over the period 2008 to 2011, the Government Accountability Office (GAO) of the United States received 6,307 reports of health problems (identified as adverse events) from use of dietary supplements containing a combination of ingredients in manufactured vitamins, minerals or other supplement products, with 92% of tested herbal supplements containing lead and 80% containing other chemical contaminants. Using undercover staff, the GAO also found that supplement retailers intentionally engaged in "unequivocal deception" to sell products advertised with baseless health claims, particularly to elderly consumers. Consumer Reports also reported unsafe levels of arsenic, cadmium, lead and mercury in several protein powder products. The Canadian Broadcasting Corporation (CBC) reported that protein spiking, i.e., the addition of amino acids to manipulate protein content analysis, was common. Many of the companies involved challenged CBC's claim. In some botanical products, undeclared ingredients were used to increase the bulk of the product and reduce its cost of manufacturing, while potentially violating certain religious and/or cultural limitations on consuming animal ingredients, such as cow, buffalo or deer. In 2015, the New York Attorney General (NY-AG) identified four major retailers with dietary supplement products that contained fraudulent and potentially dangerous ingredients, requiring the companies to remove the products from retail stores.
Sources: en.wikipedia.org
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.
Reversed-phase HPLC establishes purity, while mass spectrometry confirms the expected molecular mass. Sequence confirmation may use tandem mass spectrometry or peptide mapping. A certificate of analysis typically reports these results alongside the analytical method applied.
In Russia it is a registered medicine available by prescription. In many other countries it is not approved for human use and is supplied only as a research chemical. Import and possession rules differ by jurisdiction, and buyers are responsible for checking local requirements.
The sequence is Thr-Lys-Pro-Arg-Pro-Gly-Pro, commonly written as TKPRPGP. It shares the first four residues with tuftsin and carries three prolines in the chain. The proline-rich tail is the main structural feature that separates it from the parent tetrapeptide.