tuftsin is one of those subjects where the details matter more than the headlines. This page pulls together the background, the mechanisms, and the practical points readers ask about most.
Last reviewed on 2025-08-30. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
Solubility behavior is a practical concern for handling. Selank dissolves readily in water and in common aqueous buffers, which simplifies preparation of working solutions. The choice of solvent, ionic strength, and pH can influence aggregation over time, particularly at higher concentrations. Aqueous solutions are typically sterile-filtered before use. Because stability depends on several variables, storage and handling notes should be treated as general guidance rather than fixed rules, and specific values are best confirmed against a certificate of analysis for each batch.
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.
| Property | Value | Notes |
|---|---|---|
| Solubility | Freely soluble in water | Also in aqueous buffers |
| Typical purity (HPLC) | 95 percent or higher | Lot-dependent |
| Dry powder storage | Minus 20 degrees Celsius | Sealed, dry, protected from light |
| Solution storage | 2 to 8 degrees Celsius | Short-term use |
| Identity confirmation | Mass spectrometry | ESI or MALDI-TOF |
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.
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.
Pharmacokinetic data are sparse and largely derived from animal work. After intranasal administration the peptide appears in plasma within minutes, and reported half-lives are short, on the order of minutes to tens of minutes. Degradation proceeds through ordinary proteolytic cleavage into constituent amino acids and smaller fragments. Direct evidence that intact Selank reaches brain tissue in meaningful amounts is limited, and the extent of blood-brain barrier penetration is debated. Some authors argue that fragments, not the parent peptide, carry much of the observed activity.
Published clinical work is concentrated in Russian-language journals and generally involves small samples without independent replication. Systematic reviews in English note the shortage of randomised, placebo-controlled trials and the difficulty of verifying methods from translated reports. Outcome measures vary between studies, which complicates pooling of results. Interest in the compound as a cognitive or anxiolytic agent therefore rests on a thinner evidence base than the volume of citations suggests. Replication in well-powered trials with preregistered endpoints would be needed before firm conclusions about efficacy can be drawn.
Proposed mechanisms centre on the GABAergic system. Animal and tissue studies report changes in GABA-A receptor expression and reduced activity of GABA transaminase, the enzyme that degrades GABA. Effects on monoamine turnover, including serotonin and dopamine pathways, are also described, and a separate line of work links the peptide to increased expression of brain-derived neurotrophic factor in hippocampal tissue. Most of these findings come from rodent models and cell preparations. How the individual observations combine into a single coherent mode of action is not settled.
Selank is not a naturally occurring peptide and has no known endogenous counterpart in human physiology. Russian-language sources frequently call it TP-7, while English-language sources use the name Selank almost exclusively. Database indexing is uneven, partly because early reports appeared in regional journals that are not widely cataloged. Some summaries describe the material as a tuftsin analog and others as a synthetic heptapeptide; the labels overlap rather than conflict. Citing the primary sequence resolves ambiguity more reliably than the research or trade name alone.
Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro, written TKPRPGP in one-letter notation. Its structure consists of the immunomodulatory tetrapeptide tuftsin, Thr-Lys-Pro-Arg, extended at the carboxyl terminus by a Pro-Gly-Pro segment. The molecular formula is commonly given as C33H57N11O9, corresponding to a monoisotopic mass near 751.4 Da and an average molecular mass near 751.9 Da. All seven residues are proteinogenic amino acids, and the molecule carries no modified side chains or non-natural linkages.
The compound was designed at the Institute of Molecular Genetics of the Russian Academy of Sciences during the 1980s and 1990s. The stated design goal was to retain the immunomodulatory and central nervous system activity attributed to tuftsin while improving resistance to enzymatic breakdown. Adding a proline-rich tail to the short parent peptide was a deliberate strategy, because proline residues restrict the conformations available to many peptidases. The same laboratory produced Semax, an ACTH fragment analog, and both compounds were developed in parallel as short, enzymatically stabilized peptides intended for intranasal use.
=== Infants and microwave ovens === There are several cases of child abuse where an infant or child has been placed in a microwave oven. The typical feature of such injuries are well-defined burns on the skin nearest to the microwave emitter, and histology examination shows higher damage extent in tissues with high content of water (e.g., muscles) than in tissues with less water (e.g., adipose tissue). One such case involved a teenage babysitter who admitted to having placed a child in the microwave oven for approximately sixty seconds. The child developed a third degree burn to the back, measuring 5 inches x 6 inches. The babysitter later took the child to the emergency department, where multiple skin grafts were placed on the back. There were no signs of lasting emotional, cognitive or physical effects. CT scan of the head was normal, and there were no cataracts. Another case involved a five-week-old female infant that had multiple full-thickness burns totaling 11% of the body surface area. The mother claimed the infant had been near a microwave oven, but not inside it. The infant survived but required amputations of parts of one leg and one hand. Additionally, there have been two alleged infant deaths caused by microwave ovens. In all these cases, the babies were placed within microwaves and died of subsequent injuries.
=== Pharmacodynamics and pharmacokinetics === The addition of sulbactam to ampicillin enhances the effects of ampicillin. This increases the antimicrobial activity by 4- to 32-fold when compared to ampicillin alone. Ampicillin is a time-dependent antibiotic. Its bacterial killing is largely related to the time that drug concentrations in the body remain above the minimum inhibitory concentration (MIC). The duration of exposure will thus correspond to how much bacterial killing will occur. Various studies have shown that, for maximum bacterial killing, drug concentrations must be above the MIC for 50-60% of the time for the penicillin group of antibiotics. This means that longer durations of adequate concentrations are more likely to produce therapeutic success. However, when ampicillin is given in combination with sulbactam, regrowth of bacteria has been seen when sulbactam levels fall below certain concentrations. As with many other antibiotics, under-dosing of ampicillin/sulbactam may lead to resistance. Ampicillin/sulbactam has poor absorption when given orally. The two drugs have similar pharmacokinetic profiles that appear unchanged when given together. Ampicillin and sulbactam are both hydrophilic substances and have a volume of distribution (Vd) similar to the volume of extra-cellular body water. The volume that the drug distributes throughout in healthy patients is approximately 0.2 liters per kilogram of body weight. Patients on hemodialysis, elderly patients, and pediatric patients have shown a slightly increased volume of distribution.
Other experiments show that a single miRNA may repress the production of hundreds of proteins, but that this repression often is relatively mild (less than 2-fold). The effects of miRNA dysregulation of gene expression seem to be important in cancer. For instance, in gastrointestinal cancers, nine miRNAs have been identified as epigenetically altered and effective in down regulating DNA repair enzymes. The let-7 family of miRNAs provides a well-characterized example of miRNA dysregulation in cancer. Let-7-5p isoforms are among the most consistently downregulated miRNAs in hepatocellular carcinoma and several other malignancies, and their suppression is associated with upregulation of oncogenes including c-MYC, CDK6, and the RNA-binding protein LIN28B, as well as efflux ATP-binding cassette (ABC) transporters that govern multidrug resistance. Loss of let-7 activity establishes a self-reinforcing circuit, as LIN28B actively suppresses let-7 maturation, further sustaining the expression of let-7 target genes and contributing to a chemotherapy-resistant phenotype. Reintroduction of depleted tumor-suppressive miRNAs has therefore been explored as a strategy to restore natural post-transcriptional regulation of oncogenic targets and resensitize resistant cancer cells to treatment.
Parafollicular cells, also called C cells, are neuroendocrine cells in the thyroid. They are called C cells because the primary function of these cells is to secrete calcitonin. They are located adjacent to the thyroid follicles and reside in the connective tissue. These cells are large and have a pale stain compared with the follicular cells. In birds and teleost fishes these cells occupy a structure outside the thyroid gland named the ultimopharyngeal body.
Sources: en.wikipedia.org
Hydrolysis of (1→4)-α-D-glucosidic linkages in polysaccharides so as to remove successive maltose units from the non-reducing ends of the chains This enzyme acts on starch, glycogen and related polysaccharides and oligosaccharides producing beta-maltose by an inversion. Beta-amylase is found in bacteria, fungi, and plants; bacteria and cereal sources are the most heat stable. Working from the non-reducing end, β-amylase catalyzes the hydrolysis of the second α-1,4 glycosidic bond, cleaving off two glucose units (maltose) at a time. During the ripening of fruit, β-amylase breaks starch into maltose, resulting in the sweet flavor of ripe fruit. β-amylase is present in an inactive form prior to seed germination. Many microbes also produce amylase to degrade extracellular starches. Animal tissues do not contain β-amylase, although it may be present in microorganisms contained within the digestive tract. The optimum pH for β-amylase is 4.0–5.0 They belong to glycoside hydrolase family 14. The substrate spectrum for beta-amylase is:
== Fraudulent markets == A large number of services pretend to be a legitimate vendor shop, or marketplace of some kind in order to defraud people. These include the notoriously unreliable gun stores, or even fake assassination websites.
=== Other awards === Fenn received his Nobel Prize fairly late in his career. Prior to being honored by the Nobel Foundation, Fenn had received numerous other awards. Early in his career, Fenn's research was focused on molecular beams, leading him to be named an honorary president of the Sixth International Symposium on Molecular Beams in 1977, and the first fellow of the International Molecular Beam Symposium in 1985. In 1982, the Alexander von Humboldt Foundation presented him with their U.S. Senior Scientist Award. Fenn's work in mass spectrometry earned him another spate of awards later in his career. In 1992, the American Society for Mass Spectrometry presented him with their Award for Distinguished Contributions in Mass Spectrometry. The International Society of Mass Spectrometry honored him with the Thomson Medal in 2000, and in the same year the American Chemical Society presented him with the Award for Advancements in Chemical Instrumentation. He was awarded the Association of Biomolecular Resource Facilities Award for outstanding contributions to Biomolecular Technologies in 2002. In 2003, Fenn was honored by his alma mater with the Wilbur Cross Medal, the Yale Graduate School Alumni Association's highest honor. Fenn maintained numerous professional affiliations, including membership in the American Chemical Society, the American Society for Mass Spectrometry, Sigma Chi, the American Association of University Professors and the Alexander von Humboldt Association of America.
Sources: en.wikipedia.org
=== Disannexation === In the northern Leribe District, rebel chief Joel Molapo and loyalist chief Jonathan Molapo continued to clash sporadically over the Leribe chieftaincy. Joel continuously attacked local loyalists in an effort to seize power, complicating the settlement of the Gun War. The fighting resulted in a wave of refugees fleeing towards the Orange Free State. A month later, a number of Basuto chiefs including Masopha, failed to appear at a pitso called by Orpen's successor Matt Blyth, thus rejecting Scanlen's new proposal for semi-autonomous rule. Aided by Masopha, Joel Molapo continued to massacre and destroy the properties of his opponents. During one of his raids, his warriors burnt the stone house of his deceased father, which shifted popular opinion against him. In May, Letsie I officially granted Jonathan the Leribe chieftaincy, but despite Letsie's declaration, violence in Leribe did not subside until the end of the year. Facing continued diplomatic protests from the Free State and unable to enforce the law in Basutoland, the Cape Parliament passed the Disannexation Act in September 1883. A pitso held at Maseru on 29 November resulted in most chiefs voting in favor of remaining British subjects. Masopha did not attend the Maseru pitso, holding one of his own; where he demanded complete independence. The British Secretary of State issued an Order-in-Council granting the queen's support to the Disannexation Act, which came into force on 18 March 1884.
small nucleolar RNA (snoRNA) A class of small non-coding RNA molecules whose primary function is to direct the post-transcriptional modification of other RNAs, mainly transfer RNAs (tRNA), small nuclear RNAs (snRNA), and especially ribosomal RNAs (rRNA) as a part of ribosome synthesis in the nucleolus. SnoRNAs contain antisense sequences that complement sequences within these target RNAs and guide ribonucleoprotein complexes to them, which can then catalyze specific nucleoside modifications, typically methylation or pseudouridylation.
This bluebottle fly can also cause human or animal myiasis (parasitization in a living individual). Forensic scientists sometimes identify it in the course of their work, such as in one case of an autopsy of a neglected child.
At this time, the Selous Scouts comprised about 120 personnel and all of its officers were white. Black soldiers were offered bonuses that almost doubled their salary if they agreed to serve with the Selous Scouts. The unit was named after the British explorer Frederick Selous (1851–1917) and its motto was pamwe chete—a Shona phrase meaning "all together", "together only" or "forward together". The charter of the Selous Scouts directed them to "the clandestine elimination of terrorism both within and without the country". The name Selous Scouts had previously been attached to the Rhodesian Armoured Car Regiment of the Federal Army of Rhodesia and Nyasaland. The South African Police's Special Branch provided funding for the Selous Scouts. This formed part of the South African Government's extensive support for the Rhodesian counterinsurgency effort. Many South African Defence Force personnel served in the Selous Scouts between 1973 and 1979, including during operations in Rhodesia, Mozambique and Zambia. After the South African Government publicly withdrew the South African Police units which had been deployed to Rhodesia in 1975 SADF personnel continued to serve with the Selous Scouts. A witness who testified at the post-Apartheid South African Truth and Reconciliation Commission stated that the Selous Scouts were covertly funded by the South African Police and South African police officers also served in the unit.
Sources: en.wikipedia.org
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.
Freeze-dried material is kept frozen, often at minus 20 degrees Celsius, and protected from light and moisture. Dissolved peptide is refrigerated for short-term use. Repeated freeze-thaw cycles are avoided.
A certificate of analysis typically lists purity by HPLC, the confirmed mass, appearance, and sometimes water or counter-ion content. It documents results for a specific batch. Details vary by supplier.
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.