Selank raises a handful of sensible questions. This page answers them in order, starting with the fundamentals and moving to applications.
Reviewed 2026-03-04. Anything still debated is marked as such rather than presented as settled.
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.
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.
Once dissolved, the peptide is markedly less stable than the dry powder. Aqueous solutions are subject to backbone hydrolysis and to microbial growth when they are handled without sterile technique. Buffered solutions near neutral pH are common for short-term laboratory work, while acidic conditions are sometimes used to improve solubility. Analytical laboratories generally prepare working solutions fresh rather than storing them, and a residual water film left in a reopened vial can seed degradation even when the container appears dry.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic heptapeptide | Tuftsin analogue with a C-terminal Pro-Gly-Pro tail |
| Amino acid sequence | Thr-Lys-Pro-Arg-Pro-Gly-Pro | Abbreviated TKPRPGP in most catalogues |
| Molecular mass | About 752 Da | Value for the free peptide |
| Solubility | Freely soluble in water | Aqueous solutions are kept cold and used promptly |
| Typical storage | -20 °C, dry, protected from light | Applies to the lyophilised powder before reconstitution |
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.
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.
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.
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.
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.
Receptors bind to the vitamin B12-gastric intrinsic factor complex and are taken into the cell. Resorption of unconjugated bile salts. Bile that was released and not used in emulsification of lipids are reabsorbed in the ileum. Also known as the enterohepatic circulation. Secretion of immunoglobulins. Immunoglobulin A from plasma cells in the mucosa are absorbed through receptor-mediated endocytosis on the basolateral surface and released as a receptor-IgA complex into the intestinal lumen. The receptor component confers additional stability to the molecule.
== Cold shutdown == The difference between a normal (hot) shutdown and a cold shutdown is essentially that the fuel has gone completely or almost completely cold. In a typical shutdown, regular levels of coolant are still required, and the fuel remains reasonably hot as it continues to react. In a cold shutdown, the coolant system is typically lowered to pump water at atmospheric pressure, and the reactor vessel remains below 93 °C (200 °F). This temperature is so low that the cooling water in a light-water reactor does not boil or vaporise even if the pressure in the cooling circuit drops completely. However no cold shutdown is possible after a core meltdown, as the structure of the fuel rods and the coolant circuit is destroyed and the residues react in an uncontrolled manner, even if the pressure and temperature fulfil the conditions for cold shutdown, at least temporarily. A cold shutdown is generally employed when operators need to access the reactor vessel for maintenance, fuel replenishing, or when the reactor has suffered damage of some kind that requires repairs. When a reactor is in cold shutdown, the fuel and control rods can be safely removed and exchanged, and maintenance can be performed. However, once a reactor has gone into a cold shutdown, it requires more time and energy to restart the chain reaction than if it had been in hot shutdown.
==== Hallucinogenic ==== Several studies have implicated CCK as a cause of visual hallucinations in Parkinson's disease. Mutations in CCK receptors in combination with mutated CCK genes potentiate this association. These studies also uncovered potential racial/ethnic differences in the distribution of mutated CCK genes.
Sources: en.wikipedia.org
A letter from a Mrs. Grace Black found in the Bentley Historical Library's historical archives illustrates the struggles of finding housing with children amid the highway construction:Sept 1950Governor Williams:Please consider a family of 6 who are desperately in need of a house to rent. Husband, wife, and four lonely children, who have been turned down because we have children. We are now living in a house of the Edsel Ford Express Highway. We have our notice to move on out before the 23rd of Oct. So far we haven't found a place to move. Nobody want to rent us because we have children. My children aren't destructive but nobody will give us a chance to find out if they are or not. We are so comfortable here. It's the first freedom we've enjoyed since we've had children. My husband work at children's hospital only mak $60 a week. Sixty dollars we are paying $50 a month which we don't mind because we are comfortable. This will be demolished if we were able we would buy this house. But are not. So if anything you can do will be appreciated from the depths of our hearts. You have done so much to help the lower income families. We are deeply grateful wishing you God's speed. This is urgent! Please give this your immediate consideration.Thank youMrs. Grace Black (a worried mother) I-75, Ford Field, and Comerica Park now occupy most of the area where Paradise Valley once stood. Historian Thomas Sugrue notes that of the families displaced by the razing of the Paradise Valley neighborhood:
Biophytum sensitivum, also known as little tree plant, or Mukkutti (in Malayalam) is a species of plant in the genus Biophytum of the family Oxalidaceae. It is commonly found in Kerala, wet lands of Nepal, tropical India and in other Southeast Asian countries and is used for medicinal purposes in Nepal and India. The plant is also a common weed in disturbed environments, but in captivity, Biophytum sensitivum is particularly sensitive to spider mites. Investigations have been undertaken into the plant's chemistry, biological activities, and medicinal uses. Similarly to Mimosa pudica, the leaflets of Biophytum sensitivum are able to move rapidly in response to mechanical stimulation such as touch.
=== Plants === In plants, ADH catalyses the same reaction as in yeast and bacteria to ensure that there is a constant supply of NAD+. Maize has two versions of ADH – ADH1 and ADH2, Arabidopsis thaliana contains only one ADH gene. The structure of Arabidopsis ADH is 47%-conserved, relative to ADH from horse liver. Structurally and functionally important residues, such as the seven residues that provide ligands for the catalytic and noncatalytic zinc atoms, however, are conserved, suggesting that the enzymes have a similar structure. ADH is constitutively expressed at low levels in the roots of young plants grown on agar. If the roots lack oxygen, the expression of ADH increases significantly. Its expression is also increased in response to dehydration, to low temperatures, and to abscisic acid, and it plays an important role in fruit ripening, seedlings development, and pollen development. Differences in the sequences of ADH in different species have been used to create phylogenies showing how closely related different species of plants are. It is an ideal gene to use due to its convenient size (2–3 kb in length with a ≈1000 nucleotide coding sequence) and low copy number.
Sources: en.wikipedia.org
Selank is a seven-amino-acid peptide built from the tuftsin sequence plus a Pro-Gly-Pro tail. It is produced by chemical synthesis rather than extracted from a natural source. The free peptide is usually supplied as a lyophilised powder or in an aqueous formulation.
Tuftsin is a natural tetrapeptide derived from the Fc portion of immunoglobulin G. Selank retains that tetrapeptide at its N-terminus and adds three residues to improve resistance to enzymatic breakdown. The relationship is structural, and the two molecules are not interchangeable in experimental work.
It holds a product registration in Russia for intranasal use as an anxiolytic. Registrations of that kind are not automatically accepted by regulators elsewhere. In most other countries it is treated as an unapproved substance or a research material.
Sealed, desiccated storage at -20 °C or colder is the standard recommendation for research-grade material. Vials should reach room temperature before they are opened, which limits condensation. Repeated temperature cycling is discouraged.