The short version of Selank fits in a sentence. The long version — which is the one that helps — is below.
This page was last updated on 2026-07-02 and is reviewed periodically as new material appears.
Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro. Its four N-terminal residues reproduce tuftsin, a tetrapeptide fragment of the immunoglobulin heavy chain, while the C-terminal Pro-Gly-Pro extension is a synthetic addition. The peptide has a molecular mass near 752 daltons and carries a net positive charge at physiological pH because of the arginine and lysine side chains. Published indexes list it under the name Selank and the sequence abbreviation TKPRPGP. Solid-phase peptide synthesis is the standard production route for research quantities.
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.
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.
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.
Aam papad, a mango preserve from the Indian subcontinent Aiyu jelly, a jelly made from the gel from the seeds of the awkeotsang creeping fig found in Taiwan and East Asian countries. Almond jelly, a sweet dessert from Hong Kong Bocadillo, a Latin American confectionery made with guava pulp and panela Cedrate fruit, from Northern Iran, is made into a jam called morabbā-ye bālang Chakkavaratti, a Southern Indian jackfruit preserve made with jaggery. Coffee jelly features in many desserts in Japan Jellied cranberry sauce is primarily a holiday treat in the US and the UK. Götterspeise, a German dessert made of gelatine or other gelling agent Grass jelly, a food from China and Southeast Asia, often served in drinks Hitlerszalonna ('Hitler's bacon'), sold today as gyümölcs íz. The original name comes from the scarcity of real bacon during wartime. This dense fruit jam was eaten by Hungarian troops and civilians during World War II. It was made from mixed fruits such as plum and sold in brick-shaped blocks. Konjac, a variety of Japanese jelly made from konnyaku Jell-O was named the official snack food of the US state of Utah in 2001. A bowl of lime-flavoured gelatine was featured on a pin for the 2002 Winter Olympics held in Salt Lake City. Mayhaw jelly is a delicacy in parts of the American South. Muk, a variety of Korean jelly, seasoned and eaten as a cold salad Nata de coco, jelly made from coconuts originating from the Philippines Turkish delight, a jelly type of Turkish dessert Yōkan, a sweet, pasty jelly dessert from Japan often made with beans, sweet potato or squash
=== Pharmacokinetics === Hydroxyzine can be administered orally or via intramuscular injection. In both cases it is rapidly absorbed and distributed. It is metabolized in the liver and the main metabolite (45%), cetirizine is formed through oxidation of the alcohol moiety to a carboxylic acid by alcohol dehydrogenase. Overall effects are observed within one hour of administration. Higher concentrations are found in the skin than in the plasma. Cetirizine, although less sedating, is non-dialyzable and possesses similar antihistamine properties. Metabolites identified include an N-dealkylated metabolite and an O-dealkylated 1/16 metabolite with a plasma half-life of 59 hours. These pathways are mediated principally by CYP3A4 and CYP3A5. The N-dealykylated metabolite, norchlorcyclizine, bears some structural similarities to trazodone, but it has not been established whether it is pharmacologically active. In animals, hydroxyzine and its metabolites are excreted in feces primarily through biliary elimination. In rats, less than 2% of the drug is excreted unchanged. The time to reach maximum concentration (Tmax) of hydroxyzine is about 2.0 hours in both adults and children and its elimination half-life is around 20.0 hours in adults (mean age 29.3 years) and 7.1 hours in children. Its elimination half-life is shorter in children compared to adults. In another study, the elimination half-life of hydroxyzine in elderly adults was 29.3 hours.
=== Trump accounts and contribution pilot program === The law creates Trump accounts, a type of tax-advantaged savings investment account. Any individual is allowed to contribute to a child's account, up to $5,000 per year per child. Employers are allowed to contribute to their employees' accounts and their employees' children's accounts, up to $2,500 per year. Contributions by an employer count against the $5,000 annual limit per child, but contributions by the federal government do not. As an exception to the annual limit, tax-exempt organizations are allowed to contribute an unlimited amount into a child's account. Contributions into a child's account are allowed until the end of the end of the year in which the child turns 18. The federal government will contribute $1,000 into a Trump account for each U.S. citizen child with a social security number who was born between January 1, 2025, and December 31, 2028. Funds in the account must be invested in mutual funds or exchange-traded funds that mirror the S&P 500 or another U.S. stock index. Investment earnings are tax-deferred. A child with a qualified disability is allowed to rollover the funds into an ABLE account when they reach age 17. For other children, rollovers and withdrawals from the account are allowed starting on the January 1 of the year in which the child turns age 18. When the child reaches age 18, the funds will be rolled into a traditional IRA.
Sources: en.wikipedia.org
The presence of ptaquiloside has been detected in a variety of ferns, including the species in the genera Pteridium (bracken), Pteris, Microlepia, and Hypolepis. Pteridium aquilinum (commonly known as bracken fern) is the most common ptaquiloside-containing fern with a wide geographical and ecological distribution. It is present in all continents from subtropic to subarctic areas. Bracken fern is a very adaptable plant and is capable of forming dense, rapidly expanding populations in course of the first phases of the ecological succession in forest cleanings and other disturbed rural areas. Its aggressive growth, characterized by an extensive rhizome system and rapidly growing fronds, sometimes enables it to be a dominant species in certain plant communities. The ptaquiloside content of bracken varies widely across species and changes with the part of the plant, the plant growing site and the collecting season. According to previous studies, the concentrations of ptaquiloside in bracken varied between 0 and 1% of the dry weight of the plant. Generally, ptaquiloside is found to occur in the highest concentrations in the young developing parts of bracken, such as the croziers and unfolding parts during the spring and early summer, while the concentrations of ptaquiloside in the rhizomes are rather low. However, studies on the concentrations of ptaquiloside in Danish bracken by Rasmussen et al. showed that the concentrations of ptaquiloside in the rhizomes were significantly higher than the previously reported values.
=== Capped score === In addition, the fact that four proteins, all with different amino acid profiles, receive identical scores of 1.0 limits its usefulness as a comparative tool. Since they have different compositions, it is natural to assume that they perform differently in the human body and should have different scores. In short, this method, however, gives no distinction of their performance relative to each other, because after they pass a certain point, they are all capped at 1.0 and receive an identical rating. This is because in 1990 at a FAO/WHO meeting, it was decided that proteins having values higher than 1.0 would be rounded or "leveled down" to 1.0 as scores above 1.0 are considered to indicate the protein contains essential amino acids in excess of the human requirements. An uncapped version can still be computed by multiplying PD with AAS.
=== Normal strain === For an isotropic material that obeys Hooke's law, a normal stress will cause a normal strain. Normal strains produce dilations. The normal strain in the x-direction of the rectangular element is defined by
Sources: en.wikipedia.org
H–D exchange has been used to characterize protein structures and protein–protein interactions. The exchange reaction needs to be carried out with the isolated proteins and with the complex. The exchanging regions are then compared. If a region is buried by the binding, the amides in this region may be protected in the complex and exchange slowly. However, one must bear in mind that H–D exchange cannot be used to locate binding interfaces for all protein-protein interactions. Some protein-protein interactions are driven by electrostatic forces of side chains and are unlikely to change the exchange rate of backbone amide hydrogens, particularly if the amide hydrogens are located in stable structural elements such as alpha helices. Lastly, H–D exchange can be used to monitor conformational changes in proteins as they relate to protein function. If conformation is altered as result of post-translational modification, enzyme activation, drug binding or other functional events, there will likely be a change to H/D exchange that can be detected.
The conservation of genetic material with the intention of conserving a breed. The conservation of genetic material is not limited to non-humans. Many services provide genetic storage or the preservation of stem cells at birth. They may be used to study the generation of cell lines or for stem-cell therapy.
=== In the media === Media coverage has largely focused on law-enforcement solutions to the epidemic, which portray the issue as criminal, whereas some see it as a medical issue. There has been differential reporting on how white suburban or rural addicts of opioids are portrayed compared to black and Hispanic urban addicts, often of heroin, reinforcing stereotypes of drug users and drug-using offenders. In newspapers, white addicts' stories are often given more space, allowing for a longer backstory explaining how they became addicted, and what potential they had before using drugs. In early 2016 the national desk of The Washington Post began an investigation with assistance from fired Drug Enforcement Administration regulator Joseph Razzazzisi on the rapidly increasing numbers of opioid related deaths. While media coverage has focused more heavily on overdoses among whites, use among African, Hispanic and Native Americans has increased at similar rates. Deaths by overdose among white, black, and Native Americans increased by 200–300% from 2010 to 2014. During this time period, overdoses among Hispanics increased 140%, and the data available on overdoses by Asians was not comprehensive enough to draw a conclusion. In August 2014, the website Annals of Emergency Medicine collaborated with the Academic Life in Emergency Medicine (ALiEM) and posted a discussion board about the opioid epidemic. The discussion acquired a little over 1000 readers and lasted roughly 14 days.
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.