The short version of tuftsin fits in a sentence. The long version — which is the one that helps — is below.
Reviewed 2026-01-06. Anything still debated is marked as such rather than presented as settled.
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.
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.
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.
| 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 |
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.
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.
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.
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.
She contested the reconstituted riding of Delta in the 2015 election, but lost to Liberal candidate Carla Qualtrough. She then ran for the Conservatives in the 2017 South Surrey—White Rock by-election, but was defeated by the Liberal's Gordie Hogg, taking 42.1% of the vote to Hogg's 47.5%. In a re-match at the 2019 election, Findlay unseated Hogg by taking 42.6% of the vote. She served as shadow minister for Environment and Climate Change from November 2019 to September 2020. She received backlash in August 2020 after retweeting another user's Twitter post trying to connect Chrystia Freeland with George Soros. She voted in support of Bill C-233 – an act to amend the Criminal Code (sex-selective abortion), which would make it an indictable or a summary offence for a medical practitioner to knowingly perform an abortion solely on the grounds of the child's genetic sex. She was re-elected in 2021 by defeating Gordie Hogg again, and served as shadow minister for National Defence from November 2021 to October 2022. Following Erin O'Toole's ousting as Conservative leader in February 2022, Findlay announced her intention to run for interim party leader; Candice Bergen was ultimately chosen for the role. On September 13, 2022, Findlay was named Chief Opposition Whip by Conservative Party leader Pierre Poilievre, becoming the first woman to serve in this role for the Conservatives. She lost re-election in the 2025 election. Some observers attributed her loss to comments made by her husband Brent Chapman, who is the MLA for Surrey South.
Islam is the state religion, with freedom of religion guaranteed by the constitution. The majority are Muslims (96.35%), followed by Hindus (2.17%) and Christians (1.37%). Other minorities include Sikhs, Buddhists, Jains, Zoroastrians (Parsi), and the unique Kalash people who practice animism. In 2012, 2% of the population identified as atheist in a Gallup survey.
Benzodiazepines such as flunitrazepam are lipophilic and rapidly penetrate membranes and, therefore, rapidly cross over into the placenta with significant uptake of the drug. Use of benzodiazepines including flunitrazepam in late pregnancy, especially high doses, may result in hypotonia, also known as floppy baby syndrome.
==== Alkylation ==== The most common method for alkylation of the lactam nitrogen of 2,5-diketopiperazines is based on the use of sodium hydride as base. However epimerisation can occur especially with proline-fused 2,5-diketopiperazines, even with milder methods such as under phase-transfer catalyst conditions for example 1 to 2.
Methadone, sold under the brand names Dolophine and Methadose, among others, is a potent synthetic opioid used medically to treat chronic pain and opioid use disorder. Prescribed for daily use, the medicine relieves cravings and opioid withdrawal symptoms. Withdrawal management using methadone can be accomplished in less than a month, or it may be done gradually over a longer period of time, or simply maintained for the rest of the patient's life. While a single dose has a rapid effect, maximum effect can take up to five days of use. After long-term use, in people with normal liver function, effects last 8 to 36 hours. Methadone is usually taken by mouth and rarely by injection into a muscle or vein. Side effects are similar to those of other opioids. These frequently include dizziness, sleepiness, nausea, vomiting, and sweating. Serious risks include opioid abuse and respiratory depression. Abnormal heart rhythms may also occur due to a prolonged QT interval. The number of deaths in the United States involving methadone poisoning declined from 4,418 in 2011 to 3,300 in 2015. Risks are greater with higher doses. Methadone is made by chemical synthesis and acts on opioid receptors. Methadone was developed in Germany in the late 1930s by Gustav Ehrhart and Max Bockmühl. It was approved for use as an analgesic in the United States in 1947, and has been used in the treatment of addiction since the 1960s. It is on the World Health Organization's List of Essential Medicines.
Sources: en.wikipedia.org
== Metabolism and excretion == Pholcodine is slowly biotransformed in the body via oxidation and conjugation to a series of metabolites that are eliminated primarily in the urine. With an average half-life of approximately 2.3 days, steady-state in someone taking the drug chronically would not be reached for nearly 2 weeks. Nearly one-half of a single dose is eventually excreted as free or conjugated parent drug. The most important urinary metabolite is conjugated morphine, which may be detectable for days or weeks after the last dose. This could trigger a positive result for opiates in a urine drug testing program.
=== Media === In France, the French syndicate of non-alcoholic beverages "Boissons Rafraîchissantes de France" (that included soft drink producers such as Coca-Cola France, Orangina, PepsiCo France) was denounced by the French journal fr:Canard Enchainé for misleading consumers using a communication on their website titled "Better understanding the NASH pathology", explaining that "NASH pathology is sometimes called the soda illness by language abuse or an unfortunate semantic shortcut, as it is not directly linked to the consumption of non-alcoholic beverages". This page and others on the same website, such as one titled "Say no to disinformation," were removed since then.
==== Hypoxia/anoxia tolerance ==== The naked mole rat (Heterocephalus glaber) is a hypoxia-tolerant species that sleeps in deep burrows and in large colonies. The depth of these burrows reduces access to oxygen, and sleeping in large groups will deplete the area of oxygen quicker than usual, leading to hypoxia. The naked mole rat has the unique ability to survive low oxygen conditions for no less than several hours, and zero oxygen conditions for 18 minutes. One of the ways of combatting hypoxia in the brain is decreasing the reliance on oxygen for ATP production, achieved by decreased respiration rates and proton leak.
This creates negative suction pressure by holding the tongue in a forward position and increasing the airway space behind the tongue. Hybrid devices combine mandibular advancement with the tongue restraint. These devices have been used for snoring and obstructive sleep apnea. Tongue retaining devices have not been well-received as a therapy choice since they are invasive, and the acclimation period is long. The devices have shown high success rates for therapy. Soft-palate lifters are devices that lift the soft palate. They are useful for people who have weak muscles in the region. Evidence to support oral appliances/functional orthopedic appliances in children is insufficient, with very low evidence of effect. However, the oral appliances/functional orthopedic appliances may be considered in specified cases as an auxiliary in the treatment of children with craniofacial anomalies, which are risk factors for apnea.
Sources: en.wikipedia.org
=== Food science === Microfluidic techniques such as droplet microfluidics, paper microfluidics, and lab-on-a-chip are used in the realm of food science in a variety of categories. Research in nutrition, food processing, and food safety benefit from microfluidic technique because experiments can be done with less reagents. Food processing requires the ability to enable shelf stability in foods, such as emulsions or additions of preservatives. Techniques such as droplet microfluidics are used to create emulsions that are more controlled and complex than those created by traditional homogenization due to the precision of droplets that is achievable. Using microfluidics for emulsions is also more energy efficient compared to homogenization in which "only 5% of the supplied energy is used to generate the emulsion, with the rest dissipated as heat" . Although these methods have benefits, they currently lack the ability to be produced at large scale that is needed for commercialization. Microfluidics are also used in research as they allow for innovation in food chemistry and food processing. An example in food engineering research is a novel micro-3D-printed device fabricated to research production of droplets for potential food processing industry use, particularly in work with enhancing emulsions. Paper and droplet microfluidics allow for devices that can detect small amounts of unwanted bacteria or chemicals, making them useful in food safety and analysis.
A notochord, a stiff but elastic rod of glycoprotein wrapped in two collagen helices, which extends along the central axis of the body. Among members of the subphylum Vertebrata (vertebrates), the notochord gets replaced by hyaline cartilage or osseous tissue of the spine, and notochord remnants develop into the intervertebral discs, which allow adjacent spinal vertebrae to bend and twist relative to each other. In wholly aquatic species, this helps the animal swim efficiently by flexing its tail side-to-side. A hollow dorsal nerve cord, also known as the neural tube, which develops into the spinal cord, the main communications trunk of the nervous system. In vertebrates, the rostral end of the neural tube enlarges into several vesicles during embryonic development, which give rise to the brain. Pharyngeal slits. The pharynx is the part of the throat immediately behind the mouth. In fish, the slits are modified to form gills, but in some other chordates they are part of a filter-feeding system that extracts food particles from ingested water. In tetrapods, they are only present during embryonic stages of the development. A post-anal tail. A muscular tail that extends backwards beyond the location of the anus. In some chordates, such as hominids, this is only present in the embryonic stage. An endostyle. This is a groove in the ventral wall of the pharynx. In filter-feeding species it produces mucus to gather food particles, which helps in transporting food to the esophagus. It also stores iodine, and may be a precursor of the vertebrate thyroid gland.
=== Balance of payments between the states === In 2019, residents and businesses in only 8 states contributed, as a whole, more money to the federal treasury than they received in services. Per capita, these were Connecticut ($1,614), Massachusetts ($1,439), New York ($1,172), New Jersey ($1,163), Minnesota ($336), Colorado ($239), California ($168), and Utah ($130). All other states received more in services than taxpayers there contributed, especially in (per capita) Kentucky ($14,153), Virginia ($13,096), and Alaska ($10,144).
== Applications == Enteropeptidase's specificity makes it an ideal tool in biochemical applications; a fusion protein containing a C-terminal affinity tag (such as poly-His) linked by this sequence can be cleaved by enteropeptidase to obtain the target protein following protein purification. On the converse, the N-terminal pro-sequence of proteases that must be cleaved prior to activation can be mutated to enable activation with enteropeptidase.
Multicolumn countercurrent solvent gradient purification (MCSGP) is a form of chromatography that is used to separate or purify biomolecules from complex mixtures. It was developed at the Swiss Federal Institute of Technology Zürich by Aumann and Morbidelli. The process consists of two to six chromatographic columns which are connected to one another in such a way that as the mixture moves through the columns the compound is purified into several fractions.
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.
Selank is a synthetic seven-amino-acid peptide modeled on tuftsin, a fragment of the immunoglobulin G heavy chain. It was designed in Russia to combine anxiolytic and immunomodulatory properties in one molecule.