The short version of TP-7 fits in a sentence. The long version — which is the one that helps — is below.
This page was last updated on 2026-08-01 and is reviewed periodically as new material appears.
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.
Reverse-phase high-performance liquid chromatography with ultraviolet detection near 214 nanometres is the standard purity method. Mass spectrometry, typically electrospray ionisation, confirms identity through the expected mass-to-charge pattern. Amino acid analysis can verify composition independently. Chiral purity requires separate techniques such as derivatisation followed by chromatographic separation, and such data are rarely reported for research-grade material.
Quantification in biological matrices relies on liquid chromatography coupled to tandem mass spectrometry with stable-isotope internal standards. Low plasma concentrations and adsorption to container surfaces both complicate measurement. Solid-phase extraction is often needed to reduce matrix interference before injection. Reported limits of quantification differ widely between laboratories, which makes direct comparison of pharmacokinetic results difficult and limits meta-analysis.
Peptide bonds are vulnerable to protease attack, and Selank is no exception. Measured half-life in serum is short, on the order of minutes in several reports, which explains why intranasal administration is the common route described in the literature. Absorption across the nasal mucosa partially bypasses first-pass hepatic metabolism. Quantitative data on human bioavailability remain limited and are difficult to compare across studies.
| Property | Value | Notes |
|---|---|---|
| Peptide sequence | Thr-Lys-Pro-Arg-Pro-Gly-Pro | Seven residues; tuftsin plus a Pro-Gly-Pro tail |
| Molecular formula | C33H57N11O9 | Commonly reported value for the free peptide |
| Monoisotopic mass | Roughly 751.4 Da | Average molecular mass near 751.9 Da |
| Appearance | White to off-white powder | Typically supplied as a lyophilized solid |
| Solubility class | Freely soluble in water | Also dissolves in saline and other polar solvents |
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.
Selank is a synthetic heptapeptide developed in Russia during the 1990s. Researchers at the Institute of Molecular Genetics of the Russian Academy of Sciences designed it as a stabilized analog of tuftsin, a naturally occurring immunomodulatory tetrapeptide. The compound has been studied primarily for its reported anxiolytic and nootropic effects. It remains largely unknown in Western pharmacology and is not approved as a medicine by major regulators such as the FDA or the EMA.
Handling follows standard practice for research peptides. Material is weighed in a low-humidity environment because the powder absorbs atmospheric moisture. Purity is reported as the percentage area of the main peak in a chromatogram, with specifications commonly set at 95 percent or higher; values below that threshold indicate the presence of truncated or modified species. Residual trifluoroacetate from purification is often present and may affect mass balance. Certificates of analysis should state the analytical method, the column and gradient used, and the lot-specific retention time so that results can be compared across suppliers.
Identity and purity of selank are established with reversed-phase high-performance liquid chromatography coupled to mass spectrometry. The peptide elutes from C18 columns with acetonitrile gradients in water containing trifluoroacetic acid or formic acid, and detection is usually performed by ultraviolet absorbance near 214 nm. Electrospray ionization in positive mode gives a doubly protonated ion near m/z 377, consistent with a mass of about 752 Da. Amino acid analysis or tandem mass spectrometry of fragment ions confirms the sequence. Because the molecule has no aromatic residues, it lacks a usable 280 nm chromophore, so low-wavelength detection or mass spectrometry is required.
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.
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.
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.
=== Musculoskeletal === Musculoskeletal symptoms include hyperflexible joints that are unstable and prone to sprain, dislocation, subluxation, and hyperextension. As a result of frequent tissue injury, there can be an early onset of advanced osteoarthritis, chronic degenerative joint disease, swan-neck deformity of the fingers, and Boutonniere deformity of the fingers. Tendon and ligament laxity offer minuscule protection from tearing in muscles and tendons, but these problems persist. Deformities of the spine, such as scoliosis (curvature of the spine), kyphosis (a thoracic hump), tethered spinal cord syndrome, craniocervical instability (CCI), and atlantoaxial instability may also be present. Osteoporosis and osteopenia are also associated with EDS and symptomatic joint hypermobility. There can also be myalgia (muscle pain) and arthralgia (joint pain), which may be severe and disabling. Trendelenburg's sign is often seen, which means that when standing on one leg, the pelvis drops on the other side. Osgood–Schlatter disease, a painful lump on the knee, is common as well. In infants, walking can be delayed (beyond 18 months of age), and bottom-shuffling instead of crawling occurs.
== Interface with other metabolic and salvage pathways == Protein catabolism produces amino acids that are used to form other proteins or oxidized to meet the energy needs of the cell. The amino acids that are produced by protein catabolism can then be further catabolized in amino acid catabolism. Among the several degradative processes for amino acids are Deamination (removal of an amino group), transamination (transfer of amino group), decarboxylation (removal of carboxyl group), and dehydrogenation (removal of hydrogen). Degradation of amino acids can function as part of a salvage pathway, whereby parts of degraded amino acids are used to create new amino acids, or as part of a metabolic pathway whereby the amino acid is broken down to release or recapture chemical energy. For example, the chemical energy that is released by oxidization in a dehydrogenation reaction can be used to reduce NAD+ to NADH, which can then be fed directly into the Krebs/Citric Acid (TCA) Cycle.
Buformin (1-butylbiguanide) is an oral antidiabetic drug of the biguanide class, chemically related to metformin and phenformin. Buformin was marketed by German pharmaceutical company Grünenthal as Silubin.
The Houthis, officially known as Ansar Allah or Ansarullah, are a Zaydi revivalist and Shia Islamist political and paramilitary organization that emerged from Yemen in the 1990s. It is predominantly made up of Zaydis, whose namesake leadership is drawn largely from the al-Houthi family. The Houthis are backed by Iran, and they are widely considered part of the Iranian-led Axis of Resistance. The group has been a central player in Yemen's civil war, drawing widespread international condemnation for its human rights abuses, including targeting civilians and using child soldiers. The movement is designated as a terrorist organization by some countries. Under the leadership of Zaydi religious leader Hussein al-Houthi, the Houthis emerged as an opposition movement to Yemeni president Ali Abdullah Saleh, whom they accused of corruption and being backed by Saudi Arabia and the United States. In 2003, influenced by the Lebanese Shia political and military organization Hezbollah, the Houthis adopted their official slogan against the United States, Israel, and the Jewish people. Al-Houthi resisted Saleh's order for his arrest, and he was killed by the Yemeni military in Saada in 2004. His death sparked the Houthi insurgency. Since then, the movement has been mostly led by his brother Abdul-Malik al-Houthi. The organization played a role in the Yemeni Revolution of 2011 by participating in street protests and coordinating with other Yemeni opposition groups. They joined Yemen's National Dialogue Conference but later rejected the 2011 reconciliation deal.
Sources: en.wikipedia.org
Beyond these cinema-specific efforts, the FBI played a surprisingly large role in the production of movies, instituting a triangular-shaped film strategy: FBI set up a surveillance operation in Hollywood, made efforts to pinpoint and blacklist Communists, secretly laundered intelligence through HUAC, and further helped in producing movies that "fostered [the FBI] image as the protector of the American people." The FBI additionally endorsed films, including Oscar winner The Hoaxters. In the 1960s, Hollywood began using spy films to create the enemy through film. Previously, the influence of the Cold War could be seen in many, if not all, genres of American film. By the 1960s, spy films were effectively a "weapon of confrontation between the two world systems." Both sides heightened paranoia and created a sense of constant unease in viewers through the increased production of spy films. Film depicted the enemy in a way that caused both sides to increase general suspicion of foreign and domestic threat.
=== Controlling pore size === The microstructural wavelength (average pore + wall thickness) can be described as a function of the solidification velocity v (λ= Av−n) where A is dependent on solids loading. There are two ways then that the pore size can be controlled. The first is to change the solidification speed that then alters the microstructural wavelength, or the solids loading can be changed. In doing so, the ratio of pore size to wall size is changed. It is often more prudent to alter the solidification velocity seeing as a minimum solid loading is usually desired. Since microstructural size (λ) is inversely related to the velocity of the freezing front, faster speeds lead to finer structures, while slower speeds produce a coarse microstructure. Controlling the solidification velocity is, therefore, crucial to being able to control the microstructure.
A theoretical plate in many separation processes is a hypothetical zone or stage in which two phases, such as the liquid and vapor phases of a substance, establish an equilibrium with each other. Such equilibrium stages may also be referred to as an equilibrium stage, ideal stage, or a theoretical tray. The performance of many separation processes depends on having series of equilibrium stages and is enhanced by providing more such stages. In other words, having more theoretical plates increases the efficiency of the separation process be it either a distillation, absorption, chromatographic, adsorption or similar process.
=== Excretion === Estradiol is excreted in the form of glucuronide and sulfate estrogen conjugates in urine. Following an intravenous injection of labeled estradiol in women, almost 90% is excreted in urine and feces within 4 to 5 days. Enterohepatic recirculation causes a delay in excretion of estradiol.
In 2004, Lilly-ICOS, Pfizer, and GlaxoSmithKline spent a combined $373.1 million to advertise Cialis, Viagra, and Levitra respectively. Cialis has sponsored many sporting events, including the America's Cup and the PGA Tour, once being title sponsor of the PGA Tour Western Open tournament.
Sources: en.wikipedia.org
As of 2009, there were 5,600 registered institutions and 30,138 Cooperative societies for Khadi which employs nearly 95 lakh (9.5 million) people. Khadi and Village Industries Commission uses government provided funds to implement its programs either directly - through its 29 state offices, by directly funding Khadi and Village institutions and cooperatives, or indirectly through 33 Khadi and Village Industries Boards, which are statutory bodies formed by the state governments within India, set up for the purpose of promoting Khadi and Village Industries in their respective states. The Khadi and Village Industries Boards, in turn, fund Khadi and Village Institutions/Co-operatives/Entrepreneurs.
=== Laser === In 2014, a CO2 infrared laser was used to produce patterned porous three-dimensional laser-induced graphene (LIG) film networks from commercial polymer films. The resulting material exhibits high electrical conductivity and surface area. The laser induction process is compatible with roll-to-roll manufacturing processes. A similar material, laser-induced graphene fibers (LIGF), was reported in 2018.
=== DNA damage === DNA damage in sperm cells that is related to infertility can be probed by analysis of DNA susceptibility to denaturation in response to heat or acid treatment and/or by detection of DNA fragmentation revealed by the presence of double-strand breaks detected by the TUNEL assay. Other techniques performed in order to measure the DNA fragmentation are: SCD (sperm chromatin dispersion test), ISNT (in situ nick translation), SCSA (sperm chromatin structural assay) and comet assay.
Molten salt baths belong to the oldest thermal cleaning systems; cleaning with a molten salt bath is very fast but implies the risk of dangerous splatters, or other potential hazards connected with the use of salt baths, like explosions or highly toxic hydrogen cyanide gas. Fluidized bed systems use sand or aluminium oxide as heating medium; these systems also clean very fast but the medium does not melt or boil, nor emit any vapors or odors; the cleaning process takes one to two hours. Vacuum ovens use pyrolysis in a vacuum avoiding uncontrolled combustion inside the cleaning chamber; the cleaning process takes 8 to 30 hours. Burn-off ovens, also known as heat-cleaning ovens, are gas-fired and used in the painting, coatings, electric motors and plastics industries for removing organics from heavy and large metal parts.
Side effects of levodopa include nausea, the wearing-off phenomenon, dopamine dysregulation syndrome, and levodopa-induced dyskinesia, among others. The drug is a centrally permeable monoamine precursor and prodrug of dopamine and hence acts as a dopamine receptor agonist. Chemically, levodopa is an amino acid, a phenethylamine, and a catecholamine. The major reason for enhanced risks for levodopa induced dyskinesia (LID) and OFF phases during late PD is the progressive dying of nigrostriatal dopaminergic neurons. This results in the conversion of levodopa into dopamine in serotonergic neurons (which cannot re-uptake dopamine and have no proper regulatory capacity for dopamine synthesis) becoming the major dopamine source in the dorsal striatum, leading to the striatal dopamine concentration following the pulsatile oral administration of levodopa with large fluctuations (see the schematic graph figure). On the other hand, in a disease like Segawa syndrome, in which dopamine synthesis is low but without progressive degeneration of dopaminergic neurons, lifelong administration of low doses of levodopa is believed to be without serious side effects. Levodopa was first synthesized and isolated in the early 1910s. The antiparkinsonian effects of levodopa were discovered in the 1950s and 1960s. Following this, it was introduced for the treatment of Parkinson's disease in 1970.
Sources: en.wikipedia.org
The sequence is Thr-Lys-Pro-Arg-Pro-Gly-Pro, written TKPRPGP in one-letter code. It combines the tetrapeptide tuftsin with a carboxyl-terminal Pro-Gly-Pro extension. This full sequence identifies the molecule more precisely than the research name.
No peptide with this exact sequence has been identified as an endogenous substance. It is a laboratory-designed analog of tuftsin, a naturally occurring immunomodulatory tetrapeptide. The Pro-Gly-Pro extension has no known natural source.
Proline introduces conformational constraints that make a peptide less accessible to common peptidases. This is a standard stabilization strategy in peptide design. The added residues also increase the distance between the active tuftsin portion and typical cleavage sites.
Dry powder is best kept sealed, protected from light, and held at minus 20 degrees Celsius or below. Desiccant packaging helps limit moisture uptake because the material is hygroscopic. A sealed vial should be allowed to equilibrate to room temperature before opening to reduce condensation.