A practical reference on Pro-Gly-Pro: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
Reviewed 2025-11-09. Anything still debated is marked as such rather than presented as settled.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Identity confirmation | Reversed-phase HPLC retention time versus reference standard | Retention depends on column, gradient, and ion-pairing agent |
| Mass confirmation | Electrospray or MALDI mass spectrometry | Doubly protonated ion near m/z 377 is consistent with about 752 Da |
| Typical purity specification | 95 percent or higher by chromatographic peak area | Lower values suggest truncated or modified peptide species |
| Storage of lyophilized powder | -20 °C, desiccated, protected from light | Powder tolerates long storage better than solution |
| Storage of solution | 2-8 °C for short periods | Freeze-thaw cycling promotes aggregation and surface adsorption |
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.
Lyophilised material kept dry at minus 20 degrees Celsius or colder is the most stable form, and suppliers commonly state a shelf life of two years or more under those conditions. Once dissolved, degradation accelerates through hydrolysis and deamidation, particularly at alkaline pH or elevated temperature. Working solutions are usually divided into single-use aliquots to avoid repeated freeze-thaw cycles. The choice of reconstitution solvent affects both stability and the ionic strength of the final preparation.
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.
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.
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.
Reported pharmacological effects center on reduced anxiety-like behavior in animal models and on measures of memory and learning. Proposed contributing mechanisms include modulation of GABAergic signaling, shifts in monoamine turnover, and changes in the activity of enzymes that degrade neuropeptides. Effects on the expression of genes linked to neuroplasticity have also been described. No single molecular target is widely accepted, and whether the behavioral findings arise from one pathway or several remains an open question.
Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro. It was designed as a stabilized analogue of tuftsin, a naturally occurring tetrapeptide fragment derived from the immunoglobulin heavy chain. The additional Pro-Gly-Pro segment at the carboxyl terminus is intended to slow enzymatic cleavage. The compound is usually described in the literature as a synthetic peptide with anxiolytic and cognitive-related activity, a label that reflects a research context rather than an approved therapeutic category.
Tuftsin, the parent structure, is a naturally occurring immunomodulatory tetrapeptide released from the Fc region of immunoglobulin G by spleen enzymes. Selank extends this four-residue sequence with three additional amino acids. The stated rationale is that the added tail slows enzymatic breakdown and may influence receptor interactions. How the full heptapeptide behaves at the molecular level is not firmly established, and proposed mechanisms often involve indirect modulation of neurotransmitter or immune signaling rather than a single defined target.
Selank is a synthetic heptapeptide developed in Russia. Its sequence is Thr-Lys-Pro-Arg-Pro-Gly-Pro, a seven-residue chain built around the natural tetrapeptide tuftsin. Researchers at the Institute of Molecular Genetics of the Russian Academy of Sciences first described the compound in the mid-1990s. The design combined the tuftsin core with an added Pro-Gly-Pro tail, a modification intended to extend the molecule's stability in biological fluids. Published work on the peptide has appeared mainly in Russian-language journals.
Dilution of indoor pollutants with outdoor air is effective to the extent that outdoor air is free of harmful pollutants. Ozone in outdoor air occurs indoors at reduced concentrations because ozone is highly reactive with many chemicals found indoors. The products of the reactions between ozone and many common indoor pollutants include organic compounds that may be more odorous, irritating, or toxic than those from which they are formed. These products of ozone chemistry include formaldehyde, higher molecular weight aldehydes, acidic aerosols, and fine and ultrafine particles, among others. The higher the outdoor ventilation rate, the higher the indoor ozone concentration and the more likely the reactions will occur, but even at low levels, the reactions will take place. This suggests that ozone should be removed from ventilation air, especially in areas where outdoor ozone levels are frequently high.
=== Hemolytic crisis === A hemolytic crisis, or hyperhemolytic crisis, is characterized by an accelerated rate of red blood cell destruction leading to anemia, jaundice, and reticulocytosis. Hemolytic crises are a major concern with sickle-cell disease and G6PD deficiency.
Alongside the general election, voters were asked to participate in a referendum regarding a proposed rewrite of the country's 2017 Constitution. On election night, unofficial results reported by Al Jazeera indicated that more than 57 per cent of voters had supported the drafting of a new constitution. People's Party leader Natthaphong Ruengpanyawut acknowledged that the referendum appeared to have been approved and stated his party would respect the parliamentary process. The proposal was carried. According to the Election Commission, 21,621,638 voters (60.16 per cent) approved the drafting of a new constitution, 11,241,653 (31.28 per cent) rejected it and 3,074,330 (8.55 per cent) expressed no opinion, from 35,937,621 valid ballots. A further 932,583 ballots were rejected as invalid. Turnout in the referendum was 36,870,266, or 69.65 per cent, about 937,000 fewer ballots than were cast in the general election held the same day. Support was broadly spread, with 288 of the 400 constituencies recording a 'yes' vote above 70 per cent and only 38 recording a 'no' vote above 50 per cent, two of them in Buriram and the remaining 36 in the upper south.
== Decay == Uranium-238 is an alpha emitter, producing thorium-234 which is a beta emitter, etc. This leads to a decay chain, commonly called the radium series or uranium series. Beginning with naturally occurring uranium-238, this series includes isotopes of astatine, bismuth, lead, polonium, protactinium, radium, radon, thallium, thorium and uranium, all of which are present in natural uranium sources. The decay proceeds as (only main decay branches shown):
==== Termination ==== There are short-term signals of satiety that arise from the head, the stomach, the intestines, and the liver. The long-term signals of satiety come from adipose tissue. The taste and odor of food can contribute to short-term satiety, allowing the body to learn when to stop eating. The stomach contains receptors to allow the body to know when it is full. The intestines also contain receptors that send satiety signals to the brain. The hormone cholecystokinin is secreted by the duodenum, and it controls the rate at which the stomach is emptied. This hormone is thought to be a satiety signal to the brain. Peptide YY 3-36 is a hormone released by the small intestine and it is also used as a satiety signal to the brain. Insulin also serves as a satiety signal to the brain. The brain detects insulin in the blood, which indicates that nutrients are being absorbed by cells and a person is getting full. Long-term satiety comes from the fat stored in adipose tissue. Adipose tissue secretes the hormone leptin, and leptin suppresses appetite. Long-term satiety signals from adipose tissue regulates short-term satiety signals. Cessation of eating within two hours of sleeping can reduce body weight.
Sources: en.wikipedia.org
Holyhead's arts centre, the Ucheldre Centre, is located in the chapel of an old convent belonging to the order of the Bon Sauveur. It holds regular art exhibitions, performances, workshops and film screenings. Holyhead Library is located in the old market hall. The Holyhead Maritime Museum is housed in what is claimed to be Wales's oldest lifeboat house. The lifeboat station was established in 1828. The 1927 National Eisteddfod was held in the town. Holyhead High School (previously County Secondary school) was the first comprehensive school in the UK. According to the United Kingdom Census 2001, 47% of the residents in the town can speak Welsh. The highest percentage of speakers is in the 15-year-old age group, of whom 66% can speak the language. According to the 2011 Census, of those in the community who were born in Wales, 52.2% of the population could speak Welsh. The town's main football team is called Holyhead Hotspur, and they play in the Cymru North, the second tier of Welsh football, with their reserves playing in the Gwynedd League. Caergybi F.C. plays in the sixth tier Anglesey League. Holyhead Sailing Club provides members with facilities for sailing and kayaking with swinging moorings, a dinghy park and a clubhouse with a restaurant and bar. It is on Newry Beach in the historic port of Holyhead. Holyhead & Anglesey Amateur Boxing Club was founded on 1 April 2012, located in Vicarage Lane, Holyhead. The club is open to anyone over the age of 10, having a class for male and female trainees.
DCPIP can also be used as an indicator for vitamin C. If vitamin C, which is a good reducing agent, is present, the blue dye, which turns pink in acidic conditions, is reduced to a colorless compound by ascorbic acid. This reaction is a redox reaction: vitamin C (ascorbic acid) is oxidized to dehydroascorbic acid, and DCPIP is reduced to the colorless compound DCPIPH2
In March and April 2025, FIFA unveiled a set of 16 posters representing each of the 2026 World Cup host cities. The posters, designed by local artists, were intended to reflect the "distinct identity and heritage" of each city. On March 3, 2026, the official poster for the tournament was unveiled. It was created by Carson Ting of Canada, Minerva GM of Mexico, and Hank Willis Thomas of the United States.
=== ZODIAC: Improved molecular formula identification === ZODIAC improves the ranking of the formula candidates provided by SIRIUS. Organisms produce related metabolites derived from multiple but limited biosynthetic pathways. For a full LC-MS/MS run that is derived from a biological sample or any other set of derivatives the relation of the metabolites is reflected in their similarity. Those similarities are in turn reflected in joint fragments and losses between the fragmentation trees and can be leveraged to improve molecular formula identification of the individual molecules. ZODIAC uses the top X molecular formula candidates for each molecule from SIRIUS to build a similarity network, and uses Bayesian statistics to re-rank those candidates. Prior probabilities are derived from fragmentation tree similarity. Finding an optimal solution to the resulting computational problem is NP-hard, therefore Gibbs sampling is used. ZODIAC stands for ZODIAC: Organic compound Determination by Integral Assignment of elemental Compositions.
Blixeprodil, also known by its developmental code name GM-1020 or as (R)-4-fluorodeschloroketamine ((R)-4-FDCK), is an NMDA receptor antagonist related to ketamine which is under development for the treatment of major depressive disorder, bipolar depression, and other depressive disorders. It is taken by mouth.
Sources: en.wikipedia.org
Thomas A. Wadden (born September 3, 1952) is an American psychologist who is known for his research on the behavioral, pharmacological, and surgical treatment of obesity. He is Professor of Psychology in Psychiatry at the Perelman School of Medicine at the University of Pennsylvania, where he served as Director of the Center for Weight and Eating Disorders for over two decades. From 2011 to 2021, he held the endowed Albert J. Stunkard Professorship in Psychiatry. Wadden has published more than 500 peer-reviewed scientific papers and edited seven volumes on obesity and eating disorders. He has contributed to national health policy on obesity management, serving on expert panels for the National Institutes of Health, the Federal Trade Commission, the Department of Veterans Affairs, and the United States House of Representatives. He is a fellow of The Obesity Society. In 2015, The Obesity Society created the Thomas A. Wadden Award for Distinguished Mentorship, recognizing his education of scientists and practitioners in the field of obesity.
=== Material characterization === Multi-parametric surface plasmon resonance, a special configuration of SPR, can be used to characterize layers and stacks of layers. Besides binding kinetics, MP-SPR can also provide information on structural changes in terms of layer true thickness and refractive index. MP-SPR has been applied successfully in measurements of lipid targeting and rupture, CVD-deposited single monolayer of graphene (3.7Å) as well as micrometer thick polymers.
==== Japan ==== In Japanese cuisine, they are called harusame (春雨), literally "spring rain". Unlike Chinese glass noodles, they are usually made from potato starch. They are commonly used to make salads, or as an ingredient in hot pot dishes. They are also often used to make Japanese adaptations of Chinese and Korean dishes. Shirataki noodles are translucent, traditional Japanese noodles made from the konjac yam and sometimes tofu.
== History == In 1989, work by the groups of Joseph T. Coyle and Ronald Schnaar showed in a neuronal cell line that excess exposure to glutamate or lowered cystine causes a decrease in glutathione levels, an accumulation in intracellular peroxides, and cytotoxicity. Later work by Pamela Maher and David Schubert noted the distinction of this cell death process from apoptosis, describing it as oxidative glutamate toxicity or oxytosis. In 2012, a study by Brent Stockwell and Scott Dixon characterized the iron dependence of this cell death process and coined the term ferroptosis. Oxytosis and ferroptosis are now thought to be the same cell death mechanism. Other early studies regarding the connection between iron and lipid peroxidation, cystine deprivation and oxidative cell death, the activity and importance of glutathione peroxidase 4 (GPX4), and the identification of small molecules that induce ferroptosis were key to the eventual characterization of ferroptosis.
Sources: en.wikipedia.org
Identity is confirmed by matching the retention time in reversed-phase chromatography against a reference standard and by measuring the molecular mass with mass spectrometry. Tandem mass spectrometry or amino acid analysis can verify the sequence of the seven residues. Because the peptide contains no aromatic amino acids, detection at 280 nm is not useful.
Lyophilized powder is normally stored desiccated at -20 °C, protected from light and moisture. Powder kept under these conditions is generally stable for long periods. Solutions are less stable and are usually prepared immediately before use.
A purity value from one chromatographic method does not capture every possible impurity. Related peptides with similar retention behavior, counterions, and residual solvents may not appear in the same analysis. Independent testing with an orthogonal method provides stronger assurance of identity and content.
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.