If you have been reading about Pro-Gly-Pro and want a single page that covers the useful parts, this is it: definitions, context, how it is studied, and the questions that come up repeatedly.
Updated 2025-11-05. Numbers and descriptions here follow the published literature rather than marketing material.
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.
Most published work on selank originates from a small number of research groups in the Russian Federation. A large share of that record appears in Russian-language journals, which limits access for readers who rely on English-indexed databases. Independent replication by laboratories outside the original research network is sparse in publicly available sources. This concentration of origin and language is a frequently noted feature when the compound is summarized in broader reviews of synthetic peptides.
Solubility behavior is a practical concern for handling. Selank dissolves readily in water and in common aqueous buffers, which simplifies preparation of working solutions. The choice of solvent, ionic strength, and pH can influence aggregation over time, particularly at higher concentrations. Aqueous solutions are typically sterile-filtered before use. Because stability depends on several variables, storage and handling notes should be treated as general guidance rather than fixed rules, and specific values are best confirmed against a certificate of analysis for each batch.
Characterization of Selank in a laboratory setting relies on standard peptide methods. Reverse-phase high-performance liquid chromatography separates the target from related impurities and provides a purity figure, commonly reported as 95 percent or higher. Mass spectrometry, typically electrospray ionization or matrix-assisted laser desorption, confirms the molecular mass and helps detect truncation or modification. Amino acid analysis can verify composition when a sequence-level check is needed. These techniques together establish identity and purity for a given lot.
Lyophilized Selank, the dry powder form, is generally stored frozen at minus 20 degrees Celsius or colder for long-term keeping. The solid is hygroscopic and should stay sealed, dry, and protected from light. Once dissolved, the peptide is less stable and is usually held refrigerated at 2 to 8 degrees Celsius for short periods. Repeated freezing and thawing is avoided because it can promote aggregation and loss of activity. Buffers and pH choice also affect how long a solution remains usable.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C33H57N11O9 | Derived from the seven-residue sequence |
| Molecular weight | About 751.9 g/mol | Average mass; the monoisotopic value is slightly lower |
| Residue count | Seven amino acids | Thr-Lys-Pro-Arg-Pro-Gly-Pro |
| Parent compound | Tuftsin (Thr-Lys-Pro-Arg) | Selank extends tuftsin at the C-terminus |
| Compound class | Synthetic short peptide | Studied in a research setting; not a licensed drug in most markets |
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.
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.
Reversed-phase high-performance liquid chromatography is the standard technique for estimating peptide purity. The result is a peak-area percentage, which describes how much of the detected material elutes as the main peak in one run. Mass spectrometry confirms the molecular mass and can reveal truncated, adducted, or otherwise modified species. Amino acid analysis or tandem mass spectrometry can address sequence fidelity when identity is in doubt. None of these measurements, taken alone, establishes that a sample is fit for any specific purpose.
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.
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.
Proposed mechanisms center on modulation of the GABA system, but no single molecular target has been confirmed. Rodent studies report changes in GABA-A receptor expression and in the turnover of serotonin, dopamine, and norepinephrine in several brain regions. Increases in brain-derived neurotrophic factor and its receptor have also been described after repeated administration. These findings come largely from animal models, and the degree to which they describe human neurochemistry remains an open question. The mechanism is best characterized as multi-system and not fully resolved.
Pharmacokinetic data are limited. Like most short peptides, Selank is vulnerable to plasma and tissue peptidases, and its measured half-life in circulation is short, on a minutes scale. The Pro-Gly-Pro tail slows this degradation but does not eliminate it. Intranasal administration is the route described in most reports, with absorption through the nasal mucosa and a hypothesized path into the central nervous system that avoids the blood-brain barrier. Direct measurements of human brain exposure are unavailable, so distribution claims rest on inference from animal work.
Clinical evidence comes mainly from small studies conducted in Russia, several of which were open-label or lacked robust blinding. Reported outcomes include lower anxiety scores, changes in attention measures, and effects on asthenic states following illness. Sample sizes are typically in the tens of participants, and independent replication outside the region is scarce. Reviews published in English generally note the limited methodological quality of the underlying trials. Whether the compound produces clinically meaningful effects under rigorous conditions remains unresolved.
== Structure == Adiponectin is a 244-amino-acid-long polypeptide (protein). It has four distinct regions: The first is a short signal sequence that targets the hormone for secretion outside the cell; next is a short region that varies between species; the third is a 65-amino acid region with similarity to collagenous proteins; the last is a globular domain. Overall, this protein shows similarity to the complement 1Q factors (C1Q), but when the three-dimensional structure of the globular region was determined, a striking similarity to TNFα was observed, despite unrelated protein sequences.
The influence of LSD in the realms of music and art became pronounced in the 1960s, especially through the Acid Tests and related events involving bands like the Grateful Dead, Jefferson Airplane, and Big Brother and the Holding Company. San Francisco-based artists such as Rick Griffin, Victor Moscoso, and Wes Wilson contributed to this movement through their psychedelic poster and album art. The Grateful Dead, in particular, became central to the culture of "Deadheads", with their music heavily influenced by LSD. In the United Kingdom, Michael Hollingshead, reputed for introducing LSD to various artists and musicians like Storm Thorgerson, Donovan, Keith Richards, and members of the Beatles, played a significant role in the drug's proliferation in the British art and music scene. Despite LSD's illegal status since 1966, it was widely used by groups including the Beatles, the Rolling Stones, and the Moody Blues. Their experiences influenced works such as the Beatles' Sgt. Pepper's Lonely Hearts Club Band and Cream's Disraeli Gears, featuring psychedelic-themed music and artwork. Psychedelic music of the 1960s often sought to replicate the LSD experience, incorporating exotic instrumentation, electric guitars with effects pedals, and elaborate studio techniques. Artists and bands used instruments such as sitars and tablas and employed studio effects such as backward tape, panning, and phasing. Songs such as John Prine's "Illegal Smile" and the Beatles' "Lucy in the Sky with Diamonds" have been associated with LSD, although the latter's authors denied such claims.
=== Binary, charge-neutral === Group 2 elements calcium, strontium, and barium can all form octacarbonyl complexes M(CO)8 (M = Ca Sr, Ba). The compounds were characterized in cryogenic matrices by vibrational spectroscopy and in gas phase by mass spectrometry. Group 4 elements with 4 valence electrons are expected to form heptacarbonyls; while these are extremely rare, substituted derivatives of Ti(CO)7 are known. Group 5 elements with 5 valence electrons, again are subject to steric effects that prevent the formation of M–M bonded species such as V2(CO)12, which is unknown. The 17-VE V(CO)6 is however well known. Group 6 elements with 6 valence electrons form hexacarbonyls Cr(CO)6, Mo(CO)6, W(CO)6, and Sg(CO)6. Group 6 elements (as well as group 7) are also well known for exhibiting the cis effect (the labilization of CO in the cis position) in organometallic synthesis. Group 7 elements with 7 valence electrons form pentacarbonyl dimers Mn2(CO)10, Tc2(CO)10, and Re2(CO)10. Group 8 elements with 8 valence electrons form pentacarbonyls Fe(CO)5, Ru(CO)5 and Os(CO)5. The heavier two members are unstable, tending to decarbonylate to give Ru3(CO)12, and Os3(CO)12. The two other principal iron carbonyls are Fe3(CO)12 and Fe2(CO)9. Group 9 elements with 9 valence electrons and are expected to form tetracarbonyl dimers M2(CO)8. In fact the cobalt derivative of this octacarbonyl is the only stable member, but all three tetramers are well known: Co4(CO)12, Rh4(CO)12, Rh6(CO)16, and Ir4(CO)12.
== See also == RO5073012 – TAAR1 weak partial agonist RO5166017 – TAAR1 partial or full agonist RO5203648 – TAAR1 partial agonist RO5256390 – TAAR1 partial or full agonist EPPTB – TAAR1 antagonist/inverse agonist
=== Pediatrics === In pediatrics, a 2023 time-series study published in JAMA Pediatrics examined first-time pediatric speech delay incidence from 2018 to 2022 using data from U.S. health systems, including those affiliated with Truveta. A 2025 study in Pediatrics Open Science examined changes in pediatric obesity treatment practices in the United States following updated guidelines from the American Academy of Pediatrics, using data from large health-system records, including those affiliated with Truveta.
Sources: en.wikipedia.org
The silver nanoparticles were found in the organic matrix of the bacteria. Lactic acid producing bacteria have been used to produce silver nanoparticles. The bacteria Lactobacillus spp., Pediococcus pentosaceus, Enteroccus faeciumI, and Lactococcus garvieae have been found to be able to reduce silver ions into silver nanoparticles. The production of the nanoparticles takes place in the cell from the interactions between the silver ions and the organic compounds of the cell. It was found that the bacterium Lactobacillus fermentum created the smallest silver nanoparticles with an average size of 11.2 nm. It was also found that this bacterium produced the nanoparticles with the smallest size distribution and the nanoparticles were found mostly on the outside of the cells. It was also found that there was an increase in the pH increased the rate of which the nanoparticles were produced and the amount of particles produced.
Only two of the Russian frigates provided important services in the Caribbean in defense of the island of Cuba, although they only made the one-way trip, they got lost, sunk when they arrived in Havana.
Pakistan's landscapes vary from coastal plains to glaciated mountains, offering deserts, forests, hills, and plateaus. Pakistan is divided into three major geographic areas: the northern highlands, the Indus River plain, and the Balochistan Plateau. The northern highlands feature the Karakoram, Hindu Kush, and Pamir mountain ranges, hosting some of the world's highest peaks, including five of the fourteen eight-thousanders (mountain peaks over 8,000 metres or 26,250 feet), notably K2 (8,611 m or 28,251 ft) and Nanga Parbat (8,126 m or 26,660 ft). The Balochistan Plateau lies in the west and the Thar Desert in the east. The 1,609 km (1,000 mi) Indus River and its tributaries traverse the nation from Kashmir to the Arabian Sea, sustaining alluvial plains along the Punjab and Sindh regions. The climate varies from tropical to temperate, with arid conditions in the coastal south. There is a monsoon season with frequent flooding due to heavy rainfall, and a dry season with significantly less rainfall or none at all. Pakistan experiences four distinct seasons: a cool, dry winter from December through February; a hot, dry spring from March through May; the summer rainy season, or southwest monsoon period, from June through September; and the retreating monsoon period of October and November. Rainfall varies greatly from year to year, with patterns of alternate flooding and drought common.
=== Special precautions === Benzodiazepines require special precaution if used in the elderly, during pregnancy, in children, in alcohol- or drug-dependent individuals, and in individuals with comorbid psychiatric disorders. Impairment of driving skills with a resultant increased risk of road traffic accidents is probably the most important adverse effect. This side-effect is not unique to flunitrazepam but also occurs with other hypnotic drugs. Flunitrazepam seems to have a particularly high risk of road traffic accidents compared to other hypnotic drugs. Extreme caution should be exercised by drivers after taking flunitrazepam.
Teicoplanin refers to a complex of related natural products isolated from the fermentation broth of a strain of Actinoplanes teichomyceticus, consisting of a group of five structures. These structures possess a common aglycone, or core, consisting of seven amino acids bound by peptide and ether bonds to form a four-ring system. These five structures differ by the identity of the fatty acyl side-chain attached to the sugar. The origin of these seven amino acids in the biosynthesis of teicoplanin was studied by 1H and 13C nuclear magnetic resonance. The studies indicate amino acids 4-Hpg, 3-Cl-Tyr, and 3-chloro-β-hydroxytyrosine are derived from tyrosine, and the amino acid 3,5-dihydroxyphenylglycine (3,5-Dpg) is derived from acetate. Teicoplanin contains 6 non-proteinogenic amino acids and three sugar moieties, N-acyl-β-D-glucosamine, N-acetyl-β-D-glucosamine, and D-mannose.
Sources: en.wikipedia.org
== Role of smoking == To date, all reported patients with SRIF have been heavy current smokers or ex-smokers, lending credence to the assertion that this condition is caused by smoking. There are no published reports of SRIF in never-smokers.
=== Detection in biological fluids === Clonazepam and 7-aminoclonazepam may be quantified in plasma, serum, or whole blood in order to monitor compliance in those receiving the drug therapeutically. Results from such tests can be used to confirm the diagnosis in potential poisoning victims or to assist in the forensic investigation in a case of fatal overdosage. Both the parent drug and 7-aminoclonazepam are unstable in biofluids, and therefore specimens should be preserved with sodium fluoride, stored at the lowest possible temperature and analyzed quickly to minimize losses.
It was part of a series of twenty performances titled Hellfest from Home, recorded shortly before at the festival site in Clisson, France. That same month, Hangman's Chair were part of the lineup for the second and final edition of the online metal music festival Slay at Home, organised by Frank Godla, co-owner of Metal Injection. Slay at Home aimed to raise funds for MusiCares, the Cancer Research Institute, the Iggy Fund and the National Alliance on Mental Illness. In early October 2021, the band released the single "Loner" with a music video. Another single titled "An Ode To Breakdown" followed in November, accompanied by a live video taken from the at-home edition of Hellfest. During the recording sessions for their upcoming album, Hangman's Chair had set aside two songs, including "Judge Penitent". It was released as a single at the beginning of December and became the theme music for the fifth season (2021) of Gang Stories, a Deezer-produced podcast narrated by NTM rapper JoeyStarr.
Generative artificial intelligence (GenAI) is a subfield of artificial intelligence (AI) that uses generative models to generate text, images, videos, audio, computer code or other forms of digital data. These models learn the underlying patterns and structures of their training data, and use them to generate new data in response to input, which often takes the form of natural language prompts. The prevalence of generative AI tools has increased significantly since the AI boom of the early 2020s. This boom was made possible by improvements in deep neural networks, particularly large language models (LLMs), which are based on the transformer architecture. Generative AI applications include chatbots such as ChatGPT, Claude, Microsoft Copilot, DeepSeek, Doubao, Google Gemini, Grok, Kimi and Qwen; text-to-image models such as DALL-E, Firefly, Stable Diffusion, and Midjourney; and text-to-video models such as Veo, LTX and Sora. Companies in a variety of sectors have used or proposed the use of generative AI, including those in software development, healthcare, finance, entertainment, sales and marketing, screenwriting, and product design. Generative AI has been used for cybercrime, and to deceive and manipulate people through fake news and deepfakes. Generative AI models have been trained on copyrighted works without the rightholders' permission. Many generative AI systems are reliant on large-scale data centers, whose environmental impacts include electronic waste, consumption of fresh water for cooling, and high energy consumption that is estimated to be growing steadily.
Sources: en.wikipedia.org
Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro, designed as a metabolically stabilized analogue of the endogenous tetrapeptide tuftsin. It has been studied mainly against anxiety-related and cognitive endpoints rather than as an approved medicine in most jurisdictions.
Tuftsin contains four residues, while selank carries an additional Pro-Gly-Pro segment at the carboxyl end. That extension is intended to reduce enzymatic cleavage. Comparative pharmacokinetic data in humans remain limited.
No single receptor target is widely accepted as the definitive mediator of the reported effects. Proposed contributors include GABAergic modulation, shifts in monoamine turnover, and altered neuropeptide degradation. The mechanism is treated in the literature as unresolved.
Reverse-phase HPLC is the usual method and gives a percentage purity value. Mass spectrometry then confirms the molecular mass. Together they provide a basic identity and purity profile for a lot.