TP-7 comes up often in conversation and rarely with the context attached. Here we lay out the basics in order, then work through the practical considerations.
Updated 2026-06-03. Numbers and descriptions here follow the published literature rather than marketing material.
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.
Peptide bonds in selank are susceptible to hydrolysis under strongly acidic or basic conditions, and the terminal proline residues are vulnerable to exopeptidase activity in biological samples. Lyophilized powder stored dry at -20 °C typically remains stable for extended periods, whereas aqueous solutions degrade faster and may lose measurable purity within days to weeks depending on pH, temperature, and microbial load. Repeated freeze-thaw cycles promote aggregation and adsorption to container surfaces. For analytical work, solutions are usually prepared fresh, kept cold, and used within a single working day.
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.
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.
| 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 |
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.
Regulatory treatment varies by jurisdiction. In Russia the compound is a registered prescription product, while in the European Union and the United States it is generally handled as a research chemical without a marketing authorization. Suppliers therefore operate outside pharmaceutical oversight, and buyers rely on supplier documentation for purity and identity claims. Chain of custody and third-party testing are the main verification tools. Analysts note that the absence of a pharmacopoeial monograph for research-grade material limits standardization across vendors.
Purity assessment relies mainly on reverse-phase high-performance liquid chromatography with ultraviolet detection. Because the peptide lacks a strong chromophore, detection often uses backbone absorbance near 214 nm. Identity is confirmed by mass spectrometry, typically electrospray ionization or matrix-assisted laser desorption, comparing the measured mass against the expected value. Amino acid analysis can verify composition after acid hydrolysis. Diastereomer content and residual counterions are reported less often, although both can influence biological assays.
Measuring peptide exposure inside the brain is technically difficult. Selank is degraded rapidly in plasma, and assays must separate intact peptide from fragments, which favors targeted mass spectrometry over immunoassays alone. Reported half-lives are short, on the order of minutes, so effects observed hours later are attributed to downstream signaling rather than to the parent compound. Blood-brain barrier permeability is debated and rarely quantified directly. Gaps include absent dose-response characterization, inconsistent reporting of purity, and almost no pharmacokinetic data from human participants.
Selank is studied chiefly as an animal-model anxiolytic with proposed secondary effects on memory and immune signaling. Reported mechanisms include modulation of the GABA-A receptor complex, inhibition of enkephalin-degrading enzymes, and shifts in monoamine turnover within limbic structures. Some experiments describe increased expression of brain-derived neurotrophic factor in the hippocampus after repeated dosing. No single molecular target has been confirmed, and the peptide does not bind any receptor with the selectivity typical of a conventional small-molecule drug. Mechanism therefore remains a set of hypotheses rather than an established pathway.
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.
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.
During the development of B cells, the immunoglobulin gene undergoes sequences of rearrangements that lead to formation of the antibody repertoire. For example, in the early stages of transition from pro-B cell to pre-B cell, a partial rearrangement of the heavy-chain gene occurs which is followed by complete rearrangement of heavy-chain gene. At this stage (Pre-B cell), the μ heavy chain and surrogate light chain are formed. The final rearrangement of the light chain gene generates immature B cell and membrane-bound IgM (mIgM). The process explained here occurs during development of naïve B cells, prior to exposure to exogenous antigens. The mature B cell formed as a result of these processing changes leaves the bone marrow and may then be stimulated by an antigen to develop into antibody-secreting plasma cells. Also at first, the mature B cell expresses membrane-bound IgD and IgM. These two classes could switch to secretory IgD and IgM during the processing of mRNAs. Finally, further class switching follows as the cell continues to divide and differentiate. For instance, a B cell expressing IgM can switch to IgG, IgA, or IgE depending on the stimulus provided (which may be dependent upon the antigenic source and the responding immune cells).
Carbohydrate synthesis is a sub-field of organic chemistry concerned with generating complex carbohydrate structures from simple units (monosaccharides). The generation of carbohydrate structures usually involves linking monosaccharides or oligosaccharides through glycosidic bonds, a process called glycosylation. Therefore, it is important to construct glycosidic linkages that have optimum molecular geometry (stereoselectivity) and the stable bond (regioselectivity) at the reaction site (anomeric centre).
The image of seedy underground, destitute smokers were often generated by anti-opium narratives and became a more accurate image of opium use following the effects of large scale opium prohibition in the 1880s.
Bleomycin is a medication primarily used to treat cancer. This includes Hodgkin's lymphoma, non-Hodgkin's lymphoma, testicular cancer, ovarian cancer, and cervical cancer among others. Typically used with other cancer medications, it can be given intravenously, by injection into a muscle or under the skin. It may also be administered inside the chest to help prevent the recurrence of a pleural effusion due to cancer; however, talc is better for this. It may sometimes be used to treat other difficult-to-treat skin lesions such as plantar warts in immunocompromised patients. Common side effects include fever, weight loss, vomiting, and rash. A severe type of anaphylaxis may occur. It may also cause inflammation of the lungs that can result in lung scarring. Chest X-rays every couple of weeks are recommended to check for this. Bleomycin may cause harm to the baby if used during pregnancy. It is believed to primarily work by preventing the synthesis of DNA. Bleomycin was discovered in 1962. It is on the World Health Organization's List of Essential Medicines. It is available as a generic medication. It is made by the bacterium Streptomyces verticillus.
The drug fenethylline has played a role in the Syrian civil war. The production and sale of fenethylline generates large revenues which are likely used to fund the purchase of weapons, and fenethylline is used as a stimulant by combatants. Poverty and international sanctions that limit legal exports are contributing factors. In May 2021, The Guardian described the effects of fenethylline production in Syria on the economy as "a dirty business that is creating a near-narco-state". Drug money flowing into Syria is destabilizing legitimate businesses, positioning it as the global centre of fenethylline production, with increased industrialization, adaptation, and technical sophistication. In June 2021, Saudi authorities at Jeddah port seized 14 million fenethylline tablets hidden inside a shipment of iron plates coming from Lebanon. In the same month, Saudi authorities seized a shipment of 4.5 million fenethylline pills, smuggled inside several orange cartons, at Jeddah port. In July 2021, Saudi customs discovered 2.1 million fenethylline pills at Al-Haditha hidden in a tomato paste shipment. In December 2024, shortly after the Assad government collapsed, Syrian former-rebels found warehouses filled with Captagon alongside factory equipment to make it and also found some Captagon pills inside the copper coils of new voltage stabilisers, showing one way the former Syrian government used to smuggle Captagon out of the country.
Sources: en.wikipedia.org
==== 1980s–early 1990s ==== The modern use of the term designer drug was coined in the 1980s to refer to various synthetic opioid drugs, based mostly on the fentanyl molecule (such as α-methylfentanyl). The term gained widespread popularity when MDMA (ecstasy) experienced a popularity boom in the mid-1980s. When the term was coined in the 1980s, a wide range of narcotics were being sold as heroin on the black market. Many were based on fentanyl or meperidine. One, MPPP, was found in some cases to contain an impurity called MPTP, which caused brain damage that could result in a syndrome identical to late stage Parkinson's disease, from only a single dose. Other problems were highly potent fentanyl analogues that caused many accidental overdoses. Because the government was powerless to prosecute people for these drugs until after they had been marketed successfully, laws were passed to give the DEA power to emergency schedule chemicals for a year, with an optional 6-month extension, while gathering evidence to justify permanent scheduling, as well as the analogue laws mentioned previously. Emergency-scheduling power was used for the first time for MDMA. In this case, the DEA scheduled MDMA as a Schedule I drug and retained this classification after review, even though their own judge ruled that MDMA should be classified Schedule III on the basis of its demonstrated uses in medicine. The emergency scheduling power has subsequently been used for a variety of other drugs including 2C-B, AMT, and BZP.
The US Navy dispatched two naval battle groups built around the aircraft carriers USS Dwight D. Eisenhower and USS Independence to the Gulf, where they were ready by 8 August. The US sent the battleships USS Missouri and USS Wisconsin. 48 US Air Force F-15s from the 1st Fighter Wing at Langley Air Force Base, Virginia, landed in Saudi Arabia and commenced round-the-clock air patrols of the Saudi–Kuwait–Iraq border to discourage Iraqi military advances. They were joined by 36 F-15 A-Ds from the 36th Tactical Fighter Wing at Bitburg, Germany. The Bitburg contingent was based at Al Kharj Air Base. The 36th TFW would be responsible for 11 confirmed Iraqi Air Force aircraft shot down during the war. Two Air National Guard units were stationed at Al Kharj Air Base, the South Carolina Air National Guard's 169th Fighter Wing flew bombing missions with 24 F-16s flying 2,000 combat missions and dropping four million pounds (1,800,000 kilograms; 1,800 metric tons) of munitions, and the New York Air National Guard's 174th Fighter Wing from Syracuse flew 24 F-16s on bombing missions. Military buildup continued, reaching 543,000 troops, twice that used in the 2003 invasion. Much of the material was airlifted or carried to the staging areas via fast sealift ships, allowing a quick buildup. Amphibious exercises were carried out in the Gulf, including Operation Imminent Thunder, which involved the USS Midway and 15 other ships, 1,100 aircraft, and a thousand Marines.
== 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.
Lawsone (2-hydroxy-1,4-naphthoquinone), also known as hennotannic acid, is a red-orange dye present in the leaves of the henna plant (Lawsonia inermis), for which it is named, as well as in the common walnut (Juglans regia) and water hyacinth (Pontederia crassipes). Humans have used henna extracts containing lawsone as hair and skin dyes for more than 5,000 years. Lawsone reacts chemically with the protein keratin in skin and hair via a Michael addition reaction, resulting in a strong permanent stain that lasts until the skin or hair is shed. Darker colored staining is due to more lawsone–keratin interactions occurring, which evidently break down as the concentration of lawsone decreases and the tattoo fades. Lawsone strongly absorbs UV light, and aqueous extracts can be effective sunless tanning agents and sunscreens. Lawsone is a 1,4-naphthoquinone derivative, an analog of hydroxyquinone containing one additional ring. Lawsone isolation from Lawsonia inermis can be difficult due to its easily biodegradable nature. Isolation involves four steps:
Sources: en.wikipedia.org
EPRS1 acts, in human cells, as a proviral factor in mammarenaviruses infection, including LCMV, JUNV, and LASV, and its inhibition using halofuginon compound, a prolyl domain inhibitor, completely abolishes the viral infection by interrupting viral assembly and budding. A diet rich in proline was linked to an increased risk of depression in humans in a study from 2022 that was tested on a limited pre-clinical trial on humans and primarily in other organisms. Results were significant in the other organisms.
Obsidian hydration dating (OHD) is a geochemical method of determining age in either absolute or relative terms of an artifact made of obsidian. Obsidian is a volcanic glass that was used by prehistoric people as a raw material in the manufacture of stone tools such as projectile points, knives, or other cutting tools through knapping, or breaking off pieces in a controlled manner, such as pressure flaking. Obsidian obeys the property of mineral hydration and absorbs water, when exposed to air at a well-defined rate. When an unworked nodule of obsidian is initially fractured, there is typically less than 1% water present. Over time, water slowly diffuses into the artifact forming a narrow "band", "rim", or "rind" that can be seen and measured with many different techniques such as a high-power microscope with 40–80 power magnification, depth profiling with SIMS (secondary ion mass spectrometry), and IR-PAS (infra red photoacoustic spectroscopy). In order to use obsidian hydration for absolute dating, the conditions that the sample has been exposed to and its origin must be understood or compared to samples of a known age (e.g. as a result of radiocarbon dating of associated materials).
== Career == Stobart was born in Cumberland in England in November 1961, the fourth child of Eddie and Nora Stobart. He worked for the family business from his teenage years, joining the management of Eddie Stobart Ltd in 1986. Stobart was Chief Operating Officer of the Stobart Group from 2007 to 2014 and chief executive officer of Eddie Stobart Logistics from 2014 to 2017. He then served as Executive Chairman of GreenWhiteStar Acquisitions from 2019 to 2021 and became Deputy Group CEO of Culina Group in 2021.
=== September === September 8, 2010: Egypt Egypt's Minister of Finance, Dr. Youssef Butros Ghali, states that Egypt emerged from the recession as indicated by increased total revenue from sales taxes and customs revenues.
=== Study of human emotions === At the beginning of her career, Barrett's research focused on the structure of affect, having developed experience-sampling methods and open-source software to study emotional experience. Barrett and members at the Interdisciplinary Affective Science Laboratory study the nature of how the brain creates the mind broadly from social-psychological, psychophysiological, cognitive science, and neuroscience perspectives, and take inspiration from anthropology, philosophy, and linguistics. They also explore the relationship between emotion and vision and other psychological phenomena. In 2010, she joined the psychology faculty at Northeastern University. Before that, she held academic positions at Boston College (1996-2010) and was an assistant professor of clinical psychology at Pennsylvania State University. Notable doctoral students of Barrett's include Tamlin Conner. Her research has focused on the main issues in the science of emotions such as:
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.
Reports describe effects on GABA-A receptor expression, monoamine turnover, and neurotrophic factor levels. These are proposed mechanisms drawn mainly from animal models. No single molecular target has been established.