If you have been reading about tuftsin 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.
Last reviewed on 2025-12-09. Where a claim depends on a specific study, the study is described rather than over-claimed.
Characterization of Selank in laboratory settings relies on standard peptide analytical techniques. Reverse-phase high-performance liquid chromatography separates the peptide from related impurities and degradation products, while mass spectrometry confirms molecular identity through accurate mass measurement. Amino acid analysis and peptide sequencing verify the primary structure when reference material is unavailable. Because Selank is a short chain, fragmentation-based analysis produces a diagnostic ion pattern that supports confident identification.
Peptide stability depends strongly on temperature, moisture, and pH. Lyophilized Selank is generally most stable when stored cold and dry, with freezer temperatures commonly used for long-term storage. In solution, the compound is susceptible to hydrolysis and to microbial growth if it is not handled aseptically. The C-terminal proline-rich extension appears to slow enzymatic cleavage relative to tuftsin, though quantitative degradation rates vary with the matrix and the conditions tested. Published stability data specific to Selank remain sparse.
Quality assessment of Selank samples typically combines purity determination with identity confirmation and counter-ion analysis. Purity is usually reported as a percentage by chromatographic area, with values above 95 percent often quoted for research-grade material. Water content and residual solvents are checked in lyophilized batches because they affect both stability and accurate mass determination. A reported purity figure does not by itself establish that a sample is the intended sequence, so orthogonal methods are needed to rule out sequence isomers or truncation products.
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.
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 |
|---|---|---|
| Typical storage temperature | -20 °C or below | For lyophilized powder, long term |
| Common analytical method | Reverse-phase HPLC | Usually paired with mass spectrometry |
| Typical reported purity | At or above 95 percent by area | Research-grade material |
| Aqueous solubility | High | Solutions used in laboratory assays |
| Moisture sensitivity | Hydrolyzes in solution | Aseptic handling reduces degradation |
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.
Laboratory work relies on standard behavioral paradigms. Rodents are tested in the elevated plus maze, open field, and passive avoidance tasks, with outcomes compared against diazepam or vehicle controls. Intranasal dosing is used most often because it bypasses first-pass metabolism, though intraperitoneal and intravenous routes also appear in published protocols. Biochemical endpoints include tissue BDNF concentrations, cytokine levels, and monoamine metabolites. Human data are limited to small Russian trials reporting reduced anxiety scores; most were not prospectively registered, and few employed independent outcome assessment.
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.
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.
Lyophilized material is generally stable for extended periods when kept dry at or below minus twenty degrees Celsius. Working solutions are less stable, and common practice is to aliquot and freeze them so that repeated freeze-thaw cycles are avoided. Aqueous solutions are sensitive to pH extremes and to microbial growth, so short-term storage at refrigerator temperature is typical. Oxidation and hydrolysis are the principal degradation routes. Reconstitution with sterile water or a mild buffer is standard, and solutions should be protected from light.
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.
=== 25 June === An RSF drone strike hit civilian and military positions in Dalang, killing four civilians and an unknown number of soldiers. The SAF claimed to have retaken the town of Baldago in Blue Nile State from the RSF and the SPLM-N (al-Hilu).
=== Policy and advocacy === Laposata served on the Institute of Medicine Committee on Diagnostic Error in Health Care. The committee produced the 2015 report Improving Diagnosis in Health Care.[5] In August 2024 he served the Association for Molecular Pathology as a plaintiff in a lawsuit challenging the FDA's final rule on regulating laboratory developed tests.[2][4] In 2025 a federal district court in Texas vacated the rule.[4] That November, the Association for Molecular Pathology gave him its Champion for Innovation Award for his role in the case.[2]
In organic chemistry, a peptide bond is an amide type of covalent chemical bond linking two consecutive alpha-amino acids from C1 (carbon number one) of one alpha-amino acid and N2 (nitrogen number two) of another, along a peptide or protein chain. It can also be called a eupeptide bond to distinguish it from an isopeptide bond, which is another type of amide bond between two amino acids.
== History of nanofiber production == Nanofibers were first produced via electrospinning more than four centuries ago. Beginning with the development of the electrospinning method, English physicist William Gilbert (1544-1603) first documented the electrostatic attraction between liquids by preparing an experiment in which he observed a spherical water drop on a dry surface warp into a cone shape when it was held below an electrically charged amber. This deformation later came to be known as the Taylor cone. In 1882, English physicist Lord Rayleigh (1842-1919) analyzed the unstable states of liquid droplets that were electrically charged, and noted that the liquid was ejected in tiny jets when equilibrium was established between the surface tension and electrostatic force. In 1887, British physicist Charles Vernon Boys (1855-1944) published a manuscript about nanofiber development and production. In 1900, American inventor John Francis Cooley (1861-1903) filed the first modern electrospinning patent. Anton Formhals was the first person to attempt nanofiber production between 1934 and 1944 and publish the first patent describing the experimental production of nanofibers. In 1966, Harold Simons published a patent for a device that could produce thin and light nanofiber fabrics with diverse motifs. Only at the end of the 20th century have the words electrospinning and nanofiber become common language among scientists and researchers. Electrospinning continues to be developed today.
Sources: en.wikipedia.org
http://www.rxlist.com/cgi/generic3/oprelvek.htm Archived 2008-08-30 at the Wayback Machine http://www.wyeth.com/products_hcp?product=/wyeth_html/home/products/prescription/Neumega®%20(oprelvekin)/Neumega®%20(oprelvekin)_overview.html Archived 2008-01-18 at the Wayback Machine (Drug Information provided by Wyeth)
==== Gene function prediction ==== While genome annotation is primarily based on sequence similarity (and thus homology), other properties of sequences can be used to predict the function of genes. In fact, most gene function prediction methods focus on protein sequences as they are more informative and more feature-rich. For instance, the distribution of hydrophobic amino acids predicts transmembrane segments in proteins. However, protein function prediction can also use external information such as gene (or protein) expression data, protein structure, or protein–protein interactions.
== Uses == In Hawaii, it is commonly used in long-lasting leis since it retains its shape and color after drying. In Nepal, the flower is known commonly as makhamali ful and is used to make a garland during Bhai Tika, last day of Tihar festival. The garland is put around the brother's neck by their sister for protection. The slow withering character of the flower symbolizes a long life for the brother. The flower was included in the gift sent to Britain by Jung Bahadur Rana in 1855. This flower is known as Rakta Mallika in Sanskrit. This plant is common in landscape design and cutting gardens for its vivid colors and color retention. The edible plant G. globosa has been used in herbal medicine. The flowers of G. globosa are rich in betacyanins which have a wide range of applications as additives and supplements in the food industry, cosmetics, and livestock feed. Stable between pH 3 and 7, the betacyanins in globe amaranth are well suited to be used as natural food dye and have a red-violet color.
Sources: en.wikipedia.org
R−H + M+ = R−M + H+. Similar to anion resins, in cation resins the regeneration involves the use of a strongly acidic solution, e.g. aqueous hydrochloric acid. During regeneration, the regenerant chemical passes through the resin and flushes out the trapped positive ions, renewing the resin exchange capacity.
diffusion The net movement of atoms or molecules from a region of higher concentration to a region of lower concentration. Diffusion is driven by a gradient in chemical potential of the diffusing species and depends on the random walk of particles; hence it results in mixing or mass transport without required directed bulk motion.
=== Structure of Green EosFP === In its anionic form, the green chromophore has an absorption maxima at 506 nm and an emission maxima at 516 nm. It is formed autocatalytically from amino acids His-62, Tyr-63 and Gly-64. Immediately surrounding the chromophore there is a cluster of charged or polar amino acids as well as structural water molecules. Above the plane of the chromophore, there is a network of hydrogen bond interactions between Glu-144, His-194, Glu-212 and Gln-38. Arg-66 and Arg-91 participate in hydrogen bonding with the carbonyl oxygen of green Eos's imidazolinone moiety. The His-62 side chain lies in an unpolar environment. Conversion from the green to red form depends on the presence of a histidine in the first position of the tripeptide HYG that forms the chromophore. When this histidine residue is substituted with M, S, T or L, Eos only emits bright green light and no longer acts as a photoconvertible fluorescent protein.
Sources: en.wikipedia.org
The most common approach combines reverse-phase liquid chromatography with mass spectrometry. Chromatography separates the components while mass spectrometry confirms the molecular mass. Peptide sequencing or tandem mass analysis can further verify the amino acid order.
Lyophilized powder is usually kept frozen and protected from moisture. Solutions are less stable and are often used promptly or divided into aliquots to avoid repeated freeze-thaw cycles. Exact shelf-life values depend on purity and handling.
No. A purity figure derived from chromatographic area does not prove the amino acid sequence. Identity requires an orthogonal method such as mass spectrometry or sequencing. Truncated or isomerized peptides can co-elute with the target compound.
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.