anxiolytic 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 2025-08-28. Numbers and descriptions here follow the published literature rather than marketing material.
Naming for this compound is not fully standardised in English sources. The spelling Selanc appears in some transliterations, and catalogue entries may instead list the peptide sequence itself as the identifier. Reference material sometimes groups it with other short synthetic peptides studied for behavioural effects, which can create confusion when citations are compared. Distinguishing the exact sequence from related tuftsin analogues is therefore a practical first step when reviewing any dataset or specification sheet.
Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro, frequently abbreviated as TKPRPGP. It was designed as a structural analogue of tuftsin, a naturally occurring tetrapeptide released by enzymatic cleavage of the immunoglobulin heavy chain. The two additional proline residues at the C-terminal end extend the parent chain and change how the molecule behaves in solution. The free peptide has a calculated molecular mass of approximately 751.9 g/mol and is generally supplied as a lyophilised white to off-white powder.
Development work on the compound began in the 1980s and 1990s at the Institute of Molecular Genetics in Moscow, within the same research programme that produced the peptide Semax. Early investigators sought a tuftsin derivative with improved resistance to enzymatic breakdown and with activity in the central nervous system after peripheral administration. Most of the primary literature from this period was published in Russian, a factor that still shapes how easily the findings can be checked by outside groups.
Reported activity for Selank centers on anxiolytic and nootropic effects. Russian clinical reports describe use in anxiety and in cognitive or attention-related complaints. Most of this evidence comes from studies conducted by the same research groups that developed the peptide. Independent replication in other countries remains limited, and no major Western regulatory agency has approved the compound for any indication. The gap between local reports and external verification is a recurring point in discussions of the peptide.
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.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic heptapeptide | Tuftsin analogue |
| Sequence | Thr-Lys-Pro-Arg-Pro-Gly-Pro | Single-letter form: TKPRPGP |
| Molecular formula | C33H57N11O9 | Calculated for the free peptide |
| Molecular weight | About 751.9 g/mol | Derived from the sequence |
| Appearance | White to off-white powder | Typical lyophilised form |
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.
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.
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.
=== Ion exchange mechanism === Another extraction mechanism is known as the ion exchange mechanism. Here, when an ion is transferred from the aqueous phase to the organic phase, another ion is transferred in the other direction to maintain the charge balance. This additional ion is often a hydrogen ion; for ion exchange mechanisms, the distribution ratio is often a function of pH. An example of an ion exchange extraction would be the extraction of americium by a combination of terpyridine and a carboxylic acid in tert-butyl benzene. In this case
PoyD installs numerous D-stereocenters in enzyme PoyA to ultimately help facilitate polytheonamide biosynthesis. Polytheoamide is a natural potent cytoxic agent by forming pores in membranes. This peptide cytotoxin is naturally produced by uncultivated bacteria that exist as symbionts in a marine sponge. YydG (EpeE) epimerase modifies two amino acid positions on YydF in Gram-positive Bacillus subtilis. Extrinsically added YydF mediates subsequent dissipation of membrane potential via membrane permeabilization, resulting in death of the organism. The structure of this enzyme also proved to be unique among RiPP-modifying enzymes.
Overseas territories of European allies, including territories in Africa. "The general area of China" – Cambodia, Laos, Vietnam, Burma, and the Philippines. In the countries referred to as being in the general area of China, the Marshall Plan (ECA) operated through Special Technical and Economic Missions (STEMs). The STEMs were set up in 1950 and 1951, and had a "Point Four character" in the sense that they emphasized services by technical experts. Minimizing overlaps with the Marshall Plan, Point Four managed assistance mainly in:
==== Summary ==== While clear benefits of using magnetic beads include the increased reaction speed, more gentle sample handling and the potential for automation, the choice of using agarose or magnetic beads based on the binding capacity of the support medium and the cost of the product may depend on the protein of interest and the IP method used. As with all assays, empirical testing is required to determine which method is optimal for a given application.
Sources: en.wikipedia.org
Until the late 1950s, the Precambrian was not believed to have hosted multicellular organisms. However, with radiometric dating techniques, it has been found that fossils initially found in the Ediacara Hills in Southern Australia date back to the late Precambrian. These fossils are body impressions of organisms shaped like disks, fronds and some with ribbon patterns that were most likely tentacles. These are the earliest multicellular organisms in Earth's history, despite the fact that unicellularity had been around for a long time before that. The requirements for multicellularity were embedded in the genes of some of these cells, specifically choanoflagellates. These are thought to be the precursors for all animals. They are highly related to sponges (Porifera), which are the simplest multicellular animals. In order to understand the transition to multicellularity during the Precambrian, it is important to look at the requirements for multicellularity—both biological and environmental.
Reismanis was an information technology consultant at Accenture and intended to keep ModDB his hobby, but he left the firm to found DesuraNET as the website's hosting company, citing the expense of running the website and his recollection of IGN's 2006 attempt to acquire it. ModDB was integrated into DesuraNET's Desura, which was a digital distribution service that focused on indie games. The service opened in April 2010 as a competitor to Valve's Steam.
=== Tax avoidance === In June 2021, the United States Senate Finance Committee, under Chair Ron Wyden (D-OR), began an investigation to determine if the company took advantage of loopholes in the Tax Cuts and Jobs Act of 2017 to significantly reduce its tax liability. In a letter to AbbVie CEO Richard Gonzalez, Wyden noted the company suffered a 2020 pretax loss in the US of $4.5 billion and an overseas pretax profit of $7.9 billion the same year. The report, released in July 2022, showed that AbbVie was able to dodge U.S. taxes by registering intellectual property in offshore jurisdictions such as Bermuda. As a result, while AbbVie received 75% of its sales of Humira in the United States, it only reported 1% of that income for U.S. tax purposes.
Sources: en.wikipedia.org
== Disease relevance == Due to its involvement in a great number of signaling pathways, GSK-3 has been associated with a host of high-profile diseases. GSK-3 inhibitors are currently being tested for therapeutic effects in Alzheimer's disease, type 2 diabetes mellitus (T2DM), some forms of cancer, and bipolar disorder. There is evidence that lithium, which is used as a treatment for bipolar disorder, acts as a mood stabilizer by selectively inhibiting GSK-3. The mechanism through which GSK-3 inhibition may stabilize mood is not known, though it is suspected that the inhibition of GSK-3's ability to promote inflammation contributes to the therapeutic effect. Inhibition of GSK-3 also destabilises Rev-ErbA alpha transcriptional repressor, which has a significant role in the circadian clock. Elements of the circadian clock may be connected with predisposition to bipolar mood disorder. GSK-3 activity has been associated with both pathological features of Alzheimer's disease, namely the buildup of amyloid-β (Aβ) deposits and the formation of neurofibrillary tangles. GSK-3 is thought to directly promote Aβ production and to be tied to the process of the hyperphosphorylation of tau proteins, which leads to the tangles. Due to these roles of GSK-3 in promoting Alzheimer's disease, GSK-3 inhibitors may have positive therapeutic effects on Alzheimer's patients and are currently in the early stages of testing. In a similar fashion, targeted inhibition of GSK-3 may have therapeutic effects on certain kinds of cancer.
The Haitian Revolution began in 1791, just before the French Revolutionary Wars, and continued until 1804. France's defeat resulted in the independence of Saint-Domingue and led Napoleon to sell the territory making up the Louisiana Purchase to the United States.
Caesium is more abundant than some commonly known elements, such as antimony, cadmium, tin, and tungsten, but is much less abundant than rubidium. Francium-223, the only naturally occurring isotope of francium, is the product of the alpha decay of actinium-227 and can be found in trace amounts in uranium minerals. In a given sample of uranium, there is estimated to be only one francium atom for every 1018 uranium atoms. It has been calculated that there are at most 30 grams of francium in the earth's crust at any time, due to its extremely short half-life of 22 minutes.
Sources: en.wikipedia.org
The sequence is Thr-Lys-Pro-Arg-Pro-Gly-Pro, commonly written as TKPRPGP. It shares the first four residues with tuftsin and carries three prolines in the chain. The proline-rich tail is the main structural feature that separates it from the parent tetrapeptide.
Selank is a synthetic analogue built on the tuftsin tetrapeptide Thr-Lys-Pro-Arg. Extra proline residues were added to the C-terminus during design work. That modification is intended to make the peptide less vulnerable to rapid enzymatic degradation.
Transliteration from Russian produces variant spellings such as Selanc. Many suppliers avoid the trade-style name entirely and list the peptide sequence. Comparing sequences rather than names is the reliable way to confirm two entries describe the same molecule.
Selank is a synthetic peptide made of seven amino acids. It is modeled on tuftsin, a natural tetrapeptide, with an added three-residue tail. It is not a small-molecule drug.