tuftsin raises a handful of sensible questions. This page answers them in order, starting with the fundamentals and moving to applications.
This page was last updated on 2026-07-30 and is reviewed periodically as new material appears.
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.
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.
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.
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.
| 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 |
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.
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.
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.
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.
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.
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.
=== Basketball === The senior men's basketball team dominated European and world basketball during the mid-to-late 1990s and early 2000s, with three EuroBasket titles (1995, 1997, and 2001), two FIBA World Cup titles (1998 and 2002), and a Summer Olympic Games silver medal (1996). The national team started competing internationally in 1995, after a three-year exile, due to a UN trade embargo. During that time, the FR Yugoslavia was not allowed to compete at the 1992 Summer Olympics in Barcelona, the 1993 EuroBasket, and also the 1994 FIBA World Championship, which was originally supposed to be hosted by Belgrade, before being taken away from the city and moved to Toronto, Canada.
Psychiatric care may be required following recovery. A liver transplant may be required if damage to the liver becomes severe. The need for transplant is often based on low blood pH, high blood lactate, poor blood clotting, or significant hepatic encephalopathy. With early treatment, liver failure is rare. Death occurs in about 0.1% of cases. Paracetamol poisoning was first described in the 1960s. Rates of poisoning vary significantly between regions of the world. In the United States more than 100,000 cases occur a year. In the United Kingdom it is the medication responsible for the greatest number of overdoses. Young children are most commonly affected. In the United States and the United Kingdom, paracetamol is the most common cause of acute liver failure.
== Further reading == Gross, E.; Witkop, B. (1962). "Nonenzymatic Cleavage of Peptide Bonds: The Methionine Residues in Bovine Pancreatic Ribonuclease" (PDF). Journal of Biological Chemistry. 237 (6): 1856–1860. doi:10.1016/S0021-9258(19)73948-9. PMID 13902203. Inglis, A. S.; Edman, P. (1970). "Mechanism of Cyanogen Bromide Reaction with Methionine in Peptides and Proteins". Analytical Biochemistry. 37 (1): 73–80. doi:10.1016/0003-2697(70)90259-9. PMID 5506566.
== Disease relevance == CHS, as the first committed step in the flavonoid pathway, facilitate production of flavanoids, isoflavonoid-type phytoalexins and other metabolites to protect the plant from stress. CHS expression is also involved in the salicyclic acid defense pathway. Being aromatic compounds, flavonoids strongly absorb UV light through a photoreceptor-mediated mechanism which effectively protects the plants from DNA damage. CHS is involved in a broader, more general phenylpropanoid pathway which serve as precursors to a range of plant metabolites important to human health such as antioxidants, anti-inflammatory agents, antiallergens, and even antioncogenic products.
Sources: en.wikipedia.org
Convulxin is a snake venom toxin found in a tropical rattlesnake known as Crotalus durissus terrificus. It belongs to the family of hemotoxins, which destroy red blood cells or, as is the case with convulxin, induce blood coagulation. It causes platelet activation in the blood, forming clots and buildup of pressure. Convulxin acts as an agonist to the GPVI receptor, the major signalling receptor for collagen. This can cause the blood stream to burst, or the heart or brain to lose blood, thus resulting in death. It is a tetramer C-type lectin with an oligomeric structure, made up of heterodimeric subunits.
"In the long term, it is very likely that the precipitation variance related to El Niño–Southern Oscillation will increase" and "It is very likely that rainfall variability related to changes in the strength and spatial extent of ENSO teleconnections will lead to significant changes at regional scale". and "There is medium confidence that both ENSO amplitude and the frequency of high-magnitude events since 1950 are higher than over the period from 1850 and possibly as far back as 1400".
=== Nuclear orbital theory === The nucleus of a nuclear isomer occupies a higher energy state than the non-excited nucleus existing in the ground state. In an excited state, one or more of the protons or neutrons in a nucleus occupy a nuclear orbital of higher energy than an available nuclear orbital. These states are analogous to excited states of electrons in atoms. When excited atomic states decay, energy is released by fluorescence. In electronic transitions, this process usually involves emission of light near the visible range. The amount of energy released is related to bond-dissociation energy or ionization energy and is usually in the range of a few to few tens of eV per bond. However, a much stronger type of binding energy, the nuclear binding energy, is involved in nuclear processes. Due to this, most nuclear excited states decay by gamma ray emission. For example, a well-known nuclear isomer used in various medical procedures is 99m43Tc, which decays with a half-life of about 6 hours by emitting a gamma ray of 140.5 keV energy; this is similar to the energy of medical diagnostic X-rays. Nuclear isomers have long half-lives because their decay to the ground state is highly "forbidden" from the large change in nuclear spin required. For example, 180m73Ta has a spin of 9 and the lower states have spins 1 and 2. Similarly, 99m43Tc has a spin of 1/2 and the lower states 7/2 and 9/2. Clearly, the latter is less "forbidden" and, as expected, much faster.
== Clinical significance == Narcolepsy is associated with a marked reduction in the number of orexinergic projection neurons from the lateral hypothalamus and very low orexin peptides in cerebrospinal fluid. This has been identified as the mechanism responsible for narcoleptic symptoms. Evidence suggest that OX1 neurons that synapse onto the dorsal nucleus of the vagus nerve and parts of the brain stem may play a role in the pathophysiology of chronic pain and visceral hypersensitivity in functional gastrointestinal disorders.
On November 19, 2019, a lawsuit was filed by a vegan from Atlanta, Georgia, against Burger King for allegedly failing to clearly disclose that Impossible Whopper burgers were heated on the same grill as their beef burgers. The lawsuit was dismissed. On March 28, 2022, a lawsuit was filed against Burger King, alleging the fast food chain falsely advertised the Whopper to "look about 35% bigger in its advertising than it is in reality". On May 5, 2025, Federal Judge Roy Altman allowed the case to proceed, stating the claims may reasonably suggest consumers were misled and that Florida law permits such misrepresentation suits without a special relationship. Burger King argued that differences between ads and actual burgers are typical of handmade food and standard marketing practices.
Sources: en.wikipedia.org
Malic acid is typically associated with the taste of green apples, while lactic acid is richer and more buttery tasting. Grapes produced in cool regions tend to be high in acidity, much of which comes from the contribution of malic acid. Malolactic fermentation generally enhances the body and flavor persistence of wine, producing wines of greater palate softness. Many winemakers also feel that better integration of fruit and oak character can be achieved if malolactic fermentation occurs during the time the wine is in barrel. A wine undergoing malolactic conversion will be cloudy because of the presence of bacteria, and may have the smell of buttered popcorn, the result of the production of diacetyl. The onset of malolactic fermentation in the bottle is usually considered a wine fault, as the wine will appear to the consumer to still be fermenting (as a result of CO2 being produced). However, for early Vinho Verde production, this slight effervesce was considered a distinguishing trait, though Portuguese wine producers had to market the wine in opaque bottles because of the increase in turbidity and sediment that the "in-bottle MLF" produced. Today, most Vinho Verde producers no longer follow this practice and instead complete malolactic fermentation prior to bottling with the slight sparkle being added by artificial carbonation.
In January 2018, a class action lawsuit was filed against LifeVantage in Connecticut alleging that the company and its chief executive officer Darren Jensen, chief sales officer Justin Rose, and chief marketing officer Ryan Goodwin were operating an illegal pyramid scheme in violation of the RICO Act, federal securities laws, and the Connecticut Unfair Trade Practices Act.
GnRH antagonists are also used for short periods in the prevention of premature LH surge and endogenous ovulation in patients undergoing ovarian hyperstimulation with FSH in preparation for in-vitro fertilization (IVF). Typically they are administered in the mid-follicular phase in stimulated cycles after administration of gonadotropins and prior to the administration of hCG – which is given to stimulate ovulation. This protocol is likely beneficial in women expected to be hyper-responders, and probably also those expected to be poor responders to ovarian hyperstimulation. There is probably little or no difference between GnRH antagonist and GnRH agonist protocols in terms of live birth or risk of miscarriage but GnRH antagonists probably reduce the risk of ovarian hyperstimulation syndrome. The GnRH antagonists that are currently licensed for use in fertility treatment are cetrorelix and ganirelix.
=== Symmetrical flow === Of these techniques flow FFF was the first to be offered commercially. Flow FFF separates particles based on size, independent of density and can measure macromolecules in the range of 1 nm to 1 μm. In this respect it is the most versatile FFF sub-technique available. The cross flow in Flow FFF enters through a porous frit at the top of the channel, exiting through a semi-permeable membrane outlet frit on the accumulation wall (i.e. the bottom wall). Symmetrical flow has been replaced by asymmetrical flow in the last two decades.
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.
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.