tuftsin raises a handful of sensible questions. This page answers them in order, starting with the fundamentals and moving to applications.
Reviewed 2026-04-15. Anything still debated is marked as such rather than presented as settled.
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 developed in Russia. Its sequence is Thr-Lys-Pro-Arg-Pro-Gly-Pro, a seven-residue chain built around the natural tetrapeptide tuftsin. Researchers at the Institute of Molecular Genetics of the Russian Academy of Sciences first described the compound in the mid-1990s. The design combined the tuftsin core with an added Pro-Gly-Pro tail, a modification intended to extend the molecule's stability in biological fluids. Published work on the peptide has appeared mainly in Russian-language journals.
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 |
|---|---|---|
| Peptide sequence | Thr-Lys-Pro-Arg-Pro-Gly-Pro | Seven residues; tuftsin plus a Pro-Gly-Pro tail |
| Molecular formula | C33H57N11O9 | Commonly reported value for the free peptide |
| Monoisotopic mass | Roughly 751.4 Da | Average molecular mass near 751.9 Da |
| Appearance | White to off-white powder | Typically supplied as a lyophilized solid |
| Solubility class | Freely soluble in water | Also dissolves in saline and other polar solvents |
Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro. Its four N-terminal residues reproduce tuftsin, a tetrapeptide fragment of the immunoglobulin heavy chain, while the C-terminal Pro-Gly-Pro extension is a synthetic addition. The peptide has a molecular mass near 752 daltons and carries a net positive charge at physiological pH because of the arginine and lysine side chains. Published indexes list it under the name Selank and the sequence abbreviation TKPRPGP. Solid-phase peptide synthesis is the standard production route for research quantities.
Development took place at the Institute of Molecular Genetics of the Russian Academy of Sciences, where a series of short peptides were designed in the 1980s and 1990s. Selank was selected from variants of tuftsin that showed resistance to plasma peptidases. Russian regulatory approval covers it as an anxiolytic agent given intranasally. Outside that market the compound is normally handled as a research chemical rather than a medicine, and no widely recognised international pharmacopoeial monograph exists. The name Selank is a coined trade designation rather than a systematic chemical name.
Enzymatic stability motivates the extra three residues at the carboxyl end. Native tuftsin is cleaved quickly by circulating aminopeptidases and carboxypeptidases, which limits its duration of action and its usefulness as a tool compound. Extending the chain with proline-rich segments is a common design tactic because proline constrains the backbone and slows proteolysis. The same Pro-Gly-Pro motif appears in other Russian-developed peptides of the era. Whether the full seven-residue chain is required for activity, or whether it acts mainly as a prodrug releasing tuftsin, remains unresolved.
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.
Reptiles were traditionally considered less intelligent on average than mammals and birds, but this is increasingly suspected to be the result of poor methodologies in past research and overreliance on brain size as indicators of intelligence rather than a genuine trait of reptiles. The size of their brain relative to their body is much less than that of mammals, the encephalization quotient being about one tenth of that of mammals, though larger reptiles can show more complex brain development. Larger lizards, like the monitors, are known to exhibit complex behavior, including cooperation and cognitive abilities allowing them to optimize their foraging and territoriality over time. Crocodiles have relatively larger brains and show a fairly complex social structure. The Komodo dragon is even known to engage in play, as are turtles, which are also considered to be social creatures, and sometimes switch between monogamy and promiscuity in their sexual behavior. One study found that wood turtles were better than white rats at learning to navigate mazes. Another study found that giant tortoises are capable of learning through operant conditioning, visual discrimination and retained learned behaviors with long-term memory. Sea turtles have been regarded as having simple brains, but their flippers are used for a variety of foraging tasks (holding, bracing, corralling) in common with marine mammals. There is evidence that reptiles are sentient and able to feel emotions including anxiety and pleasure.
=== Synthesis === Several techniques exist for the creation of apomorphine from morphine. In the past, morphine had been combined with hydrochloric acid at high temperatures (around 150 °C) to achieve a low yield of apomorphine, ranging anywhere from 0.6% to 46%.
=== Direct air capture === Anion exchange resins readily absorb CO2 when dry and release it again when exposed to moisture. This makes them one of the most promising materials for direct carbon capture from ambient air or direct air capture, as the moisture swing works to replace the more energy-intensive temperature swing or pressure swing used with other sorbents which then facilitates the desired outcome. A prototype demonstrating this process has been developed by Klaus Lackner at the Center for Negative Carbon Emissions.
Sources: en.wikipedia.org
Microscopic analysis is an important activity of the pathologist and the laboratory technologist. They have many different stains at their disposal (GRAM, MGG, Grocott, Ziehl–Neelsen, etc.). Immunofluorescence, cytochemistry, the immunocytochemistry, and FISH are also used in order make a correct diagnosis. Pathologists may review samples such as pleural, peritoneal, synovial, or pericardial fluids to characterize them as "normal", tumoral, inflammatory, or even infectious. Microscopic examination can also determine the causal infectious agent – often a bacterium, mould, yeast, parasite, or (rarely) virus.
=== Functional selectivity === Some nonbenzodiazepines can be subtype-selective, possibly providing anxiolytic effects with little to no hypnotic or amnesic effects or providing hypnotic effects with little or no anxiolytic effect. Non-sedating anxiolytic drugs derived from the same structural families as the Z-drugs have been developed, such as alpidem, indiplon, pagoclone and suriclone. A number of non-sedating benzodiazepine anxiolytics such as imidazenil and clobazam also exist, with the caveat that neither is a traditional 1,4-benzodiazepine. The functional selectivity is not unique to the nonbenzodiazepine structural class and has more to do with selectivity among different types of GABAA receptors or partial agonism, though this structural class does have more drug candidates.
The therapeutic window is the amount of a medication between the amount that gives an effect (effective dose) and the amount that gives more adverse effects than desired effects. For instance, medication with a small pharmaceutical window must be administered with care and control, e.g. by frequently measuring blood concentration of the drug, since it easily loses effects or gives adverse effects.
Sources: en.wikipedia.org
=== Phase 1 === ABL-301 (SAR-446159) – bispecific antibody against α-synuclein [72] ALS-205 (PMX-205) – complement C5a receptor antagonist [73] ALX-001 (BMS-984923) – metabotropic glutamate mGlu5 receptor silent allosteric modulator [74] ARV-102 – leucine-rich repeat kinase 2 (LRRK2) inhibitor [75] ATH-399A (DWP-307399; HL-192) – nuclear receptor subfamily 4 group A member 2 (NR4A2) agonist [76] CT-2500 – undefined mechanism of action [77] FB-418 – Bcr-Abl tyrosine kinase inhibitor and leucine-rich repeat kinase 2 (LRRK2) inhibitor [78] GT-02287 – β-glucocerebrosidase (GCase) activator and/or chaperone [79] HL-400 – NLR family pyrin domain containing 3 (NLRP3) inhibitor [80] HNC-364 (rasagiline prodrug) – monoamine oxidase B (MAO-B) inhibitor [81] Human amniotic epithelial cell therapy - Shanghai iCELL Biotechnology (hAECs; hAESCs) – cell replacement [82] JNJ-0376 – undefined mechanism of action [83] JX-2105 – undefined mechanism of action [84] Lu AF28996 (Lu AF-28996) – dopamine D1 and D2 receptor agonist [85] LY-3962681 – RNA interference and α-synuclein expression modulator [86] MEDI-1341 (TAK-341) – monoclonal antibody against α-synuclein [87] NEU-723 – leucine-rich repeat kinase 2 (LRRK2) inhibitor [88] NN-9001 – undefined mechanism of action [89] PK-081 – α-synuclein degrader [90] Selnoflast (NLRP3i; RG-6418; RO-7486967; Somalix) – NLR family pyrin domain containing 3 (NLRP3) inhibitor inhibitor [91] TRN-501 – undefined mechanism of action [92] VQ-101 – glucosylceramidase stimulant [93] WID-2301 – undefined mechanism of action [94] WIT-2001 – undefined mechanism of action [95]
== Diuretics and masking agents == Diuretics, which increase the production of urine, and masking agents, chemical compounds which interfere with drug tests, are banned for two reasons. First, by decreasing water retention and thus decreasing an athlete's weight, an important consideration in many speed sports (e.g. track and field, speed skating), they increase the speed of an athlete. Secondly, increased urine production depletes the concentration of both the banned drugs and their metabolites, making their detection more difficult. Masking agents, on the other hand, work by making drug tests ineffective, leading to false-negative results. Desmopressin, plasma expanders (such as glycerol; intravenous administration of albumin, dextran, hydroxyethyl starch and mannitol), probenecid, and other substances with similar biological effects are also banned. Local application of felypressin in dental anesthesia is not prohibited.
Lead (chemical symbol: Pb, atomic number: 82) is one of the earliest metals worked by humans. It is known to have been smelted as early as the 7th millennium BC and spread widely due to its frequent association with silver ores. Ancient civilizations across the Near East, Mediterranean, Asia, Africa, and the Americas employed lead in construction, tools, currency, cosmetics, warfare, and writing, with production reaching a peak during the Roman Empire. After the fall of the Western Roman Empire, lead mining and use expanded in Asia and later revived in Europe during the Middle Ages and Renaissance, when it was also central to alchemy, printing, architecture, and armaments. The Industrial Revolution marked a new period of large-scale production and widespread exposure, leading to increased recognition of lead’s toxicity and the introduction of public health regulations. In the 20th century, lead was progressively restricted in paints, plumbing, and fuels due to its health impacts, while remaining important in industrial applications such as lead–acid batteries, with global production patterns shifting toward Eastern Europe and Asia.
== Causes == Mitochondrial disorders may be caused by mutations (acquired or inherited), in mitochondrial DNA (mtDNA), or in nuclear genes that code for mitochondrial components. They may also be the result of acquired mitochondrial dysfunction due to adverse effects of drugs, infections, or other environmental causes.
Sources: en.wikipedia.org
The sequence is Thr-Lys-Pro-Arg-Pro-Gly-Pro, written TKPRPGP in one-letter code. It combines the tetrapeptide tuftsin with a carboxyl-terminal Pro-Gly-Pro extension. This full sequence identifies the molecule more precisely than the research name.
No peptide with this exact sequence has been identified as an endogenous substance. It is a laboratory-designed analog of tuftsin, a naturally occurring immunomodulatory tetrapeptide. The Pro-Gly-Pro extension has no known natural source.
Proline introduces conformational constraints that make a peptide less accessible to common peptidases. This is a standard stabilization strategy in peptide design. The added residues also increase the distance between the active tuftsin portion and typical cleavage sites.
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.