Peptide mapping 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 2025-11-05 and is reviewed periodically as new material appears.
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.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic heptapeptide | Modeled on tuftsin |
| Amino acid sequence | Thr-Lys-Pro-Arg-Pro-Gly-Pro | Seven residues |
| Approximate molecular mass | Around 750 Da | Depends on counter-ion and hydration |
| Common forms | Lyophilized powder | Also described as aqueous solution |
| Primary origin of research | Russian laboratories | Mid-1990s onward |
The primary structure of Selank is Thr-Lys-Pro-Arg-Pro-Gly-Pro, corresponding to the molecular formula C33H57N11O9 and a monoisotopic mass of roughly 751.9 daltons. The N-terminal threonine and the arginine residue in the fourth position are shared with tuftsin, which carries the sequence Thr-Lys-Pro-Arg. The three additional residues at the C-terminus, Pro-Gly-Pro, extend the chain and are associated with greater resistance to enzymatic degradation. This extension also separates Selank from the shorter parent peptide.
Naming conventions place Selank in the same research family as Semax, another Russian-developed peptide investigated for cognitive effects. The two compounds share a lineage but differ in sequence and in the biological systems proposed as their targets. Semax descends from ACTH fragments, whereas Selank descends from tuftsin. Publications sometimes identify Selank by its full peptide sequence or by laboratory codes rather than one uniform trade name. Because replication outside Russia is limited, reports on its properties are best read alongside the study design and the purity of the material tested.
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.
Outside its country of origin the compound is generally handled as a research chemical rather than an approved medicine. No regulatory approval from the United States Food and Drug Administration or the European Medicines Agency has been granted for human use. Identity and purity are normally checked by reverse-phase high-performance liquid chromatography, with mass spectrometry used to confirm the molecular mass. Lyophilised material is stored cold and desiccated, and repeated freeze-thaw cycles are avoided.
Published work on this peptide almost always uses intranasal delivery, with drops or a spray applied to the nasal mucosa. Some animal experiments have used subcutaneous or intraperitoneal injection, and a smaller number have compared routes directly. Oral administration is not a focus of the literature, because short peptides of this size are broken down by digestive enzymes and cross intestinal barriers poorly. How much of an intranasal dose reaches the bloodstream intact in humans remains an open question.
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.
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.
== Career == Coon was a postdoctoral student in Donald Hunt's lab at the University of Virginia from 2002 to 2005. There Joshua Coon and John Syka developed electron-transfer dissociation (ETD). In 2005, Coon joined the University of Wisconsin-Madison. He became an associate professor in 2010, and a professor in 2012.
Third-hand smoke (THS) is contamination by tobacco smoke that lingers following the extinguishing of a cigarette, cigar, or other combustible tobacco product. First-hand smoke refers to the smoke inhaled by the person who smokes. Passive smoke, or second-hand smoke, is a mixture of exhaled smoke and other substances leaving the smoldering end of the cigarette that enters the atmosphere and can be inhaled by others. Third-hand smoke or "THS" is a neologism coined by a research team from the Dana–Farber/Harvard Cancer Center, where "third-hand" is a reference to the smoking residue on surfaces after "passive smoke" has cleared out. These residual compounds can accumulate on furniture, clothing and dust, where they may persist for long periods even after ventilation or standard cleaning. Humans may subsequently be exposed to THS through inhalation, skin contact, or ingestion of contaminated particles and dust. Infants and young children are considered particularly vulnerable because they frequently crawl on contaminated surfaces, place their hands and objects in their mouths, and have developing systems. Research has associated THS exposure with respiratory problems, asthma, DNA damage, inflammatory responses, impaired wound healing, and potential developmental effects, although many long-term effects in humans remain under investigation. Studies have also shown that tobacco-specific carcinogens such as NNK can persist in indoor environments and on fabrics long after smoking has ceased.
18 January The ONS reports that inflation dropped for the second month running, to 10.5% in December, from 10.7% the previous month. At the two extremes of the ONS's list of "notable movements" that contribute to the overall figure, 'clothing and footwear' price inflation dropped from 7.5% to 6.4%, 'furniture and household goods' dropped from 10.8% to 9.8%, 'food and non-alcoholic beverages' rose from 16.5% to 16.9%, and 'restaurants and hotels' rose from 10.2% to 11.4%. BBC News reports that Church of England bishops will not give their backing to a change in teaching that would allow them to marry same-sex couples, but the Church will offer "prayers of dedication, thanksgiving or God's blessing" to gay couples. 19 January – Prime Minister Rishi Sunak apologises for taking his seat belt off in a moving car to film a social media clip. Lancashire Police later say they are "looking into" the incident. He is issued with a fixed-penalty notice the following day. 20 January The Church of England issues an apology for the "shameful" times it has "rejected or excluded" LGBTQ+ people, while Archbishop of Canterbury Justin Welby says he supports the changes that allow blessings to be offered to gay couples, but says he will not personally use them because he has a "responsibility to the whole communion". The High Court awards £39m in damages against Frimley Health NHS Foundation Trust in Surrey to a girl whose limbs were amputated after she was wrongly diagnosed.
All triterpenoids are synthesized via the cyclization of the C30 isoprenoid chain, squalene. Eukaryotes use oxidosqualene cyclase and several other enzymes to create the tetracyclic skeleton found in steroids, a process that requires molecular oxygen. Bacteria use a similar enzyme (shc) to create the pentacyclic hopanoid precursor, diploptene; however, this biosynthesis does not require oxygen. It was recently discovered that tetrahymanol-producing bacteria form diploptene using shc then elongate the final cyclopentane into a fifth ring using tetrahymanol synthase (ths). It is unknown whether bacteria modify diploptene into other hopene molecules before creating tetrahymanol. It has also been found with a methylation at the C-3 site. Eukaryotes that live in anaerobic environments cannot synthesize their own sterols because of a lack of molecular oxygen. These organisms can gain sterols through predation. However, there can be times of sterol starvation. Tetrahymanol biosynthesis does not require oxygen, and can substitute readily for sterols. It is hypothesized that ciliates synthesize tetrahymanol in response to lack of oxygen and exogenous sterols. The gene for tetrahymanol synthase was found in the genomes of many genera of alpha-, delta-, and gammaproteobacteria, including Rhodopseudomonas, Bradyrhizobium and Methylomicrobium.
With the invention of the Geiger gaseous ionization detector in 1913, which became the Geiger-Müller gaseous ionization detector in 1928 - named after the physicists Hans Geiger (1882-1945) and Walther Müller (1905-1979) - the individual particles or quanta of ionizing radiation could be detected and measured. Detectors developed later, such as proportional counters or scintillation counters, which not only "count" but also measure energy and distinguish between types of radiation, also became important for radiation protection. Scintillation measurement is one of the oldest methods of detecting ionizing radiation or X-rays; originally, a zinc sulfide screen was held in the path of the beam and the scintillation events were either counted as flashes or, in the case of X-ray diagnostics, viewed as an image. A scintillation counter known as a spinthariscope was developed in 1903 by William Crookes (1832-1919) and used by Ernest Rutherford (1871-1937) to study the scattering of alpha particles from atomic nuclei.
Sources: en.wikipedia.org
"On the basis of creativity, and research and development, JEOL (日本電子) positively challenges the world’s highest technology thus forever contributing to the progress in both science and human society through its products." In commemoration of JEOL's 20th anniversary, the Kazato Research Foundation was created to support electron microscopy research. Kenji Kazato retired as president of JEOL in 1975, but continued to act as an adviser to the company until his death in 2012. Kazuo Ito was JEOL's president from 1982 to 1987. The Pittcon Heritage Award was posthumously awarded to them in 2016 for their contributions to scientific instrumentation. In 2014, a STEM resolution of 45 pm with a 300 kV microscope was first demonstrated with the atomic transmission electron microscope JEM-ARM300F.
Elagolix is a small-molecule and non-peptide compound. This is in contrast to GnRH analogues such as leuprorelin and cetrorelix, which are peptides and analogues of GnRH. Other small-molecule and non-peptide orally active GnRH antagonists besides elagolix include linzagolix, opigolix, relugolix, and sufugolix, although none of these compounds have been introduced for medical use at this time. Elagolix is used as elagolix sodium, the sodium salt of elagolix. It is a white to off white to light yellow powder. The compound is freely soluble in water. The chemical name of elagolix sodium is sodium 4-({(1R)-2-[5-(2-fluoro-3-methoxyphenyl)-3-{[2-fluoro-6-(trifluoromethyl)phenyl]methyl}-4-methyl-2,6-dioxo-3,6-dihydropyrimidin-1(2H)-yl]-1-phenylethyl}amino)butanoate. It has a molecular formula of C32H29F5N3O5Na and a molecular weight of 653.58 g/mol. The free acid form of elagolix has a molecular formula of C32H29F5N3O5 and a molecular weight of 631.60 g/mol.
=== Cause === As well as attempting to find disease-modifying agents for osteoarthritis, there is emerging evidence that a system-based approach is necessary to find the causes of osteoarthritis. A study conducted by scientists at the University of Twente found that osmolarity induced intracellular molecular crowding might drive the disease pathology.
== History == An early report on indigo-blue pigment-producing bacteria was published by Heinr Claessen in 1890, describing a Bacillus isolated from water that produced an indigo-blue dye. Otto Voges researched and described the bacterial species Bacillus indigoferus in 1893, renamed after him to Vogesella indigofera, in Kiel, which continuously discolored the surrounding medium (water) from slightly bluish (24 hours) to royal blue (48 hours). In 1964 and 1965, Nobel laureate Richard Kuhn and his colleagues published several articles in the scientific press on the occurrence, structure and synthesis of indigoidine. In 1979, Carl-Gerd Dieris and H.-D. Scharf described another synthesis of the compound.
Sources: en.wikipedia.org
In March 2007, in the final verdict by the Supreme Court of Cassation, stated that "in the years of 1994 to 1998 there was no ascertained positive case of doping substances by Juventus players, that the purchase of erythropoietin or its administration to the athletes of the club does not emerge from any act of the trial, and that the same expert had identified the possibility of an administration of erythropoietin in distant terms from the sure evidence ("very probable" and in two cases "practically certain"): it is that therefore, the judgement of probability and not of certainty, did not allow for a statement of responsibility." The verdict also went on to say: "In response to the conclusion taken, the territorial court notes that there were no deferred values higher than the limits set in the various antidoping protocols and that the situation of the Juventus players, both with reference to the average hematological values, and in relation to that of material balance, did not differ from the national average population.
When glucose is fermented, it enters glycolysis or the pentose phosphate pathway and is converted to pyruvate. From pyruvate, pathways branch out to form a number of end products (e.g. lactate). At several points, electrons are released and accepted by redox cofactors (NAD and ferredoxin). At later points, these cofactors donate electrons to their final acceptor and become oxidized. ATP is also formed at several points in the pathway.
=== Nuclear magnetic resonance spectroscopy === In NMR spectroscopy, e.g. of the nuclei 1H, 13C and 29Si, frequencies depend on the magnetic field, which is not the same across all experiments. Therefore, frequencies are reported as relative differences to tetramethylsilane (TMS), an internal standard that George Tiers proposed in 1958 and that the International Union of Pure and Applied Chemistry has since endorsed. The relative difference to TMS is called chemical shift. TMS works as an ideal standard because it is relatively inert and its identical methyl protons produce a strong upfield signal, isolated from most other protons. It is soluble in most organic solvents and is removable via distillation due to its low boiling point. In practice, the difference between the signals of common solvents and TMS are known. Therefore, no TMS needs to be added to commercial deuterated solvents, as modern instruments are capable of detecting the small quantities of protonated solvent present. By specifying the lock solvent to be used, modern spectrometers are able to correctly reference the sample; in effect, the solvent itself serves as the internal standard.
== Etymology == In Old Japanese, me stood for edible seaweeds in general as opposed to mo standing for algae. In kanji, such as 海藻, 軍布 and 和布 were applied to transcribe the word. Among seaweeds, wakame was likely most often eaten, therefore me especially meant wakame. It expanded later to other seaweeds like kajime, hirome (kombu), arame, etc. Wakame is derived from waka + me (若布, lit. 'young seaweed'). If this waka is a eulogistic prefix, the same as the tama of tamagushi, wakame likely stood for seaweeds widely in ancient times. In the Man'yōshū, in addition to 和可米 and 稚海藻 (both are read as wakame), nigime (和海藻, soft wakame) can be seen. Besides, tamamo (玉藻, lit. 'beautiful algae'), which often appeared in the Man'yōshū, may be wakame depending on poems.
In about 5–10% of cases, the nodes will calcify circumferentially, producing so-called "eggshell" calcification. This finding, however, is not exclusively diagnostic of silicosis. In some cases, the pulmonary nodules may also become calcified. A computed tomography or CT scan can also provide a mode detailed analysis of the lungs, and can reveal cavitation due to concomitant mycobacterial infection.
Sources: en.wikipedia.org
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.
It originates from research in Russia, associated with the Institute of Molecular Genetics of the Russian Academy of Sciences. The first descriptions date to the mid-1990s. Most published studies come from Russian laboratories.
No, Selank itself does not occur naturally. Its backbone is based on tuftsin, which is produced in the body, but the seven-residue version is a synthetic construct. It is supplied as a manufactured peptide.
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.