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Identity And Structural Background — Worked Examples

By Editorial Desk · published 2026-02-18 · last reviewed 2026-03-18 · News

This is a working overview of Tuftsin analogue, written for readers who want more than a one-paragraph summary but less than a textbook.

Reviewed 2026-03-18. Anything still debated is marked as such rather than presented as settled.

Identity and Structural Background

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.

Selank Handling, Stability, and Analysis

Lyophilized selank is normally supplied as a dry powder and is considered stable for extended periods when kept cold and dry. Moisture uptake is the main practical threat, because absorbed water promotes both hydrolysis and aggregation in the solid state. Vials are usually warmed to room temperature before opening so that condensation does not form on the powder. Supplier documentation commonly specifies -20 °C for routine storage, with -80 °C used for material intended to be archived for years.

Once dissolved, the peptide is markedly less stable than the dry powder. Aqueous solutions are subject to backbone hydrolysis and to microbial growth when they are handled without sterile technique. Buffered solutions near neutral pH are common for short-term laboratory work, while acidic conditions are sometimes used to improve solubility. Analytical laboratories generally prepare working solutions fresh rather than storing them, and a residual water film left in a reopened vial can seed degradation even when the container appears dry.

Reversed-phase high-performance liquid chromatography is the standard technique for estimating peptide purity. The result is a peak-area percentage, which describes how much of the detected material elutes as the main peak in one run. Mass spectrometry confirms the molecular mass and can reveal truncated, adducted, or otherwise modified species. Amino acid analysis or tandem mass spectrometry can address sequence fidelity when identity is in doubt. None of these measurements, taken alone, establishes that a sample is fit for any specific purpose.

Selank at a glance

PropertyValueNotes
Chemical classSynthetic heptapeptideTuftsin analogue
SequenceThr-Lys-Pro-Arg-Pro-Gly-ProSingle-letter form: TKPRPGP
Molecular formulaC33H57N11O9Calculated for the free peptide
Molecular weightAbout 751.9 g/molDerived from the sequence
AppearanceWhite to off-white powderTypical lyophilised form

Administration, Testing and Availability

Animal studies have examined behaviour in tests of anxiety, memory retention and stress response, and several report changes in neurotrophic or neurotransmitter-related markers. The human evidence base is much smaller, consisting mainly of short trials conducted in Russia with limited reporting in English-language journals. Sample sizes are modest and outcome measures vary between studies, so the findings are best described as preliminary. Independent replication under modern trial standards has not been widely reported.

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.

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Selank Background And Chemical Identity

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.

Selank is a synthetic heptapeptide developed in Russia during the 1990s. Researchers at the Institute of Molecular Genetics of the Russian Academy of Sciences designed it as a stabilized analog of tuftsin, a naturally occurring immunomodulatory tetrapeptide. The compound has been studied primarily for its reported anxiolytic and nootropic effects. It remains largely unknown in Western pharmacology and is not approved as a medicine by major regulators such as the FDA or the EMA.

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.

Notes from published material

Austin has said he is "eternally indebted" to Ross for helping his character become popular. On both his podcasts, Austin credited Bret Hart as the wrestler who got him over the most, had most influence on his early wrestling style, and who he had his best matches with. Austin would later go on to induct Bret Hart into the WWE Hall of Fame. The match between Austin and Bret Hart at WrestleMania 13 has been widely regarded as one of the greatest professional wrestling matches of all time, and has been voted by IGN as the greatest match in WrestleMania history, and was number 1 among their list of top 20 WrestleMania matches of all time. The match would later receive the inaugural "Immortal Moment" Award at the 2025 WWE Hall of Fame ceremony. A 12-minute match between Undertaker and Stone Cold Steve Austin drew a 9.5 rating on June 28, 1999. It stands as the highest-rated segment in Raw history. According to the data collected by US-bookies, Stone Cold Steve Austin is still WWE's best merchandise seller earning an estimated $3,600,000 from merchandise on WWE Shop site. John Cena takes the #2 spot, earning almost $2,700,000 from WWE Shop. The 'Austin 3:16' T-shirt is among the best selling T-shirts in wrestling history. In August 2001, Austin began frequently shouting "What?" to interrupt wrestlers who were trying to speak and to initiate fan participation chants.

Micrococcus, from Ancient Greek μικρός (mikrós), meaning "small", and κόκκος (kókkos), meaning "sphere", is a genus of bacteria in the Micrococcaceae family. Micrococcus occurs in a wide range of environments, including water, dust, and soil. Micrococci have Gram-positive spherical cells ranging from about 0.5 to 3 micrometers in diameter and typically appear in tetrads. They are catalase positive, oxidase positive, indole negative and citrate negative. Micrococcus has a substantial cell wall, which may comprise as much as 50% of the cell mass. The genome of Micrococcus is rich in guanine and cytosine (GC), typically exhibiting 65 to 75% GC-content. Micrococci often carry plasmids (ranging from 1 to 100 MDa in size) that provide the organism with useful traits. Some species of Micrococcus, such as M. luteus (yellow) and M. roseus (red) produce yellow or pink colonies when grown on mannitol salt agar. Isolates of M. luteus have been found to overproduce riboflavin when grown on toxic organic pollutants like pyridine.

=== EC 2.7.8: Transferases for other substituted phosphate groups === EC 2.7.8.1: diacylglycerol ethanolaminephosphotransferase EC 2.7.8.2: diacylglycerol cholinephosphotransferase EC 2.7.8.3: ceramide cholinephosphotransferase EC 2.7.8.4: serine ethanolaminephosphotransferase EC 2.7.8.5: CDP-diacylglycerol—glycerol-3-phosphate 1-phosphatidyltransferase EC 2.7.8.6: undecaprenyl-phosphate galactose phosphotransferase EC 2.7.8.7: holo-[acyl-carrier-protein] synthase EC 2.7.8.8: CDP-diacylglycerol—serine O-phosphatidyltransferase EC 2.7.8.9: phosphomannan mannosephosphotransferase EC 2.7.8.10: sphingosine cholinephosphotransferase EC 2.7.8.11: CDP-diacylglycerol—inositol 3-phosphatidyltransferase EC 2.7.8.12: CDP-glycerol glycerophosphotransferase EC 2.7.8.13: phospho-N-acetylmuramoyl-pentapeptide-transferase EC 2.7.8.14: CDP-ribitol ribitolphosphotransferase EC 2.7.8.15: UDP-N-acetylglucosamine—dolichyl-phosphate N-acetylglucosaminephosphotransferase EC 2.7.8.16: deleted, now included with EC 2.7.8.2 diacylglycerol cholinephosphotransferase EC 2.7.8.17: UDP-N-acetylglucosamine—lysosomal-enzyme N-acetylglucosaminephosphotransferase EC 2.7.8.18: UDP-galactose—UDP-N-acetylglucosamine galactose phosphotransferase EC 2.7.8.19: UDP-glucose—glycoprotein glucose phosphotransferase EC 2.7.8.20: phosphatidylglycerol—membrane-oligosaccharide glycerophosphotransferase EC 2.7.8.21: membrane-oligosaccharide glycerophosphotransferase EC 2.7.8.22: 1-alkenyl-2-acylglycerol choline phosphotransferase EC 2.7.8.23: carboxyvinyl-carboxyphosphonate phosphorylmutase EC 2.7.8.24: CDP-diacylglycerol—choline O-phosphatidyltransferase EC 2.7.8.25: Now EC 2.4.2.52, triphosphoribosyl-dephospho-CoA synthase EC 2.7.8.26: adenosylcobinamide-GDP ribazoletransferase EC 2.7.8.27: sphingomyelin synthase EC 2.7.8.28: 2-phospho-L-lactate transferase EC 2.7.8.29: L-serine-phosphatidylethanolamine phosphatidyltransferase EC 2.7.8.30: Now EC 2.4.2.53, undecaprenyl-phosphate 4-deoxy-4-formamido-L-arabinose transferase EC 2.7.8.31: undecaprenyl-phosphate glucose phosphotransferase EC 2.7.8.32: 3-O-α-D-mannopyranosyl-α-D-mannopyranose xylosylphosphotransferase EC 2.7.8.33: UDP-N-acetylglucosamine—undecaprenyl-phosphate N-acetylglucosaminephosphotransferase EC 2.7.8.34: CDP-L-myo-inositol myo-inositolphosphotransferase EC 2.7.8.35: UDP-N-acetylglucosamine—decaprenyl-phosphate N-acetylglucosaminephosphotransferase EC 2.7.8.36: undecaprenyl phosphate N,N′-diacetylbacillosamine 1-phosphate transferase EC 2.7.8.37: α-D-ribose 1-methylphosphonate 5-triphosphate synthase EC 2.7.8.38: archaetidylserine synthase EC 2.7.8.39: archaetidylinositol phosphate synthase EC 2.7.8.40: UDP-N-acetylgalactosamine-undecaprenyl-phosphate N-acetylgalactosaminephosphotransferase EC 2.7.8.41: cardiolipin synthase (CMP-forming) EC 2.7.8.42: Kdo2-lipid A phosphoethanolamine 7′′-transferase EC 2.7.8.43: lipid A phosphoethanolamine transferase EC 2.7.8.44: teichoic acid glycerol-phosphate primase EC 2.7.8.45: teichoic acid glycerol-phosphate transferase EC 2.7.8.46: teichoic acid ribitol-phosphate primase EC 2.7.8.47: teichoic acid ribitol-phosphate polymerase

Sources: en.wikipedia.org

Further detail

Senate Majority Leader John Thune and U.S. Senate Republican Whip John Barrasso say that McConnell has spoken with them. July 8 2026 United States Senate elections: U.S. Senate Democratic Party nominee Graham Platner suspends his campaign in the upcoming U.S. Senate race in Maine amidst ongoing controversies surrounding his campaign, leaving the party to seek a replacement challenger to incumbent Republican Susan Collins. Iran war: The interim ceasefire between the United States and Iran breaks down after Iranian attacks on commercial vessels in the Strait of Hormuz. Trump declares the agreement "over", while saying that negotiations may continue. The U.S. Central Command says it struck around 90 Iranian military targets, including air defense, missile, drone and naval facilities. An additional U.S. strike hits a railway bridge in Golestan province on a trade route linking Iran with Russia and China. At the 2026 NATO summit in Ankara, Trump says that he has ordered Treasury Secretary Scott Bessent to halt all U.S. trade with Spain, calls Spain a "terrible partner" in NATO amid disputes over Spain's defense spending and the Iran War, and declares that the US will provide Ukraine a license to build Patriot missiles. July 9 Iran war: Trump says that Iran contacted him and they want to make an agreement. The U.S. Department of Justice announces that a federal grand jury has indicted eight men over an alleged plot to attack the UFC Freedom 250 event at the White House in Washington, D.C. last month.

The iron-containing co-factor is found tightly associated with the protein. It can be released upon denaturation with 2-mercaptoethanol or guanidine hydrochloride. Expression of the Hmd gene in E. coli without the co-factor results in an inactive holoenzyme. However, hydrogenase activity can be rescued by the addition of the iron-containing cofactor taken from denatured active enzyme. As mentioned, irradiation of the cofactor with UV light results in the loss of CO and Fe. In addition the 542 Da compound can be further degraded by a phosphodiesterase (which specifically cleaves phosphate bonds). Hydrolysis of the phosphate bonds generates the ribonucleotide guanosine monophosphate and a modified 2-pyridone. On the basis of spectroscopic characterization, Shima et al. have proposed a structure for this organic cofactor (minus the iron atom and CO molecules) as shown:

In 2020, PTC acquired Censa Pharmaceuticals, Inc., a biopharmaceutical company focused on the development of CNSA-001 (sepiapterin), a clinical-stage investigational therapy for orphan metabolic diseases, including phenylketonuria (PKU) and other diseases associated with defects in the tetrahydrobiopterin (BH4) biochemical pathways diagnosed at birth. In 2020, PTC announced the FDA approval of Evrysdi (risdiplam) for the treatment of spinal muscular atrophy (SMA) in adults and children 2 months and older. In 2024, Novartis has committed $1 billion upfront in a licensing deal with PTC Therapeutics for an experimental treatment for Huntington’s disease, with the potential for an additional $1.9 billion tied to achieving specific development, regulatory, and commercial milestones. PTC Therapeutics’ therapy, known as PTC518, is an oral medication designed to reduce the production of the mutant protein linked to the genetic mutation responsible for the disease. This mutant protein is believed to contribute to neuronal death, driving disease progression. In June, interim data from a Phase 2 trial indicated that PTC518 successfully lowered levels of the mutant protein in both blood and cerebrospinal fluid.

A nonradioactive zirconium sample can be extracted from spent fuel by extracting strontium-90 and allowing enough of it to decay (e.g. in an RTG). The zirconium can then be separated from the remaining strontium leaving a very isotopically pure Zr-90 sample.

Sources: en.wikipedia.org

Background from the literature

=== U.S. response on humanitarian aid === In May 2026, U.S. Secretary of State Marco Rubio said the United States had offered $100 million in humanitarian aid to Cuba, including food and medical supplies. He criticized the Cuban government, saying it was preventing humanitarian aid from reaching the population. The statement was made in the context of long-standing U.S. sanctions and trade restrictions on Cuba, which have restricted economic and humanitarian flows to the country. Rubio also described the situation in Cuba as "unacceptable" and called for major changes in the country's governance.

== Literature == Emanuel Gil-Av, Present status of enantiomeric analysis by gas chromatography, J. Mol. Evol. 6 (1975) 131–144. Nelu Grinberg: Emanuel Gil-Av (1916–1996): A man with a legacy, In: Chirality, 1998;10(5):372. Volker Schurig: In Memoriam – Emanuel Gil-Av. In: Journal of High Resolution Chromatography 19 (1996) 462. Volker Schurig: On the Centenary of Emanuel Gil-Av, Former Professor of the Weizmann Institute of Science and Pioneer of Enantioselective Chromatography, Isr. J. Chem. 56 (2016) 890–906.

== Promotional sponsorship == Major League Soccer team Real Salt Lake announced on October 29, 2013, that it had partnered with LifeVantage for a long-term, multimillion-dollar jersey-front sponsorship. The partnership was set to formally go into effect on January 1, 2014, with the LifeVantage logo appearing on the Real Salt Lake jersey starting in the next season. In July 2015, Real Salt Lake owner Dell Loy Hansen was reported by the U.S. Securities and Exchange Commission to have bought a 5.1 percent ownership stake in LifeVantage.

An increase in the expression of Group 2 mGluRs, which could arise from a chronic under stimulation of these receptors, has been associated with schizophrenia. An increase in levels of system Xc- has also been found in postmortem schizophrenia patients, indicating that there may have been a decrease in net function of these receptors as well, leading to greater expression. It has been observed that Schizophrenia patients have a decreased level of glutathione in their prefrontal cortex, further supporting the conclusion that system Xc- may not be functioning properly. Clinical trials have shown therapeutic potential for N-acetylcysteine in treating schizophrenia. Again, changes in EAATs due to disruptions in Glutamate homeostasis may also be involved. Recent study showed that mRNA expression levels of both SLC3A2 and SLC7A11 in WBCs of schizophrenia patients are lower than that of healthy individuals. The finding supports the hypo-glutamatergic neurotransmission hypothesis in schizophrenia.

Besides the core data on panning experiments and their results, broad background information on target, template, library and structure is included. An accompanied benchmark has also been compiled for bioinformaticians to develop and evaluate their new models, algorithms and programs. In addition, the MimoDB database provides tools for simple and advanced searches, structure visualization, BLAST and alignment view on the fly. The experimental biologists can easily use the database as a virtual control to exclude possible target-unrelated peptides. The MimoDB database is freely available.

Sources: en.wikipedia.org

Frequently asked questions

What is the peptide sequence of Selank?

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.

How is it related to tuftsin?

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.

Why do different sources use different names?

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.

How should selank powder be stored?

Sealed, desiccated storage at -20 °C or colder is the standard recommendation for research-grade material. Vials should reach room temperature before they are opened, which limits condensation. Repeated temperature cycling is discouraged.

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