Everything below concerns elevated plus maze. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Updated 2025-09-09. Numbers and descriptions here follow the published literature rather than marketing material.
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.
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.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Typical purity report | 95% or higher by HPLC | Area percentage at 214 nm |
| Identity confirmation | Mass spectrometry | Electrospray or MALDI |
| Powder storage | -20 C, desiccated | Protect from light |
| Solution storage | 2-8 C short term | Freeze aliquots for longer |
| Quality document | Certificate of analysis | States method and value |
Proposed mechanisms centre on modulation of the GABAergic system, with reports of altered expression of genes related to GABA-A receptor subunits and changed monoamine turnover. Some studies describe inhibition of enkephalinase, the enzyme that degrades endogenous enkephalins, which may prolong opioid peptide signalling. Effects on brain-derived neurotrophic factor and on cytokine expression have also been reported. These findings come largely from animal models and small human studies, and the precise primary target remains unresolved.
Published clinical evidence is limited. Most controlled trials were conducted in Russia, enrolled modest numbers of participants, and appeared in Russian-language journals, which restricts independent verification. Reported outcomes include lower anxiety scores, improved attention and memory measures, and changes in fatigue ratings. Reviews written in English note methodological limitations such as small samples and inconsistent endpoints. Whether the compound produces clinically meaningful benefit relative to established anxiolytics is therefore an open question rather than an established finding.
Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro. It was designed at the Institute of Molecular Genetics of the Russian Academy of Sciences as a structural analogue of tuftsin, a naturally occurring tetrapeptide fragment of the immunoglobulin heavy chain. The added Pro-Gly-Pro tail was intended to slow enzymatic degradation and extend biological activity. In Russia it is registered as an anxiolytic nasal preparation, while regulators elsewhere have not approved it for clinical use.
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.
Measuring peptide exposure inside the brain is technically difficult. Selank is degraded rapidly in plasma, and assays must separate intact peptide from fragments, which favors targeted mass spectrometry over immunoassays alone. Reported half-lives are short, on the order of minutes, so effects observed hours later are attributed to downstream signaling rather than to the parent compound. Blood-brain barrier permeability is debated and rarely quantified directly. Gaps include absent dose-response characterization, inconsistent reporting of purity, and almost no pharmacokinetic data from human participants.
Selank is studied chiefly as an animal-model anxiolytic with proposed secondary effects on memory and immune signaling. Reported mechanisms include modulation of the GABA-A receptor complex, inhibition of enkephalin-degrading enzymes, and shifts in monoamine turnover within limbic structures. Some experiments describe increased expression of brain-derived neurotrophic factor in the hippocampus after repeated dosing. No single molecular target has been confirmed, and the peptide does not bind any receptor with the selectivity typical of a conventional small-molecule drug. Mechanism therefore remains a set of hypotheses rather than an established pathway.
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.
Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro. It was designed as a stabilized analogue of tuftsin, a naturally occurring tetrapeptide fragment derived from the immunoglobulin heavy chain. The additional Pro-Gly-Pro segment at the carboxyl terminus is intended to slow enzymatic cleavage. The compound is usually described in the literature as a synthetic peptide with anxiolytic and cognitive-related activity, a label that reflects a research context rather than an approved therapeutic category.
== Microscopic appearance == Melanin is brown, non-refractile, and finely granular, with individual granules having a diameter of less than 800 nanometers. This differentiates melanin from common blood breakdown pigments, which are larger, chunky, and refractile, and range in color from green to yellow or red-brown. In heavily pigmented lesions, dense aggregates of melanin can obscure histologic detail. A dilute solution of potassium permanganate is an effective melanin bleach.
Subjects in Byzantine art were primarily Christian and typically non-naturalistic in their representation. Emerging from both the earliest Christian and Late Antique art, many early examples were lost amid the Roman Persecutions; the fragmented mosaics of the 3rd-century Dura-Europos church are a unique exception. Such Byzantine mosaics, known for their gold ground style, became a hallmark of the empire, displaying both secular and sacred themes in diverse places, including churches (Basilica of San Vitale), the circus (Hippodrome of Constantinople), and the Great Palace of Constantinople. The early 6th-century reign of Justinian I saw systemic developments: religious art came to dominate, and once-popular public marble and bronze monumental sculpture fell out of favour due to pagan associations. Justinian commissioned the monumental Hagia Sophia church, and its influential elements became architectural hallmarks for the empire: the immense size, large dome, innovative use of pendentives and highly decorative interior were imitated as far north as the Cathedral of Saint Sophia in Novgorod and the Saint Sophia Cathedral in Kiev. The Hagia Sophia's creators, the engineer-architects Isidore of Miletus and Anthemius of Tralles, are uniquely esteemed; most Byzantine artists were unrecorded and typically deemed to have little importance.
=== Norbornene cycloaddition === 1,3 dipolar cycloadditions have been developed as a bioorthogonal reaction using a nitrile oxide as a 1,3-dipole and a norbornene as a dipolarophile. Its primary use has been in labeling DNA and RNA in automated oligonucleotide synthesizers, and polymer crosslinking in the presence of living cells.
== Interpretation == A reference range is usually defined as the set of values 95 percent of the normal population falls within (that is, 95% prediction interval). It is determined by collecting data from vast numbers of laboratory tests.
== Function == POMC is cut (cleaved) to give rise to multiple peptide hormones. Each of these peptides is packaged in large dense-core vesicles that are released from the cells by exocytosis in response to appropriate stimulation:
Sources: en.wikipedia.org
=== Clothing === A process to apply zinc pyrithione to cotton with washable results was patented in the United States in 1984. Zinc pyrithione is used to prevent microbe growth in polyester. Textiles with applied zinc pyrithione protect against odor-causing microorganisms. Export of antimicrobial textiles reached US$497.4 million in 2015.
== Rate of reaction == The rate of the conversion reaction is determined by several factors. The regiochemical position of the carboxyl group and the 3-hydroxyl group plays one role in the reaction, in which the rate of reaction of 1,3-cis-substituted substrate gives about 40-fold higher kcat/Km value than the 1,3-trans-substituted substrate.
== Applications in biotechnology == Inteins are very efficient at protein splicing, and they have accordingly found an important role in biotechnology. There are more than 200 inteins identified to date; sizes range from 100–800 AAs. Inteins have been engineered for particular applications such as protein semisynthesis and the selective labeling of protein segments, which is useful for NMR studies of large proteins. Pharmaceutical inhibition of intein excision may be a useful tool for drug development; the protein that contains the intein will not carry out its normal function if the intein does not excise, since its structure will be disrupted. It has been suggested that inteins could prove useful for achieving allotopic expression of certain highly hydrophobic proteins normally encoded by the mitochondrial genome, for example in gene therapy. The hydrophobicity of these proteins is an obstacle to their import into mitochondria. Therefore, the insertion of a non-hydrophobic intein may allow this import to proceed. Excision of the intein after import would then restore the protein to wild-type. Affinity tags have been widely used to purify recombinant proteins, as they allow the accumulation of recombinant protein with little impurities. However, the affinity tag must be removed by proteases in the final purification step. The extra proteolysis step raises the problems of protease specificity in removing affinity tags from recombinant protein, and the removal of the digestion product.
Neuromodulation, whether electrical or magnetic, employs the body's natural biological response by stimulating nerve cell activity that can influence populations of nerves by releasing transmitters, such as dopamine, or other chemical messengers such as the peptide Substance P, that can modulate the excitability and firing patterns of neural circuits. There may also be more direct electrophysiological effects on neural membranes as the mechanism of action of electrical interaction with neural elements. The end effect is a "normalization" of a neural network function from its perturbed state. Presumed mechanisms of action for neurostimulation include depolarizing blockade, stochastic normalization of neural firing, axonal blockade, reduction of neural firing keratosis, and suppression of neural network oscillations. A recent review (2024) has identified relevant etiological hypotheses of non-invasive neuromodulation in different techniques. Data analysis revealed that mitochondrial activity seems to play a central role in different techniques. Analysis of the mother-fetus neurocognitive model provided insights into the conditions of natural neuromodulation of the fetal nervous system during pregnancy.
Sources: en.wikipedia.org
== Interaction with other nutrients == Selenium interactes with iodine and vitamin E; see section "Deficiency" above. Selenium interacts with other minerals, such as zinc and copper. High doses of selenium supplements in pregnant animals might disturb the zinc:copper ratio and lead to zinc reduction; in such treatment cases, zinc levels should be monitored. Further studies are needed to confirm these interactions.
== 2A function in FMDV virus == Foot-and-mouth disease virus (FMDV) is a virus in the genus Aphthovirus that causes foot-and-mouth disease in cattle. As a member of the family Picornaviridae, FMDV is a positive-sense, single-stranded RNA virus. 2A is located between the capsid proteins and polymerases and proteases required for the capsid assembly in the late stages of the infection. The incomplete ribosomal skipping during the viral RNA translation mediated by the 2A results in "ribosome drop off" in some cases, after which the translation doesn't restart. This leads to a prevalence of the N-terminal proteins and allows for the increased production of the structural proteins relative to the non-structural proteins.
Both The Guardian newspaper (UK) and the American non-profit publication ICIJ received documents in July 2014 revealing the details of past and present offshore clients of wealth managers Kleinwort Benson, including the Nando's restaurant group. The Guardian published its belief that, through the use of businesses in Malta, Guernsey and the Netherlands, Enthoven legally reduces the group's UK corporation tax bill by "up to a third." According to the British newspaper, Enthoven's profits eventually accumulate in the Kleinwort Benson-managed "Taro III Trust" that is based in Jersey and contains at least £750 million. While no member of the Enthoven family agreed to speak with The Guardian, a company representative explained that UK tax laws are not applicable to Enthoven, as "he is not resident in the US or the UK." The spokesperson also stated that, in the UK, Nando's paid corporation tax of £12.6 million on a profit of £58.2 million for the year ending February 2013. In its 2023 tax strategy, the company states that "Nando's policy is to maintain its tax affairs responsibly and transparently. Nando's doesn’t enter into transactions simply to secure tax advantages."
Gives aid to "Catholic Communications" which produces TV and radio programs explaining the Catholic faith to Catholics and non-Catholics alike; annual pilgrimages to shrines; prayer card distributions; conducts picnics, bus trips, socials, etc.
==== Electrical conductivity ==== Completely de-gassed ultrapure water has a conductivity of 1.2 × 10−4 S/m, whereas on equilibration to the atmosphere it is 7.5 × 10−5 S/m due to dissolved CO2 in it. The highest grades of ultrapure water should not be stored in glass or plastic containers because these container materials leach (release) contaminants at very low concentrations. Storage vessels made of silica are used for less-demanding applications and vessels of ultrapure tin are used for the highest-purity applications. Although electrical conductivity only indicates the presence of ions, the majority of common contaminants found naturally in water ionize to some degree. This ionization is a good measure of the efficacy of a filtration system, and more expensive systems incorporate conductivity-based alarms to indicate when filters should be refreshed or replaced. For comparison, seawater has a conductivity of perhaps 5 S/m (53 mS/cm is quoted), while normal un-purified tap water may have conductivity of 5 × 10−3 S/m (50 μS/cm) (to within an order of magnitude), which is still about 2 or 3 orders of magnitude higher than the output from a well-functioning demineralizing or distillation mechanism, so low levels of contamination or declining performance are easily detected.
Sources: en.wikipedia.org
Purity is usually reported as an HPLC area percentage, most often measured at 214 nm. Identity is confirmed separately by mass spectrometry. A certificate of analysis should state both the method and the observed value.
Dry powder is kept frozen, desiccated, and shielded from light. Dissolved material is aliquoted and frozen to limit freeze-thaw cycles. Short-term refrigerated storage is common for working solutions.
Russia registers it as a prescription nasal product. Most other markets classify it as a research chemical with no approved medical use. Oversight of purity and labeling is consequently minimal in those markets.
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.