Everything below concerns heptapeptide. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Last reviewed on 2026-01-14. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
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.
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.
| 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 |
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.
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.
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.
Selank is a synthetic heptapeptide developed in Russia as a structural analogue of tuftsin, a naturally occurring immunomodulatory tetrapeptide. Its sequence, Thr-Lys-Pro-Arg-Pro-Gly-Pro, keeps the tuftsin core at the N-terminus and appends a Pro-Gly-Pro tail. Researchers at the Institute of Molecular Genetics in Moscow synthesized the compound during the 1990s while searching for peptides with combined anxiolytic and immunomodulatory activity. The added tail was intended to resist enzymatic cleavage and prolong the molecule's presence in circulation.
The compound has a calculated molecular weight near 751.9 daltons and carries a net positive charge at physiological pH because of its arginine residue. It dissolves freely in water and in common aqueous buffers, and typically appears as a white or off-white lyophilized powder. The amide backbone makes the molecule susceptible to peptidases, which limits oral use and favors intranasal or parenteral routes. Nomenclature in the literature varies: the substance is also described by the sequence abbreviation TP-7 and by a Russian trade designation.
=== With nitrogen species === With primary amines, thionyl chloride gives sulfinylamine derivatives (RNSO), one example being N-sulfinylaniline. Thionyl chloride reacts with primary formamides to form isocyanides and with secondary formamides to give chloroiminium ions; as such a reaction with dimethylformamide will form the Vilsmeier reagent. By an analogous process, secondary amides will react with thionyl chloride to form imidoyl chlorides, with tertiary amides giving chloroiminium ions. These species are highly reactive and can be used to catalyse the conversion of carboxylic acids to acyl chlorides; they are also exploited in the Bischler–Napieralski reaction as a means of forming isoquinolines.
===== Ophthalmological use ===== Cocaine eye drops have traditionally been used by neurologists when examining people suspected of having Horner syndrome. In Horner syndrome, sympathetic innervation to the eye is blocked. In a healthy eye, cocaine stimulates the sympathetic nervous system (SNS) by inhibiting norepinephrine reuptake, causing the pupil to dilate. In patients with Horner syndrome, sympathetic innervation to the eye is disrupted, so the affected pupil does not dilate in response to cocaine and remains constricted, or dilates to a lesser extent than the unaffected eye, which also receives the eye drop test. If both eyes dilate equally, the patient does not have Horner syndrome. However, apraclonidine has largely replaced cocaine as the first-line pharmacologic agent for the diagnosis of Horner syndrome in routine clinical practice.
Type I IFNs can induce expression of genes with either ISRE or GAS elements, but gene induction by type II IFN can occur only in the presence of a GAS element. In addition to the JAK-STAT pathway, IFNs can activate several other signaling cascades. For instance, both type I and type II IFNs activate a member of the CRK family of adaptor proteins called CRKL, a nuclear adaptor for STAT5 that also regulates signaling through the C3G/Rap1 pathway. Type I IFNs further activate p38 mitogen-activated protein kinase (MAP kinase) to induce gene transcription. Antiviral and antiproliferative effects specific to type I IFNs result from p38 MAP kinase signaling. The phosphatidylinositol 3-kinase (PI3K) signaling pathway is also regulated by both type I and type II IFNs. PI3K activates P70-S6 Kinase 1, an enzyme that increases protein synthesis and cell proliferation; phosphorylates ribosomal protein s6, which is involved in protein synthesis; and phosphorylates a translational repressor protein called eukaryotic translation-initiation factor 4E-binding protein 1 (EIF4EBP1) in order to deactivate it. Interferons can disrupt signaling by other stimuli. For example, interferon alpha induces RIG-G, which disrupts the CSN5-containing COP9 signalosome (CSN), a highly conserved multiprotein complex implicated in protein deneddylation, deubiquitination, and phosphorylation. RIG-G has shown the capacity to inhibit NF-κB and STAT3 signaling in lung cancer cells, which demonstrates the potential of type I IFNs.
== Function == The gene is expressed in spindle-shaped cells located along nerve fibers between the auditory ganglion and sensory epithelium. These cells accompany neurites at the habenula perforata, the opening through which neurites extend to innervate hair cells. This and the pattern of expression of this gene in chicken inner ear paralleled the histologic findings of acidophilic deposits, consistent with mucopolysaccharide ground substance, in temporal bones from DFNA9 (autosomal dominant nonsyndromic sensorineural deafness 9) patients. Mutations that cause DFNA9 have been reported in this gene. Cochlin has been identified in the trabecular meshwork (TM) of glaucoma patients, but not in healthy controls. The TM is a filter like area of tissue in the eye; cochlin may have a role in cell adhesion, mechanosensation, and modulation of the TM filter. It is also expressed in follicular dendritic cells in spleen and lymph nodes. Here, cochlin is cleaved by aggrecanases and secreted into blood circulation during inflammation, contributing to the antibacterial innate immune response.
=== Side effects === Side effects of laudanum are generally the same as with morphine, and include euphoria, dysphoria, pruritus, sedation, constipation, reduced tidal volume, respiratory depression, as well as psychological dependence, physical dependence, miosis, and xerostomia. Overdose can result in severe respiratory depression or collapse and death. The ethanol component can also induce adverse effects at higher doses; the side effects are the same as with alcohol. Long-term use of laudanum in nonterminal diseases is discouraged due to the possibility of drug tolerance and addiction. Long-term use can also lead to abnormal liver function tests; specifically, prolonged morphine use can increase ALT and AST blood serum levels.
Sources: en.wikipedia.org
== Availability == There is an overall shortage of antivenom to treat snakebites. Because of this shortage, clinical researchers are considering whether lower doses may be as effective as higher doses in severe neurotoxic snake envenoming. Antivenom undergoes successive price markups after manufacturing, by licencees, wholesalers and hospitals. When weighed against profitability (especially for sale in poorer regions), the result is that many snake antivenoms, world-wide, are very expensive. Availability, from region to region, also varies. Internationally, antivenoms must conform to the standards of pharmacopoeia and the World Health Organization (WHO). Antivenoms have been developed for the venoms associated with the following animals:
===== Copper catalyzed Huisgen cyclization of azides ===== Azide has become a popular target for chemoselective protein modification, because they are small in size and have a favorable thermodynamic reaction potential. One such azide reactions is the [3+2] cycloaddition reaction with alkyne, but the reaction requires high temperature and often gives mixtures of regioisomers.
is electron mobility E is the electric field across the depletion region Dn is the diffusion coefficient for electrons Gn is the rate of generation of electrons Rn is the rate of recombination of electrons Similarly, for holes:
The term "Quechua Nation" occurs in such contexts as the name of the Education Council of the Quechua Nation (Consejo Educativo de la Nación Quechua, CENAQ), which is responsible for Quechua instruction or bilingual intercultural schools in the Quechua-speaking regions of Bolivia. Some Quechua say that if nation-states in Latin America had been built following the European pattern, they would be a single, independent nation.
== Modelling the Basal Rate == Most adult diabetics (over the age of 21) will have a fairly constant ratio of bolus:basal of 60%:40%, where 60% of all insulin intake in a single 24-hour period will be attributed to meals (bolus) and 40% should then be attributed to the basal rate. This ratio will fluctuate from person to person depending on their size, activity level, and caloric intake as well but is a good baseline for determining the correct basal rate for an adult diabetic. Thus, the basal rate could theoretically be set based on an averaged bolus insulin intake of several days. Averaging the total bolus, and then dividing this number by 36 would then give the required hourly basal rate intake for any individual with a 60:40 ratio established.
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.
Most published work uses intranasal application, either as drops or as a nasal spray. Injection routes appear in a smaller set of animal experiments. Oral use is uncommon in the literature because peptide breakdown and poor absorption limit this route.