This is a working overview of intranasal delivery, written for readers who want more than a one-paragraph summary but less than a textbook.
This page was last updated on 2026-03-09 and is reviewed periodically as new material appears.
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.
Peptide bonds are vulnerable to protease attack, and Selank is no exception. Measured half-life in serum is short, on the order of minutes in several reports, which explains why intranasal administration is the common route described in the literature. Absorption across the nasal mucosa partially bypasses first-pass hepatic metabolism. Quantitative data on human bioavailability remain limited and are difficult to compare across studies.
Lyophilised material kept dry at minus 20 degrees Celsius or colder is the most stable form, and suppliers commonly state a shelf life of two years or more under those conditions. Once dissolved, degradation accelerates through hydrolysis and deamidation, particularly at alkaline pH or elevated temperature. Working solutions are usually divided into single-use aliquots to avoid repeated freeze-thaw cycles. The choice of reconstitution solvent affects both stability and the ionic strength of the final preparation.
Reverse-phase high-performance liquid chromatography with ultraviolet detection near 214 nanometres is the standard purity method. Mass spectrometry, typically electrospray ionisation, confirms identity through the expected mass-to-charge pattern. Amino acid analysis can verify composition independently. Chiral purity requires separate techniques such as derivatisation followed by chromatographic separation, and such data are rarely reported for research-grade material.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic heptapeptide | Tuftsin analogue |
| Sequence | Thr-Lys-Pro-Arg-Pro-Gly-Pro | Single-letter form: TKPRPGP |
| Molecular formula | C33H57N11O9 | Calculated for the free peptide |
| Molecular weight | About 751.9 g/mol | Derived from the sequence |
| Appearance | White to off-white powder | Typical lyophilised form |
Proposed mechanisms centre on the GABAergic system. Animal and tissue studies report changes in GABA-A receptor expression and reduced activity of GABA transaminase, the enzyme that degrades GABA. Effects on monoamine turnover, including serotonin and dopamine pathways, are also described, and a separate line of work links the peptide to increased expression of brain-derived neurotrophic factor in hippocampal tissue. Most of these findings come from rodent models and cell preparations. How the individual observations combine into a single coherent mode of action is not settled.
Pharmacokinetic data are sparse and largely derived from animal work. After intranasal administration the peptide appears in plasma within minutes, and reported half-lives are short, on the order of minutes to tens of minutes. Degradation proceeds through ordinary proteolytic cleavage into constituent amino acids and smaller fragments. Direct evidence that intact Selank reaches brain tissue in meaningful amounts is limited, and the extent of blood-brain barrier penetration is debated. Some authors argue that fragments, not the parent peptide, carry much of the observed activity.
Published clinical work is concentrated in Russian-language journals and generally involves small samples without independent replication. Systematic reviews in English note the shortage of randomised, placebo-controlled trials and the difficulty of verifying methods from translated reports. Outcome measures vary between studies, which complicates pooling of results. Interest in the compound as a cognitive or anxiolytic agent therefore rests on a thinner evidence base than the volume of citations suggests. Replication in well-powered trials with preregistered endpoints would be needed before firm conclusions about efficacy can be drawn.
Characterization of Selank in laboratory settings relies on standard peptide analytical techniques. Reverse-phase high-performance liquid chromatography separates the peptide from related impurities and degradation products, while mass spectrometry confirms molecular identity through accurate mass measurement. Amino acid analysis and peptide sequencing verify the primary structure when reference material is unavailable. Because Selank is a short chain, fragmentation-based analysis produces a diagnostic ion pattern that supports confident identification.
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.
Nicotine, which is contained in cigarettes and other smoked tobacco products, is a stimulant and is one of the main factors leading to continued tobacco smoking. Nicotine is a highly addictive psychoactive chemical. When tobacco is smoked, most of the nicotine is pyrolyzed; a dose sufficient to cause mild somatic dependency and mild to strong psychological dependency remains. The amount of nicotine absorbed by the body from smoking depends on many factors, including the type of tobacco, whether the smoke is inhaled, and whether a filter is used. There is also a formation of harmane (a MAO inhibitor) from the acetaldehyde in cigarette smoke, which seems to play an important role in nicotine addiction probably by facilitating dopamine release in the nucleus accumbens in response to nicotine stimuli. According to studies by Henningfield and Benowitz, nicotine is more addictive than cannabis, caffeine, alcohol, cocaine, and heroin when considering both somatic and psychological dependence. However, due to the stronger withdrawal effects of alcohol, cocaine and heroin, nicotine may have a lower potential for somatic dependence than these substances. About half of Canadians who currently smoke have tried to quit. McGill University health professor Jennifer O'Loughlin stated that nicotine addiction can occur as soon as five months after the start of smoking.
=== 7 April === An Iraqi national, identified as Abbas Abuthar Witwit, died in a hospital in Luhansk due to injuries sustained while fighting as a member of the Wagner Group in Bakhmut the previous day, in what is believed to be the first confirmed case of a Middle East native to have died fighting in the war. His death was confirmed by Wagner's head Yevgeny Prigozhin, who said he had been recruited from a Russian jail, on 1 June.
== Types == Fomentations – heated poultices – may be used to promote blood circulation to an affected area; these may be unmedicated. Cold poultices are sometimes used. An example is the use of cabbage leaves to reduce breast engorgement in breastfeeding mothers. The leaves are applied directly to the breast, often simply held in place by a bra. Evidence for effectiveness as a treatment is weak: cabbage poultices are about as effective as the frequent, unrestricted feeding of the infant; they have no effect on the rate of progression to mastitis. There is some slight evidence that cabbage poultices reduce the pain of engorgement.
Sources: en.wikipedia.org
==== Research and traditional medicine ==== Preliminary research indicates that the phytochemicals, betulin and possibly other triterpenes, are active in Episalvan gel and wound healing properties of birch bark. Over centuries, birch bark was used in traditional medicine practices by North American indigenous people for treating superficial wounds by applying bark directly to the skin. Splints made with birch bark were used as casts for broken limbs in the 16th century.
Trammell, SAJ; Schmidt, MS; Weidemann, BJ; Redpath, P; Jaksch, F; Dellinger, RW; Li, Z; Abel, ED; Migaud, ME; Brenner, C (10 October 2016). "Nicotinamide riboside is uniquely and orally bioavailable in mice and humans". Nature Communications. 7 (1) 12948. Bibcode:2016NatCo...712948T. doi:10.1038/ncomms12948. PMC 5062546. PMID 27721479. Trammell, SAJ; Weidemann, BJ; Chadda, A; Yorek, MS; Holmes, A; Coppey, LJ; Obrosov, A; Kardon, RH; Yorek, MA; Brenner, C (2016). "Nicotinamide Riboside Opposes Type 2 Diabetes and Neuropathy in Mice". Scientific Reports. 6 26933. Bibcode:2016NatSR...626933T. doi:10.1038/srep26933. PMC 4882590. PMID 27230286. Wu, B-K; Brenner, C (2014). "Suppression of TET1-Dependent DNA Demethylation Is Essential for KRAS-Mediated Transformation". Cell Reports. 9 (5): 1827–1840. doi:10.1016/j.celrep.2014.10.063. PMC 4268240. PMID 25466250. Fagan, RL; Cryderman, DE; Kopelovich, L; Wallrath, LL; Brenner, C (2013). "Laccaic Acid A Is a Direct, DNA-competitive Inhibitor of DNA Methyltransferase 1". J. Biol. Chem. 288 (33): 23858–23867. doi:10.1074/jbc.M113.480517. PMC 3745332. PMID 23839987. Brenner, C (2013). "Changes in Chemistry and Biochemistry Education: Creative Responses to MCAT Revisions in the Age of the Genome". Biochemistry and Molecular Biology Education. 41 (1): 1–4. doi:10.1002/bmb.20653. PMID 23281187. S2CID 4659938. Brenner, C (2013). "Rethinking Premedical and Health Professional Curricula in Light of MCAT 2015" (PDF). J. Chem. Educ. 90 (7): 807–812. Bibcode:2013JChEd..90..807B. doi:10.1021/ed4002738. S2CID 98274150.
* Disputed ** Separated to Maroodi Jeex and Sahil by Somaliland *** Shared by Puntland and Galmudug Northern Somalia is now de facto divided up among the autonomous regions of Puntland (which considers itself an autonomous state), Somaliland (a self-declared, partially-recognised state) and newly established North East State of Somalia. In central Somalia, Galmudug is another regional entity that emerged just south of Puntland. Jubaland in the far south is a fourth autonomous region within the federation. In 2014, a new South West State was likewise established. In April 2015, a formation conference was also launched for a new Hirshabelle State. The Federal Parliament was tasked in 2012 with selecting the ultimate number and boundaries of the autonomous regional states (officially Federal Member States) within the Federal Republic of Somalia.
Sources: en.wikipedia.org
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== Residual topology == Residual topology is a descriptive stereochemical term to classify a number of intertwined and interlocked molecules, which cannot be disentangled in an experiment without breaking of covalent bonds, while the strict rules of mathematical topology allow such a disentanglement. Examples of such molecules are rotaxanes, catenanes with covalently linked rings (so-called pretzelanes), and open knots (pseudoknots) which are abundant in proteins. The term "residual topology" was suggested on account of a striking similarity of these compounds to the well-established topologically nontrivial species, such as catenanes and knotanes (molecular knots). The idea of residual topological isomerism introduces a handy scheme of modifying the molecular graphs and generalizes former efforts of systemization of mechanically bound and bridged molecules.
=== Afonso Dias === In one of the Dias' hearings, it was brought up that the defendant came from a poor family, was 22 and played with an 11 year old child at the time of the disappearance. It was also brought up that the defendant was meeting up with Mendonça in private as Mendonça's parents had forbidden it, after Dias came back changed from the army and as a deserter. Manuel Mendonça said that he and the neighbors noticed that Dias' financial resources increased after the boy's disappearance and that the first PJ team did not believe the information received from both the prostitute and the family. Dias was an unhygienic person, however in the day of the disappearance he took two baths. When Manuel Mendonça got to the PJ they said it was not possible to extract anything from the suspect's clothes. Manuel Mendonça also said that Dias laughed while talking to Filomena Teixeira. He also said that the defendant's lawyer and family did not want to help to find Mendonça. The chief-inspector Henrique Noronha said in 2011 that in the reconstitution there was "a hiatus of time that we couldn't figure out (...) We were a bit perplexed [when Afonso Dias said that he] stood in a place looking at nothing and burning the midnight". The inspector also said that he did not understand the reason of not following the lead of Alcina Dias. Hélder Silva, that was one of the five children that saw Mendonça for the last time, told the Correio da Manhã that Dias "Was very weird. Afonso knew Rui Pedro's whole life, where he was, who he was with, what he would do the next day.
Sources: en.wikipedia.org
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.
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.
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.
Dry powder is best kept sealed, protected from light, and held at minus 20 degrees Celsius or below. Desiccant packaging helps limit moisture uptake because the material is hygroscopic. A sealed vial should be allowed to equilibrate to room temperature before opening to reduce condensation.