Research chemical is one of those subjects where the details matter more than the headlines. This page pulls together the background, the mechanisms, and the practical points readers ask about most.
Updated 2026-02-17. Numbers and descriptions here follow the published literature rather than marketing material.
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.
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.
| 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 |
Lyophilized Selank, the dry powder form, is generally stored frozen at minus 20 degrees Celsius or colder for long-term keeping. The solid is hygroscopic and should stay sealed, dry, and protected from light. Once dissolved, the peptide is less stable and is usually held refrigerated at 2 to 8 degrees Celsius for short periods. Repeated freezing and thawing is avoided because it can promote aggregation and loss of activity. Buffers and pH choice also affect how long a solution remains usable.
Solubility behavior is a practical concern for handling. Selank dissolves readily in water and in common aqueous buffers, which simplifies preparation of working solutions. The choice of solvent, ionic strength, and pH can influence aggregation over time, particularly at higher concentrations. Aqueous solutions are typically sterile-filtered before use. Because stability depends on several variables, storage and handling notes should be treated as general guidance rather than fixed rules, and specific values are best confirmed against a certificate of analysis for each batch.
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.
Laboratory work relies on standard behavioral paradigms. Rodents are tested in the elevated plus maze, open field, and passive avoidance tasks, with outcomes compared against diazepam or vehicle controls. Intranasal dosing is used most often because it bypasses first-pass metabolism, though intraperitoneal and intravenous routes also appear in published protocols. Biochemical endpoints include tissue BDNF concentrations, cytokine levels, and monoamine metabolites. Human data are limited to small Russian trials reporting reduced anxiety scores; most were not prospectively registered, and few employed independent outcome assessment.
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.
Dry powder is normally held at -20 degrees Celsius or lower, in a sealed container with desiccant and protection from light. Reconstituted solutions are usually kept at 2 to 8 degrees Celsius for short periods and frozen for longer ones. Proline residues at several positions are generally associated with some resistance to peptidase attack, but chemical stability still declines at neutral to alkaline pH and at elevated temperature. Exact shelf-life figures are product-specific and are not standardised across suppliers.
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.
Islam is the state religion, with freedom of religion guaranteed by the constitution. The majority are Muslims (96.35%), followed by Hindus (2.17%) and Christians (1.37%). Other minorities include Sikhs, Buddhists, Jains, Zoroastrians (Parsi), and the unique Kalash people who practice animism. In 2012, 2% of the population identified as atheist in a Gallup survey.
== Current status == Many exogenous agents have been developed since the discovery of 5-HT2C receptors. Thus far a small number of agonists, with sufficient selectivity for the 5-HT2C receptors over the other subtypes have been studied in clinical trials. A variety of other 5-HT2C receptor agonists remain in preclinical development, including Ro60-0175, WAY-163,909, and the inverse agonist SB-243,213. Evidence supports a therapeutic potential of 5-HT2C receptor modulation in the treatment of a variety of pathological conditions, including schizophrenia, obesity, urinary incontinence and sexual dysfunction.
Within a few months of his joining the Committee, what had previously been an innovative and forward-looking group became riven with strife. It was strictly Lindemann versus the rest, with his hostility to radar and his insistence on totally impractical ideas about intercepting enemy aircraft by means of wires dangled from balloons, or by infrared, which at that time simply did not have the sensitivity to detect aircraft at long range. Churchill's backing meant the other members' complaints about his behaviour were ignored. The matter was eventually referred back to Lord Swinton, the new Secretary of State for Air. Swinton solved the problem by dissolving the original Committee and reforming it with Appleton in Lindemann's place. As the development effort grew, Watt requested a central research station be established "of large size and with ground space for a considerable number of mast and aerial systems". Several members of the team went on scouting trips with Watt to the north of Orfordness but found nothing suitable. Then Wilkins recalled having come across an interesting site about 10 mi (16 km) south of Orfordness, some time earlier while on a Sunday drive. He recalled it because it was some 70–80 ft (21–24 m) above sea level, which was unusual in that area. The large manor house on the property would have ample room for experimental labs and offices. In February and March 1936, the team moved to Bawdsey Manor and established the Air Ministry Experimental Station (AMES). When the scientific team left in 1939, the site became the operational CH site RAF Bawdsey.
Germany is home to Volkswagen Group, the world's second-largest automotive manufacturer by vehicle production. Of the world's 500 largest stock market-listed companies by revenue in 2024, the Fortune Global 500, 29 were based in Germany. The DAX, Germany's stock market index operated by the Frankfurt Stock Exchange, includes 30 major Germany-based companies. Prominent German companies include Mercedes-Benz, BMW, Volkswagen, Audi, Porsche, Siemens, Adidas, SAP, Bosch and BASF. Berlin is a hub for startup companies and has become the leading location for venture capital-funded firms in Europe. Germany is recognised for its large portion of specialised small and medium enterprises known as the Mittelstand; these companies represent around 48% of the global market leaders in their segments, labelled hidden champions. Research and development efforts form an integral part of the German economy, with the country ranking fourth in research and development expenditure since 2005. In 2018, Germany ranked fourth globally in terms of number of science and engineering research papers published and third in the quality-adjusted Nature Index in 2023. Well-known research institutions in Germany include the Max Planck Society, the Helmholtz Association, the Fraunhofer Society, and the Leibniz Association. Germany is the largest contributor to the European Space Agency. The country was ranked 11th in the Global Innovation Index in 2025.
==== Canada ==== After completing medical school, internists in Canada require an additional four years of training. Internists desiring to subspecialize are required to complete two additional years of training that may begin after the third year of internist training. The Royal College of Physicians and Surgeons of Canada (RCPSC) is a national non-profit agency that oversees and accredits medical education in Canada. A full medical license in Internal Medicine in Canada requires a medical degree, a license from the Medical Council of Canada, completion of the required post-graduate education, and certification from the RCPSC. Any additional requirements from separate medical regulatory authorities in each province or territory is also required. Internists may practice in Canada as generalists in Internal Medicine or serve in one of seventeen subspecialty areas. Internists may work in many settings including outpatient clinics, inpatient wards, critical care units, and emergency departments. The currently recognized subspecialties include the following:
Sources: en.wikipedia.org
Fig. 2 shows a typical PTR-MS measurement performed in food and flavor research. The test person swallows a sip of a vanillin flavored drink and breathes via his nose into a heated inlet device coupled to a PTR-MS instrument. Due to the high time resolution and sensitivity of the instrument used here, the development of vanillin in the person's breath can be monitored in real-time (please note that isoprene is shown in this figure because it is a product of human metabolism and therefore acts as an indicator for the breath cycles). The data can be used for food design, i.e. for adjusting the intensity and duration of vanillin flavor tasted by the consumer.
== Uses == Common skin conditions treated by topical retinoids include acne, psoriasis, and effects of photoaging. In addition, retinoids are used to treat some rare skin disorders, including discoid lupus and mycosis fungoides. In Japan, isotretinoin may be used for neuroblastoma treatment, but it is not approved in other countries due to a lack of consistency in studies of its effectiveness. Oral retinoids are readily toxic, requiring consistent clinical oversight, and are approved in several diseases for which said toxicity is paradoxically useful, including acute promyelocytic leukemia, cutaneous T-cell lymphoma, and heterotopic ossification.
=== Chemical === The chemistry of nihonium is expected to be very different from that of thallium. This difference stems from the spin–orbit splitting of the 7p shell, which results in nihonium being between two relatively inert closed-shell elements (copernicium and flerovium). Nihonium is expected to be less reactive than thallium, because of the greater stabilisation and resultant chemical inactivity of the 7s subshell in nihonium compared to the 6s subshell in thallium. The standard electrode potential for the Nh+/Nh couple is predicted to be 0.6 V. Nihonium should be a rather noble metal. The metallic group 13 elements are typically found in two oxidation states: +1 and +3. The former results from the involvement of only the single p electron in bonding, and the latter results in the involvement of all three valence electrons, two in the s-subshell and one in the p-subshell. Going down the group, bond energies decrease and the +3 state becomes less stable, as the energy released in forming two additional bonds and attaining the +3 state is not always enough to outweigh the energy needed to involve the s-electrons. Hence, for aluminium and gallium +3 is the most stable state, but +1 gains importance for indium and by thallium it becomes more stable than the +3 state. Nihonium is expected to continue this trend and have +1 as its most stable oxidation state. The simplest possible nihonium compound is the monohydride, NhH. The bonding is provided by the 7p1/2 electron of nihonium and the 1s electron of hydrogen.
==== Infectious causes ==== Parasitic infections, like Trichinella infection and sarcocystosis for example, may present with muscle pain, weakness, and inflammatory changes too. Viruses such as the influenza virus, also known as ‘the flu,’ can also cause muscle pain/weakness.
Sources: en.wikipedia.org
He wrote that: "They want to control our brotherhood... It is up to authentic Cuban Freemasons to prevent any of this from happening; once aware of the ever-growing influence State Security seeks to exert over our institution, we must not allow anyone likely linked to these agencies to assume the position." After arriving in the United States, Alfonso Vidal told reporters that former Grand Master Zamora Fernández, despite publicly appearing to stand against the injustice of the Cuban government, had privately apologized to the Communist Party. Alfonso Vidal said that at a special session of the Cuban Supreme Court of Masonic Justice, Zamora Fernández accused Master Mason Brian José Infante Machín from Logia Luz Caballero (English: Luz Caballero Lodge) of leading a conspiracy against the government, after which the Supreme Court expelled Infante Machín. Alfonso Vidal said that: "Zamora Fernández is weak-willed; his desire for recognition makes him vulnerable to State Security. I caught him crying the day he had to leave his post, and even now he hasn't come to terms with the fact that he's no longer the Grand Master. State Security takes advantage of all this; they seem to study your profile. They repeatedly emphasized that I was a noble and humble person, and that's how they approached me. Furthermore, officials from the Office of Religious Affairs speak very highly of him; in fact, they were confident that I would follow in Zamora's footsteps." He also called on the Freemasons of Cuba to elect Viñas Alonso as the Grand Master of Cuba.
Themed core specialties (A&E, Intensive Therapy Unit [ITU] and anaesthetics) Surgical specialties Medical specialties Psychiatry Run-through specialties (e.g., general practice, clinical radiology, pathology, paediatrics) The first four categories all run on a similar structure: the Trainee first completes a two-year structured and broad-based core training programme in that field (e.g., core medical training), which makes them eligible for competitive entry into an associated specialty training scheme (e.g., gastroenterology if core medical training has been completed). The Core training years are referred to as CT1 and CT2, and the specialist years are ST3 onwards until completing training. Core training and the first year or two of speciality training are equivalent to the old Senior House Officer jobs. It is customary for trainees in these areas to sit their Membership examinations (e.g., Royal College of Physicians (MRCP), Royal College of Surgeons (MRCS)) in order to progress and compete for designated sub-specialty training programmes that attract a national training number as specialty training year 3 (ST3) and beyond – up to ST9 depending on the particular training specialty. In the fifth category, the trainee immediately starts specialty training (ST1 instead of CT1) progressing up to Consultant level without break or further competitive application process (run-through training).
Based on solution structures and sequence alignments, bacteriocins appear to take on similar 3D structures despite little sequence homology, contributing to stability and resistance to degradation. Conopeptides and other toxoglossan peptides are the components of the venom of predatory marine snails, such as the cone snails or Conus. Venom peptides from cone snails are generally smaller than those found in other animal venoms (10-30 amino acids vs. 30-90 amino acids) and have more disulfide crosslinks. A single species may have 50-200 conopeptides encoded in its genome, recognizable by a well-conserved signal sequence. Cyclotides are RiPPs with a head-to-tail cyclization and three conserved disulfide bonds that form a knotted structure called a cyclic cysteine knot motif. No other posttranslational modifications have been observed on the characterized cyclotides, which are between 28 - 37 amino acids in size. Cyclotides are plant natural products and the different cyclotides appear to be species-specific. While many activities have been reported for cyclotides, it has been hypothesized that all are united by a common mechanism of binding to and disrupting the cell membrane. Glycocins are RiPPs that are glycosylated antimicrobial peptides. Only two members have been fully characterized, making this a small RiPP class. Sublancin 168 and glycocin F are both Cys-glycosylated and, in addition, have disulfide bonds between non-glycosylated Cys residues.
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.
Selank is a synthetic heptapeptide designed as a stabilized analog of the natural tetrapeptide tuftsin. It has been investigated mainly for anxiolytic and cognitive effects. It is not an approved pharmaceutical in most countries.