This is a working overview of lyophilization, written for readers who want more than a one-paragraph summary but less than a textbook.
This page was last updated on 2025-08-26 and is reviewed periodically as new material appears.
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.
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.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Molecular class | Synthetic heptapeptide | Stabilized analog of tuftsin |
| Sequence | Thr-Lys-Pro-Arg-Pro-Gly-Pro | Single-letter form: TKPRPGP |
| Molecular formula | C33H57N11O9 | Monoisotopic mass about 751.9 Da |
| Appearance | White to off-white powder | Typically supplied as lyophilized solid |
| Solubility | Freely soluble in water | Also soluble in common polar solvents |
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.
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.
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.
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.
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.
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=== Other === Population studies suggest that vitamin K status may have roles in inflammation, brain function, endocrine function and an anti-cancer effect. For all of these, there is not sufficient evidence from intervention trials to draw any conclusions. From a review of observational trials, long-term use of vitamin K antagonists as anticoagulation therapy is associated with lower cancer incidence in general. There are conflicting reviews as to whether agonists reduce the risk of prostate cancer.
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Banking, monetary and fiscal policy is overseen by the European Central Bank, member states, and the EU Commission. This is vital for European society as it affects the human rights to full employment, to fair wages, housing, and to an adequate standard of living. When the Eurozone and common currency of the euro was established, there was no political agreement to develop a full EU fiscal policy (i.e. tax and spending), so that governments would pool money and lend to countries in trouble, because it was thought that wealthier member states should not have to subsidise poorer member states. However, there was planned to be a common central bank, which would aim to have common interest rates. The ECB, based in Frankfurt, controls monetary policy that underpins the euro. Member states also have central banks (such as the Bundesbank, Banque de France, Banco de España), and these 19 Eurozone member state central banks have a duty to act compatibly with ECB policy. The ECB has an executive board with a president, vice president and four other members, all appointed by the European Council by qualified majority, after consulting the European Parliament, and the Governing Council of the ECB. The Governing Council is made up of the ECB executive board and member state central banks using the euro, they have 8 year terms, and can be removed only for gross misconduct.
On 23 June, Lula separately met with French president Emmanuel Macron and Paris mayor Anne Hidalgo. In October 2023, Brazil said Macron accepted an invitation by Lula to visit the country in the first half of 2024, which was subsequently confirmed by Macron himself during a bilateral meeting with Lula during the COP28 on 2 December 2023. In March 2024, Macron was welcomed by Lula for a three days-long state visit in the northern Brazilian city of Belém, where they met indigenous leader Raoni Metuktire who was awarded the Legion of Honour). Both leaders also announced France and Brazil were launching a four years-long investment plan worth of €1.1 billion to develop the Amazon region including French Guiana. Macron and Lula also visited Itaguaí to launch a third out of four conventional submarines being developed through the French-Brazilian Submarine Development Programme (PROSUB), before visiting Brasília to sign twenty bilateral agreements on 28 March 2024. Macron announced France will help Brazil build its nuclear-powered submarine under PROSUB. During the visit, Lula stated that "Among traditional powers, none is closer to Brazil than France".
==== Non-peptide ==== CA7 – among smallest-known oxytocin receptor agonists; considerable selectivity over the vasopressin V1A receptor KNX-200 (KNX200) – series; chemical structure(s) not yet disclosed LIT-001 — improved social deficits in mice; non-selective over vasopressin receptors LIT-002 – extremely potent; improved social deficits in mice; non-selective over vasopressin receptors TC OT 39 – non-selective over vasopressin receptors WAY-267,464 – anxiolytic in mice; possibly non-selective over vasopressin receptors WJ0679 – among smallest-known oxytocin receptor agonists; produces prosocial effects in rodents
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The Dogras and various organisations of Hindu-majority Jammu region have demanded a separate state after bifurcation of the territory, on the basis of cultural, linguistic and religious differences from neighbouring Kashmiris (who are predominantly Muslim by faith). In 2022, only 808 Kashmiri Hindu Pandit families remained in the valley after their forced displacement by Islamic militants.
Protein DAMPs include intracellular proteins, such as heat-shock proteins or HMGB1, and materials derived from the extracellular matrix that are generated following tissue injury, such as hyaluronan fragments. Non-protein DAMPs include ATP, uric acid, heparin sulfate and DNA.
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Sources: en.wikipedia.org
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.
It was developed in Russia, at the Institute of Molecular Genetics of the Russian Academy of Sciences, during the 1990s. Most published research originates from Russian institutions. Independent international replication remains limited.
Tuftsin is a natural tetrapeptide with the sequence Thr-Lys-Pro-Arg that participates in immune signaling. Selank extends that sequence with Pro-Gly-Pro at the C-terminus. The added residues are linked to greater resistance to enzymatic breakdown.
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.