The short version of Tuftsin analog fits in a sentence. The long version — which is the one that helps — is below.
This page was last updated on 2026-05-06 and is reviewed periodically as new material appears.
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.
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.
Regulatory status differs sharply by region. Selank holds a Russian marketing authorization, where it is supplied mainly as nasal drops, while authorities elsewhere have not approved it for medical use. Material sold internationally is therefore usually labeled as a research chemical rather than a medicine. Peer-reviewed publications come predominantly from Russian laboratories, and sample sizes are generally small. Whether the compound produces comparable effects under independent, well-controlled replication remains an open question that the broader literature has not settled.
| Property | Value | Notes |
|---|---|---|
| Typical purity specification | 95 percent or higher by RP-HPLC | Area percentage of the main peak |
| Identity confirmation | Electrospray ionization mass spectrometry | Observed mass compared with the theoretical value near 751.9 Da |
| Recommended dry storage | -20 °C, desiccated | -80 °C for multi-year archival material |
| Solution handling | Prepare fresh; avoid long storage | Sterile filtration reduces microbial load |
| Common synonyms | TKPRPGP; TP-7 | Sequence code and laboratory designation used interchangeably |
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.
The compound was designed at the Institute of Molecular Genetics of the Russian Academy of Sciences during the 1980s and 1990s. The stated design goal was to retain the immunomodulatory and central nervous system activity attributed to tuftsin while improving resistance to enzymatic breakdown. Adding a proline-rich tail to the short parent peptide was a deliberate strategy, because proline residues restrict the conformations available to many peptidases. The same laboratory produced Semax, an ACTH fragment analog, and both compounds were developed in parallel as short, enzymatically stabilized peptides intended for intranasal use.
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.
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.
moderate to severe plaque psoriasis in adults, children and adolescents from the age of six years who are candidates for systemic therapy. active psoriatic arthritis in adults, alone or in combination with methotrexate (MTX), when the response to previous disease modifying anti rheumatic drug (DMARD) therapy has been inadequate. active ankylosing spondylitis in adults who have responded inadequately to conventional therapy. active non-radiographic axial spondyloarthritis with objective signs of inflammation as indicated by elevated C-reactive protein (CRP) and/or magnetic resonance imaging (MRI) evidence in adults who have responded inadequately to non steroidal anti inflammatory drugs (NSAIDs). active moderate to severe hidradenitis suppurativa in adults with an inadequate response to conventional systemic HS therapy. active enthesitis-related arthritis in patients 6 years and older whose disease has responded inadequately to, or who cannot tolerate, conventional therapy. active juvenile psoriatic arthritis in patients 6 years and older whose disease has responded inadequately to, or who cannot tolerate, conventional therapy.
Another important piece of evidence is from detailed phylogenetic trees (i.e., "genealogic trees" of species) mapping out the proposed divisions and common ancestors of all living species. In 2010, Douglas L. Theobald published a statistical analysis of available genetic data, mapping them to phylogenetic trees, that gave "strong quantitative support, by a formal test, for the unity of life." Traditionally, these trees have been built using morphological methods, such as appearance, embryology, etc. Recently, it has been possible to construct these trees using molecular data, based on similarities and differences between genetic and protein sequences. All these methods produce essentially similar results, even though most genetic variation has no influence over external morphology. That phylogenetic trees based on different types of information agree with each other is strong evidence of a real underlying common descent.
Thickening foliage provided the insurgents with concealment from South African patrols, and their tracks were obliterated by the rain. At the end of April or early May, PLAN cadres returned to Angola to escape renewed SADF search and destroy efforts and retrain for the following year. Another significant factor of the physical environment was South West Africa's limited road network. The main arteries for SADF bases on the border were two highways leading west to Ruacana and north to Oshikango, and a third which stretched from Grootfontein through Kavangoland to Rundu. Much of this vital road infrastructure was vulnerable to guerrilla sabotage: innumerable road culverts and bridges were blown up and rebuilt multiple times over the course of the war. After their destruction PLAN saboteurs sowed the surrounding area with land mines to catch the South African engineers sent to repair them. One of the most routine tasks for local sector troops was a morning patrol along their assigned stretch of highway to check for mines or overnight sabotage. Despite their efforts, it was nearly impossible to guard or patrol the almost limitless number of vulnerable points on the road network, and losses from mines mounted steadily; for instance, in 1977 the SADF suffered 16 deaths due to mined roads. Aside from road sabotage, the SADF was also forced to contend with regular ambushes of both military and civilian traffic throughout Ovamboland.
mosaicism The presence of two or more populations of cells with different genotypes in an individual organism which has developed from a single fertilized egg. A mosaic organism can result from many kinds of genetic phenomena, including nondisjunction of chromosomes, endoreduplication, or mutations in individual stem cell lineages during the early development of the embryo. Mosaicism is similar to but distinct from chimerism.
Sources: en.wikipedia.org
Two people were killed in a Russian airstrike in Zolochiv, Kharkiv Oblast. Two people were also killed in a Russian missile strike in Hirnyk, Donetsk Oblast. A missile strike on Odesa injured 14 people. In Russia, the governor of Ryazan Oblast claimed that an oil refinery was set on fire by a drone. The governor of Voronezh Oblast claimed that a drone was shot down over Voronezh city, while energy infrastructure was also damaged by drones in Kursk and Oryol Oblasts. Ukrainian special forces claimed to have disabled two Russian Buk missile systems in Sumy Oblast using attack drones. Several Russian personnel were claimed killed and equipment destroyed during a Ukrainian strike on Rohove, Luhansk Oblast. It is believed three missiles, either ATACMS or Tochka-U, were used with cluster munitions. The head of the SBU's cybersecurity unit, Illia Vitiuk, was dismissed by Zelenskyy following investigations into suspicious financial activities by the former's wife while he was in office and attempts by SBU personnel to harass journalists. The United States Department of State alleged the use of chloropicrin by Russian forces in Ukraine and imposed fresh sanctions against Russian individuals and entities as a response. Russia placed several captured and destroyed Western armored vehicles on display at Moscow, including an M1A1 Abrams, M2A2 Bradley, Leopard 2A6 and several types of lighter NATO-origin armored vehicles.
High-field asymmetric-waveform ion mobility spectrometry (FAIMS or RF-DC ion mobility spectrometry) is an ion mobility spectrometry technique in which ions at atmospheric pressure are separated by the application of a high-voltage asymmetric waveform at radio frequency (RF) combined with a static (DC) waveform applied between two electrodes. Depending on the ratio of the high-field and low-field mobility of the ion, it will migrate toward one or the other electrode. Only ions with specific mobility will pass through the device.
=== Synthesis and release === The corpus luteum produces the 6-kDa peptide hormone relaxin. Prolactin and insulin-like growth factor binding protein are two examples of the hormones and growth factors that relaxin can stimulate the secretion of. Preprorelaxin is the collective term for the signal peptide, B chain, C peptide, and A chain found in the coding area of human relaxin genes. The signal peptide is cleaved to produce prorelaxin. Prohormone convertases, such as prohormone convertase-1 and prohormone convertase-2, can convert prorelaxin to mature relaxin.
Sources: en.wikipedia.org
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.
A reported purity value reflects the share of the main peak in one chromatographic run and says nothing about identity. Confirming that the expected sequence is present requires a separate measurement such as mass spectrometry. Purity and identity are distinct questions.
A mass spectrum reports the molecular masses present in a sample and shows whether they match the value expected for selank, near 751.9 Da. It also flags common artifacts such as truncation or adduct formation. It does not establish correct stereochemistry or complete sequence order on its own.
Selank is a synthetic seven-amino-acid peptide modeled on tuftsin, a fragment of the immunoglobulin G heavy chain. It was designed in Russia to combine anxiolytic and immunomodulatory properties in one molecule.