The short version of tuftsin fits in a sentence. The long version — which is the one that helps — is below.
Reviewed 2026-04-29. Anything still debated is marked as such rather than presented as settled.
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.
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.
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.
| 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 |
Quality assessment of Selank samples typically combines purity determination with identity confirmation and counter-ion analysis. Purity is usually reported as a percentage by chromatographic area, with values above 95 percent often quoted for research-grade material. Water content and residual solvents are checked in lyophilized batches because they affect both stability and accurate mass determination. A reported purity figure does not by itself establish that a sample is the intended sequence, so orthogonal methods are needed to rule out sequence isomers or truncation products.
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 bonds in selank are susceptible to hydrolysis under strongly acidic or basic conditions, and the terminal proline residues are vulnerable to exopeptidase activity in biological samples. Lyophilized powder stored dry at -20 °C typically remains stable for extended periods, whereas aqueous solutions degrade faster and may lose measurable purity within days to weeks depending on pH, temperature, and microbial load. Repeated freeze-thaw cycles promote aggregation and adsorption to container surfaces. For analytical work, solutions are usually prepared fresh, kept cold, and used within a single working day.
Handling follows standard practice for research peptides. Material is weighed in a low-humidity environment because the powder absorbs atmospheric moisture. Purity is reported as the percentage area of the main peak in a chromatogram, with specifications commonly set at 95 percent or higher; values below that threshold indicate the presence of truncated or modified species. Residual trifluoroacetate from purification is often present and may affect mass balance. Certificates of analysis should state the analytical method, the column and gradient used, and the lot-specific retention time so that results can be compared across suppliers.
Identity and purity of selank are established with reversed-phase high-performance liquid chromatography coupled to mass spectrometry. The peptide elutes from C18 columns with acetonitrile gradients in water containing trifluoroacetic acid or formic acid, and detection is usually performed by ultraviolet absorbance near 214 nm. Electrospray ionization in positive mode gives a doubly protonated ion near m/z 377, consistent with a mass of about 752 Da. Amino acid analysis or tandem mass spectrometry of fragment ions confirms the sequence. Because the molecule has no aromatic residues, it lacks a usable 280 nm chromophore, so low-wavelength detection or mass spectrometry is required.
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.
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.
Formation of secondary structures is a strong indication of increased stability within the protein, and only one combination of secondary structures assumed by the polypeptide backbone will have the lowest energy and therefore be present in the native state of the protein. Among the first structures to form once the polypeptide begins to fold are alpha helices and beta turns, where alpha helices can form in as little as 100 nanoseconds and beta turns in 1 microsecond. There exists a saddle point in the energy funnel landscape where the transition state for a particular protein is found. The transition state in the energy funnel diagram is the conformation that must be assumed by every molecule of that protein if the protein wishes to finally assume the native structure. No protein may assume the native structure without first passing through the transition state. The transition state can be referred to as a variant or premature form of the native state rather than just another intermediary step. The folding of the transition state is shown to be rate-determining, and even though it exists in a higher energy state than the native fold, it greatly resembles the native structure. Within the transition state, there exists a nucleus around which the protein is able to fold, formed by a process referred to as "nucleation condensation" where the structure begins to collapse onto the nucleus.
=== Ink sac === The ink sac is located under the digestive gland. A gland attached to the sac produces the ink, and the sac holds it. The sac is close enough to the funnel for the octopus to shoot out the ink with a water jet. As the animal begins to shoot, the ink passes through glands which mix it with mucus and it leaves the funnel as a thick, dark blob, which helps the animal to escape from a predator. The main pigment in the ink is melanin, which gives it its black colour. Cirrate octopuses usually lack the ink sac.
=== Biosciences === Culture tubes are test tubes used in biology and related sciences for handling and culturing all kinds of live organisms, such as molds, bacteria, seedlings, plant cuttings, etc.. Some racks for culture tubes are designed to hold the tubes in a nearly horizontal position, so as to maximize the surface of the culture medium inside. Culture tubes for biology are usually made of clear plastic (such as polystyrene or polypropylene) by injection molding and are often discarded after use. Plastic test tubes with a screwtop cap are often called "Falcon tubes" after a line manufactured by Becton Dickinson. Some sources consider that the presence of a lip is what distinguishes a test tube from a culture tube.
There are three common naming conventions for specifying one of the two enantiomers (the absolute configuration) of a given chiral molecule: the R/S system is based on the geometry of the molecule; the (+)- and (−)- system (also written using the obsolete equivalents d- and l-) is based on its optical rotation properties; and the D/L system is based on the molecule's relationship to enantiomers of glyceraldehyde. The R/S system is based on the molecule's geometry with respect to a chiral center. The R/S system is assigned to a molecule based on the priority rules assigned by Cahn–Ingold–Prelog priority rules, in which the group or atom with the largest atomic number is assigned the highest priority and the group or atom with the smallest atomic number is assigned the lowest priority. The (+) or (−) symbol is used to specify a molecule's optical rotation — the direction in which the polarization of light rotates as it passes through a solution containing the molecule. When a molecule is denoted dextrorotatory, it rotates the plane of polarized light clockwise and can also be denoted as (+). When it is denoted as levorotatory, it rotates the plane of polarized light counterclockwise and can also be denoted as (−). The Latin words for left are laevus and sinister, and the word for right is dexter (or rectus in the sense of correct or virtuous). The English word right is a cognate of rectus. This is the origin of the D/L and R/S notations and the employment of prefixes levo- and dextro- in common names. In some contexts, the prefixes ar- and es- are used in the names.
== Early life == Arsène Charles Ernest Wenger was born on 22 October 1949 in Strasbourg, Bas-Rhin, the youngest of three children born to Alphonse and Louise Wenger. He lived in Duppigheim during the 1950s, but spent most of his time in the neighbouring village of Duttlenheim, 16 km (10 miles) south-west of Strasbourg. Arsène's father, Alphonse, like many Alsatians, was conscripted into the German Army by force following Germany's earlier annexation of the French region of Alsace-Lorraine. He was sent to fight on the Eastern Front in October 1944, at the age of 24. The Wenger family owned an automobile spare parts business and a bistro named La Croix d'Or. In his book, My Life in Red and White, Wenger says the "alcohol, brawling and violence" of the bistro's patrons sparked his early interest in human psychology. His parents had difficulty looking after their children, but Duttlenheim was a village where everyone took care of the young; Wenger compared it in later years to a kibbutz. Before Wenger started school, he expressed himself in the local Alsatian dialect of Low Alemannic German. The primary school which Wenger attended was run by the Catholic Church, and as one of its brightest students, he later was accepted into a secondary school in Obernai. According to his father, who also managed the village team, Wenger was introduced to football "at about the age of six". He was taken to games in Germany, where he held an affection for Borussia Mönchengladbach.
Sources: en.wikipedia.org
The Socialist Republic of Serbia (SR Serbia), known from 1946 to 1963 as the People's Republic of Serbia and commonly referred to as Serbia, was one of the six constituent republics of the Socialist Federal Republic of Yugoslavia. Its formation was initiated in 1941, and achieved in 1944–1946, when it was established as a federated republic within Yugoslavia. In that form, it lasted until the constitutional reforms from 1990 to 1992, when it was reconstituted, as the Republic of Serbia within the Federal Republic of Yugoslavia. It was the largest constituent republic of Yugoslavia, in terms of population and territory. Within Serbia were the two autonomous provinces: Kosovo and Vojvodina. Its capital, Belgrade, was also the federal capital of Yugoslavia.
=== Heart failure === Cilostazol is dangerous for people with severe heart failure. Cilostazol has been studied in people without heart failure, without evidence of harm, but much more data would be needed to determine no risk exists. Although cilostazol would not be approvable for a trivial condition the Cardio-Renal Advisory Committee and FDA concluded that fully informed patients and physicians should be able to choose to use it to treat intermittent claudication. Patient and physician labeling will describe the basis for concern and the incomplete information available.
=== Prosecution === Filomena Teixeira said that police did not investigate members of the family, neighbors and Dias' car, in which witnesses said they saw Mendonça go into. She also said she was sexually harassed by one of the investigators."In the Judiciary Police they were incompetent at first, the case was very badly treated. It was the worst nightmare I could have. I was alone fighting against incompetent people. They even told me that they weren't ready for these kind of things. How is that possible? (...) At the time they didn't do anything. They said [that I couldn't] go to the hills [to look for my son]. They said that they didn't like me." "[I] went everyday to the police to know if they had done something. I look in their files, everything was on paper and then there were tapes. In the beginning they had computers and they didn't know how to work with computers, because the officers there were old and didn't know how to work with computers."
=== Prevalence === Of the 350 million to 400 million individuals worldwide infected with the hepatitis B virus (HBV), one-third reside in China, with 130 million carriers and 30 million chronically infected. Since the Expanded Program on Immunization (EPI) beginning 1992, the prevalence of HBV has declined, especially among children 3 to 12 years old. During a 5-year period, 10.0% of patients with chronic hepatitis developed cirrhosis, and 20.3% of the cases with compensated cirrhosis progressed to decompensated cirrhosis. 6.5% of the people with cirrhosis and chronic hepatitis progressed to hepatocellular carcinoma (HCC). 5-year survival for compensated cirrhosis is 55%, that for decompensated cirrhosis is 14%, and that for HCC is less than 5%. Every year, 300,000 people die from HBV-related diseases in China, including 180,000 patients with HCC. However, the incidence of hepatitis B is still increasing, from 21.9 in 100,000 people in 1990 to 53.3 in 100,000 in 2003. That increase has occurred despite a vaccination program for newborn babies since the 1990s, which showed good effectiveness for reducing chronic HBV infection in children.
Physical pharmacy is the branch of pharmacy that concentrates on the applications of physics and chemistry to the study of pharmacy. In other words, it is the study of the effects that dosage forms have on their environment by addressing issues at the molecular level. It emphasis on the physical characteristics and actions of the drug delivery system before the same is given to the patient. It forms the basis for design, manufacture, and distribution of drug products and serves as the foundation for the stable and proper use of medical drugs. It covers areas such as solubility, pharmacokinetics and drug delivery. Physical pharmacy serves as principles that guide the pharmaceutical developments. It also serves as a basis for the understanding of drug absorptions, distributions, metabolism, and eliminations that happen during the course of drug treatment.
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 normally held at -20 degrees Celsius or below in a sealed, light-protected container with desiccant. Brief room-temperature handling during weighing is generally tolerated. Storage instructions vary between suppliers, so the accompanying certificate of analysis should be followed.