This is a working overview of TP-7, written for readers who want more than a one-paragraph summary but less than a textbook.
Reviewed 2025-10-08. Anything still debated is marked as such rather than presented as settled.
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.
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.
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.
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 |
|---|---|---|
| Typical storage temperature | -20 °C or below | For lyophilized powder, long term |
| Common analytical method | Reverse-phase HPLC | Usually paired with mass spectrometry |
| Typical reported purity | At or above 95 percent by area | Research-grade material |
| Aqueous solubility | High | Solutions used in laboratory assays |
| Moisture sensitivity | Hydrolyzes in solution | Aseptic handling reduces degradation |
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.
Selank is a synthetic heptapeptide developed in Russia as a structural analogue of tuftsin, a naturally occurring immunomodulatory tetrapeptide. Its sequence, Thr-Lys-Pro-Arg-Pro-Gly-Pro, keeps the tuftsin core at the N-terminus and appends a Pro-Gly-Pro tail. Researchers at the Institute of Molecular Genetics in Moscow synthesized the compound during the 1990s while searching for peptides with combined anxiolytic and immunomodulatory activity. The added tail was intended to resist enzymatic cleavage and prolong the molecule's presence in circulation.
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.
=== Protein fold === A protein fold refers to the general protein architecture, like a helix bundle, β-barrel, Rossmann fold or different "folds" provided in the Structural Classification of Proteins database. A related concept is protein topology.
=== Knowledge-based === A typical data-mining-based prediction uses support-vector machines, decision trees, or neural networks. This method is usually very successful for calculating log P values when used with compounds that have similar chemical structures and known log P values. Molecule mining approaches apply a similarity-matrix-based prediction or an automatic fragmentation scheme into molecular substructures. Furthermore, there exist also approaches using maximum common subgraph searches or molecule kernels.
is different for different electrolytes, even at the same ionic strength. There does not need to be any chemical interaction between the species in equilibrium and the background electrolyte, but such interactions might occur in particular cases. For example, phosphates form weak complexes with alkali metals, so, when determining stability constants involving phosphates, such as ATP, the background electrolyte used will be, for example, a tetralkylammonium salt. Another example involves iron(III), which forms weak complexes with halide and other anions, but not with perchlorate ions. When published constants refer to an ionic strength other than the one required for a particular application, they may be adjusted by means of specific ion theory (SIT) and other theories.
The Leidenfrost effect or film boiling is a physical phenomenon in which a liquid, close to a solid surface of another body that is significantly hotter than the liquid's boiling point, produces an insulating vapor layer that keeps the liquid from boiling rapidly. Because of this repulsive force, a droplet hovers over the surface, rather than making physical contact with it. The effect is named after the German doctor Johann Gottlob Leidenfrost, who described it in A Tract About Some Qualities of Common Water. This is most commonly seen when cooking, when drops of water are sprinkled onto a hot pan. If the pan's temperature is at or above the Leidenfrost point, which is approximately 193 °C (379 °F) for water, the water skitters across the pan and takes longer to evaporate than it would take if the water droplets had been sprinkled onto a cooler pan.
Sources: en.wikipedia.org
Bacon – some forms of bacon are dried, such as freeze-dried bacon. Bakkwa – a Chinese salty-sweet dried meat product similar to jerky. Bakkwa is made with a meat preservation and preparation technique originating from China. Bayonne ham – an air dried salted ham that takes its name from the ancient port city of Bayonne in the far South West of France, a city located in both the cultural regions of Basque Country and Gascony. Jambon de Bayonne has PGI status. It is a slightly sweet, delicately flavored meat with little salt to the taste. Biltong – a variety of cured meat that originated in Southern Africa, various types of meat are used to produce it, ranging from beef and game meats to fillets of ostrich from commercial farms. It is typically made from raw fillets of meat. Black Forest ham – a variety of dry-cured smoked ham, a pork product, produced in the Black Forest region of Germany. Ham is the thigh and rump from the haunch of a pig or boar. It is the best-selling smoked ham in Europe. Borts – a Mongolian air-dried meat with preparation involving cutting the meat into long strips which are hung in the shade. Bresaola – air-dried, salted beef that has been aged two or three months until it becomes hard and turns a dark red, almost purple color. It is made from top (inside) round, and is lean and tender, with a sweet, musty smell. It originated in Valtellina, a valley in the Alps of northern Italy's Lombardy region. Brési – beef which has been salted, dried and smoked over a period of three months, which is made in the Department of Doubs.
== Death == Kimon Georgiev died suddenly of a stroke at around 1 pm on 28 September 1969 at the rest station of the Council of Ministers in Varna, shortly after visiting the Varna Thermal Power Plant, which had opened a month earlier. He was buried on 30 September in the Central Sofia Cemetery with state honours, with Prime Minister Todor Zhivkov attending the ceremony.
== Human uses == Human uses of AGPs include the use of Gum arabic in the food and pharmaceutical industries because of natural properties in thickening and emulsification. AGPs in cereal grains have potential applications in biofortification, as sources of dietary fibre to support gut bacteria and protective agents against ethanol toxicity.
Sources: en.wikipedia.org
The incompressible Navier–Stokes equations with uniform density and viscosity and conservative external field is the fundamental equation of hydraulics. The domain for these equations is commonly a 3 or fewer dimensional Euclidean space, for which an orthogonal coordinate reference frame is usually set to explicit the system of scalar partial differential equations to be solved. In 3-dimensional orthogonal coordinate systems are 3: Cartesian, cylindrical, and spherical. Expressing the Navier–Stokes vector equation in Cartesian coordinates is quite straightforward and not much influenced by the number of dimensions of the euclidean space employed, and this is the case also for the first-order terms (like the variation and convection ones) also in non-cartesian orthogonal coordinate systems. But for the higher order terms (the two coming from the divergence of the deviatoric stress that distinguish Navier–Stokes equations from Euler equations) some tensor calculus is required for deducing an expression in non-cartesian orthogonal coordinate systems. A special case of the fundamental equation of hydraulics is the Bernoulli's equation. The incompressible Navier–Stokes equation is composite, the sum of two orthogonal equations,
The Foreign Ministry also confirmed that no Malaysians in the country were affected by the strikes, stating that the situation is closely monitored and actively obtaining updates to ensure safety of Malaysians. Prime Minister Anwar Ibrahim described the operation on Facebook as "unusual in scope and nature" as well as constitutes a "clear violation of international law and amounts to an unlawful use of force against a sovereign state". Oman: The Ministry of Foreign Affairs stated that it respects state sovereignty and independence and fully supports international law. In order to avoid escalation and bring about reconciliation, it urged all sides to use moderation and promote communication. Pakistan: The Ministry of Foreign Affairs stated that it attaches "great importance" to the wellbeing of the Venezuelan people, and urges the need for restraint and de-escalation in line with the principles of the Charter of the United Nations. It added that it is engaged with the situation on the ground to ensure the safety and security of Pakistanis in Venezuela. Philippines: The Department of Foreign Affairs stated that it is monitoring the situation in Venezuela and urged "concerned parties to resolve disputes through peaceful means, and to exercise restraint to prevent escalation of conflict". It said the Philippine Embassy in Bogotá, the non-resident mission for Venezuela, had "issued a travel and safety advisory to Filipinos in Venezuela" and was prepared to provide assistance.
Cancer cells are cells that have lost their ability to divide in a controlled fashion. A malignant tumor consists of a population of rapidly dividing and growing cancer cells that progressively accrues mutations. However, tumors need a dedicated blood supply to provide the oxygen and other essential nutrients they require in order to grow beyond a certain size (generally 1–2 mm3). Tumors induce blood vessel growth (angiogenesis) by secreting various growth factors (e.g. VEGF) and proteins. Growth factors such as bFGF and VEGF can induce capillary growth into the tumor, which some researchers suspect supply required nutrients, allowing for tumor expansion. Unlike normal blood vessels, tumor blood vessels are dilated with an irregular shape. Other clinicians believe angiogenesis really serves as a waste pathway, taking away the biological end products secreted by rapidly dividing cancer cells. In either case, angiogenesis is a necessary and required step for transition from a small harmless cluster of cells, often said to be about the size of the metal ball at the end of a ball-point pen, to a large tumor. Angiogenesis is also required for the spread of a tumor, or metastasis. Single cancer cells can break away from an established solid tumor, enter the blood vessel, and be carried to a distant site, where they can implant and begin the growth of a secondary tumor. Evidence now suggests the blood vessel in a given solid tumor may, in fact, be mosaic vessels, composed of endothelial cells and tumor cells.
Sources: en.wikipedia.org
The most common approach combines reverse-phase liquid chromatography with mass spectrometry. Chromatography separates the components while mass spectrometry confirms the molecular mass. Peptide sequencing or tandem mass analysis can further verify the amino acid order.
Lyophilized powder is usually kept frozen and protected from moisture. Solutions are less stable and are often used promptly or divided into aliquots to avoid repeated freeze-thaw cycles. Exact shelf-life values depend on purity and handling.
No. A purity figure derived from chromatographic area does not prove the amino acid sequence. Identity requires an orthogonal method such as mass spectrometry or sequencing. Truncated or isomerized peptides can co-elute with the target compound.
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.