TP-7 comes up often in conversation and rarely with the context attached. Here we lay out the basics in order, then work through the practical considerations.
Updated 2025-08-07. Numbers and descriptions here follow the published literature rather than marketing material.
Regulatory treatment varies by jurisdiction. In Russia the compound is a registered prescription product, while in the European Union and the United States it is generally handled as a research chemical without a marketing authorization. Suppliers therefore operate outside pharmaceutical oversight, and buyers rely on supplier documentation for purity and identity claims. Chain of custody and third-party testing are the main verification tools. Analysts note that the absence of a pharmacopoeial monograph for research-grade material limits standardization across vendors.
Purity assessment relies mainly on reverse-phase high-performance liquid chromatography with ultraviolet detection. Because the peptide lacks a strong chromophore, detection often uses backbone absorbance near 214 nm. Identity is confirmed by mass spectrometry, typically electrospray ionization or matrix-assisted laser desorption, comparing the measured mass against the expected value. Amino acid analysis can verify composition after acid hydrolysis. Diastereomer content and residual counterions are reported less often, although both can influence biological assays.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Typical purity report | 95% or higher by HPLC | Area percentage at 214 nm |
| Identity confirmation | Mass spectrometry | Electrospray or MALDI |
| Powder storage | -20 C, desiccated | Protect from light |
| Solution storage | 2-8 C short term | Freeze aliquots for longer |
| Quality document | Certificate of analysis | States method and value |
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.
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.
Enzymatic stability motivates the extra three residues at the carboxyl end. Native tuftsin is cleaved quickly by circulating aminopeptidases and carboxypeptidases, which limits its duration of action and its usefulness as a tool compound. Extending the chain with proline-rich segments is a common design tactic because proline constrains the backbone and slows proteolysis. The same Pro-Gly-Pro motif appears in other Russian-developed peptides of the era. Whether the full seven-residue chain is required for activity, or whether it acts mainly as a prodrug releasing tuftsin, remains unresolved.
Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro. Its four N-terminal residues reproduce tuftsin, a tetrapeptide fragment of the immunoglobulin heavy chain, while the C-terminal Pro-Gly-Pro extension is a synthetic addition. The peptide has a molecular mass near 752 daltons and carries a net positive charge at physiological pH because of the arginine and lysine side chains. Published indexes list it under the name Selank and the sequence abbreviation TKPRPGP. Solid-phase peptide synthesis is the standard production route for research quantities.
Furthermore, Peukert argued that völkisch racism was part of a male backlash against women's emancipation, and was a way of asserting control over women's bodies, which were viewed in a certain sense as public property since women had the duty of bearing the next generation that would pass on the "healthy genes". Peukert maintained that as the bearers of the next generation of Germans that Nazi social policies fell especially heavily upon German women. Peukert argued that for volksgenossinnen (female "national comrades"), any hint of non-conformity and the "pleasures of refusal" in not playing their designated role within the volksgemeinschaft as the bearers of the next generation of soldiers could expect harsh punishments such as sterilization, incarceration in a concentration camp or for extreme case vernichtung ("extermination"). Peukert wrote that "after 1933 any critical public discussion and any critique of racism in the human sciences from amongst the ranks of the experts was eliminated: from then on, the protective...instances of the Rechtsstaat (legal state) no longer stood between the racist perpetrators and their victims; from then on, the dictatorial state put itself solely on the side of racism". Peukert argued that all of the National Socialist social policies such as natalist policies that relentlessly pressured Aryan women to have more and children were all part of the same effort to strengthen the volksgemeinschaft.
After independence, the government began a deliberate process of crafting a uniquely Singaporean identity and culture. Singapore has a reputation as a nanny state. The government also places a heavy emphasis on meritocracy, where one is judged based on one's ability. The national flower of Singapore is the hybrid orchid, Vanda Miss Joaquim, named in memory of Agnes Joaquim, who crossbred the flower in her garden at Tanjong Pagar in 1893. Singapore is known as the Lion City and many national symbols such as the coat of arms and the lion head symbol make use of a lion. Major religious festivals are public holidays. UNESCO recognises Singapore as a "Design City."
== Histology == Skin samples under a microscope show thinned epidermis, reduced collagen, and extravasation of red blood cells. There are typically no inflammatory cells seen on solar purpura samples, but not always.
The jararaca (Bothrops jararaca) is a species that is often abundant within its range, where it is an important cause of snakebite. It is the best-known venomous snake in the wealthy and heavily populated areas of southeastern Brazil, where it was responsible for 52% (3,446 cases) of snakebites between 1902 and 1945, with a 0.7% mortality rate (25 deaths). The average venom yield is 25–26 milligrams (0.39–0.40 gr) with a maximum of 300 milligrams (4.6 gr) of dried venom. The venom is slightly more toxic than that of the terciopelo or fer-de-lance (B. asper). In mice, the median lethal dose (LD50) is 1.2–1.3 mg/kg IV, 1.4 mg/kg IP and 3.0 mg/kg SC. The lethal dose for a 60 kg adult human is 70 mg.
Sources: en.wikipedia.org
== Components == Honey bee venom is a complex mixture of proteins and smaller molecules. The main component is melittin, which amounts to 52% of venom peptides. One of the main allergens is phospholipase A2, which amounts to 12% and is an enzyme that catalyzes the hydrolysis of phospholipids, causing degradation of cell membranes, causing cell death. Adolapin contributes 2–5% of the peptides. Further protein components include apamin (2%), a neurotoxin, hyaluronidase (2%), which dilates blood vessels, increasing their permeability and facilitating the spread of the venom, mast cell degranulating peptide (2%), tertiapin, and secapin. Small molecules in bee venom include histamine (0.1–1%), dopamine and noradrenaline.
== Background == Competence is the ability of bacteria to pull DNA fragments from the environment and integrate it into their chromosome. Competence stimulating peptides (CSP) are a 17-amino acid signal peptide that triggers quorum sensing, which aids competence, biofilm formation, and virulence. The propensity of S. pneumoniae to become competent is critical to the bacterium's development of antibiotic resistance. A substantial fraction of cells in the culture of species whose appearance of competence has been studied shows that specific growth conditions (ex. growth-limiting conditions) have led to the development of competence. S. pneumoniae is unique in the sense that virtually all cells of a culture develop the ability to become competent at the same time. The density that the cells have reached during exponential growth plays a role at determining when the competency is triggered. This competency period only lasts for a short period of time, and studies indicate that this does not affect the growth rate of the culture. There are two main specificity groups that S. pneumoniae can be divided into based on the CSP signal they produce and their compatible receptors. The CSP1 signal is received by receptor ComD1 and the CSP2 signal is received by ComD2.
In Portugal, public prosecution is conducted by the Public Prosecution Service which is headed by the prosecutor general. The main police organisations of Portugal are the Guarda Nacional Republicana (National Republican Guard), the Polícia de Segurança Pública (Public Security Police), a civilian police force that works in urban areas; and the Polícia Judiciária (Judiciary Police), a senior criminal police body, under the authority of the Minister of Justice and endowed with administrative autonomy. Portugal has 49 correctional facilities run by the Directorate-General for Reintegration and Prison Services (DGRSP). The facilities are classified by security level, and by degree of management complexity, and often house inmates with different legal statuses, risk levels, and criminal trajectories within the same facilities. Despite following a reintegration-oriented penal model, Portugal retains high prison occupancy and an average sentence length of 31.3 months and one of the world's highest prison suicide rates representing around 30% of the 60 to 70 deaths occurring annually.
=== Floriculture === Many species of Lilieae (in genera Tulipa, Fritillaria, Lilium, and Erythronium) and Calochortoideae (Calochortus and Tricyrtis) are grown as ornamental plants worldwide. Within these genera a wide range of cultivars have been developed by breeding and hybridisation. They are generally used in outdoor gardens and other displays, although in common with many bulbous flowering plants they are often induced to bloom indoors, particularly during the winter months. They also form a significant part of the cut flower market, in particular Tulipa and Lilium.
gamete A haploid cell that is the meiotic product of a progenitor germ cell and the final product of the germ line in sexually reproducing multicellular organisms. Gametes are the means by which an organism passes its genetic information to its offspring; during fertilization, two gametes (one from each parent) are fused into a single diploid zygote.
Sources: en.wikipedia.org
A great number of software tools for protein structure prediction exist. Approaches include homology modeling, protein threading, ab initio methods, secondary structure prediction, and transmembrane helix and signal peptide prediction. In particular, deep learning based on long short-term memory has been used for this purpose since 2007, when it was successfully applied to protein homology detection and to predict subcellular localization of proteins. Some recent successful methods based on the CASP experiments include I-TASSER, HHpred and AlphaFold. In 2021, AlphaFold was reported to perform best. Knowing the structure of a protein often allows functional prediction as well. For instance, collagen is folded into a long-extended fiber-like chain and it makes it a fibrous protein. Recently, several techniques have been developed to predict protein folding and thus protein structure, for example, Itasser, and AlphaFold.
=== Antibody heterogeneity === Product heterogeneity is common in monoclonal antibodies and other recombinant biological products and is typically introduced either upstream during expression or downstream during manufacturing. These variants are typically aggregates, deamidation products, glycosylation variants, oxidized amino acid side chains, as well as amino and carboxyl terminal amino acid additions. These seemingly minute structural changes can affect preclinical stability and process optimization as well as therapeutic product potency, bioavailability and immunogenicity. The generally accepted purification method of process streams for monoclonal antibodies includes capture of the product target with protein A, elution, acidification to inactivate potential mammalian viruses, followed by ion chromatography, first with anion beads and then with cation beads. Displacement chromatography has been used to identify and characterize these often unseen variants in quantities that are suitable for subsequent preclinical evaluation regimens such as animal pharmacokinetic studies. Knowledge gained during the preclinical development phase is critical for enhanced product quality understanding and provides a basis for risk management and increased regulatory flexibility. The recent Food and Drug Administration's Quality by Design initiative attempts to provide guidance on development and to facilitate design of products and processes that maximizes efficacy and safety profile while enhancing product manufacturability.
Early scientific bird collections included those belonging to Pallas and Naumann in Germany, Latham and Tunstall in England and Adanson in France. Collections grew in size with increasing maritime activity, exploration and colonialism. For example, Charles Darwin collected over 400 bird specimens during his travels on the Beagle, and it was many years after his return to England that his bird collections from the Galapagos inspired (in part) his theory of evolution through natural selection. The Paris museum had 463 bird specimens in 1793 and this grew to 3411 in 1809; the Berlin museum had 2000 specimens in 1813 growing to 13,760 around 1850. In 1753 there were 1172 bird specimens in the museum established by Sir Hans Sloane but these appear to have perished before they moved to the British Museum. Early specimens from Captain Cook's voyages as well as those described by Latham in his General Synopsis of Birds (1781–1785) were also lost possibly due to poor preservation technique. The scale of collections grew to the point where they needed more space and full-time curators. In the earliest days of ornithology, collecting was the dominant method of bird observation and study. This approach has diminished with the growth of the discipline.
Reuse of needles and syringes has caused spread of diseases, especially HIV and hepatitis, among intravenous drug users. Syringes are also commonly reused by diabetics, as they can go through several in a day with multiple daily insulin injections, which becomes an affordability issue for many. Even though the syringe and needle are only used by a single person, this practice is still unsafe as it can introduce bacteria from the skin into the bloodstream and cause serious and sometimes lethal infections. In medical settings, single-use needles and syringes effectively reduce the risk of cross-contamination. Medical syringes are sometimes used without a needle for orally administering liquid medicines to young children or animals, or milk to small young animals, because the dose can be measured accurately and it is easier to squirt the medicine into the subject's mouth instead of coaxing the subject to drink out of a measuring spoon.
Sources: en.wikipedia.org
Purity is usually reported as an HPLC area percentage, most often measured at 214 nm. Identity is confirmed separately by mass spectrometry. A certificate of analysis should state both the method and the observed value.
Dry powder is kept frozen, desiccated, and shielded from light. Dissolved material is aliquoted and frozen to limit freeze-thaw cycles. Short-term refrigerated storage is common for working solutions.
Russia registers it as a prescription nasal product. Most other markets classify it as a research chemical with no approved medical use. Oversight of purity and labeling is consequently minimal in those markets.
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.