Everything below concerns tuftsin. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Last reviewed on 2026-05-13. Where a claim depends on a specific study, the study is described rather than over-claimed.
Lyophilized material is generally stable for extended periods when kept dry at or below minus twenty degrees Celsius. Working solutions are less stable, and common practice is to aliquot and freeze them so that repeated freeze-thaw cycles are avoided. Aqueous solutions are sensitive to pH extremes and to microbial growth, so short-term storage at refrigerator temperature is typical. Oxidation and hydrolysis are the principal degradation routes. Reconstitution with sterile water or a mild buffer is standard, and solutions should be protected from light.
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.
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.
| 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 |
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.
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.
Tuftsin, the parent structure, is a naturally occurring immunomodulatory tetrapeptide released from the Fc region of immunoglobulin G by spleen enzymes. Selank extends this four-residue sequence with three additional amino acids. The stated rationale is that the added tail slows enzymatic breakdown and may influence receptor interactions. How the full heptapeptide behaves at the molecular level is not firmly established, and proposed mechanisms often involve indirect modulation of neurotransmitter or immune signaling rather than a single defined target.
Selank is a synthetic heptapeptide developed in Russia. Its sequence is Thr-Lys-Pro-Arg-Pro-Gly-Pro, a seven-residue chain built around the natural tetrapeptide tuftsin. Researchers at the Institute of Molecular Genetics of the Russian Academy of Sciences first described the compound in the mid-1990s. The design combined the tuftsin core with an added Pro-Gly-Pro tail, a modification intended to extend the molecule's stability in biological fluids. Published work on the peptide has appeared mainly in Russian-language journals.
== Mechanisms == The mechanisms by which healthy cells transform into cancer cells are described in detail elsewhere (see Cancer main page; Carcinogenesis main page). The precise molecular changes that result in sarcoma are not always known, but certain types of sarcomas are associated with particular genetic mutations. Examples include:
Marie Maynard Daly (April 16, 1921 – October 28, 2003) was an American biochemist. She was the first African-American to receive a Ph.D. from Columbia University and the first African-American woman in the United States to earn a Ph.D. in chemistry. Daly made important contributions in four areas of research: the chemistry of histones, protein synthesis, the relationships between cholesterol and hypertension, and creatine's uptake by muscle cells.
In Koch's postulates, he set out criteria to test if an organism is the cause of a disease, and these postulates are still used today. Both Koch and Pasteur played a role in improving antisepsis in medical treatment. In 1870–1885 the modern methods of bacteriology technique were introduced by the use of stains, and by the method of separating mixtures of organisms on plates of nutrient media. Though it had been known since the nineteenth century that bacteria are a cause of many diseases, no effective antibacterial treatments were available until the 20th century. In 1910, Paul Ehrlich developed the first antibiotic, by changing dyes that selectively stained Treponema pallidum—the spirochaete that causes syphilis—into compounds that selectively killed the pathogen. Ehrlich was awarded a 1908 Nobel Prize for his work on immunology, and pioneered the use of stains to detect and identify bacteria, with his work being the basis of the Gram stain and the Ziehl–Neelsen stain. In the early 20th century, there was debate about the classification of bacteria. In 1904, cyanobacteria were usually classified as a class of algae, which are eukaryotic. However, Haeckel at this time classed cyanobacteria with bacteria because they lacked nuclei. In 1938, Herbert Faulkner Copeland proposed that prokaryotes be granted their own kingdom. The development of the transmission electron microscope allowed better visualization of cell structure and helped to clarify issues.
Branstad also stated that he would recommend that Iowa state public schools continue to use ground beef which contains the product, and stated plans to "send a letter to the state's public schools, encouraging them to continue to buy LFTB". On March 22, 2012, 41 Democrats in Congress, led by Representative Chellie Pingree of Maine, wrote a letter to United States Secretary of Agriculture Tom Vilsack, head of the USDA, that "creating a two-tiered school lunch program where kids in less affluent communities get served this low-grade slurry is wrong" and urged its elimination from all public-school lunches. Senator Jon Tester of Montana issued a news release in March 2012 urging Agriculture Secretary Vilsack to remove "pink slime" from school lunches and replace it with "high-quality Montana beef". Tester stated he planned to include provisions in the upcoming farm bill that would allow schools more flexibility in using USDA commodity funds, to increase options in purchasing locally grown and produced foods. In December 2018, lean finely textured beef was reclassified as "ground beef" by the Food Safety And Inspection Service of the United States Department Of Agriculture. This occurred after Beef Products Incorporated submitted new production processes and "a new product" to the Food Safety And Inspection Service, the agency determined that the product may be labeled as "ground beef".
=== Cachexia and sarcopenia === Cachexia and sarcopenia are similar because both cause weight and muscle loss, along with symptoms like weakness and loss of appetite. The difference is sarcopenia is caused by aging, while cachexia happens due to long-term disease and inflammation.
Sources: en.wikipedia.org
To ease the tensions, Eisenhower sent John Sherman Cooper as ambassador in 1956–57. Cooper got along very well with Nehru. In terms of rhetoric, Jawaharlal Nehru—as both prime minister and foreign minister (1947–64), promoted a moralistic rhetoric attacking both the Soviet bloc and the U.S. and its bloc. Instead Nehru tried to build a nonaligned movement, paying special attention to the many new nations in the Third World released from European colonial status at this time. President Dwight D. Eisenhower and his Secretary of State John Foster Dulles themselves used moralistic rhetoric to attack the evils of Communism. In 1959, Eisenhower became the first U.S. president to visit India to strengthen the staggering ties between the two nations. He was so supportive that the New York Times remarked, "It did not seem to matter much whether Nehru had actually requested or been given a guarantee that the US would help India to meet further Chinese Communist aggression. What mattered was the obvious strengthening of Indian–American friendship to a point where no such guarantee was necessary." During John F. Kennedy's presidency from 1961 to 1963, India was considered a strategic partner and counterweight to the rise of Communist China. Kennedy said,
== History == The first mentioned intoxication goes back to ancient India and also Hippocrates mentions a neurological disorder 46 B.C. in Greece caused by Lathyrus seed. During the Spanish War of Independence against Napoleon, grasspea served as a famine food. This was the subject of one of Francisco de Goya's famous aquatint prints titled Gracias a la Almorta ("Thanks to the Grasspea"), depicting poor people surviving on a porridge made from grasspea flour, one of them lying on the floor, already crippled by it. During WWII, on the order of Colonel I. Murgescu, commandant of the Vapniarka concentration camp in Transnistria, the detainees - most of them Jews - were fed nearly exclusively with fodder pea. Consequently, they became ill from lathyrism.
=== Guanidinium cation === The conjugate acid is called the guanidinium cation, (C(NH2)+3). This planar, symmetric ion consists of three amino groups each bonded to the central carbon atom with a covalent bond of order 4/3. It is a highly stable +1 cation in aqueous solution due to the efficient resonance stabilization of the charge and efficient solvation by water molecules. As a result, its pKa is 13.6 (pKb of 0.4) meaning that guanidine is a very strong base in water; in neutral water, it exists almost exclusively as guanidinium. Due to this, most guanidine derivatives are salts containing the conjugate acid.
On the basis of the type of human cells/tissues that have been used for engraftment, humanized mouse models for cancer can be classified as patient-derived xenografts or cell line-derived xenografts. PDX models are considered to retain the parental malignancy characteristics at a greater extent and hence these are regarded as the more powerful tool for evaluating the effect of anticancer drugs in pre-clinical studies. Humanized mouse models for studying cancers of various organs have been designed. A mouse model for the study of breast cancer has been generated by the intrahepatic engraftment of SK-BR-3 cells in NSG mice. Similarly, NSG mice intravenously engrafted with patient-derived AML cells, and those engrafted (via subcutaneous, intravenous or intra-pancreatic injections) with patient-derived pancreatic cancer tumors have also been developed for the study of leukemia and pancreatic cancer respectively. Several other humanized rodent models for the study of cancer and cancer immunotherapy have also been reported.
Sources: en.wikipedia.org
=== Counterfeits === In October 2023, there were reports of counterfeit Ozempic pens being sold in Europe. The pens possibly contained insulin, and led to several people being hospitalised with hypoglycemia and seizures. In December 2023, the US FDA issued a warning about counterfeit Ozempic.
=== Transmission === Once a significant enantiomeric enrichment has been produced in a single biomolecule or biological class of molecules in a system, the transference of chirality through the entire system is possible. This last step is known as the chiral transmission or propagation step. Independently achieving homochirality in every biomolecule (e.g., creating significant enantiomeric enrichment or complete homochirality for all 19 chiral amino acids separately) would be statistically improbable for compounds with different physical and chemical properties and has not yet been experimentally demonstrated. Stereoselective pressure from one biomolecule or biological class to others would eliminate the need to supply all prebiotically-relevant biological precursors in their enantiopure form. Some proposed models for the transmission of chiral asymmetry are polymerization, epimerization or copolymerization. Experimental work has demonstrated that enantiomerically enriched amino acids could assert chiral pressure on sugars and RNA precursors, and vice versa. For example, laboratory experiments demonstrated enantioenrichment of the 3-carbon sugar D-glyceraldehyde from a racemic solution via the interaction of L-proline-valine dipeptide. Furthermore, the stereoselective preference of D-aminoacyl-RNA for L-amino acids in nonenzymatic aminoacylation reactions provide a prebiotically plausible mechanism of chiral information transfer.
== Research == Along with the clinical trials in obesity that generated the data submitted to regulatory authorities, rimonabant was also studied in clinical trials for diabetes, atherosclerosis, and smoking cessation.
== Medical uses == In the US, sirolimus, as Rapamune, is indicated for the prevention of organ transplant rejection and for the treatment of lymphangioleiomyomatosis; and, as Fyarro, in the form of protein-bound particles, for the treatment of adults with locally advanced unresectable or metastatic malignant perivascular epithelioid cell tumour (PEComa). In the EU, sirolimus, as Rapamune, is indicated for the prophylaxis of organ rejection in adults at low to moderate immunological risk receiving a renal transplant and for the treatment of people with sporadic lymphangioleiomyomatosis with moderate lung disease or declining lung function; and, as Hyftor, for the treatment of facial angiofibroma associated with tuberous sclerosis complex.
Public health care services are available for transgender individuals in Spain, although there has been debate over whether certain procedures should be covered under the public system. The region of Andalusia was the first to approve sex reassignment procedures, including sex reassignment surgery and mastectomies, in 1999, and several other regions have followed their lead in the following years. Multiple interdisciplinary clinics exist in Spain to cater specifically to diagnosing and treating transgender patients, including the Andalusian Gender Team. As of 2013, over 4000 transgender patients had been treated in Spain, including Spaniards and international patients. Beginning in 2007, Spain has begun allowing transgender individuals who are eighteen years or older to change their name and gender identity on public records and documents if they have been receiving hormone replacement therapy for at least two years.
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 seven-amino-acid peptide built from the tuftsin sequence plus a Pro-Gly-Pro tail. It is produced by chemical synthesis rather than extracted from a natural source. The free peptide is usually supplied as a lyophilised powder or in an aqueous formulation.