Everything below concerns Reversed-phase HPLC. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Updated 2026-03-01. Numbers and descriptions here follow the published literature rather than marketing material.
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.
Selank is not a naturally occurring peptide and has no known endogenous counterpart in human physiology. Russian-language sources frequently call it TP-7, while English-language sources use the name Selank almost exclusively. Database indexing is uneven, partly because early reports appeared in regional journals that are not widely cataloged. Some summaries describe the material as a tuftsin analog and others as a synthetic heptapeptide; the labels overlap rather than conflict. Citing the primary sequence resolves ambiguity more reliably than the research or trade name alone.
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.
The primary structure of Selank is Thr-Lys-Pro-Arg-Pro-Gly-Pro, corresponding to the molecular formula C33H57N11O9 and a monoisotopic mass of roughly 751.9 daltons. The N-terminal threonine and the arginine residue in the fourth position are shared with tuftsin, which carries the sequence Thr-Lys-Pro-Arg. The three additional residues at the C-terminus, Pro-Gly-Pro, extend the chain and are associated with greater resistance to enzymatic degradation. This extension also separates Selank from the shorter parent peptide.
| Property | Value | Notes |
|---|---|---|
| Peptide sequence | Thr-Lys-Pro-Arg-Pro-Gly-Pro | Seven residues; tuftsin plus a Pro-Gly-Pro tail |
| Molecular formula | C33H57N11O9 | Commonly reported value for the free peptide |
| Monoisotopic mass | Roughly 751.4 Da | Average molecular mass near 751.9 Da |
| Appearance | White to off-white powder | Typically supplied as a lyophilized solid |
| Solubility class | Freely soluble in water | Also dissolves in saline and other polar solvents |
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.
Animal studies have examined behaviour in tests of anxiety, memory retention and stress response, and several report changes in neurotrophic or neurotransmitter-related markers. The human evidence base is much smaller, consisting mainly of short trials conducted in Russia with limited reporting in English-language journals. Sample sizes are modest and outcome measures vary between studies, so the findings are best described as preliminary. Independent replication under modern trial standards has not been widely reported.
Outside its country of origin the compound is generally handled as a research chemical rather than an approved medicine. No regulatory approval from the United States Food and Drug Administration or the European Medicines Agency has been granted for human use. Identity and purity are normally checked by reverse-phase high-performance liquid chromatography, with mass spectrometry used to confirm the molecular mass. Lyophilised material is stored cold and desiccated, and repeated freeze-thaw cycles are avoided.
Published work on this peptide almost always uses intranasal delivery, with drops or a spray applied to the nasal mucosa. Some animal experiments have used subcutaneous or intraperitoneal injection, and a smaller number have compared routes directly. Oral administration is not a focus of the literature, because short peptides of this size are broken down by digestive enzymes and cross intestinal barriers poorly. How much of an intranasal dose reaches the bloodstream intact in humans remains an open question.
A hematoma, also spelled haematoma, or blood suffusion is a localized bleeding outside of blood vessels, due to either disease or trauma including injury or surgery and may involve blood continuing to seep from broken capillaries. A hematoma is benign and is initially in liquid form spread among the tissues including in sacs between tissues where it may coagulate and solidify before blood is reabsorbed into blood vessels. An ecchymosis is a hematoma of the skin larger than 10 mm. They may occur among and or within many areas such as skin and other organs, connective tissues, bone, joints and muscle. A collection of blood (or even a hemorrhage) may be aggravated by anticoagulant medication (blood thinner). Blood seepage and collection of blood may occur if heparin is given via an intramuscular route; to avoid this, heparin must be given intravenously or subcutaneously.
Most spectrophotometers are used in the UV and visible regions of the spectrum, and some of these instruments also operate into the near-infrared region as well. The concentration of a protein can be estimated by measuring the OD at 280 nm due to the presence of tryptophan, tyrosine and phenylalanine. This method is not very accurate since the composition of proteins varies greatly and proteins with none of these amino acids do not have maximum absorption at 280 nm. Nucleic acid contamination can also interfere. This method requires a spectrophotometer capable of measuring in the UV region with quartz cuvettes. Ultraviolet-visible (UV-vis) spectroscopy involves energy levels that excite electronic transitions. Absorption of UV-vis light excites molecules that are in ground-states to their excited-states. Visible region 400–700 nm spectrophotometry is used extensively in colorimetry science. It is a known fact that it operates best at the range of 0.2–0.8 O.D. Ink manufacturers, printing companies, textiles vendors, and many more, need the data provided through colorimetry. They take readings in the region of every 5–20 nanometers along the visible region, and produce a spectral reflectance curve or a data stream for alternative presentations. These curves can be used to test a new batch of colorant to check if it makes a match to specifications, e.g., ISO printing standards. Traditional visible region spectrophotometers cannot detect if a colorant or the base material has fluorescence.
== Types == Neurotherapy, like many medical therapies, is based on knowledge from conventional medicine, relying on a scientific approach and evidence-based practice. However, some neuromodulation techniques are still attributed to alternative medicine (healthcare procedures "not readily integrated into the dominant healthcare model") because of their novelty and lack of evidence to support them. The wide range of neurotherapy techniques can be divided into three groups based on the application of energy stimulus:
== Bibliography == Khalaf, Issa (1991). Politics in Palestine: Arab Factionalism and Social Disintegration, 1939–1948. SUNY Press. ISBN 978-0-7914-0707-3 Levenberg, Haim (1993). Military Preparations of the Arab Community in Palestine: 1945–1948. London: Routledge. ISBN 978-0-7146-3439-5 Milton-Edwards, Beverly (1999). Islamic Politics in Palestine. I. B. Tauris. p. 25. ISBN 978-0-8223-2814-8 – via Internet Archive. David Tal (2004) "Israel-Arab War, 1948 -1949/ Armistices" Routledge ISBN 978-0-7146-5275-7 Sayigh, Yezid (2000). Armed Struggle and the Search for State: The Palestinian National Movement, 1949–1993. Oxford: Oxford University Press. ISBN 978-0-19-829643-0 Segev, Tom. One Palestine, Complete: Jews and Arabs Under the British Mandate. Trans. Haim Watzman. New York: Henry Holt and Company, 2001. ISBN 978-0-316-64859-2
== Toxicity and deficiency == There is an optimal range of selenium concentration in animals (or broadly speaking, in almost every selenium-dependent lifeform). Too much results in toxicity, too little results in deficiency.
Sources: en.wikipedia.org
Muscimol, the compound from which gaboxadol was derived, is a naturally occurring constituent of Amanita mushrooms such as Amanita muscaria (fly agaric) and is a potent GABAA receptor agonist similarly. However, muscimol is less selective, more toxic, and far less-researched than gaboxadol. Muscimol is reported to induce sleep in humans in addition to its well-known hallucinogenic effects that occur at sufficiently high doses. The drug shows similar effects on sleep in rodents as gaboxadol. By the mid-2020s, microdosing of muscimol and Amanita mushrooms for claimed therapeutic benefits, the most prominently cited of which is improved sleep, has become increasingly prominent.
=== Takeshita === The Takeshita geometry consists of a 54.43° electric sector, and short drift length, a second electric sector of the same curvature direction followed by another drift length before a 180° magnetic sector of opposite curvature direction.
Comfort temperature is interchangeable with neutral temperature in the scientific literature, which can be calculated through regression analysis between thermal sensation votes and indoor temperature. The neutral temperature is the solution of the resulting regression model by setting the thermal sensation vote as zero. The American Heritage Dictionary of the English Language identifies room temperature as around 20–22 °C (68–72 °F; 293–295 K), while the Oxford English Dictionary states that it is "conventionally taken as about 20 °C (68 °F; 293 K)". Ideal room temperature varies vastly depending on the surrounding climate . Studies from Indonesia have shown that the range of comfortable temperature is 24–29 °C (75–84 °F) for local residents. Studies from Nigeria show a comfortable temperature range of 26–28 °C (79–82 °F), comfortably cool 24–26 °C (75–79 °F) and comfortably warm 28–30 °C (82–86 °F). A field study conducted in Hyderabad, India returned a comfort band of 26–32.45 °C (79–90 °F) with a mean of 29.23 °C (85 °F). A study conducted in Jaipur, India among healthy young men showed that the neutral thermal comfort temperature was analyzed to be 30.15 °C (86 °F), although a range of 25.9–33.8 °C (79–93 °F) was found. People are highly sensitive to even small differences in environmental temperature. At 24 °C (75 °F), a difference of 0.38 °C (0.68 °F) can be detected between the temperature of two rooms.
=== Tempe satay === Tempeh skewered and grilled as satay. Sate kere (Javanese for 'poor man's satay') from Solo in Central Java is made from fluffy tempe gembus. Ground tempeh can also be made into a thick sauce, such as in sate ambal, a chicken satay from Kebumen, Central Java where tempeh flavored with chili and spices replaces the more common peanut sauce.
=== Canada === Wagyu cattle farming in Canada appeared after 1991 when the Canadian Wagyu Association was formed. Wagyu style cattle and farms in Canada are located in Alberta, Saskatchewan, Ontario, Quebec, British Columbia, Prince Edward Island, and Newfoundland and Labrador. Canadian Wagyu beef products are exported to the United States (including Hawaii), Australia, New Zealand, Korea, Taiwan, Singapore, Hong Kong and Europe.
Sources: en.wikipedia.org
The sequence is Thr-Lys-Pro-Arg-Pro-Gly-Pro, written TKPRPGP in one-letter code. It combines the tetrapeptide tuftsin with a carboxyl-terminal Pro-Gly-Pro extension. This full sequence identifies the molecule more precisely than the research name.
No peptide with this exact sequence has been identified as an endogenous substance. It is a laboratory-designed analog of tuftsin, a naturally occurring immunomodulatory tetrapeptide. The Pro-Gly-Pro extension has no known natural source.
Proline introduces conformational constraints that make a peptide less accessible to common peptidases. This is a standard stabilization strategy in peptide design. The added residues also increase the distance between the active tuftsin portion and typical cleavage sites.
Selank is a synthetic heptapeptide designed as a stabilized analog of the natural tetrapeptide tuftsin. It has been investigated mainly for anxiolytic and cognitive effects. It is not an approved pharmaceutical in most countries.