Everything below concerns Heptapeptide. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Last reviewed on 2025-10-04. Where a claim depends on a specific study, the study is described rather than over-claimed.
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 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.
Development took place at the Institute of Molecular Genetics of the Russian Academy of Sciences, where a series of short peptides were designed in the 1980s and 1990s. Selank was selected from variants of tuftsin that showed resistance to plasma peptidases. Russian regulatory approval covers it as an anxiolytic agent given intranasally. Outside that market the compound is normally handled as a research chemical rather than a medicine, and no widely recognised international pharmacopoeial monograph exists. The name Selank is a coined trade designation rather than a systematic chemical name.
| 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 |
Laboratory work relies on standard behavioral paradigms. Rodents are tested in the elevated plus maze, open field, and passive avoidance tasks, with outcomes compared against diazepam or vehicle controls. Intranasal dosing is used most often because it bypasses first-pass metabolism, though intraperitoneal and intravenous routes also appear in published protocols. Biochemical endpoints include tissue BDNF concentrations, cytokine levels, and monoamine metabolites. Human data are limited to small Russian trials reporting reduced anxiety scores; most were not prospectively registered, and few employed independent outcome assessment.
Measuring peptide exposure inside the brain is technically difficult. Selank is degraded rapidly in plasma, and assays must separate intact peptide from fragments, which favors targeted mass spectrometry over immunoassays alone. Reported half-lives are short, on the order of minutes, so effects observed hours later are attributed to downstream signaling rather than to the parent compound. Blood-brain barrier permeability is debated and rarely quantified directly. Gaps include absent dose-response characterization, inconsistent reporting of purity, and almost no pharmacokinetic data from human participants.
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.
Reported activity for Selank centers on anxiolytic and nootropic effects. Russian clinical reports describe use in anxiety and in cognitive or attention-related complaints. Most of this evidence comes from studies conducted by the same research groups that developed the peptide. Independent replication in other countries remains limited, and no major Western regulatory agency has approved the compound for any indication. The gap between local reports and external verification is a recurring point in discussions of the peptide.
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 with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro. It was designed as a stabilized analogue of tuftsin, a naturally occurring tetrapeptide fragment derived from the immunoglobulin heavy chain. The additional Pro-Gly-Pro segment at the carboxyl terminus is intended to slow enzymatic cleavage. The compound is usually described in the literature as a synthetic peptide with anxiolytic and cognitive-related activity, a label that reflects a research context rather than an approved therapeutic category.
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.
=== Proteroglyphous snakes === The effect of the venom of proteroglyphous snakes (sea snakes, kraits, mambas, black snakes, tiger snakes, and death adders) is mainly on the nervous system, respiratory paralysis being quickly produced by bringing the venom into contact with the central nervous mechanism that controls respiration; the pain and local swelling that follow a bite are not usually severe. The bite of all the proteroglyphous elapids, even of the smallest and gentlest, such as the coral snakes, is, so far as known, deadly to humans. However, some mildly venomous elapids remain, such as the hooded snakes (Parasuta), bandy-bandies (Vermicella), etc.
== Organs and tissues affected by IGF-1 == Since many distinct tissue types express the IGF-1 receptor, IGF-1's effects are diverse. It acts as a neurotrophic factor, inducing the survival of neurons. It may catalyse skeletal muscle hypertrophy, by inducing protein synthesis, and by blocking muscle atrophy. It is protective for cartilage cells, and is associated with activation of osteocytes, and thus may be an anabolic factor for bone. Since at high concentrations it is capable of activating the insulin receptor, it can also complement for the effects of insulin. Receptors for IGF-1 are found in vascular smooth muscle, while typical receptors for insulin are not found in vascular smooth muscle.
=== Preclinical === Acne vaccine – immunostimulant ADA-308 – antiandrogen (androgen receptor antagonist) Research programme: acne vulgaris therapeutics - Attillaps Pharmaceuticals – acetylcholinesterase inhibitors
Sources: en.wikipedia.org
=== History === Calendula was not a major medicinal herb but it was used in historic times for headaches, red eye, fever and toothaches. As late as the 17th century Nicholas Culpeper claimed Calendula benefited the heart, but it was not considered an especially efficacious medicine. In historic times Calendula was more often used for magical purposes than medicinal ones. One 16th-century potion containing Calendula claimed to reveal fairies. An unmarried woman with two suitors would take a blend of powdered Calendula, marjoram, wormwood and thyme simmered in honey and white wine used as an ointment in a ritual to reveal her true match. Ancient Romans and Greeks used the golden Calendula in many rituals and ceremonies, sometimes wearing crowns or garlands made from the flowers. One of its nicknames is "Mary's Gold", referring to the flowers' use in early Christian events in some countries. Calendula flowers are sacred flowers in India and have been used to decorate the statues of Hindu deities since early times. The most common use in historic times was culinary, however, and the plant was used for both its color and its flavor. They were used for dumplings, wine, oatmeal and puddings. In English cuisine Calendula were often cooked in the same pot with spinach, or used to flavor stewed birds. According to sixteenth-century Englishman John Gerard, every proper soup of Dutch cuisine in his era would include Calendula petals.
The two substrates of this enzyme are (-)-ureidoglycolic acid and oxidised nicotinamide adenine dinucleotide (NAD+). Its products are oxaluric acid, reduced NADH, and a proton. This enzyme can use the alternative cofactor, nicotinamide adenine dinucleotide phosphate. This enzyme belongs to the family of oxidoreductases, specifically those acting on the CH-OH group of donor with NAD+ or NADP+ as acceptor. The systematic name of this enzyme class is (S)-ureidoglycolate:NAD(P)+ oxidoreductase. This enzyme participates in purine metabolism.
The Peace of Riga settled the eastern border by preserving for Poland a substantial portion of the old Commonwealth's eastern territories at the cost of partitioning the lands of the former Grand Duchy of Lithuania (Lithuania and Belarus) and Ukraine. The Ukrainians ended up with no state of their own and felt betrayed by the Riga arrangements; their resentment gave rise to extreme nationalism and anti-Polish hostility. The Kresy (or borderland) territories in the east won by 1921 would form the basis for a swap arranged and carried out by the Soviets in 1943–1945, who at that time compensated the re-emerging Polish state for the eastern lands lost to the Soviet Union with conquered areas of eastern Germany. The successful outcome of the Polish–Soviet War gave Poland a false sense of its prowess as a self-sufficient military power and encouraged the government to try to resolve international problems through imposed unilateral solutions. The territorial and ethnic policies of the interwar period contributed to bad relations with most of Poland's neighbors and uneasy cooperation with more distant centers of power, especially France and Great Britain.
Whose power is to be balanced? Today, no nation or group challenges American power … In fact, should the balance of power operate in its classical form, it would trigger countermoves by states seeking to pose a counterweight to America's expressed ambitions. According to Leffler's exegesis, Bush has invoked a balance of power vocabulary in purpose to integrate the tradition with the hegemonic dilemma. British Orwell Prize-winning policy analyst, Anatol Lieven, comments: In this conception, however, a phrase "was a form of Orwellian doublespeak. The clear intention actually was to be so strong that other countries had no choice but to rally to the side of the United States, concentrating all real power and freedom of action in the hands of America." The surprising rehabilitation of the balance-of-power term in the 2002 NSS "can be accounted for in terms of mythopoetic function that the terminology serves in the document." It keeps alive the traditional concept in a new unipolar world.
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.
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.