The short version of Heptapeptide fits in a sentence. The long version — which is the one that helps — is below.
Reviewed 2026-03-01. Anything still debated is marked as such rather than presented as settled.
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, 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.
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.
| 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 |
Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro. It was designed at the Institute of Molecular Genetics of the Russian Academy of Sciences as a structural analogue of tuftsin, a naturally occurring tetrapeptide fragment of the immunoglobulin heavy chain. The added Pro-Gly-Pro tail was intended to slow enzymatic degradation and extend biological activity. In Russia it is registered as an anxiolytic nasal preparation, while regulators elsewhere have not approved it for clinical use.
Proposed mechanisms centre on modulation of the GABAergic system, with reports of altered expression of genes related to GABA-A receptor subunits and changed monoamine turnover. Some studies describe inhibition of enkephalinase, the enzyme that degrades endogenous enkephalins, which may prolong opioid peptide signalling. Effects on brain-derived neurotrophic factor and on cytokine expression have also been reported. These findings come largely from animal models and small human studies, and the precise primary target remains unresolved.
Proposed mechanisms center on modulation of the GABA system, but no single molecular target has been confirmed. Rodent studies report changes in GABA-A receptor expression and in the turnover of serotonin, dopamine, and norepinephrine in several brain regions. Increases in brain-derived neurotrophic factor and its receptor have also been described after repeated administration. These findings come largely from animal models, and the degree to which they describe human neurochemistry remains an open question. The mechanism is best characterized as multi-system and not fully resolved.
Pharmacokinetic data are limited. Like most short peptides, Selank is vulnerable to plasma and tissue peptidases, and its measured half-life in circulation is short, on a minutes scale. The Pro-Gly-Pro tail slows this degradation but does not eliminate it. Intranasal administration is the route described in most reports, with absorption through the nasal mucosa and a hypothesized path into the central nervous system that avoids the blood-brain barrier. Direct measurements of human brain exposure are unavailable, so distribution claims rest on inference from animal work.
Clinical evidence comes mainly from small studies conducted in Russia, several of which were open-label or lacked robust blinding. Reported outcomes include lower anxiety scores, changes in attention measures, and effects on asthenic states following illness. Sample sizes are typically in the tens of participants, and independent replication outside the region is scarce. Reviews published in English generally note the limited methodological quality of the underlying trials. Whether the compound produces clinically meaningful effects under rigorous conditions remains unresolved.
John Boyd Orr, 1st Baron Boyd-Orr, (23 September 1880 – 25 June 1971), styled Sir John Boyd Orr from 1935 to 1949, was a British teacher, medical doctor, biologist, nutritional physiologist, politician, businessman and farmer who was awarded the Nobel Peace Prize for his scientific research into nutrition and his work as the first Director-General of the United Nations Food and Agriculture Organization (FAO). He was the co-founder and the first President (1960–1971) of the World Academy of Art and Science (WAAS). In 1945, he was elected President of the National Peace Council and was President of the World Union of Peace Organisations and the World Movement for World Federal Government.
On the other hand, TFEU article 65(1) does not prevent taxes that distinguish taxpayers based on their residence or the location of an investment (as taxes commonly focus on a person's actual source of profit) or any measures to prevent tax evasion. Apart from tax cases, largely following from cases originating in the UK, a series of cases held that government owned golden shares were unlawful. In Commission v Germany the Commission claimed the 1960 German Volkswagen Act violated article 63, in that §2(1) restricted any party having voting rights exceeding 20% of the company, and §4(3) allowed a minority of 20% of shares held by the Lower Saxony government to block any decisions. Although this was not an impediment to actual purchase of shares, or receipt of dividends by any shareholder, the Court of Justice's Grand Chamber agreed that it was disproportionate for the government's stated aim of protecting workers or minority shareholders. Similarly, in Commission v Portugal the Court of Justice held that Portugal infringed free movement of capital by retaining golden shares in Portugal Telecom that enabled disproportionate voting rights, by creating a "deterrent effect on portfolio investments" and reducing "the attractiveness of an investment". This suggested the Court's preference that a government, if it sought public ownership or control, should nationalise in full the desired proportion of a company in line with TFEU article 345.
Michael Peter Epstein (born April 4, 1943), nicknamed "Super Jew", is an American former professional baseball player for the Baltimore Orioles, Washington Senators / Texas Rangers, Oakland Athletics, and California Angels of Major League Baseball (MLB).
== Interactions == A combination of ACE inhibitor with other drugs may increase effects of these drugs, but also the risk of adverse effects. Commonly reported adverse effects of drug combination with ACE inhibitor are acute renal failure, hypotension, and hyperkalemia. Drugs interacting with ACE inhibitor should be prescribed with caution. Special attention should be given to combinations of ACE inhibitor with diuretics (especially potassium-sparing diuretics), NSAIDs, anticoagulants, cyclosporine, DPP-4 inhibitors, and potassium supplements Angiotensin II receptor antagonists (ARBs) should not be used with ACE inhibitors. Dual RAAS inhibitor therapy (ACE inhbitors, ARBs, direct renin inhibitors, or mineralocorticoid receptor antagonists) has been found to significantly increase the risk of developing kidney damage and hyperkalemia. Potassium supplementation should be used with caution and under medical supervision owing to the hyperkalemic effect of ACE inhibitors. Concomitant use with cyclooxygenase inhibitors tends to decrease ACE inhibitor's hypotensive effect.
Sources: en.wikipedia.org
Flaminius had overseen the construction of the road named after him from Bononia (Bologna) to Arretium (Arezzo). Acidinus had conquered the Taurisci in 183. The triumvirate led 3,000 families to settle the area meaning Aquileia probably had a population of 20,000 soon after its founding. Meanwhile, based on the evidence of names chiselled on stone, the majority of colonizing families came from Picenum, Samnium, and Campania, which also explains why the colony was Latin and not Roman. Among these colonists, pedites received 50 iugera of land each, centuriones received 100 iugera each, and equites received 140 iugera each. Either at the founding or not long afterwards, colonists from the nearby Veneti supplemented these families. Roads soon connected Aquileia with the Roman colony of Bologna probably in 173 BC. In 148 BC, it was connected with Genua by the Via Postumia, which stretched across the Padanian plain from Aquileia through or near to Opitergium, Tarvisium, Vicetia, Verona, Bedriacum, and the three Roman colonies of Cremona, Placentia, and Dertona. The construction of the Via Popilia from the Roman colony of Ariminium to Ad Portum near Altinum in 132 BC improved communications still further. In the first century, the Via Gemina would link Aquileia with Emona to the east of the Julian Alps, and by 78 or 79 the Via Flavia would link Aquileia to Pula.
Crystal violet stains both Gram positive and Gram negative organisms. Treatment with alcohol removes the crystal violet colour from gram negative organisms only. Safranin as counterstain is used to colour the gram negative organisms that got decolorised by alcohol. While ex vivo, many cells continue to live and metabolize until they are "fixed". Some staining methods are based on this property. Those stains excluded by the living cells but taken up by the already dead cells are called vital stains (e.g. trypan blue or propidium iodide for eukaryotic cells). Those that enter and stain living cells are called supravital stains (e.g. New Methylene Blue and brilliant cresyl blue for reticulocyte staining). However, these stains are eventually toxic to the organism, some more so than others. Partly due to their toxic interaction inside a living cell, when supravital stains enter a living cell, they might produce a characteristic pattern of staining different from the staining of an already fixed cell (e.g. "reticulocyte" look versus diffuse "polychromasia"). To achieve desired effects, the stains are used in very dilute solutions ranging from 1:5000 to 1:500000 (Howey, 2000). Note that many stains may be used in both living and fixed cells.
=== Successful prevention and identification === The first successful preventive measure against beriberi was discovered by Takaki Kanehiro, a British-trained Japanese medical doctor of the Imperial Japanese Navy, in the mid-1880s. Beriberi was a serious problem in the Japanese navy; sailors fell ill an average of four times a year in the period 1878 to 1881, and 35% were cases of beriberi. In 1882, Takaki learned of a very high incidence of beriberi among cadets on a training mission from Japan to Hawaii, via New Zealand and South America. The voyage lasted more than nine months and resulted in 169 cases of sickness and 25 deaths on a ship of 376 men. Takaki observed that beriberi was common among low-ranking crew who were often provided free rice, thus ate little else, but not among crews of Western navies, nor among Japanese officers who consumed a more varied diet. With the support of the Japanese Navy, he conducted an experiment in which another ship was deployed on the same route, except that its crew was fed a diet of meat, fish, barley, rice, and beans. At the end of the voyage, this crew had only 14 cases of beriberi and no deaths. Takaki's results of his experiment impressed the Japanese Navy, which adopted his proposed solution. By 1887, beriberi had been eliminated on Navy ships. In the same year, Takaki's experiment was described favorably in The Lancet, but his nutritional deficiency etiology was not taken seriously, with Western medicine overwhelmingly favoring miasmatic theories, believing the disease to be caused either by microorganisms or toxins.
Sources: en.wikipedia.org
The league's official statement concluded: "Reid strongly supports the AFL in its fundamental priority of looking after the health and welfare of players. He shares his concern over the serious circumstances which gave rise to the supplements saga at the Essendon Football Club ... The AFL accepts Dr Reid’s position and withdraws all charges against him, without penalty." Hird remained on the Essendon payroll and received his full salary during the suspension. The AFL initially demanded that the payments stopped when they were made public in December 2013 but acquiesced after determining that its legal position was weak. In Hird's absence, Mark Thompson stepped up to serve as senior coach in the 2014 season. At the time of the penalties for governance failures, no charges were laid against any players, whether or not banned substances had been used was unproven, and the ASADA and AFL investigation remained open.
=== Neurology and cardiology === Theranostics extends beyond oncology and holds potential in the fields of neurology and cardiology. In neurology, theranostic approaches offer new avenues for the diagnosis and treatment of various neurodegenerative diseases, such as Alzheimer's disease, Parkinson's disease, and multiple sclerosis. Advanced imaging techniques, including magnetic resonance imaging (MRI) and positron emission tomography (PET), allow for the visualization of neuroanatomy, functional connectivity, and molecular changes in the brain. This enables early detection, precise diagnosis, and monitoring of disease progression, facilitating the development of targeted therapeutic interventions. Similarly, in cardiology, theranostics play a significant role in the diagnosis and treatment of cardiovascular conditions. Non-invasive imaging modalities like MRI and computed tomography (CT) provide detailed information about cardiac structure, function, and blood flow, aiding in the assessment of heart disease and the guidance of interventions. Theranostic approaches in cardiology involve targeted drug delivery systems for the treatment of conditions such as atherosclerosis and restenosis, as well as image-guided interventions for precise stenting or catheter-based therapies.
=== Nitriles === The principle fragmentation mode is the loss of an H-atom (M – 1) from the carbon next to the CN group due to the resonance stabilization. McLafferty rearrangement can be observed when they have longer chain lengths.
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.
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.