A practical reference on Selank: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
Reviewed 2025-10-06. Anything still debated is marked as such rather than presented as settled.
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.
Identity and purity of selank are established with reversed-phase high-performance liquid chromatography coupled to mass spectrometry. The peptide elutes from C18 columns with acetonitrile gradients in water containing trifluoroacetic acid or formic acid, and detection is usually performed by ultraviolet absorbance near 214 nm. Electrospray ionization in positive mode gives a doubly protonated ion near m/z 377, consistent with a mass of about 752 Da. Amino acid analysis or tandem mass spectrometry of fragment ions confirms the sequence. Because the molecule has no aromatic residues, it lacks a usable 280 nm chromophore, so low-wavelength detection or mass spectrometry is required.
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.
| Property | Value | Notes |
|---|---|---|
| Identity confirmation | Reversed-phase HPLC retention time versus reference standard | Retention depends on column, gradient, and ion-pairing agent |
| Mass confirmation | Electrospray or MALDI mass spectrometry | Doubly protonated ion near m/z 377 is consistent with about 752 Da |
| Typical purity specification | 95 percent or higher by chromatographic peak area | Lower values suggest truncated or modified peptide species |
| Storage of lyophilized powder | -20 °C, desiccated, protected from light | Powder tolerates long storage better than solution |
| Storage of solution | 2-8 °C for short periods | Freeze-thaw cycling promotes aggregation and surface adsorption |
Reverse-phase high-performance liquid chromatography with ultraviolet detection near 214 nanometres is the standard purity method. Mass spectrometry, typically electrospray ionisation, confirms identity through the expected mass-to-charge pattern. Amino acid analysis can verify composition independently. Chiral purity requires separate techniques such as derivatisation followed by chromatographic separation, and such data are rarely reported for research-grade material.
Quantification in biological matrices relies on liquid chromatography coupled to tandem mass spectrometry with stable-isotope internal standards. Low plasma concentrations and adsorption to container surfaces both complicate measurement. Solid-phase extraction is often needed to reduce matrix interference before injection. Reported limits of quantification differ widely between laboratories, which makes direct comparison of pharmacokinetic results difficult and limits meta-analysis.
Peptide bonds are vulnerable to protease attack, and Selank is no exception. Measured half-life in serum is short, on the order of minutes in several reports, which explains why intranasal administration is the common route described in the literature. Absorption across the nasal mucosa partially bypasses first-pass hepatic metabolism. Quantitative data on human bioavailability remain limited and are difficult to compare across studies.
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.
Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro, written TKPRPGP in one-letter notation. Its structure consists of the immunomodulatory tetrapeptide tuftsin, Thr-Lys-Pro-Arg, extended at the carboxyl terminus by a Pro-Gly-Pro segment. The molecular formula is commonly given as C33H57N11O9, corresponding to a monoisotopic mass near 751.4 Da and an average molecular mass near 751.9 Da. All seven residues are proteinogenic amino acids, and the molecule carries no modified side chains or non-natural linkages.
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.
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.
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.
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.
Other serotonin receptors may also be involved. As such, numerous serotonin receptors appear to be involved in the regulation of oxytocin secretion. Alcohol and γ-hydroxybutyrate (GHB), though producing acute anxiolytic and prosocial effects, do not affect oxytocin levels in humans. Naturally, exogenous oxytocin increases oxytocin levels in humans. Single 16 to 40 IU doses of oxytocin increased oxytocin levels, with a peak of about 2- to 3-fold, albeit with a very short duration of around 1 to 1.5 hours. However, salivary oxytocin levels may remain elevated for longer, for instance more than 2 to 7 hours, though it is unclear that salivary oxytocin levels are a useful marker of oxytocin exposure. There is no correlation of circulating oxytocin with oxytocin in cerebrospinal fluid (CSF) with intranasal oxytocin administration and levels of oxytocin in CSF do not start to increase until 75 minutes post-administration.
=== Insulin delivery === Aquasomes with calcium phosphate ceramic cores may be useful for the pharmaceutical administration of substrates such as insulin where drug action is conformationally specific. In a 2000 study by Cherian et al., disaccharides such as trehalose were used to coat the core before insulin was loaded onto the coated cores via adsorption. Albino rats were used as test subjects to test these aquasome insulin formulations, and the efficiency of different carbohydrate coat molecules on the aquasome was explored. Pyridoxal-5-phosphate-coated particles were shown to lower blood glucose levels more efficiently when compared to trehalose- or cellobiose-coated particles, which may be due to their differences in structural stability. The use of these nanoparticles for the delivery of insulin in vivo in rabbits demonstrated that insulin-bearing aquasomes showed slower release and prolonged activity compared to standard insulin solution. Similar to their role in carrying hemoglobin, the carbohydrate layer of aquasomes may be responsible for the ability to protect insulin from degradation when injected subcutaneously as in the albino rats tested. Aquasomes were also shown to release insulin in controlled manners, mimicking the typical release of insulin from the pancreas.
AB + e− → A− + B+ + e− Calibration of the mass spectrometer is important in electron capture ionization mode. A calibration compound is needed to ensure reproducibility in EC-MS. It is used to ensure that the mass scale used is correct and that the groups of ions are constant on a regular basis. Fragmentation in ECI has been studied by tandem mass spectrometry. The technique can be used with gas chromatography-mass spectrometry.
=== Synthesis === One of the earliest syntheses of DMPEA (then referred to as "homoveratrylamine") was that of Pictet and Finkelstein, who made it in a multi-step sequence starting from vanillin. A similar sequence was subsequently reported by Buck and Perkin, as follows:
24997Bk + 4820Ca → 297117* → 294117 + 3 n → 290115 + α → 286113 + α 24997Bk + 4820Ca → 297117* → 293117 + 4 n → 289115 + α → 285113 + α The new isotopes 285113 and 286113 produced did not overlap with the previously claimed 282113, 283113, and 284113, so this reaction could not be used as a cross-bombardment to confirm the 2003 or 2006 claims. In March 2010, the Riken team again attempted to synthesise 274Rg directly through the 205Tl + 70Zn reaction with upgraded equipment; they failed again and abandoned this cross-bombardment route. After 450 more days of irradiation of bismuth with zinc projectiles, Riken produced and identified another 278113 atom in August 2012. Although electricity prices had soared since the 2011 Tōhoku earthquake and tsunami, and Riken had ordered the shutdown of the accelerator programs to save money, Morita's team was permitted to continue with one experiment, and they chose their attempt to confirm their synthesis of element 113. In this case, a series of six alpha decays was observed, leading to an isotope of mendelevium:
Sources: en.wikipedia.org
== History == Investigation into the causes and characteristics of periodontal diseases began in the 18th century with pure clinical observation, and this remained the primary form of investigation well into the 19th century. During this time, the signs and symptoms of periodontal diseases were firmly established. Rather than a single disease entity, periodontal disease is a combination of multiple disease processes that share a common clinical manifestation. The cause includes both local and systemic factors. The disease consists of a chronic inflammation associated with loss of alveolar bone. Advanced disease features include pus and exudates. Essential aspects of successful treatment of periodontal disease include initial debridement and maintenance of proper oral hygiene. The advent of microscopy allowed later studies performed at the turn of the 19th century to report the histological structures and features of periodontal lesions, but most were limited to advanced stages of the disease. High correlation with protozoa Entamoeba gingivalis and Trichomonas tenax was then established. Progress in microscopy in the 1960s, such as advances in histopathology and stereology, allowed researchers to focus on earlier stages of inflammatory processes while the innovation of experimentally-induced periodontal disease in both human and animal models allowed for more detailed research into the temporal progression of the pathogenesis of plaque-induced periodontal disease.
Na3NO4 + H2O + CO2 → NaNO3 + NaOH + NaHCO3 Despite its limited chemistry, the orthonitrate anion is interesting from a structural point of view due to its regular tetrahedral shape and the short N–O bond lengths, implying significant polar character to the bonding.
At Alan Gross's espionage trial in 2011, the Cuban government prosecutors alleged that Alan Gross was running a secret program for USAID called the "Cuba democracy program." The prosecution said that Gross had been coordinating with Akram Elias about this project, and at their meeting in December 2009, they discussed extending USAID's development program into Freemasonry in Cuba. The prosecution also presented evidence at the trial of two flash drives that contained material relating to projects "against the Cuban state." In 2004, they alleged that Alan Gross smuggled a video camera to Grand Master José Manuel Collera Vento, which originated from the office of Marc Wachtenheim. That office, they pointed out, was a block away from the White House. In 2011, Grand Master Collera Venta went on a series of Cuban television broadcasts called Las Razones de Cuba, in which he publicly admitted that he had been working for the Cuban government as a counterintelligence officer his entire life, and that he had only been planted as Grand Master so that the Cuban government could monitor Freemasons. On April 1, 2011, the Cuban government awarded José Manuel Collera Vento with the Escudo Pinareño (English: Shield of Pinar del Rio), the highest award of the Provincial Assembly of People's Power in Pinar del Río. This was awarded for his services to the state. Exiled Cuban Freemasons called this a betrayal of the institution of Freemasonry itself.
====== Palliative medicine ====== To train in the add-on specialty of palliative medicine a physician must first be a specialist in one of the pediatric class specialties, one of the independent class specialties (excluding occupational and environmental medicine, clinical pharmacology, clinical genetics, forensic medicine, and social medicine), one of the internal medicine class specialties, one of the surgical class specialties, one of the neurological class specialties (excluding clinical neurophysiology) or one of the psychiatric class specialties.
Sources: en.wikipedia.org
Due to their high porosity and large surface area-to-volume ratio, nanofibers are widely used to construct scaffolds for biological applications. Major examples of natural polymers used in scaffold production are collagen, cellulose, silk fibroin, keratin, gelatin and polysaccharides such as chitosan and alginate. Collagen is a natural extracellular component of many connective tissues. Its fibrillary structure, which varies in diameter from 50-500 nm, is important for cell recognition, attachment, proliferation and differentiation. Using type I collagen nanofibers produced via electrospinning, Shih et al. found that the engineered collagen scaffold showed an increase in cell adhesion and decrease in cell migration with increasing fiber diameter. Using silk scaffolds as a guide for growth for bone tissue regeneration, Kim et al. observed complete bone union after 8 weeks and complete healing of defects after 12 weeks whereas the control in which the bone did not have the scaffold displayed limited mending of defects in the same time period. Similarly, keratin, gelatin, chitosan and alginate demonstrate excellent biocompatibility and bioactivity in scaffolds. However, cellular recognition of natural polymers can easily initiate an immune response. Consequently, synthetic polymers such as poly(lactic acid) (PLA), polycaprolactone (PCL), polyurethane (PU), poly(lactic-co-glycolic acid) (PLGA), poly(L-lactide) (PLLA), and poly(ethylene-co-vinylacetate) (PEVA) have been developed as alternatives for integration into scaffolds.
== Uses == Putrescine reacts with adipic acid to yield the polyamide nylon 46, which is marketed by Envalior (formerly DSM) under the trade name Stanyl. Due to its role in putrification, putrescine has also been proposed as a biochemical marker for determining how long a corpse has been decomposing.
In 1783, a series of earthquakes across Calabria caused around 50,000 deaths and damaged property. Many of the buildings were rebuilt thereafter. In 1733, after the outbreak of the War of Polish Succession, the Spanish Bourbons, allies of France against Austria, decided to attack Naples and secure that kingdom for Charles VII. Charles, who entered Naples in 1734, defeated the Austrian troops at the Battle of Bitonto, securing control of the kingdom, despite pockets of resistance, including Reggio Calabria, which fell on 20 June 1734. For ten years, however, the young Bourbon monarchy had to cope with the intrigues of the Austrian party present in Naples. This was particularly strong in Calabria, where the Duke of Verzino promised the Austrians that he could arm 12,000 rebels for their cause of reconquest during the War of Austrian Succession. The Duke had already armed an infantry regiment against the Infante in 1734. But after the Battle of Velletri in 1744, in which Charles VII repelled an Austrian invasion, the Austrian party disappeared, decimated by the Bourbon trials and inquisitions. Charles VII of Naples ascension aroused enthusiasm throughout the Mezzogiorno, as the population hoped that the resources of the Kingdom of Naples would be used for the development of state and social structures. Sicily, too, united politically with southern Italy; this was an advantage for Calabria, which moved to the center of the state structure. This was seen in Charles' popular journey in 1735, while on his way to Palermo to be crowned King of Sicily.
=== Thyroid cancer === At exposures eight times greater than those used in humans, liraglutide caused a statistically significant increase in thyroid tumors in rats. The clinical relevance of these findings is unknown. In clinical trials, the rate of thyroid tumors in participants treated with liraglutide was 1.3 per 1000 participant years (4 people) compared to 1.0 per 1000 participants (1 person) in comparison groups. The sole participant in the comparator group and four of the five participants in the liraglutide group had serum markers (elevated calcitonin) suggestive of pre-existing disease at baseline. The US Food and Drug Administration (FDA) said serum calcitonin, a biomarker of medullary thyroid cancer, was slightly increased in liraglutide patients, but still within normal ranges, and it required ongoing monitoring for 15 years in a cancer registry.
=== Category:EC 3.4 (act on peptide bonds - Peptidase) === Category:EC 3.4.11 Alanine aminopeptidase Category:EC 3.4.15 Angiotensin converting enzyme Category:EC 3.4.21 Serine protease Chymotrypsin (EC 3.4.21.1) Trypsin (EC 3.4.21.4) Thrombin (EC 3.4.21.5) Factor X (EC 3.4.21.6) Plasmin (EC 3.4.21.7) Acrosin (EC 3.4.21.10) Factor VII (EC 3.4.21.21) Factor IX (EC 3.4.21.22) Prolyl oligopeptidase (EC 3.4.21.26) Factor XI (EC 3.4.21.27) Elastase (EC 3.4.21.37) Factor XII (EC 3.4.21.38) Proteinase K (EC 3.4.21.64) Tissue plasminogen activator (EC 3.4.21.68) Protein C (EC 3.4.21.69) Category:EC 3.4.22 Separase (EC 3.4.22.49) Category:EC 3.4.23 Pepsin (EC 3.4.23.1) Rennet (EC 3.4.23.4) Renin (EC 3.4.23.15) Trypsinogen (EC 3.4.23.18) and (20/21/23/24/26) Plasmepsin (EC 3.4.23.39) Category:EC 3.4.24 Matrix metalloproteinase (EC 3.4.24.7) Category:EC 3.4.25 Metalloendopeptidase
Sources: en.wikipedia.org
Identity is confirmed by matching the retention time in reversed-phase chromatography against a reference standard and by measuring the molecular mass with mass spectrometry. Tandem mass spectrometry or amino acid analysis can verify the sequence of the seven residues. Because the peptide contains no aromatic amino acids, detection at 280 nm is not useful.
Lyophilized powder is normally stored desiccated at -20 °C, protected from light and moisture. Powder kept under these conditions is generally stable for long periods. Solutions are less stable and are usually prepared immediately before use.
A purity value from one chromatographic method does not capture every possible impurity. Related peptides with similar retention behavior, counterions, and residual solvents may not appear in the same analysis. Independent testing with an orthogonal method provides stronger assurance of identity and content.
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.