A practical reference on tetrapeptide: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
This page was last updated on 2025-12-25 and is reviewed periodically as new material appears.
Because epitalon has no pharmacopoeial monograph, quality assessment depends on supplier documentation and independent testing. Certificates of analysis typically report a purity figure from a single chromatographic run, a measured mass and sometimes an appearance description, but methods and acceptance criteria are not harmonised across vendors. Third-party laboratories can repeat identity and purity measurements, and mismatches between labelled and measured peptide content have been described for research peptides generally. What constitutes adequate identity confirmation for a molecule of this size stays an open question, since mass agreement alone does not separate closely related sequences.
Identity testing for epitalon relies on reversed-phase high-performance liquid chromatography for purity and mass spectrometry for mass confirmation. Because the sequence contains no tryptophan or tyrosine, ultraviolet detection at 280 nanometres is insensitive, so chromatographic methods usually monitor absorbance near 214 nanometres, where the peptide backbone absorbs. Electrospray ionisation or matrix-assisted laser desorption/ionisation then checks the intact mass against the expected value near 390 daltons. Peptide mapping or amino acid analysis after acid hydrolysis can supplement these measurements, although such confirmatory work is seldom reported on commercial certificates of analysis.
Published work on this compound consists mainly of in vitro experiments, animal studies, and small clinical investigations, a substantial share of which appeared in Russian-language journals. Sample sizes are generally small, control conditions differ between studies, and several endpoints rely on markers whose clinical meaning is itself debated. Reviews of the longevity field treat the peptide as an early example of telomerase-directed research rather than an established intervention. Regulatory treatment varies by country: some jurisdictions place it under prescription controls, others treat it as a laboratory material, and importation may be restricted regardless of local status.
Epitalon is a synthetic tetrapeptide whose sequence is alanine–glutamate–aspartate–glycine, commonly abbreviated AEDG. It was developed in Russia during the 1980s and 1990s by investigators associated with the St. Petersburg Institute of Bioregulation and Gerontology, who studied short peptides as regulators of gene expression and tissue function. The alternative spelling epithalon appears interchangeably in the literature, and the two names refer to the same molecule. Outside Russia it is encountered chiefly as a research chemical rather than a licensed medicine, and it holds no approval from the United States Food and Drug Administration or the European Medicines Agency.
| Property | Value | Notes |
|---|---|---|
| Analytical method | Reversed-phase HPLC | Purity determination, typically 214 nm |
| Mass confirmation | ESI or MALDI mass spectrometry | Compared with mass near 390 Da |
| Common synonyms | Epitalon, epithalon, AEDG | Naming differs between suppliers |
| Storage temperature | −20 °C or lower | Lyophilised powder, kept desiccated |
| Solution stability | Limited in neutral aqueous buffer | Aspartimide and hydrolysis pathways |
Identity is normally established by reversed-phase high-performance liquid chromatography combined with mass spectrometry, a pairing that separates components and confirms molecular mass at once. Purity is quoted as a percentage from the chromatogram, and figures above ninety-five percent are a frequent commercial specification. Amino acid analysis or sequencing supplies further confirmation when required. Because many short peptides behave similarly under chromatography, retention time alone does not establish sequence; the mass measurement is what separates one tetrapeptide from another, and certificates should report both.
Short peptides such as AEDG are normally supplied as a freeze-dried solid and are kept dry, cold, and shielded from light. Holding at minus twenty degrees Celsius is common for the long term, while a refrigerator suffices for brief periods before use. The material takes up moisture to some degree, so containers should stay sealed and be allowed to reach room temperature before opening, which limits condensation on the contents. Repeated warming and cooling of a single container is discouraged because it admits water and can lower the amount of intact peptide.
Dissolution is usually performed in water or a suitable aqueous buffer, and the resulting liquid is divided into single-use portions before freezing. Freeze-thaw cycling is a recognised source of loss for short peptides, since each cycle can encourage aggregation or adsorption onto container walls. Working solutions are generally kept cold and used within a short window, although published stability data specific to epitalon are thin. Containers should be marked with concentration and date, and solutions examined for cloudiness before use.
Material supplied for laboratory use is normally a lyophilised white to off-white powder that dissolves readily in water and in isotonic saline. Lyophilised cakes are hygroscopic and should be equilibrated to room temperature before opening to limit condensation on the solid. Solutions are typically prepared at milligram-per-millilitre concentrations and divided into single-use aliquots, because repeated freeze–thaw cycles degrade short peptides. Aqueous solutions are far less stable than the dry powder, and identity is usually verified by mass spectrometry alongside purity estimation from reversed-phase high-performance liquid chromatography.
Epitalon is a synthetic linear tetrapeptide with the sequence alanine–glutamate–aspartate–glycine, abbreviated AEDG. Its molecular formula is C14H22N4O9 and the calculated mass is approximately 390.35 g/mol. The compound is made by solid-phase peptide synthesis rather than extracted from tissue, although early work described it as a short fragment of a peptide fraction obtained from bovine pineal extract. In the research literature the spelling epitalon and the variant epithalone both appear, while AEDG is the standard code used in peptide nomenclature.
Several names circulate for the same molecule, including epitalon, epithalone, epithalamin tetrapeptide, and the sequence code AEDG. A CAS registry number, 307297-39-8, is commonly cited for it, though catalogue entries should be checked against supplier documentation because mislabelled records occur. In its usual form the peptide carries free amino and carboxyl termini and is neither glycosylated nor lipidated. Researchers distinguish the defined tetrapeptide from epithalamin itself, a crude pineal preparation containing many peptides that is not chemically characterised.
Documentation accompanying research peptides usually includes a certificate of analysis listing the batch number, purity figure, and test methods applied. Buyers comparing suppliers should check whether the reported purity refers to chromatographic area or to a mass-balance calculation, because the two are not equivalent. Counter-ion content, residual solvents, and water content are sometimes omitted from such certificates even though they affect the actual peptide mass present. Independent verification through a second laboratory is the most direct way to confirm that a supplied material matches its label.
Purity assessment of peptide reagents normally relies on reversed-phase high-performance liquid chromatography. A gradient of acetonitrile in water with trifluoroacetic acid, paired with a C18 stationary phase, separates the target tetrapeptide from truncated sequences and deletion analogues. Detection at 214 nanometres exploits absorbance of the peptide backbone, since the molecule contains no aromatic residue. Results are expressed as a percentage of total peak area. Values above ninety-five percent are typical for research-grade material, although reporting conventions vary between suppliers.
Identity confirmation uses mass spectrometry, usually electrospray ionisation in positive mode or matrix-assisted laser desorption. The protonated free peptide produces a signal near three hundred and ninety-one daltons, while salt adducts shift that value slightly. Tandem mass spectrometry or amino acid analysis supplies sequence-level confirmation, which a single mass measurement cannot. Peptides containing aspartate can cyclise into succinimide intermediates that hydrolyse to isoaspartate isomers of identical mass. Because those isomers are difficult to separate chromatographically, identity and purity results carry more weight when interpreted together.
Epitalon is a synthetic tetrapeptide whose sequence is alanine-glutamate-aspartate-glycine, written in single-letter code as AEDG. The four residues are joined by three peptide bonds, giving a linear backbone with no branching and no disulfide bridges. Its calculated molecular mass for the free form is approximately 390.3 daltons, a figure that rises when the compound is supplied as an acetate or trifluoroacetate salt. Because the chain is short, the molecule is defined entirely by its residue order rather than by any folded three-dimensional structure.
The compound is described in the literature as a derivative of epithalamin, a preparation obtained from bovine pineal tissue. Work on this peptide family was carried out mainly by a research group in Saint Petersburg beginning in the 1980s, and the substance was later registered for clinical use in Russia under the name Epitalon. Outside that region it is generally treated as a research chemical rather than an approved medicine. Statements about its biological activity rest on a relatively small number of studies, and independent replication remains limited.
He merged as many as fourteen neighboring municipalities and suburbs to the city on the Strait.although four, by government decree of 26 January 1933, broke away to form Villa San Giovanni (Campo Calabro and Fiumara again became autonomous after the war). The urban population thus exceeded 100,000. The reasons for this restructuring included a desire to speed up earthquake reconstruction, to make trade and communication by sea easier, and to entice emigration from small mountain towns into an urban center. During the 1920s and 1930s Reggio Calabria modernized, building new neighborhoods. Social housing districts sprang up and public facilities such as the Reggio di Calabria Centrale railway station, the National Museum of Magna Graecia and the Francesco Cilea Municipal Theater were built. Other cities benefited from the Fascist building policy. Minister of Public Works Luigi Razza built a new municipal palace for his hometown of Monteleone di Calabria (renamed Vibo Valentia). Vibo Valentia named its military airport, stadium, a square and a street in the historic center after Razza. As with the rest of Italy, Calabria's maximum support for fascism came with the Second Italo-Ethiopian War of 1935–1936, in which many Calabrians participated, momentarily relieving the region's prevailing misery with soldier's remittances. Many members of the Calabrian clergy supported the war. This marked the pinnacle of collaboration between Church and State following the Lateran Pacts of 1929.
== Connections with Morocco == Belgian Justice Minister Vincent Van Quickenborne described Morocco as a nation known for interfering in the EU. He said the investigation was focusing on multiple subjects, including the EU-Morocco trade agreements and the fisheries agreement. A report by the Financial Times revealed that the Pier Antonio Panzeri received bribes, gifts and luxury hotel stays from the Moroccan government. The former Italian MEP had ties with Moroccan officials since he was the head of the European Parliament's EU-Maghreb delegation. Records revealed that during his time in the parliament Panzeri supported decisions favoring the Moroccan government. He had raised a request to the European Commission for allocation of more funds for Morocco, and also voted in favor of Morocco's trade agreement with the EU and the fisheries agreement. Panzeri received secret payments from Morocco's ambassador to Poland Abderrahim Atmoun through the NGOs. Panzeri and Atmoun worked together as co-chairs of the Morocco-EU joint parliamentary committee. Panzeri admitted Atmoun provided financial help for his 2014 electoral campaign, including covering a €50,000 cost of a party in Milan. In 2014, Moroccan King Mohammed VI awarded Panzeri with the third class Order of Ouissam Alaouite for his services to Rabat. Atmoun received the same decoration at the same event. Belgium has drafted a request for a European arrest warrant for Atmoun who is believed to have received funds from Moroccan officials to bribe members of European Parliament to favour Morocco.
Too bad the story is so mindnumbingly dense." Fellow trade magazine The Hollywood Reporter called it a "half-baked action thriller" but still deemed it "enjoyable." Owen Gleiberman of Entertainment Weekly deemed that "the routinely scripted but kinetic Stone Cold is a throwback to Roger Corman's Hell's Angels flicks." He praised Henriksen and Forsythe for elevating the material, writing: "When they're on-screen, [the film] doesn't feel quite as B-movie-ish." Michael Wilmington of the Los Angeles Times accepted that "[t]he movie, full of unrelenting sadism, sleazy posturing and ludicrous dialogue—and some nice cinematography by Alexander Gruszynski—is far from boring." However he saw it as the ultimate example of "action movies [which] have begun to seem an end in themselves [...] as if nothing mattered any more but the sheer logistics of reducing some location to fiery chaos and rubble." Chris Hicks of Utah's Deseret News was put off by the film's violence, calling it "the bottom of the barrel" and Bosworth "a boorish clown on the field and even more boorish and clownish in his movie debut". In her nationally syndicated San Jose Mercury News review, Annette John-Hall found that "Stone Cold is a taylor-made vehicle for Bosworth, but the unpredictability and zaniness that made 'the Boz' a household name as a football player is lacking for Boz, the actor." In the city that Bosworth once called home, Steve Kelley of The Seattle Times urged: "Don’t fall for the Bosworth pitch.
== Species distribution == Across vertebrates, four paralogous TCAPs (TCAP-1–4) exhibit structural similarity to corticotropin-releasing hormone (CRH) and other secretin-family peptides and have been shown in rodent and non-mammalian models to exert anxiolytic-like effects, modulate glucose and energy homeostasis, and participate in broader tissue-specific signaling, highlighting TCAPs as evolutionarily conserved peptides.
Athletes competing in power sports, bodybuilding, professional wrestling, mixed martial arts, swimming, baseball, strength sports, track and field, cycling, soccer, weight lifting, skiing and endurance sports have been said to abuse human growth hormone, including in combination with other performance-enhancing drugs such as androgenic anabolic steroids including testosterone, certain products which claim to enhance HGH, and erythropoietin (among others). There has never been an adequately large randomized controlled trial showing definitively that HGH provides benefits to athletes and that there are no significant adverse drug reactions; there have been many small studies and several of these studies were recently reviewed and analyzed in a meta-analysis. While the authors indicated that the meta-analysis was limited by the fact that few of the included studies evaluated athletic performance and by the fact that dosing protocols in the studies may not reflect real-world doses and regimens, their conclusions were as follows:
Sources: en.wikipedia.org
=== Diet === People with autoimmune hyperthyroidism (such as in Graves' disease) should not eat foods high in iodine, such as edible seaweed and seafood. From a public health perspective, the general introduction of iodized salt in the United States in 1924 resulted in lower rates of disease and goiters, and improved the lives of children whose mothers would not have eaten enough iodine during pregnancy, which would have lowered the IQs of their children.
== Synthesis == The synthesis (in this case, of carbon-14-labelled material) can be seen in figure 1. In the first step, o-nitroaniline (compound 1) is purified through dissolution in hot water-ethanol mixture in relation 2:1. [Activated carbon] is added and the result is filtrated for clarifying. The filtrate is chilled while kept in movement to generate crystals, usually at 4 °C, but if needed it can also be cooled to −10 °C. The crystals are then collected, washed and dried. If it is pure enough it is used for the following steps, which take place at 0 till 5 °C. To produce o-Nitrobenzonitrile-14C (compound 2), the first component o-nitroaniline and (concentrated reagent grade) hydrochloric acid are put together with ice and water. Sodium nitrite, dissolved in water, is added to this thin slurry. After the formation of a pale-yellow solution, which indicates the completion of the diazotization reaction, the pH should be adjusted to 6. After this, the solution is introduced to a mixture of cuprous cyanide and toluene. At room temperature the toluene layer is removed. The aqueous layer is washed and dried and the purified product is isolated by crystallization. The third product is Anthranilamide-14C (compound 3). It is formed out of o-Nitrobenzonitrile-14C, which is first solved in ethanol and hydrazine hydrate. The solvent is heated subsequently, treated in a well-ventilated hood with small periodic charges, smaller than 10 mg, of Raney nickel. Under nitrogen atmosphere the ethanolic solution is clarified and dried.
== Clinical significance == Increased and supraphysiological ER stress in pancreatic β cells disrupts normal insulin secretion, leading to hyperinsulinemia and consequently peripheral insulin resistance associated with obesity in humans. Human clinical trials also suggested a causal link between obesity-induced increase in insulin secretion and peripheral insulin resistance. Abnormalities in XBP1 lead to a heightened endoplasmic reticulum stress response and subsequently causes a higher susceptibility for inflammatory processes that may even contribute to Alzheimer's disease. In the colon, XBP1 anomalies have been linked to the inflammatory bowel diseases including Crohn's disease. The unfolded protein response (UPR) is a cellular stress response related to the endoplasmic reticulum. The UPR is activated in response to an accumulation of unfolded or misfolded proteins in the lumen of the endoplasmic reticulum. The UPR functions to restore normal function of the cell by halting protein translation, degrading misfolded proteins, and activating the signaling pathways that lead to increasing the production of molecular chaperones involved in protein folding. Sustained overactivation of the UPR has been implicated in prion diseases as well as several other neurodegenerative diseases and the inhibition of the UPR could become a treatment for those diseases.
Previously, many studies used Mass Spectrometry (MS) in different fragmentation modes to detect AMPylated peptides. In responses to the distinctive fragmentation techniques, AMPylated protein sequences disintegrated at different parts of AMP. While electron transfer dissociation (ETD) creates minimum fragments and less complicated spectra, collision-induced dissociation (CID) and high-energy collision (HCD) fragmentation generate characteristic ions suitable for AMPylated proteins identification by generating multiple AMP fragments. Due to AMP's stability, peptide fragmentation spectra is easy to read manually or with search engines. Inhibitors of protein AMPylation with inhibitory constant (Ki) ranging from 6 - 50 μM and at least 30-fold selectivity versus HypE have been discovered.
KIAA0232 is a nuclear phosphoserine protein which in humans is encoded by the KIAA0232 gene. KIAA0232 is located at 4p16.1 neighboring TBC1 domain family member 14 and an uncharacterized locus. It has 10 exons which comprise its 4 known transcript variants. KIAA0232 is expressed fairly ubiquitously, but particularly highly in the brain relative to other tissues according to GEO normal tissue expression profiling. Other notable areas of high expression identified by EST profiling include nerves, umbilical cord, and parathyroid. There are no known paralogs of KIAA0232. KIAA0232 is conserved in most animals, including mammals, reptiles, birds, amphibians, insects, and as far back as Trichnella spiralis, a species of nematode. It is not found in fungi, plants, or prokaryotes. The KIAA0232 protein is 1395 amino acids in length with a molecular weight of 154.8kDa. It has higher than average frequencies of serine and glutamic acid residues as well as several multi-serine runs that are evolutionarily conserved. It has an isoelectric point of 4.52. KIAA0232 is largely composed of DUF4603.
Sources: en.wikipedia.org
The molecule lacks aromatic residues, so it absorbs weakly near 280 nanometres, the wavelength applied to many other peptides. The peptide bond absorbs strongly below 220 nanometres, making 214 nanometres a practical compromise. Gradient methods must therefore use mobile phases with low ultraviolet absorbance to keep the baseline clean.
Neutral and slightly basic aqueous conditions promote aspartimide formation at the aspartate-glycine step, often followed by deamidation. Elevated temperature and repeated freeze-thaw cycles accelerate the loss. Acidic solutions and dry lyophilised powder are comparatively stable over short periods.
No monograph exists in the United States Pharmacopeia or the European Pharmacopoeia, and no widely distributed certified reference standard is available. Purity and identity therefore rest on supplier methods that are not harmonised. This absence is the main reason reported purities are difficult to compare between sources.
Epitalon is a synthetic four-amino-acid peptide with the sequence alanine–glutamate–aspartate–glycine, also written AEDG. It was developed in Russian gerontology research and is studied for proposed effects on telomerase, melatonin regulation, and neuroendocrine function. It is not an approved pharmaceutical in the United States or the European Union.