epitalon raises a handful of sensible questions. This page answers them in order, starting with the fundamentals and moving to applications.
This page was last updated on 2026-03-30 and is reviewed periodically as new material appears.
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.
The peptide is a synthetic analogue of epithalamin, a preparation extracted from bovine pineal glands. Investigators sought a short, chemically defined molecule that would reproduce some of the endocrine and gerontological observations attributed to the glandular extract. Proposed mechanisms centre on induction of telomerase activity, an effect reported in cultured human somatic cells in the early 2000s, together with influences on melatonin secretion and neuroendocrine regulation. Those mechanisms remain incompletely characterised, and the reported telomerase response has not been consistently reproduced by independent groups working in comparable systems.
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.
| Property | Value | Notes |
|---|---|---|
| Peptide sequence | Ala-Glu-Asp-Gly | Often abbreviated AEDG in research literature |
| Common synonyms | Epithalon, epitalon, AEDG | Spelling variants refer to the same tetrapeptide |
| Molecular formula | C14H22N4O9 | Theoretical monoisotopic mass near 390.35 Da |
| Appearance | White to off-white powder | Typically supplied as a lyophilised solid |
| Solubility class | Freely soluble in water | Hydrophilic peptide; dissolves in aqueous buffer |
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.
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.
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.
Storage practice centres on limiting moisture, oxygen, and repeated temperature cycling. Freeze-dried powder is generally held desiccated at minus twenty degrees Celsius or colder and protected from light. Reconstituted solutions are markedly less stable, and the aspartate-glycine junction is prone to succinimide formation at neutral to mildly alkaline pH. Portioning material into single-use aliquots reduces degradation compared with repeated freeze-thaw cycles. Stability data specific to this tetrapeptide remain scarce, so most handling guidance is extrapolated from general peptide chemistry rather than measured directly.
=== Sources of toxicity === Diet – Liver is high in vitamin A. The liver of certain animals, including the polar bear, bearded seal, fish and walrus, are particularly toxic (see Liver (food) § Poisoning). It has been estimated that consumption of 500 grams (18 oz) of polar bear liver would result in an acute toxic dose for humans. Supplements – Dietary supplements can be toxic when taken above recommended dosages. Cod liver oil - According to the United States Department of Agriculture, a tablespoon (13.6 grams or 14.8 mL) of cod liver oil contains 4,080 μg of vitamin A. The tolerable upper intake level (UL) is 3000 μg/day for adults, 600 μg/day for children ages 1–3 years and 900 μg/day for children ages 4–8 years, so for all ages, but especially for young children, a tablespoon a day exceeds the UL.
== Career == Eaton spent his academic career within the Department of Environmental and Occupational Health Sciences (DEOHS) at the University of Washington School of Public Health. He served as the Director of the UW Toxicology Program from 1986 to 1991. From 1995 to 2015, he led the National Institute of Environmental Health Sciences (NIEHS) Core Center as the founding director of the Center for Ecogenetics and Environmental Health (CEEH). In university-wide administration, Eaton served as Associate Dean for Research in the School of Public Health and Community Medicine from 1999 to 2005. He served as Associate Vice Provost for Research from 2006 to 2013, Interim Vice Provost for Research from 2010 to 2011, and Dean and Vice Provost of The Graduate School from 2013 until 2018. He retired as Professor Emeritus in 2019.
== Uses == In February 2010, the Food and Drug Administration of the United States approved Xiaflex for the treatment of Dupuytren's contracture. It is the first approved nonsurgical treatment for this condition. In a case of Dupuytren's contracture, collagen accumulates in the palmar fascia of the hands, so that the fingers cannot be straightened. A similar phenomenon occurs in Peyronie's disease, a contracture of the penis.
=== CNO-II === In a minor branch of the above reaction, occurring in the Sun's core 0.04% of the time, the final reaction involving 157N shown above does not produce carbon-12 and an alpha particle, but instead produces oxygen-16 and a photon and continues
According to the Council of Europe, the intentional targeting of journalists constitutes a war crime. During the conflict, Reporters Without Borders (RSF) claimed that the Israeli army had deliberately targeted journalists. An RSF investigation said that Israel had targeted journalists in two missile strikes on 13 October 2023 that killed Reuters reporter Issam Abdallah and injured four others. These two strikes, 30 seconds apart, hit a group of seven journalists in southern Lebanon who were reporting on the border fighting between Israel and Hezbollah. In a video, the journalists are seen wearing vests and helmets identifying them as "PRESS". The marking was also present on the roof of their car, which exploded after being hit by the second missile. The Netherlands Organisation for Applied Scientific Research, which tests and analyses munitions and weapons, assisted Reuters by examining the material collected at the site of the explosion and found that a piece of metal was the fin of a 120 mm tank round fired 1.34 km away from the border from a smoothbore tank gun. A February 2024 report by the United Nations Interim Force in Lebanon (UNIFIL) concluded that an Israeli tank killed Abdallah when it fired at "clearly identifiable journalists", and that this broke international law. The report "assessed that there was no exchange of fire across the Blue Line at the time of the incident", with no records of any exchange of fire across the border for the 40 minutes before the tank firing.
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Adenylyl-sulfate reductase (glutathione) (EC 1.8.4.9) is an enzyme that catalyzes the chemical reaction AMP + sulfite + glutathione disulfide ⇌ {\displaystyle \rightleftharpoons } adenylyl sulfate + 2 glutathione The 3 substrates of this enzyme are adenosine monophosphate, sulfite, and glutathione disulfide, whereas its two products are adenylyl sulfate and glutathione. This enzyme belongs to the family of oxidoreductases, specifically those acting on a sulfur group of donors with a disulfide as acceptor. The systematic name of this enzyme class is AMP,sulfite:glutathione-disulfide oxidoreductase (adenosine-5'-phosphosulfate-forming). Other names in common use include 5'-adenylylsulfate reductase (also used for, internal_xref(ec_num(1,8,99,2))), AMP,sulfite:oxidized-glutathione oxidoreductase, (adenosine-5'-phosphosulfate-forming), and plant-type 5'-adenylylsulfate reductase. In plants, APS is reduced by the plastidic enzyme APS reductase (APR; EC 1.8.4.9) in the presence of physiological concentrations of reduced glutathione (GSH), which acts as an electron donor.
Gympietides are a peptide family of neurotoxins that target pain receptors and permanently change and inactivate voltage-gated sodium channels in sensory neurons to produce long-lasting pain. The highly stable nature of these peptides means that they can repeatedly stimulate these sensory neurons, prolonging the pain. Their 3D molecular structure makes Gympietides similar to spider or cone snail toxins. The species Dendrocnide moroides produces gympietides. These toxins give D. moroides its notoriously painful toxic stings, which can last from a few hours up to a year. Dendrocnide excelsa also produces gympietides. They get their name after the species of plant Dendrocnide moroides, commonly known as gympie-gympie. All known gympietides have a very similar primary structure. The tertiary structure of Excelsatoxin A was determined via NMR spectroscopy, showing a cystine-knot structure. The other members of the family are predicted to have very similar 3D structures.
Donkey Kong Country for the SNES helped Nintendo's comeback against Sega. Doom, released 1993, helped drive adoption of IBM PC compatibles as a major video gaming platform. By late 1995, it was estimated that Doom was installed on more computers than the Microsoft Windows operating system. Myst and The 7th Guest, both released in 1993, drove adoption of CD-ROM drives for personal computers. Virtua Fighter 2, Nights into Dreams, and Sakura Wars are the killer apps for the Sega Saturn. Euro 96 and Sega Rally Championship are major system-sellers for the Sega Saturn in the United Kingdom, with the latter becoming the fastest selling CD game. Dragon Ball Z: Legends served as a killer app for the Sega Saturn in Portugal. Die Hard Arcade and Fighters Megamix boosted the Sega Saturn's sales in the United States. Ridge Racer, Tekken, Wipeout, Tomb Raider, and Crash Bandicoot are the killer apps for the PlayStation. Tomb Raider was released for the Sega Saturn first and for MS-DOS at the same time, but the games contributed substantially to the original PlayStation's early success. Final Fantasy VII is another killer app for the PlayStation. Computing Japan magazine said that it was largely responsible for the PlayStation's global installed base increasing 60% from 10 million units sold by November 1996 to 16 million units sold by May 1997. Super Mario 64 and GoldenEye 007 are the killer apps for the Nintendo 64. Virtua Fighter 3, Sonic Adventure, and The House of the Dead 2 are the killer apps for the Dreamcast. NFL 2K is a killer app for the Dreamcast in the United States.
Long after the Cisplatine War that resulted in the independence of Uruguay, Brazil won three international wars during the 58-year reign of Pedro II: the Platine War, the Uruguayan War and the devastating Paraguayan War, the largest war effort in Brazilian history. Although there was no desire among the majority of Brazilians to change the country's form of government, on 15 November 1889, in disagreement with the majority of the Imperial Army officers, as well as with rural and financial elites, the monarchy was overthrown by a military coup. A few days later, the national flag was replaced with a new design that included the national motto "Ordem e Progresso", influenced by positivism. 15 November is now Republic Day, a national holiday.
Sources: en.wikipedia.org
H2SO4 ⇌ SO3 + H2O This means that sulfuric acid above said concentration will readily degenerate until it reaches 98.3%; this is impractical in some applications such as synthesis where anhydrous conditions are preferred (like alcohol eliminations). Adding sulfur trioxide alters the chemical equilibrium, allowing concentration to be increased beyond 98.3%.
However, it was hypothesized that even if the putative first RNA-dependent RNA-polymerases are estimated to be longer—the smallest reported up-to-date RNA-dependent polymerase ribozyme is 165 nucleotides long—they did not have to arise in one step. It is more plausible that ligation of smaller RNA chains performed by the first RNA ligases resulted in a longer chain with the desired catalytically active polymerase domain. Forty years after the publication of Manfred Eigen's primary work dedicated to hypercycles, Nilesh Vaidya and colleagues showed experimentally that ribozymes can form catalytic cycles and networks capable of expanding their sizes by incorporating new members. However, this is not a demonstration of a hypercycle in accordance with its definition, but an example of a collectively autocatalytic set. Earlier computer simulations showed that molecular networks can arise, evolve and be resistant to parasitic RNA branches. In their experiments, Vaidya et al. used an Azoarcus group I intron ribozyme that, when fragmented, has an ability to self-assemble by catalysing recombination reactions in an autocatalytic manner. They mutated the three-nucleotide-long sequences responsible for recognition of target sequences on the opposite end of the ribozyme (namely, Internal Guide Sequences or IGSs) as well as these target sequences. Some genotypes could introduce cooperation by recognizing target sequences of the other ribozymes, promoting their covalent binding, while other selfish genotypes were only able to self-assemble.
South Africa In South Africa, the five-door-only 323 proved an immediate success. The 1.3 was gradually replaced by the larger 1.4 from July 1978, while a Special and a CS model were added at the low and high ends of the lineup respectively, complementing the existing De Luxe models. Well-equipped versions of the 1978 facelift model were sold as the "323 GLC" in South Africa. A 1600-cc model was also available in South Africa – however this model did not have a Mazda engine, unlike the rest of the range. To satisfy that country's local content regulations, a locally built Mitsubishi Saturn 1.6-litre unit was used. This produces 77 PS (57 kW) and was the most powerful engine to be installed in the FA-series Familia/323. It arrived in early 1979, but period testers felt that the less-revvy 1.6 provided very little that the 1.4 did not offer, and could not be considered to be worth the price. Fuel consumption dropped, while top speed of 148 km/h (92 mph) was only marginally higher than the 145 km/h (90 mph) of the smaller version. Sigma also fielded a rotary-engined 323 in the South African national rally championship.
Henry initially boards the plane but refuses to abandon his identity after seeing a forged passport, rebukes Whitney, and returns home, where he is arrested. He later accepts a plea deal for breach of fiduciary duty and attempts to relay his concerns to Bevan and Otto about Russian involvement, but is warned away by Otto, who cites the risk of assassination. Henry reconciles with Norton and serves house arrest at the family estate, where he is last seen fishing with Norton and Otto.
as a function of wavelength will yield a superposition of the effects of absorption and scattering. Because the absorption portion is more distinct and tends to ride on a background of the scatter portion, it is often used to identify and quantify the absorbing species. Consequently, this is often referred to as absorption spectroscopy, and the plotted quantity is called "absorbance", symbolized as
Sources: en.wikipedia.org
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.
No. Epithalamin is a peptide-rich extract prepared from bovine pineal glands, while epitalon is a short synthetic peptide designed as a defined analogue of it. The synthetic version was intended to provide a reproducible molecule with some of the same proposed biological activity.
Telomere elongation and telomerase activation have been reported in cultured human somatic cells, but evidence from living human subjects is limited and has not been independently confirmed at scale. Reported findings come largely from small studies with differing designs, so the question remains open rather than settled.
Reversed-phase high-performance liquid chromatography is run alongside mass spectrometry. The chromatogram separates components and gives a purity figure, while the mass spectrum confirms that the measured molecular mass matches the expected sequence. Neither measurement on its own is treated as sufficient.