The short version of AEDG fits in a sentence. The long version — which is the one that helps — is below.
This page was last updated on 2026-02-28 and is reviewed periodically as new material appears.
In its supplied form epitalon is a white to off-white powder, usually lyophilized and often hygroscopic. It dissolves readily in water and in aqueous buffers, and it is commonly handled as the acetate or trifluoroacetate salt to improve stability during purification and drying. The amide backbone is labile in aqueous media, so solutions are less durable than the dry solid. Handling notes in the chemical literature therefore emphasize keeping the powder dry, cool and shielded from light until it is dissolved.
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.
Epitalon is a synthetic tetrapeptide with the residue sequence alanine-glutamate-aspartate-glycine, commonly abbreviated AEDG. Its monoisotopic mass is approximately 390.35 daltons, and it is usually supplied as a lyophilised trifluoroacetate or acetate salt. The compound was derived from a pineal gland extract called epithalamin, a heterogeneous preparation investigated in the former Soviet Union. Researchers associated with the Saint Petersburg Institute of Bioregulation and Gerontology described the tetrapeptide as a constituent fragment of that extract. Commercial material is offered as a laboratory reagent rather than as a finished pharmaceutical product.
Literature searches for this compound must account for several spelling variants. Indexing databases contain epitalon, epithalon, epithalone, and AEDG, and relevant records are scattered across Russian-language and English-language journals that do not consistently cross-cite. Early publications describe the parent extract as a mixture of many peptides, whereas later work addresses the single synthetic tetrapeptide. That shift in nomenclature complicates comparison between studies, because extract data and tetrapeptide data are sometimes cited interchangeably. A search strategy omitting the alternate spellings will return an incomplete set of references.
Reported biological findings come mainly from cell culture and rodent experiments. Those studies describe changes in telomerase catalytic subunit expression, melatonin rhythm amplitude, and antioxidant enzyme activity after peptide exposure. Human data are sparse and consist of small trials with limited blinding and inconsistent endpoints. The proposed mechanisms remain hypotheses rather than established facts, and there is no consensus on whether effects observed in animals carry over to people. Independent replication outside the original research groups is limited, which is a recognised gap in the published literature.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic tetrapeptide | Four residues, linear chain |
| Residue sequence | Ala-Glu-Asp-Gly | Single-letter form AEDG |
| Calculated mass | 390.3 daltons | Value for the free, uncharged form |
| Appearance | White to off-white powder | Usually supplied lyophilized |
| Solubility | Freely soluble in water | Often handled as a salt form |
Epitalon is a synthetic tetrapeptide with the amino acid sequence alanine-glutamate-aspartate-glycine, abbreviated Ala-Glu-Asp-Gly or AEDG. It was developed by the Russian researcher Vladimir Khavinson and colleagues during work on peptide bioregulators derived from the pineal gland. The compound is short enough to be produced by standard solid-phase peptide synthesis and is typically handled as a lyophilized white powder. Its small size distinguishes it from larger pineal peptides such as epithalamin, a complex extract from which the tetrapeptide was conceptually derived.
The four residues give epitalon a molecular formula of C14H22N4O9 and a molecular weight near 390.35 daltons. The presence of two acidic residues, glutamate and aspartate, makes the free peptide strongly acidic, while the alanine and glycine ends provide neutral, nonpolar character. This combination produces a molecule with substantial water solubility. Because there are no cysteine, methionine, or tryptophan residues, the peptide lacks the most common oxidation-sensitive side chains, which simplifies handling compared with many longer peptides.
The proposed relationship between epitalon and pineal function is a central part of its background. Khavinson's group reported that short peptides corresponding to regions of larger pineal proteins could influence gene expression in cells. Epitalon was framed as a synthetic analogue of an active fragment rather than a direct isolation product. Whether the tetrapeptide reproduces the effects of the parent extract is an open question, because comparative studies are limited and the parent extract itself is not a single defined substance.
Residue composition is the property that most cleanly separates verified material from mislabelled samples. Alanine, glutamate, aspartate and glycine appear in that order from the N-terminus, and the two acidic residues sit in the middle of the chain. Because the peptide is short, it can be produced by solid-phase synthesis and characterised by mass spectrometry without ambiguity. Any reported sample whose measured mass departs substantially from 390 daltons is a different compound or a degraded mixture rather than epitalon.
Epitalon is a synthetic tetrapeptide whose four residues are alanine, glutamate, aspartate and glycine, commonly abbreviated AEDG. Its molecular formula is C14H22N4O9 and its monoisotopic mass is near 390.35 daltons. The peptide carries two acidic side chains, so it is neutral to negatively charged in most aqueous buffers. Published reference summaries usually list it under both spellings, epitalon and epithalon, and treat the two names as the same material.
The most frequently cited proposed action is induction of telomerase, the enzyme that adds repeat sequences to chromosome ends. Cell-culture work from the originating group reported higher telomerase reverse transcriptase expression and measurable telomere elongation in human somatic cells after exposure. How a four-residue peptide would reach nuclear gene regulation is not established, and no cell-surface receptor or uptake route has been identified. Additional reports describe changes in melatonin secretion, antioxidant enzyme activity and lipid peroxidation in aged animals, but these findings remain mechanistically unconnected to the telomerase observation.
Published evidence comes mainly from Russian-language journals and from a single research group, with small sample sizes and limited independent replication. A few laboratories outside that group have examined related peptides and reported weaker or absent telomerase effects, so the central claim is best described as contested rather than settled. Rodent studies report modest changes in some ageing markers and in survival, but designs vary and control conditions are often sparse. No large randomised trial in humans has been published, and long-term safety data in healthy populations are correspondingly thin.
Epitalon is a synthetic four-amino-acid peptide with the sequence alanine-glutamate-aspartate-glycine, commonly abbreviated AEDG. Its molecular formula is C14H22N4O9, and its calculated molar mass is approximately 390.35 grams per mole. The compound is a short fragment related to a peptide fraction isolated from bovine pineal gland extracts, and it is normally supplied as a lyophilised powder intended for laboratory research. It is not a registered pharmaceutical product in most countries.
The peptide emerged from research carried out in Saint Petersburg from the late 1980s onward, where investigators searched for shorter active fragments of a pineal preparation known as epithalamin. The name epitalon was chosen to reflect that parent extract. Early reports described effects on neuroendocrine markers and on the lifespan of laboratory animals. Much of that work appeared in Russian-language journals, with English translations following later, which affects how readily the original protocols can be assessed by outside groups.
Manchester Museum organised a public discussion, "Should We Display the Dead?", which considered both Lindow Man and the Body Worlds exhibition then showing elsewhere in the city. A study by curators Jody Joy and Julia Farley examined 69 enquiries about Lindow Man received by British Museum curators between 2009 and 2018. Questions about the ethics of displaying his remains came mainly from students researching dissertations; none of the enquiries classified as coming from the general public raised that issue. Public enquiries instead tended to concern his life, death and scientific investigation. The authors distinguished these interests from the ethical questions prominent in academic and museum discussions.
In the original 1952 experiment, methane (CH4), ammonia (NH3), and hydrogen (H2) were all sealed together in a 2:2:1 ratio (1 part H2) inside a sterile 5-L glass flask connected to a 500-mL flask half-full of water (H2O). The gas chamber was intended to represent Earth's prebiotic atmosphere, while the water simulated an ocean. The water in the smaller flask was boiled such that water vapor entered the gas chamber and mixed with the "atmosphere". A continuous electrical spark was discharged between a pair of electrodes in the larger flask. The spark passed through the mixture of gases and water vapor, simulating lightning. A condenser below the gas chamber allowed aqueous solution to accumulate into a U-shaped trap at the bottom of the apparatus, which was sampled. After a day, the solution that had collected at the trap was pink, and after a week of continuous operation the solution was deep red and turbid, which Miller attributed to organic matter absorbed onto colloidal silica. The boiling flask was then removed, and mercuric chloride (a poison) was added to prevent microbial contamination. The reaction was stopped by adding barium hydroxide and sulfuric acid, and evaporated to remove impurities. Using paper chromatography, Miller identified five amino acids present in the solution: glycine, α-alanine and β-alanine were positively identified, while aspartic acid and α-aminobutyric acid (AABA) were less certain, due to the spots being faint.
On 11 January 1922, Leonard Thompson, a 14-year-old diabetic who lay dying at the Toronto General Hospital, was given the first injection of insulin. However, the extract was so impure that Thompson had a severe allergic reaction, and further injections were cancelled. Over the next 12 days, Collip worked day and night to improve the ox-pancreas extract. A second dose was injected on 23 January, eliminating the glycosuria that was typical of diabetes without causing any obvious side-effects. The first American patient was Elizabeth Hughes, the daughter of U.S. Secretary of State Charles Evans Hughes. The first patient treated in the U.S. was future woodcut artist James D. Havens; John Ralston Williams imported insulin from Toronto to Rochester, New York, to treat Havens. Banting and Best never worked well with Collip, regarding him as something of an interloper, and Collip left the project soon after. Over the spring of 1922, Best managed to improve his techniques to the point where large quantities of insulin could be extracted on demand, but the preparation remained impure. The drug firm Eli Lilly and Company had offered assistance not long after the first publications in 1921, and they took Lilly up on the offer in April. In November, Lilly's head chemist, George B. Walden discovered isoelectric precipitation and was able to produce large quantities of highly refined insulin. Shortly thereafter, insulin was offered for sale to the general public.
=== Vision === In May 2005, the US Food and Drug Administration (FDA) found that tadalafil (along with other PDE5 inhibitors) was associated with vision impairment related to NAION (non-arteritic anterior ischemic optic neuropathy). Most, but not all, of these patients, had underlying anatomic or vascular risk factors for the development of NAION, unrelated to PDE5 inhibitor use. The FDA concluded that they were not able to draw a cause and effect relationship, only an association; the label of all three PDE5 inhibitors was changed to alert clinicians to that fact. A 2019 meta-analysis found that tadalafil exposure was not associated with NAION.
The two substrates of this enzyme are cyclopentanol and oxidised nicotinamide adenine dinucleotide (NAD+). Its products are cyclopentanone, reduced NADH, and a proton. 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 cyclopentanol:NAD+ oxidoreductase.
Sources: en.wikipedia.org
=== Pre-1900 === Early film (pre-1900) was dominated by the novelty of showing an event. Single-shot moments were captured on film, such as a train entering a station, a boat docking, or factory workers leaving work. These short films were called "actuality" films; the term "documentary" was not coined until 1926. Many of the first films, such as those made by Auguste and Louis Lumière, were a minute or less in length, due to technological limitations. Films showing many people (for example, leaving a factory) were often made for commercial reasons: the people being filmed were eager to see, for payment, the film showing them. One notable film clocked in at over an hour and a half, The Corbett-Fitzsimmons Fight. Using pioneering film-looping technology, Enoch J. Rector presented the entirety of a famous 1897 prize-fight on cinema screens across the United States. In May 1896, Bolesław Matuszewski recorded on film a few surgical operations in Warsaw and Saint Petersburg hospitals. In 1898, French surgeon Eugène-Louis Doyen invited Matuszewski and Clément Maurice to record his surgical operations. They started in Paris a series of surgical films sometime before July 1898. Until 1906, the year of his last film, Doyen recorded more than 60 operations. Doyen said that his first films taught him how to correct professional errors he had been unaware of.
=== 2019 === A number of Chipotle mobile ordering app customers claimed that their mobile ordering app accounts had been hacked and reported fraudulent orders charged to their credit cards. Chipotle claimed that the customers were using unsecured passwords, and that any fraudulent orders were a result of this. The customers then argued that the passwords they were using were secure, and that their complaints involved an issue with the server.
=== Digestive system === Somatostatin is secreted by delta cells at several locations in the digestive system, namely the pyloric antrum, the duodenum and the pancreatic islets. Somatostatin released in the pyloric antrum travels via the portal venous system to the heart, then enters the systemic circulation to reach the locations where it will exert its inhibitory effects. In addition, somatostatin release from delta cells can act in a paracrine manner. In the stomach, somatostatin acts directly on the acid-producing parietal cells via a G-protein coupled receptor (which inhibits adenylate cyclase, thus effectively antagonising the stimulatory effect of histamine) to reduce acid secretion. Somatostatin can also indirectly decrease stomach acid production by preventing the release of other hormones, including gastrin and histamine which effectively slows down the digestive process.
== In other species == There is much controversy as to the effects of various artemisinin derivatives on α-cell-to-β-cell differentiation in rodents and zebrafish. Li et al., 2017 find artemisinin itself forces α⇨β conversion in rodents (via gephyrin) and zebrafish while Ackermann et al., 2018 find artesunate does not and van der Meulen et al., 2018 find the same absence of effect for artemether (although artemether does inhibit ARX). (Shin et al., 2019 further finds no such effect for GABA in rhesus macaque, although GABA is not an artemisinin but has a related action.) Both Eizirik & Gurzov 2018 and Yi et al., 2020 consider it possible that these are all legitimately varying results from varying combinations of substance, subject, and environment. On the other hand, a large number of reviewers are uncertain whether these are separate effects, instead questioning the validity of Li on the basis of Ackermann and van der Meulen – perhaps GABA receptor agonists as a whole are not β-cell-ergic. Coppieters et al., 2020 goes further, highlighting Ackermann and van der Meulen as publications that catch an unreplicatable scientific result, Li.
Sources: en.wikipedia.org
The peptide contains four residues in the order alanine, glutamate, aspartate and glycine, abbreviated AEDG. The chain is linear and held together by three peptide bonds. Its calculated mass for the uncharged free form is about 390.3 daltons.
Epithalamin refers to a crude preparation derived from bovine pineal tissue, which contains many components. Epitalon is a single synthetic tetrapeptide identified from that material and produced by chemical synthesis. The two names are sometimes confused because early reports treated the synthetic peptide as an active fragment of the extract.
It has been registered for clinical use in Russia, where it is associated with a small family of short peptides. In most other jurisdictions it is not an approved medicine and is traded as a research chemical. Regulatory status varies by country and changes over time.
It is based on epithalamin, a peptide-rich preparation obtained from pineal gland tissue and studied in the former Soviet Union. Researchers later identified the tetrapeptide AEDG as a constituent fragment of that material. Modern supplies are produced by chemical synthesis rather than tissue extraction.