If you have been reading about tetrapeptide and want a single page that covers the useful parts, this is it: definitions, context, how it is studied, and the questions that come up repeatedly.
Last reviewed on 2026-03-24. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Amino acid sequence | Ala-Glu-Asp-Gly | Tetrapeptide, often abbreviated AEDG |
| Molecular formula | C14H22N4O9 | Free peptide, unmodified termini |
| Molecular weight | ~390.35 Da | Calculated for the free acid form |
| Appearance | White to off-white powder | Typical lyophilized product form |
| Solubility class | Freely soluble in water | Two acidic residues dominate ionic character |
Epitalon is the common name for a synthetic tetrapeptide with the sequence alanine-glutamate-aspartate-glycine, usually abbreviated AEDG. All four residues are proteinogenic amino acids, and the free peptide has a calculated mass near 390 grams per mole. Because the chain is short and carries no modifications, it is assembled readily by solid-phase synthesis and is distributed mainly as a freeze-dried solid for laboratory work. Catalogue listings use the spellings epitalon, epithalone, and simply AEDG, and the three refer to the same sequence.
The compound is generally presented as a synthetic fragment of epithalamin, a pineal gland extract investigated in the former Soviet Union from the 1970s onward. Vladimir Khavinson and colleagues in Saint Petersburg developed short peptides modelled on such extracts, and epitalon became the most widely cited of those sequences. Most primary reports appeared in Russian-language journals or in proceedings with limited international circulation. Independent replication in laboratories outside that network remains sparse, and much repeated secondary material traces back to a small number of originating groups.
Laboratory work has examined effects on telomerase activity in cultured cells, on melatonin rhythms in animals, and on markers of oxidative stress. Some experiments report measurable changes while others show none, and the reported findings rest largely on small studies. The absence of large independent trials means the generality of these results is unresolved rather than settled. Review articles occasionally apply the label geroprotector, a term that reflects a research hypothesis about ageing rather than an established clinical finding.
Discussions in the literature often conflate three distinct entities: the pineal extract epithalamin, the isolated tetrapeptide AEDG, and commercial preparations sold under similar names. Reviews citing older Russian-language studies sometimes omit detail on purity, route of administration and control groups, which makes cross-study comparison difficult. Researchers working with the compound generally note the need for independent replication, standardized enzyme assays, and clearer reporting of peptide identity. These caveats are relevant when weighing claims that appear in secondary sources rather than in primary reports.
（TG:@pojiaai）Epitalon is a synthetic linear tetrapeptide with the sequence alanine-glutamate-aspartate-glycine, abbreviated AEDG. It emerged from work on epithalamin, a peptide fraction prepared from bovine pineal tissue, and was designed as a short, chemically defined analogue of that extract. Early publications came mainly from Russian laboratories studying pineal peptides and aging-related endpoints. The compound appears in the literature under several spellings, including epithalon and epithalone, which complicates systematic searching. Its small size makes solid-phase assembly and routine analytical characterization straightforward.
They are an important item in sadya, a vegetarian feast prepared during festive occasions in Kerala. The chips are typically labeled "plantain chips" when they are made of green plantains that taste starchy, like potato chips. In Tamil Nadu, a thin variety made from green plantains is used to make chips seasoned with salt, chili powder and asafoetida. In the western/central Indian language Marathi, the plantain is called rajeli kela (figuratively meaning "king-sized" banana), and is often used to make fried chips.
== Further reading == Adams, Jad (2004) Hideous absinthe: a history of the devil in a bottle, London: I.B. Tauris. ISBN 1860649203 Arnold, Wilfred Niels (June 1989). "Absinthe". Scientific American. 260 (6): 112–117. Bibcode:1989SciAm.260f.112A. doi:10.1038/scientificamerican0689-112. PMID 2658044. S2CID 215053033. Retrieved 18 September 2010. Blumer, D. (2002). "The Illness of Vincent van Gogh". American Journal of Psychiatry. 159 (4): 519–526. doi:10.1176/appi.ajp.159.4.519. PMID 11925286. S2CID 43106568. Conrad, Barnaby (1996). Absinthe: History in a Bottle. San Francisco: Chronicle Books. ISBN 978-0811816502. Crowley, Aleister (1918). "Absinthe: The Green Goddess" (PDF). The International. XII (2). Archived from the original (PDF) on 18 September 2020. Retrieved 5 March 2016. Eadie, MJ (2009). "Absinthe, epileptic seizures and Valentin Magnan". The Journal of the Royal College of Physicians of Edinburgh. 39 (1): 73–78. doi:10.1177/1478271520093901011. PMID 19831287. Guthrie, R. Winston (2010). A Taste for Absinthe. New York: Clarkson Potter. p. 176. ISBN 978-0307587534. Archived from the original on 28 February 2019. Retrieved 26 September 2012. Huisman, M.; Brug, J.; MacKenbach, J. (2007). "Absinthe is its history relevant for current public health?". International Journal of Epidemiology. 36 (4): 738–744. doi:10.1093/ije/dym068. hdl:1765/36056. PMID 17982755. Lachenmeier, Dirk W.; Nathan-Maister, David; Breaux, Theodore A.; Sohnius, Eva-Maria; Schoeberl, Kerstin; Kuballa, Thomas (2008).
When a beer has been brewed using a cool fermentation of around 10 °C (50 °F), compared to typical warm fermentation temperatures of 18 °C (64 °F), then stored (or lagered) for typically several weeks (or months) at temperatures close to freezing point, it is termed a "lager". During the lagering or storage phase several flavour components developed during fermentation dissipate, resulting in a "cleaner" flavour. Though it is the slow, cool fermentation and cold conditioning (or lagering) that defines the character of lager, the main technical difference is with the yeast generally used, which is Saccharomyces pastorianus. Technical differences include the ability of lager yeast to metabolise melibiose, and the tendency to settle at the bottom of the fermenter (though ale yeasts can also become bottom settling by selection); though these technical differences are not considered by scientists to be influential in the character or flavour of the finished beer, brewers feel otherwise – sometimes cultivating their own yeast strains which may suit their brewing equipment or for a particular purpose, such as brewing beers with a high abv.
Sources: en.wikipedia.org
== Investigation == Officers of the Metropolitan Police undertook the investigation, under pressure to find the perpetrator by press coverage and public outrage at the circumstances of the murder. Thirty-two men were questioned in connection with the killing, and the investigation quickly targeted Colin Stagg, a man from Roehampton who was known to walk his dog on the Common. As there was no forensic evidence linking him to the scene, the police asked Paul Britton, a criminal psychologist, to create an offender profile of the killer. They decided that Stagg matched the profile and asked the psychologist to assist with designing a covert operation, code-named Operation Edzell, to see whether he would eliminate or implicate himself. This operation was later criticised by the media and the trial judge as effectively a "honeytrap".
The 2015 Australian Football League draft consisted of the various periods where the 18 clubs in the Australian Football League (AFL) can trade and recruit players following the completion of the 2015 AFL season. Additions to each club's playing list are not allowed at any other time during the year. The key dates for the trading and drafting periods were:
The United States Food and Drug Administration's Investigational New Drug (IND) program is the means by which a pharmaceutical company obtains permission to start human clinical trials and to ship an experimental drug across state lines (usually to clinical investigators) before a marketing application for the drug has been approved. Regulations are primarily at 21 CFR 312. Similar procedures are followed in the European Union, Japan, and Canada due to regulatory harmonization efforts by the International Council for Harmonisation.
Sources: en.wikipedia.org
=== Pediatrics === In pediatrics, a 2023 time-series study published in JAMA Pediatrics examined first-time pediatric speech delay incidence from 2018 to 2022 using data from U.S. health systems, including those affiliated with Truveta. A 2025 study in Pediatrics Open Science examined changes in pediatric obesity treatment practices in the United States following updated guidelines from the American Academy of Pediatrics, using data from large health-system records, including those affiliated with Truveta.
== Advantages and limitations == A major advantage of ABPP is the ability to monitor the availability of the enzyme active site directly, rather than being limited to protein or mRNA abundance. Ideal ABPs would target a large, but manageable, number of enzymes (tens to hundreds) to provide researchers with a global view of the functional state of the proteome. This degree of target promiscuity must be balanced by minimal cross-reactivity with unrelated proteins. Most ABPs achieve this combination of intraclass coverage and limited extraclass reactivity by coupling appropriate reactive groups with binding elements that recognize conserved mechanistic or structural features within enzyme active sites. Furthermore, ABPP could be used to target specific proteins which were previously viewed as undruggable targets. A disadvantage of ABPs is that their design is somewhat restricted by the need to attach an electrophile or photocrosslinker, which can limit chemical diversity. Another potential drawback is that covalent modification of the active site irreversibly inhibits the target enzyme. However, in many cases it is possible to use concentrations of ABP such that only a small fraction of the active enzyme pool is labeled, minimizing perturbation of overall enzymatic activity.
According to historian Asif Siddiqi, Korolev's accomplishments marked "the absolute zenith of the Soviet space program, one never, ever attained since." There was a two-year pause in Soviet piloted space flights while Voskhod's replacement, the Soyuz spacecraft, was designed and developed.
Sources: en.wikipedia.org
Epitalon is a synthetic tetrapeptide composed of four amino acids: alanine, glutamate, aspartate, and glycine. It is written as Ala-Glu-Asp-Gly. The free peptide has a molecular weight of about 390 daltons and is normally supplied as a lyophilized powder.
No. Epitalon is chemically synthesized, not extracted. It was designed as a short synthetic fragment conceptually related to larger pineal peptides studied in the same research tradition, particularly the extract known as epithalamin. The two are distinct materials with different compositions.
The term bioregulator is used in this research tradition for short peptides proposed to influence gene expression or cell function. Epitalon is grouped with other synthetic short peptides under this label. The term reflects a proposed mechanism rather than an established drug classification.
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.