If you have been reading about AEDG 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 2026-06-29. Where a claim depends on a specific study, the study is described rather than over-claimed.
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 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 |
|---|---|---|
| Amino acid sequence | Ala-Glu-Asp-Gly | Linear tetrapeptide, also written AEDG |
| Molecular mass | About 390.35 g/mol | Value calculated from the sequence |
| Appearance | White to off-white powder | Lyophilised material forms a loose cake |
| Solubility | Freely soluble in water | Also dissolves in isotonic saline |
| Storage | -20 °C, desiccated | Aliquot solutions to avoid freeze–thaw cycling |
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.
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.
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.
Stability of the tetrapeptide follows ordinary peptide chemistry rather than any unusual structural feature. The aspartate-glycine pair is prone to aspartimide formation under mildly basic or neutral conditions, and deamidation can follow, altering both mass and chromatographic retention. Dry lyophilised powder kept at or below minus twenty degrees Celsius is the usual handling recommendation, with repeated freeze-thaw cycles avoided. Once dissolved in neutral aqueous buffer, degradation proceeds over days to weeks depending on pH and temperature, while acidic conditions generally slow the aspartimide route. A formal stability-indicating study has not been published in the indexed literature.
The compound is generally described as a synthetic analogue of a fragment isolated from a pineal gland extract. Researchers associated with the Saint Petersburg Institute of Bioregulation and Gerontology introduced it during the 1980s and 1990s while studying short peptides from animal tissue. The original extract, called epithalamin, is a heterogeneous mixture, whereas epitalon is a single defined sequence. That distinction matters because findings reported for the extract are not automatically findings about the pure tetrapeptide, and claims about broader biological effects remain a separate question from the chemical identity described here.
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.
Regulatory treatment differs by country. No formulation of epitalon holds a marketing authorisation as a medicine in the United States or the European Union, where material sold for laboratory use is handled as a research chemical and is not intended for human consumption. In Russia, several short peptide preparations from the same institute's peptide series are registered medicinal products, and epitalon appears in that national context. Elsewhere it is frequently offered as a cosmetic ingredient, a category with lighter requirements. Advertising claims about longevity or disease prevention are restricted in most jurisdictions, which limits how sellers describe the compound.
Freeze-dried epitalon is normally kept at minus twenty degrees Celsius in a sealed, desiccated container, protected from light. Short excursions at ambient temperature during shipping are generally tolerated, but repeated warming and cooling cycles encourage moisture uptake, which shortens shelf life. Once dissolved, the peptide is far less stable than the solid: aqueous solutions are subject to hydrolysis and to deamidation at the aspartate and glutamate residues. Working solutions are therefore held refrigerated and used within days, and repeated freezing and thawing of the same vial is best avoided.
Identity and purity are checked by reversed-phase high-performance liquid chromatography, usually with ultraviolet detection near 214 nanometres, where the peptide bond absorbs. Mass spectrometry confirms the expected mass and reveals whether truncation products or adducts are present. Acid hydrolysis followed by amino acid analysis gives the residue ratio, which should approximate one alanine, one glutamate, one aspartate and one glycine. Counter-ions such as acetate or trifluoroacetate remain in the dried product and lower net peptide content, so a stated purity figure on a label does not by itself describe how much peptide a vial holds.
Their Diversions in the Winter is Riding Sleys about three or four Miles out of Town, where they have Houses of entertainment at a place called Bowery, and some go to friends Houses who handsomely treat them. [...] I believe we mett 50 or 60 slays that day – they fly with great swiftness and some are so furious that they'le turn out of the path for none except a Loaden Cart. Nor do they spare for any diversion the place affords, and sociable to a degree, they'r Tables being as free to their Naybours as to themselves. By 1766, when John Montresor made his detailed plan of New York, "Bowry Lane", which took a more north-tending track at the rope walk, was lined for the first few streets with buildings that formed a solid frontage, with market gardens behind them; when Lorenzo Da Ponte, the librettist for Mozart's Don Giovanni, The Marriage of Figaro, and Così fan tutte, immigrated to New York City in 1806, he briefly ran one of the shops along the Bowery, a fruit and vegetable store. In 1766, straight lanes led away at right angles to gentlemen's seats, mostly well back from the dusty "Road to Albany and Boston", as it was labeled on Montresor's map; Nicholas Bayard's was planted as an avenue of trees. James Delancey's grand house, flanked by matching outbuildings, stood behind a forecourt facing Bowery Lane; behind it was his parterre garden, ending in an exedra, clearly delineated on the map.
Reith revealed in a 2009 letter to the Journal of the Royal College of Physicians of Edinburgh that she and her colleagues made no money from the invention, with the then Greater Glasgow Health Board holding the patent on their behalf and receiving income until it sold the rights to pharmaceutical company Novo.
==== Strategies for EPS yield-increase ==== Although the EPS from microalgae have many potential applications, their low yield is one of the major limitations for scale-up in industry. The type and amount of EPS obtained from a certain microalgae-culture depends on several factors, such as culture system design, nutritional and culture conditions, as well as the recovery and purification process. Therefore, the configuration and optimization of production systems are critical for the further development of applications. Examples of successful increase of EPS yield include
A review of lichen taxonomic literature from 2018 to 2020 found that of over 700 new species published, only 39% included any DNA sequences. The most commonly used gene was the ITS (present in roughly 82% of those that had molecular data), while only about 10% of new species were supported by three or more genes. These figures show that while multilocus sequencing underpins higher-level systematics, species-level descriptions (alpha taxonomy) often remain constrained by practical limits on sequencing or by the sufficiency of morphological evidence. Sanger-era phylogenetics laid the groundwork for later genomic studies. By the late 2000s lichenologists had a working framework for most major lineages and clearer criteria for natural versus artificial groups. The framework relied on what now seem small datasets—only a few kilobases per species—yet these sequences resolved many relationships. Although some 2010-era authors questioned the value of small multigene matrices, Lücking (2020) contends that sound sampling and analysis can outweigh sheer data volume. By the early 2020s, many new species—even some higher taxa—are still described from a few gene regions plus morphology, a practise that remains practical where large-scale sequencing is not yet feasible. The Sanger era showed that modest molecular datasets could overturn classifications—splitting some genera, merging others—and it supplied a scaffold for later genome-scale studies.
Argon has approximately the same solubility in water as oxygen and is 2.5 times more soluble in water than nitrogen. Argon is colorless, odorless, nonflammable and nontoxic as a solid, liquid or gas. Argon is chemically inert under most conditions and forms no confirmed stable compounds at room temperature. Although argon is a noble gas, it can form some compounds under various extreme conditions. Argon fluorohydride (HArF), a compound of argon with fluorine and hydrogen that is stable below 17 K (−256.1 °C; −429.1 °F), has been demonstrated. Although the neutral ground-state chemical compounds of argon are presently limited to HArF, argon can form clathrates with water when atoms of argon are trapped in a lattice of water molecules. Ions, such as ArH+, and excited-state complexes, such as ArF, have been demonstrated. Theoretical calculation predicts several more argon compounds that should be stable but have not yet been synthesized.
Sources: en.wikipedia.org
In early 1936, Thomas met Caitlin Macnamara (1913–1994), a 22-year-old dancer of Irish and French Quaker descent. She had run away from home, intent on making a career in dance, and aged 18 joined the chorus line at the London Palladium. Introduced by Augustus John, Caitlin's lover, they met in The Wheatsheaf pub on Rathbone Place in London's West End. Laying his head in her lap, a drunken Thomas proposed. Thomas liked to assert that he and Caitlin were in bed together ten minutes after they first met. Although Caitlin initially continued her relationship with John, she and Thomas began a correspondence, and in the second half of 1936 were courting. They married at the register office in Penzance, Cornwall, on 11 July 1937. For the first months of their relationship and marriage the couple lived at the Macnamara family home in Blashford, Hampshire. In May 1938 they moved to Wales, to the village of Laugharne, Carmarthenshire where they rented a cottage in Gosport Street before moving into 'Sea View', a larger property, a couple of months later. They left Laugharne in July 1940 and then led a peripatetic lifestyle over the next few years, returning to Blashford and subsequently living at Marshfield (1940), Bishopston (1940–41), Chelsea, in London (1942–43), Talsarn (1942–44), East Knoyle, Beaconsfield (1944), Bosham, Sussex (1944), Blaencwm (Llansteffan) (1944 and 1945), New Quay (1944–45), and in premises arranged by Margaret Taylor, one of Dylan's benefactors (the wife of the historian A. J. P.
More generally, an NAD(P)H-hydrate epimerase (EC 5.1.99.6, NAD(P)HX epimerase) is a type of enzyme with systematic name (6R)-6beta-hydroxy-1,4,5,6-tetrahydronicotinamide-adenine dinucleotide 6-epimerase. Enzymes of this class, especially NAXE and its orthologs, catalyse the following chemical reaction
=== Cognitive impairment and Alzheimer's disease === Two meta-analyses reported lower vitamin E blood levels in AD people compared to healthy, age-matched people. However, a review of vitamin E supplementation trials concluded that there was insufficient evidence to state that supplementation reduced the risk of developing AD or slowed the progression of AD.
Diplomatic Service and Overseas List Bathsheba Abse, Curator, Keats–Shelley Memorial House, Rome. Duncan Bnerton Allan, Second Secretary, British Embassy, Moscow. Jean Armstrong del Bianco. For services to British cultural interests in Venice. Au Chi-lau, . For services to civil engineering in Hong Kong. Christopher Rodney Baker, Honorary Consul, Dunkirk. Sigrid Geraldine Wells Barnes. For charitable services in the Falkland Islands. Janet Bershers, British Vice-Consul, Chicago. Kenneth Geoffrey Birch, British Vice-Consul, Zurich. John Basil Boursot. For services to zoology in El Salvador. Chan Kim-to. For public service, Hong Kong. Chan Kong-sang. For public service, Hong Kong. Peter Chau Cham-chiu, , Assistant Commissioner (Auxiliary), Royal Hong Kong Police Force. Maureen Anne Chesterton, British Vice-Consul, Lima. Michael Chik Wah-wai, Assistant Commissioner, Customs and Excise, Hong Kong. Mary Matilda Cooper, . For services to nursing and welfare, Montserrat. Nicola Jane Crews. For services to disabled people, Indonesia. Brendan William Laurence Egan. For services to the British School, Manila. Margaret Elsworth. For services to education and health, South Africa. John Barrymore Eustice. For services to disabled people, Botswana. The Reverend Father Anthony Fleming. For charitable and welfare services to the community in Orissa, India. Frank Charles Gamble, Director, British Red Cross Society, Bermuda. Christopher Garratt. For services to the British community in Brussels. Martin Fraser Gibson. For services to the British community in Uruguay.
Sources: en.wikipedia.org
The reaction often affords a mixture of products comprising various pyridines as well as quinolines, isoquinolines, and nitrogen-free compounds. However, the outcome can be controlled to a limited extent by appropriate choice of reaction conditions and catalysts. For example, three molecules of acetaldehyde and one molecule of ammonia predominantly yield picolines. The results can be improved by using ammonia or its equivalent in excess.
The human body's immune response to a surgically-implanted foreign object (prosthetic breast, cardiac pacemaker, orthopedic prosthesis) is to biologically isolate the foreign object with a capsule of tightly-woven collagen fibres. Afterwards, the capsular contracture occurs over time when the thickened, collagen-fibre capsule has compressed inwards, against the breast-implant with great mechanical pressure that deforms and breaks the implant, and so disfigures the breast; the causes of capsular contracture include bacterial contamination, shell-rupture of the medical device, leakage of the prosthetic filler-material, and hematoma. The prosthetic-breast implantation surgeries that have a low-rate of capsular contractures include surgical approaches that feature the submuscular emplacement of the breast-implant and the use of breast implants with a textured surface; limited handling of the breast implants before the surgery, limited contact with and handling of the skin of the implant-pocket, and irrigation of the surgical site with antibiotic solutions. To correct a capsular contraction, the plastic surgeon realises an open capsulotomy procedure to loosen and release the collagen-fibre capsule from the implant-pocket, for removal and replacement with a new model of prosthetic breast. Moreover, non-surgical therapies for treating collagen-fibre capsules include massage, external ultrasonic therapy, pharmaceutic therapy with leukotriene pathway inhibitor medications, and Diapulse therapy (Pulsed Electromagnetic Field Therapy, PEMFT).
=== Media and arts representation of sickle cell disease === Popular media and art have been important educational tools about sickle cell disease. Hertz Nazaire was a Haitian-American visual artist, writer, and advocate who lived with sickle cell disease and used his art to raise awareness, combat stigma, and champion better access to care. Representations of sickle cell disease in television shows include in the longrunning American medical drama ER (season 4 "Obstruction of Justice" and season 15 "Separation Anxiety" and "Dream Runner"), the 2024 British superhero series Supacell, in the 2024 period drama Lady in the Lake, and in the 2025 medical procedural drama The Pitt (episode "8:00 am"). Noah Wyle, who plays Dr. Michael "Robby" Robinavitch on The Pitt, has spoken about the importance of popular media representation of sickle cell and the impacts of racism on the quality of care patients receive. Sickle cell disease has also been featured in several movies including the 1973 Sydney Poitier classic, A Warm December, 1996 Nigerian drama Mortal Inheritance, Genie Award- winning 2008 Canadian drama Nurse.Fighter.Boy, the 2017 animated documentary Spilled Milk, the 2020 Nigerian drama Strain, the 2022 animated short The Park Bench, and the 2023 American sci-fi action film Transformers: Rise of the Beasts.
Sources: en.wikipedia.org
It is a synthetic tetrapeptide. Its sequence was derived from research on peptide fractions of bovine pineal extract, and the intact AEDG sequence has not been demonstrated as an abundant free peptide in human tissue.
AEDG is the one-letter code for the four amino acids alanine, glutamate, aspartate and glycine in that order. The same molecule is written in three-letter form as Ala-Glu-Asp-Gly.
Identity is normally confirmed by mass spectrometry against the calculated mass of roughly 390.35 g/mol. Purity is then estimated by reversed-phase high-performance liquid chromatography with ultraviolet detection.
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.