A practical reference on AEDG: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
Reviewed 2026-02-25. Anything still debated is marked as such rather than presented as settled.
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.
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 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 tetrapeptide with the sequence alanine-glutamate-aspartate-glycine, commonly abbreviated AEDG. It was designed at the St. Petersburg Institute of Bioregulation and Gerontology as a short, chemically defined analogue of epithalamin, a fraction obtained from bovine pineal tissue. Small peptide bioregulators of this type formed a long-running line of work there from the 1980s onward. Because the molecule is produced by solid-phase synthesis rather than extraction, its composition is exact and its purity can be measured directly.
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.
| 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 |
No pharmacopoeial monograph exists for this peptide, so quality rests on the supplier's internal specifications and on whatever independent testing a purchaser arranges. Certificates of analysis differ widely in which tests they report and in the limits applied. The counter-ion introduced during purification, commonly acetate or trifluoroacetate, changes the net peptide content of a given mass of powder, so two samples of equal weight may not contain equal amounts of the active sequence. Third-party laboratories can verify purity, identity, residual solvents, and counter-ion content for a fee, which makes documentation more informative than labelling.
Verification of a sample usually begins with reversed-phase high-performance liquid chromatography, which resolves the peptide from truncated sequences and other impurities and expresses purity as a percentage of total peak area. Mass spectrometry by electrospray ionisation or matrix-assisted laser desorption supplies an independent check, because the measured mass can be compared against the theoretical value for AEDG. Amino acid analysis or tandem mass spectrometry sequencing can confirm residue order. Each of these methods answers a different question: a purity figure does not establish identity, and an identity match does not establish how much of the material is intact peptide.
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 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.
Lyophilised epitalon is generally held at minus twenty degrees Celsius in a sealed container kept dry and dark. Cooler conditions are sometimes recommended for long-term archives. The solid takes up moisture readily enough that repeated opening of a vial introduces water, so dividing a batch into smaller portions before storage lowers degradation risk. Aqueous solutions are less durable than the dry powder and are usually prepared shortly before use, then kept cold and shielded from light to slow hydrolysis and oxidation.
Verification of research-grade material involves comparing a supplier chromatogram against an in-house reference, checking the observed mass against the calculated value, and where possible confirming residue order by tandem mass spectrometry or enzymatic peptide mapping. Purity claims should be read alongside the method used to obtain them, because detection wavelength and integration settings alter the result. Batch-specific data, rather than a generic grade statement, is the informative part of a certificate.
Identity and purity of epitalon samples are normally established by reversed-phase high-performance liquid chromatography with ultraviolet detection near 214 nanometres, combined with mass spectrometry. The mass spectrum confirms the expected molecular ion and can reveal truncated or oxidised by-products. Amino acid analysis after acid hydrolysis verifies that the four residues are present in the expected ratio. Certificates typically report a purity figure taken from chromatographic peak area, expressed as a percentage of total integrated signal.
=== September === 1 September – Prime Minister Keir Starmer performs a cabinet reshuffle. 2 September – Zack Polanski is elected leader of the Green Party of England and Wales. Mothin Ali and Rachel Millward are elected as joint deputy leaders. 3 September – Deputy Prime Minister Angela Rayner admits to underpaying stamp duty on an £800,000 flat in Hove. First Minister of Scotland John Swinney announces a pause of public money from the Scottish Government to arms companies supplying weapons to Israel. Addressing a US congressional committee, Nigel Farage urges US politicians and businesses to oppose what he feels is the UK government's stance on freedom of speech. 4 September – The Scottish Government publishes a new paper setting out the case for Scottish independence. First Minister John Swinney urges the UK government to hold a second Scottish independence referendum if the SNP wins a majority at the 2026 Scottish Parliament election. Former Conservative Party minister Nadine Dorries defects to Reform UK. Warwickshire County Council's Reform cabinet votes to strip the chief executive of responsibility for deciding what flags can be flown outside its building, handing it to the council chairman. 5 September – Angela Rayner resigns as both Deputy Prime Minister and Deputy Leader of the Labour Party after admitting underpaying stamp duty on her £800,000 home in Hove, East Sussex.
Extrinsic factors may also increase the risk of infection in those with cirrhosis, including proton pump inhibitor use, alcohol use, frailty, antibiotic overuse, and hospitalizations or invasive procedures (which increase the risk of bacterial translocation to other areas of the body). Infections that are common in those in the hospital with cirrhosis include spontaneous bacterial peritonitis (with a prevalence of 27% among hospitalized patients), urinary tract infections (22–29%), pneumonia (19%), spontaneous bacteremia (8–13%), skin and soft tissue infections (8-12%) and C. difficile colitis (2.4-4%). It is estimated that 3.5% of people with cirrhosis and ascites may have asymptomatic spontaneous bacterial peritonitis. The mortality rate for infections in those with cirrhosis is higher than that of the general population. In those with cirrhosis and severe infections with sepsis, the mortality rate is greater than 50%, and in those with septic shock, the mortality rate is 65%.
== See also == Curculin, a sweet protein from Malaysia with taste-modifying activity Miraculin, a protein from West Africa with taste-modifying activity Monellin, a sweet protein found in West Africa Stevia, a non-nutritive sweetener up to 150 times sweeter than sugar Lugduname, a sweetening agent up to 300,000 times sweeter than sugar
=== Convenience === Enteral routes are generally the most convenient for the patient, as no punctures or sterile procedures are necessary. Enteral medications are therefore often preferred in the treatment of chronic disease. However, some drugs can not be used enterally because their absorption in the digestive tract is low or unpredictable. Transdermal administration is a comfortable alternative; there are, however, only a few drug preparations that are suitable for transdermal administration.
== Pressure field in a Leidenfrost droplet == The equation for the pressure field in the vapor region between the droplet and the solid surface can be solved for using the standard momentum and continuity equations using a Boundary layer model. In this model for the sake of simplicity in solving, a linear temperature profile and a parabolic velocity profile are assumed within the vapor phase. The heat transfer within the vapor phase is assumed to be through conduction. With these approximations, the Navier–Stokes equations can be solved to get the pressure field.
Sources: en.wikipedia.org
In the initial step, 2-Amino-5-bromobenzophenone undergoes acylation, leveraging its amino group with a lone pair on the nitrogen atom. This lone pair facilitates a nucleophilic attack, where the nitrogen attacks the carbon of chloroacetyl chloride, inducing a negatively charged oxygen. Subsequently, the oxygen re-establishes the carbon-oxygen double bond, expelling a chloride ion, leading to the formation of bromoacetamide-2-chloro-5-benzophenone. Following this, bromoacetamide-2-chloro-5-benzophenone engages in a nucleophilic substitution reaction with ammonium hydroxide as a nucleophile, replacing the second chloride ion with ammonia. This reaction yields 2-amino-N-(2-benzoyl-4-bromophenyl)acetamide. Upon the formation of 2-amino-N-(2-benzoyl-4-bromophenyl)acetamide, an intramolecular reaction ensues, resulting in 7-bromo-5-phenyl-1,3-dihydro-1,4-benzodiazepin-2-one, characterized by a seven-membered ring known as diazepine. Subsequently, through the aid of acetohydrazide, another acylation event takes place, giving rise to a 1,2,4-triazole ring and ultimately yielding bromazolam. This synthesis can also be used to obtain alprazolam by using 2-amino-5-chlorobenzophenone as the starting material.
== Career == Butler began as an instructor of medicine at Yale University (1994–1995) and later served as assistant professor at Vanderbilt University (1999–2006), where he was medical director of both the Heart Transplant and heart-lung transplant programs. In 2007, he joined Emory University as a full professor of medicine and director of the Heart Failure Research Program. At Stony Brook University, Butler served as Director of Cardiovascular Medicine and co-director of the Heart Institute (2014–2017), where he held the Charles A. Gargano Chair in Cardiology. From 2018 to 2022, he chaired the Department of Medicine at the University of Mississippi Medical Center, where he was also a professor of Physiology and Biophysics and held the Patrick H. Lehan Chair in Cardiovascular Research. Butler has combined clinical work with research, education, and leadership, directing heart failure and transplant programs at Vanderbilt and Tennessee Valley Healthcare systems. He served as Deputy Chief Science Officer for the American Heart Association (AHA) from 2009 to 2016. He has chaired committees for the Heart Failure Society of America and the American College of Cardiology, and represented the U.S. on the European Society of Cardiology Heart Failure Guidelines panel. Butler is a Fellow of the AHA, ACC, HFSA, and ESC. Butler chairs the U.S. Food and Drug Administration's Cardio-Renal Advisory Committee, co-chairs the NIH-funded HeartShare study on heart failure progression, and serves as principal investigator for several international cardiovascular trials.
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The acute and chronic inflammatory processes of osteoradionecrosis are prevented by the administration of steroidal anti-inflammatory drugs. In addition, the administration of pentoxifylline and antioxidant treatments, such as superoxide dismutase and tocopherol (vitamin E) are recommended.
== Work == During his career, Roderich Süssmuth worked in the field of peptide synthesis, addressing current research questions from both a chemical perspective (natural product synthesis) and a biological perspective, particularly with regard to new classes of active compounds with activity against fungi, bacteria, and viruses. Compounds derived from plant-pathogenic bacteria such as Xanthomonas albilineans play an important role, including albicidin, which is an inhibitor of plant gyrase and also a highly potent antibacterial agent. He elucidated the structure of the antibacterial compound albicidin, investigated its biosynthesis, developed the total synthesis of the peptide, and studied a range of bacterial resistance factors, mostly from plant-associated bacteria. Another example is the recent elucidation of a lipopeptide from Burkholderia sp., which exhibits pronounced activity against plant-pathogenic fungi. Another area of research involves fungal toxins of the death cap mushroom, phalloidin and amanitin, for which total syntheses were developed and, with the ansamer concept, a novel non-classical atropisomerism was described.
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.
No. Epithalamin is a peptide-containing extract of bovine pineal glands, while epitalon is a single synthetic tetrapeptide. The extract contains many peptides and other tissue components, so its composition varies between batches in ways that a synthesised sequence does not.