The short version of tetrapeptide fits in a sentence. The long version — which is the one that helps — is below.
This page was last updated on 2025-10-05 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.
Peptides of this size are generally stable as dry solids but degrade in solution over time. The principal routes are hydrolysis of the peptide backbone and oxidation, with hydrolysis favoured by elevated temperature and extreme pH. Aqueous solutions held at room temperature can show measurable loss of purity within days, while frozen aliquots are considerably more durable. Because the sequence contains neither cysteine nor methionine, oxidation is less of a concern than for many other peptides, but pH control during handling still matters.
Typical storage for the lyophilized powder is −20 °C or lower, in a sealed container protected from light and moisture. Hygroscopic material should be allowed to equilibrate to room temperature before the vial is opened, which limits condensation on the contents. Working solutions are commonly divided into single-use aliquots and frozen to avoid repeated freeze-thaw cycles. Dilute solutions are more prone to adsorption onto plastic surfaces and to loss during filtration, so procedures that minimize transfers and use low-binding labware are preferable.
Reversed-phase high-performance liquid chromatography is the standard approach for assessing purity, usually with ultraviolet detection near 214 nm, where the peptide bond absorbs. Mass spectrometry, most often with electrospray ionization, confirms the molecular mass and helps reveal truncation or deletion byproducts. Amino acid analysis can verify composition, and counterion content is sometimes measured because peptides purified with trifluoroacetic acid retain variable amounts of that salt. Purity figures reported without a stated method and detection wavelength are difficult to interpret.
| 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 |
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.
Published studies on epitalon are dominated by a small number of research groups, and independent replication in other laboratories remains limited. Proposed mechanisms include activation of telomerase and modulation of melatonin rhythms, but the evidence for either rests mainly on cell cultures and animal models. Whether the peptide produces comparable effects in humans is an open question, and the absence of large controlled trials means the literature is best read as exploratory rather than settled.
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.
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.
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.
The molecule is a short, linear, hydrophilic peptide that dissolves readily in water or aqueous buffer. Its principal chemical liabilities are hydrolytic rather than oxidative, since it contains no cysteine, methionine, or tryptophan residues. The aspartate–glycine step is a recognised site for aspartimide formation under mildly acidic or basic conditions, generating isoaspartate and succinimide-related products over time. Desiccated lyophilised powder held at −20 °C is comparatively stable, whereas dilute solutions degrade faster and are best frozen as single-use aliquots rather than thawed repeatedly.
==== Gene and protein expression ==== Approximately 20,000 protein coding genes are expressed in human cells and 75% of these genes are expressed in at least one of the different parts of the digestive organ system. Over 600 of these genes are more specifically expressed in one or more parts of the GI tract and the corresponding proteins have functions related to digestion of food and uptake of nutrients. Examples of specific proteins with such functions are pepsinogen PGC and the lipase LIPF, expressed in chief cells, and gastric ATPase ATP4A and gastric intrinsic factor GIF, expressed in parietal cells of the stomach mucosa. Specific proteins expressed in the stomach and duodenum involved in defence include mucin proteins, such as mucin 6 and intelectin-1.
== Signs and symptoms == Often, food illnesses are not attributed to A. parasiticus because it is mistaken for A. flavus. Serious symptoms of aflatoxin exposure by either ingestion or inhalation of spores, or through direct skin contact, can occur amongst humans and animals. Signs and symptoms of exposure in humans may include delayed development and stunted growth among children, while adults may experience teratogenic effects, lung damage, ulcers, skin irritation, fever, and acute liver disease, which can later lead to liver carcinoma and death.
α-ketoglutarate + NH+4 ⇄ glutamate The α-ketoglutarate family of amino acid synthesis (synthesis of glutamate, glutamine, proline and arginine) begins with α-ketoglutarate, an intermediate in the Citric Acid Cycle. The concentration of α-ketoglutarate is dependent on the activity and metabolism within the cell along with the regulation of enzymatic activity. In E. coli citrate synthase, the enzyme involved in the condensation reaction initiating the Citric Acid Cycle is strongly inhibited by α-ketoglutarate feedback inhibition and can be inhibited by DPNH as well high concentrations of ATP. This is one of the initial regulations of the α-ketoglutarate family of amino acid synthesis. The regulation of the synthesis of glutamate from α-ketoglutarate is subject to regulatory control of the Citric Acid Cycle as well as mass action dependent on the concentrations of reactants involved due to the reversible nature of the transamination and glutamate dehydrogenase reactions. The conversion of glutamate to glutamine is regulated by glutamine synthetase (GS) and is a key step in nitrogen metabolism. This enzyme is regulated by at least four different mechanisms: 1. Repression and depression due to nitrogen levels; 2. Activation and inactivation due to enzymatic forms (taut and relaxed); 3. Cumulative feedback inhibition through end product metabolites; and 4. Alterations of the enzyme due to adenylation and deadenylation.
Observe the value of the friction factor for laminar flow at a Reynolds number of 1000. If the value of the friction factor is 0.064, then the Darcy friction factor is plotted in the Moody diagram. Note that the nonzero digits in 0.064 are the numerator in the formula for the laminar Darcy friction factor: fD = 64/Re. If the value of the friction factor is 0.016, then the Fanning friction factor is plotted in the Moody diagram. Note that the nonzero digits in 0.016 are the numerator in the formula for the laminar Fanning friction factor: f = 16/Re. The procedure above is similar for any available Reynolds number that is an integer power of ten. It is not necessary to remember the value 1000 for this procedure—only that an integer power of ten is of interest for this purpose.
By at least 1731, it was officially codified in Naval regulation that each sailor was rationed one pound (450 g) of biscuit per day. Hardtack was also utilized by the Pilgrims during their 1620 voyage, primarily due to its easy storage and long lifespan. However, the travelers struggled with insect infestation, as well as having to dip the hardtack into water for it to be edible. Hardtack, crumbled or pounded fine and used as a thickener, was a key ingredient in New England seafood chowders from the late 1700s. In 1801, Josiah Bent began a baking operation in Milton, Massachusetts, selling "water crackers" made of flour and water that would be resistant to deterioration during long sea voyages from the port of Boston. These were also used extensively as a source of food by the gold prospectors who migrated to the gold mines of California in 1849. Since the journey took months, hardtack was stored in the wagon trains. Bent's company later sold the original hardtack crackers used by troops during the American Civil War. The G. H. Bent Company operated in Milton and sold these items to Civil War re-enactors and others until 2018.
Sources: en.wikipedia.org
Newsom has been widely considered a prominent figure in liberal American politics during the 2020s. In 2023, he launched Campaign for Democracy, a political action committee to take on "authoritarian leaders" in the U.S. It is thought to be a starting point for a possible 2028 presidential bid. By July 2024, Campaign for Democracy had raised $24 million for direct contributions to candidates and other spending. The group is not subject to contribution limits and can coordinate with Newsom as long as he is not a candidate for federal office. Many journalists and political analysts have mentioned Newsom as a presidential hopeful. According to a June 2023 poll by NewsNation, 22% of California voters wanted him to enter the 2024 U.S. presidential election. In May 2023, Arnold Schwarzenegger said it was a "no-brainer" that Newsom would someday run for president. An April 2023 The Hill article by Sharon Udasin also discussed the inevitability of a Newsom presidential run. In September 2022, Newsom said he would not run for president in 2024, citing his "vulnerable" 2021 recall. After his 2022 reelection, he told White House staff that he would not challenge President Joe Biden in the 2024 Democratic Party presidential primaries; he endorsed Biden's reelection campaign on April 25, 2023. Newsom has become an outspoken critic of the policies of Florida governor Ron DeSantis, denouncing DeSantis's orchestration of the Martha's Vineyard migrant airlift. DeSantis responded by saying California has "huge problems" and dared Newsom to run against Biden.
The rate of proteolysis may also depend on the physiological state of the organism, such as its hormonal state as well as nutritional status. In time of starvation, the rate of protein degradation increases.
The combination of heroin and xylazine produces a potentially more deadly high than heroin alone. Xylazine is also frequently found in "speedball", a mixture of a stimulant drug such as cocaine with a depressant drug such as heroin, morphine and/or fentanyl. As of 2012, causal factors underlying xylazine's increasing popularity were still unknown. As of 2022, more information on the distribution of xylazine in the body, physical symptoms, and factors predictive of chronic use was known: frequency of use depended on social or economic factors, as well as each user's subjective response to the drug's addictive properties. From November 2021 until August 2022, 80% of drug paraphernalia which tested positive for fentanyl at needle exchange programs in Maryland also contained xylazine. As of 2022, xylazine was almost invariably combined with opioids when used recreationally, and the drug produced a characteristic withdrawal syndrome which complicates treatment of addicted users. In April 2023, the Biden administration declared xylazine-laced fentanyl an official emerging drug threat to the nation, the first time such a label has been given. In 2022, the Drug Enforcement Administration (DEA) reported that 23% of seized fentanyl powder and 7% of fentanyl pills were found to have been adulterated with xylazine. In July 2023, the first death following xylazine use outside of North America was reported to have taken place in Solihull, England on May 22. A 43-year-old male was found dead at home with postmortem toxicology detecting heroin, cocaine, fentanyl and xylazine.
Maureen Vevers. Chair of Governors, Askham Bryan College, York. For services to Further Education. Alexandra Ellen Vincent. Lately Chief Operating Officer, Arts and Humanities Research Council. For services to Research Funding. Suman Vohra. Vice Chair, Edinburgh Hindu Mandir and Cultural Centre. For services to the community in Edinburgh. Belinda Alison Voos. Lately Nurse Consultant in Paediatric Neurosurgery, Great Ormond Street Hospital for Children NHS Foundation Trust. For services to Paediatric Neurosurgical Nursing. Dorothy Helen Wagstaff. Founder, CASCAID. For services to Charity. David Walker. Chair of Trustees, Horizons Specialist Academy Trust. For services to Education. Susan Walker. Chief Commissioner, Girlguiding Scotland. For services to Young People. David Wallace. Senior Fleet Staff Engineer, Royal National Lifeboat Institution. For voluntary service to Maritime Safety. Lady (Julia Elizabeth) Walport (Dr. Julia Neild). Lately Trustee, The Amber Trust and Trustee, Ealing Youth Orchestra. For services to Young People and to Charity. Keith Norman Walton. Founder, Severnside Community Rail Partnership. For services to Urban Rail Transport in Bristol. John Ward. Chair, Charles and Elsie Sykes Trust. For services to Charity and to the community in Harrogate, North Yorkshire. Pamela Joan Ward. For services to the community in Whipsnade, Bedfordshire. William John Ward. For services to the community in the New Forest, Hampshire. Edward Charles Warner. Disability and Access Ambassador, Cabinet Office Disability Unit. For services to Disabled People.
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.
The powder is normally kept at −20 °C or below in a sealed, moisture-protected container. Letting the vial reach room temperature before opening helps prevent condensation on the contents.