AEDG is one of those subjects where the details matter more than the headlines. This page pulls together the background, the mechanisms, and the practical points readers ask about most.
Last reviewed on 2025-12-26. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
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 |
|---|---|---|
| Molecular formula | C14H22N4O9 | Calculated from the four residues with three water losses |
| Molecular mass | About 390.35 g/mol | Monoisotopic mass near 390.14, used for mass-spectrometric identification |
| Peptide sequence | Ala-Glu-Asp-Gly | Single-letter form AEDG; no disulfide bonds or modified residues |
| Appearance | White to off-white solid | Supplied as a dried powder |
| Isoelectric point | Around 4 | Estimated from aspartate and glutamate side-chain pKa values |
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.
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.
Proposed mechanisms centre on cell-culture observations rather than a defined receptor interaction. Several reports describe increased expression of the telomerase catalytic subunit after exposure of cultured human cells, and the authors attributed the effect to short peptide fragments entering the nucleus and influencing gene transcription. No receptor for the tetrapeptide has been identified, and the free peptide is expected to be degraded rapidly by plasma peptidases. Whether any measurable fraction reaches intact tissues after administration remains an unresolved question rather than an established finding.
The published literature is dominated by a small number of research groups, much of it in Russian-language journals, and independent replication outside those groups is limited. Studies are typically small, use cultured cells or rodent models, and report endpoints that differ between papers, which makes comparison difficult. Large randomised human trials have not appeared in the indexed literature. Questions about absorption, distribution and clearance are therefore still treated as open in reviews that mention the compound.
== Interactions == Methamphetamine is metabolized by the liver enzyme CYP2D6, so CYP2D6 inhibitors will prolong the elimination half-life of methamphetamine. Methamphetamine also interacts with monoamine oxidase inhibitors (MAOIs), since both MAOIs and methamphetamine increase plasma catecholamines; therefore, concurrent use of both is dangerous. Methamphetamine may decrease the effects of sedatives and depressants and increase the effects of antidepressants and other stimulants as well. Methamphetamine may counteract the effects of antihypertensives and antipsychotics owing to its effects on the cardiovascular system and cognition respectively. The pH of gastrointestinal content and urine affects the absorption and excretion of methamphetamine. Specifically, acidic substances will reduce the absorption of methamphetamine and increase urinary excretion, while alkaline substances do the opposite. Owing to the effect pH has on absorption, proton pump inhibitors, which reduce gastric acid, are known to interact with methamphetamine. Norepinephrine reuptake inhibitors (NRIs) like atomoxetine prevent norepinephrine release induced by amphetamines and have been found to reduce the stimulant, euphoriant, and sympathomimetic effects of dextroamphetamine in humans. Similarly, norepinephrine–dopamine reuptake inhibitors (NRIs) like methylphenidate and bupropion prevent norepinephrine and dopamine release induced by amphetamines and bupropion has been found to reduce the subjective and sympathomimetic effects of methamphetamine in humans.
15 May to 14 August The 1st Brigade, 101st Airborne Division conducted Operation Lamar Plain in Quảng Tín Province. The operation resulted in 524 PAVN/VC killed and 21 captured and U.S. losses were 116 killed and one missing.
== History == NeoGenomics first received state and national-level laboratory certifications in 2002. Three years later in 2005, the company developed a technical-only service model using FISH. In 2013, the company launched its sequencing platform and was listed on the Nasdaq Stock Market as NEO. In 2014, NeoGenomics launched molecular tests including BTK and CALR mutation analysis. In 2015, NeoGenomics acquired Clarient, Inc. and its subsidiary company, Clarient Diagnostic Services, Inc., a national cancer diagnostics laboratory with capabilities in immunohistochemistry for solid tumor cancers from GE Healthcare. Clarient is headquartered in Aliso Viejo, California; with an ancillary laboratory in Houston, Texas. In November 2017, NeoGenomics established their first headquarters outside the United States in Rolle, Switzerland. In September 2024, the District Court for the Middle District of North Carolina entered a permanent injunction against NeoGenomics’ accused RaDaR assay, which was preliminarily enjoined in December 2023.
This reagent is a good formylating agent and can regenerate the unsubstituted imidazole (with formation of carbon monoxide) upon heating. Yet another reaction involves the acylation of triphenylalkelynephosphoranes.
Sources: en.wikipedia.org
=== Surgery === A surgery of any type inherently carries more risks when done on a patient who has (especially moderate to severe) OI. Skeletal deformities and dentinogenesis imperfecta may hinder access to the airway. Use of, and weaning off of, mechanical ventilation is also more challenging to carry out on patients with OI. During the procedure itself or the healing process, defective OI collagen may lead to bleeding diatheses. The safety of anesthesia is also of more concern among patients with OI, with anesthetic complications 5.6x more likely to occur when the patient has OI type III. A unique concern of anesthesia in OI is perioperative fracture—fractures sustained due to patient transfer and airway access techniques that, while routine when a patient's bones are strong, may cause injury with brittle OI bones. As an example, due to a 1972 report of a humerus fracture from a sphygmomanometer cuff sustained in an OI patient during surgery, blood pressure monitoring protocols are often modified for patients with OI, with neonatal size cuffs and machine settings being used even in adults; further, the least deformed of the patient's limbs is preferred to receive the cuff.
However, new kits such as "NETSPOT" for more rapidly preparing Ga-68 edotreotide or DOTATATE from Ga-68(III) ions have increased the flexibility of sourcing of this radiopharmaceutical for Ga-68 endocrine receptor (octreotide) scans. With NETSPOT the preparation of the Ga-68 DOTATATE is immediate once the Ga-68 has been acquired from the generator and mixed with the reagent.
=== Mechanism of Action === In humans, uric acid is the final step in the catabolic pathway of purines. Rasburicase catalyzes enzymatic oxidation of poorly soluble uric acid into an inactive and more soluble metabolite allantoin with carbon dioxide and hydrogen peroxide as byproducts in the chemical reaction.
trace the evolution of a large number of organisms by measuring changes in their DNA, rather than through physical taxonomy or physiological observations alone, compare entire genomes, which permits the study of more complex evolutionary events, such as gene duplication, horizontal gene transfer, and the prediction of factors important in bacterial speciation, build complex computational population genetics models to predict the outcome of the system over time track and share information on an increasingly large number of species and organisms
363 people were arrested by the end of the day, primarily for what the police called "minor crimes", but Trevor Manuel of the UDF warned that the house searches were pointless: "the authorities are looking for something they cannot find under beds or wardrobes. The anger of the people over rentals and lack of participation in government does not hide in those places".
Sources: en.wikipedia.org
== Inhibitors == Many inhibitors of OGT enzymatic activity have been reported. OGT inhibition results in global downregulation of O-GlcNAc. Cells appear to upregulate OGT and downregulate OGA in response to OGT inhibition.
According to Stéphane Quideau, the term "polyphenol" refers to compounds derived from the shikimate/phenylpropanoid and/or the polyketide pathway, featuring more than one phenolic unit and deprived of nitrogen-based functions. Ellagic acid, a molecule at the core of naturally occurring phenolic compounds of varying sizes, is itself not a polyphenol by the WBSSH definition, but is by the Quideau definition. The raspberry ellagitannin, on the other hand, with its 14 gallic acid moieties (most in ellagic acid-type components), and more than 40 phenolic hydroxyl groups, meets the criteria of both definitions of a polyphenol. Other examples of compounds that fall under both the WBSSH and Quideau definitions include the black tea theaflavin-3-gallate shown below, and the hydrolyzable tannin, tannic acid.
=== Biosensors === Aminopeptidases have been utilized in creating biosensors for detecting specific amino acids or peptides. These biosensors generate a measurable signal in the presence of the target analyte, leveraging the catalytic activity of aminopeptidases.
=== 2010s and 2020s === Wolverine joined the Avengers and appeared as a regular character throughout the Avengers (2010–2013) and New Avengers (2010–2013) series, both written by Brian Michael Bendis. Jason Aaron wrote a fourth volume of Wolverine that began in August 2010 and lasted 40 issues. Aaron also wrote a new X-Men storyline, X-Men: Schism (2011), in which Wolverine and Cyclops come into conflict, dividing the team. The same year, he began writing Wolverine and the X-Men, in which Wolverine becomes the headmaster of the Jean Grey School for Higher Learning and must mentor a younger generation of mutants as well as leading one of the X-Men teams. In the Avengers vs. X-Men storyline of 2012, Wolverine sides with the Avengers against his previous team. In 2013, a fifth volume of Wolverine began, written by Paul Cornell and Alan Davis and lasted 13 issues. Cornell then collaborated with Ryan Stegman on Wolverine volume 6 (February 2014 - February 2015). In 2014, Charles Soule wrote the "Death of Wolverine" storyline, in which Wolverine contracts a virus that disables his healing factor, allowing his enemies to finally kill him. He is resurrected in 2018, in the Return of Wolverine miniseries. 2019 saw the beginning of a new era for the X-Men, spearheaded by Jonathan Hickman, starting with the House of X and Powers of X series. This launched the "Krakoan Age", with mutants founding a new nation on the living island of Krakoa, where they are capable of regularly resurrecting mutants after their death.
Sources: en.wikipedia.org
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.
It is not recognised as an endogenous peptide hormone. The four-residue sequence can appear inside larger proteins and in digestive fragments of dietary protein, but no dedicated pathway producing it as a signalling molecule has been identified.
Several cell-culture reports describe increased telomerase activity after treatment, measured by enzyme assays or by transcript levels. Results differ between cell types and laboratories, and measured telomere lengthening has been reported in some studies but not in others, which leaves the physiological relevance open.
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.