This is a working overview of lyophilised powder, written for readers who want more than a one-paragraph summary but less than a textbook.
Reviewed 2026-07-13. Anything still debated is marked as such rather than presented as settled.
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.
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.
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.
| 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 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.
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.
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.
==== Effects of pH ==== The uranium fraction diagrams in the presence of carbonate illustrate this further: when the pH of a uranium(VI) solution increases, the uranium is converted to a hydrated uranium oxide hydroxide; At high pH, it becomes an anionic hydroxide complex. When carbonate is added, uranium is converted to a series of carbonate complexes if the pH is increased. One effect of these reactions is increased solubility of uranium in the pH range 6 to 8, a fact that has a direct bearing on the long term stability of spent uranium dioxide nuclear fuels.
== Role in cancer == Most germline or somatic mutations in the MEN1 gene predict truncation or absence of encoded menin resulting in the inability of MEN1 to act as a tumor suppressor gene. Such mutations in MEN1 have been associated with defective binding of encoded menin to proteins implicated in genetic and epigenetic mechanisms. Menin is a 621 amino acid protein associated with insulinomas which acts as an adapter while also interacting with partner proteins involved in vital cell activities such as transcriptional regulation, cell division, cell proliferation, and genome stability. Insulinomas are neuroendocrine tumors of the pancreas with an incidence of 0.4 % which usually are benign solitary tumors but 5-12 % of cases have distant metastasis at diagnosis. These familial MEN-1 and sporadic tumors may arise either due to loss of heterozygosity or the chromosome region 11q13 where MEN1 is located, or due to presence of mutations in the gene. MEN1 mutations comprise mostly frameshift deletions or insertions, followed by nonsense, missense, splice-site mutations and either part or complete gene deletions resulting in disease pathology. Frameshift and nonsense mutations result in a supposed inactive and truncated menin protein while splice-site mutations result in incorrectly spliced mRNA. Missense mutations of MEN1 are especially important as they result in a change to crucial amino acids needed in order to bind and interact with other proteins and molecules.
The statue's iconography is frequently compared to that of the carmen saeculare by Horace, and commemorates Augustus's establishment of the Pax Romana. The breastplate is carved in relief with numerous small figures depicting the return, thanks to the diplomacy of Augustus, of the Roman legionary eagles or aquilae lost to Parthia by Mark Antony in the 40s BC and by Crassus in 53 BC. The figure in the centre, according to the most common interpretation, is the subjected Parthian king (Phraates IV) returning Crassus's standard to an armored Roman (possibly Tiberius, or symbolically Mars Ultor or the incarnation of the ideal legionary). Another theory sees in the male figure the ideal incarnation of the Roman legions. This was a very popular subject in Augustan propaganda, as one of his greatest international successes, and had to be especially strongly emphasized, since Augustus had been deterred by Parthian military strength from the war which the Roman people had expected and had instead opted for diplomacy. Below the armed figure we can see a dog, or probably a wolf or, according to archaeologist Ascanio Modena Altieri, a she-wolf, nurse of Romulus and Remus. To the left and right sit mourning female figures; the figure on the one side with a sheathed sword personifies the peoples in the East (and possibly the Teutons) forced to pay tribute to Rome, and the one on the other side with an unsheathed sword personifies the subjected peoples (the Celts). From the top, clockwise, we see:
=== Organophosphates === Organophosphates are another large class of contact insecticides. These also target the insect's nervous system. Organophosphates interfere with the enzymes acetylcholinesterase and other cholinesterases, causing an increase in synaptic acetylcholine and overstimulation of the parasympathetic nervous system, killing or disabling the insect. Organophosphate insecticides and chemical warfare nerve agents (such as sarin, tabun, soman, and VX) have the same mechanism of action. Organophosphates have a cumulative toxic effect to wildlife, so multiple exposures to the chemicals amplifies the toxicity. In the US, organophosphate use declined with the rise of substitutes. Many of these insecticides, first developed in the mid 20th century, are very poisonous. Many organophosphates do not persist in the environment.
== Organizations == National Academy of Design NAD Electronics, a Canadian audio equipment manufacturer (originally New Acoustic Dimension) National Advertising Division, the Council of Better Business Bureaus in the United States and Canada National Appeals Division, an agency within the United States Department of Agriculture National Association of the Deaf (disambiguation), one of several associations for deaf people Norwegian Association of the Disabled
Sources: en.wikipedia.org
As with all other arteries, the aorta is made up of three layers, the intima, the media, and the adventitia. The intima is in direct contact with the blood inside the vessel, and mainly consists of a layer of endothelial cells on a basement membrane; the media contains connective and muscle tissue, and the vessel is protected on the outside by the adventitia, comprising connective tissue. In an aortic dissection, blood penetrates the intima and enters the media layer. The high pressure rips the tissue of the media apart along the laminated plane splitting the inner two-thirds and the outer one-third of the media apart. This can propagate along the length of the aorta for a variable distance forward or backward. Dissections that propagate towards the iliac bifurcation (with the flow of blood) are called anterograde dissections and those that propagate towards the aortic root (opposite of the flow of blood) are called retrograde dissections. The initial tear is usually within 100 mm of the aortic valve, so a retrograde dissection can easily compromise the pericardium leading to a hemopericardium. Anterograde dissections may propagate all the way to the iliac bifurcation of the aorta, rupture the aortic wall, or recanalize into the intravascular lumen leading to a double-barrel aorta. The double-barrel aorta relieves the pressure of blood flow and reduces the risk of rupture. Rupture leads to hemorrhaging into a body cavity, and prognosis depends on the area of rupture. Retroperitoneal and pericardial ruptures are both possible.
=== Maturation of the electrical properties of the action potential === A neuron's ability to generate and propagate an action potential changes during development. How much the membrane potential of a neuron changes as the result of a current impulse is a function of the membrane input resistance. As a cell grows, more channels are added to the membrane, causing a decrease in input resistance. A mature neuron also undergoes shorter changes in membrane potential in response to synaptic currents. Neurons from a ferret lateral geniculate nucleus have a longer time constant and larger voltage deflection at P0 than they do at P30. One consequence of the decreasing action potential duration is that the fidelity of the signal can be preserved in response to high frequency stimulation. Immature neurons are more prone to synaptic depression than potentiation after high frequency stimulation. In the early development of many organisms, the action potential is actually initially carried by calcium current rather than sodium current. The opening and closing kinetics of calcium channels during development are slower than those of the voltage-gated sodium channels that will carry the action potential in the mature neurons. The longer opening times for the calcium channels can lead to action potentials that are considerably slower than those of mature neurons. Xenopus neurons initially have action potentials that take 60–90 ms. During development, this time decreases to 1 ms. There are two reasons for this drastic decrease.
Xi said that one of the reasons for the collapse of the Soviet Union has been historical nihilism. Subscribing to the view that socialism will eventually triumph over capitalism, Xi has said "Marx and Engels's analysis of the basic contradictions of capitalist society is not outdated, nor is the historical materialist view that capitalism is bound to die out and socialism bound to win." Xi has called for the further Sinicization of Marxism, referring to adapting Marxism to the Chinese context. In July 2021, he formulated the Two Integrations, calling for integrating Marxism with China's specific conditions and China's traditional culture. Xi has called on CCP members to "remain true to our original aspiration", meaning to work for the happiness and well-being of the Chinese people and the rejuvenation of China, and launched an educational campaign for that goal from 2019 to 2020. Xi has said that the "feeling of devotion and sense of attachment to our motherland is a duty and responsibility of every Chinese", while adding "In contemporary China, the essence of patriotism is loving the country, the Party and socialism all at the same time".
=== Breast cancer === Keratin constitutes a large multigene family known as cytokeratins. These cytokeratins are differentially expressed across various epithelial types and have been extensively studied as markers for breast cancer. They are categorized into acidic type I and basic-to-neutral type II cytokeratins. The intermediate filament network is formed by the necessary pairing of equal amounts of type I and type II keratins. While hair keratins, such as KRT81, are typical in hard-keratinized structures like hair and nails, they are thought to serve as structural proteins specific to these organs without expression elsewhere, such as the mammary gland. KRT81, a type II hair keratin, is a major hair protein expressed in the hair cortex. Despite being typically associated with hair structures, KRT81 expression has been observed in the SKBR3 human breast cancer cell line and metastatic lymph nodes of breast carcinomas, but not in normal breast epithelial cells. Moreover, the expressed KRT81 was found to be a 5′-truncated isoform (ΔHb1), with the full-length protein not being expressed. However, the exact function of this truncated form in breast cancer cells remains unclear. Western blot analysis detected the presence of the complete 55-kDa KRT81 in various human breast cancer cell lines (MCF7, SKBR3, MDA-MB-231), normal human mammary epithelial cells (HMEC), and non-neoplastic cells (MCF10A). Reverse transcription-polymerase chain reaction confirmed the expression of the full-length KRT81, encompassing its 5' region, in breast cells.
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.
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.