The short version of AEDG fits in a sentence. The long version — which is the one that helps — is below.
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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.
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.
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.
| 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 |
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.
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.
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.
Dissolution is usually performed in water or a suitable aqueous buffer, and the resulting liquid is divided into single-use portions before freezing. Freeze-thaw cycling is a recognised source of loss for short peptides, since each cycle can encourage aggregation or adsorption onto container walls. Working solutions are generally kept cold and used within a short window, although published stability data specific to epitalon are thin. Containers should be marked with concentration and date, and solutions examined for cloudiness before use.
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.
The electoral process for the president was also changed, from being directly elected by the Togolese people to being indirectly elected by the Parliament. Opposition members criticised these changes due to the lack of term limits for Gnassingbé's new position. The changes came into effect in May 2025, when Gnassingbé was sworn in as president of the Council of Ministers, with former opposition leader Jean-Lucien Savi de Tové becoming president. Since June 2025, protests against Gnassingbé grew demanding his resignation. Gnassingbé has been widely criticized for contributing to democratic backsliding in Togo and critics have described him as a dictator.
=== Indications === Persons with G6PD deficiency are asymptomatic. An attack of acute haemolytic anaemia can appear out of nowhere and can be very severe and life-threatening. Indications of such a sudden attack of favism are dark urine, pallor, jaundice, abdominal pain and in most cases fever.
=== Honors === "10 Best Books of 2022" by The Washington Post "10 Best Books of 2022" by The New York Times. It is listed #61 on The New York Times' 100 Best Books of the 21st Century list Note: The novel was ranked #1 in its Reader's Picks List
== In cancer progression and metastasis == Initiation of metastasis requires invasion, which is enabled by EMT. Carcinoma cells in a primary tumor lose cell-cell adhesion mediated by E-cadherin repression and break through the basement membrane with increased invasive properties, and enter the bloodstream through intravasation. Later, when these circulating tumor cells (CTCs) exit the bloodstream to form micro-metastases, they undergo MET for clonal outgrowth at these metastatic sites. Thus, EMT and MET form the initiation and completion of the invasion-metastasis cascade. At this new metastatic site, the tumor may undergo other processes to optimize growth. For example, EMT has been associated with PD-L1 expression, particularly in lung cancer. Increased levels of PD-L1 suppresses the immune system which allows the cancer to spread more easily. EMT confers resistance to oncogene-induced premature senescence. Twist1 and Twist2, as well as ZEB1 protects human cells and mouse embryonic fibroblasts from senescence. Similarly, TGF-β can promote tumor invasion and evasion of immune surveillance at advanced stages. When TGF-β acts on activated Ras-expressing mammary epithelial cells, EMT is favored and apoptosis is inhibited. This effect can be reversed by inducers of epithelial differentiation, such as GATA-3. EMT has been shown to be induced by androgen deprivation therapy in metastatic prostate cancer. Activation of EMT programs via inhibition of the androgen axis provides a mechanism by which tumor cells can adapt to promote disease recurrence and progression.
In the 1990s, the national health ministries of the listed countries reviewed the pertinent studies for causal links among silicone-gel breast implants and systemic and diagnosed autoimmune diseases and breast cancer. A study by researchers at the U.S. National Institute of Health reported an increase in four types of cancer among women with breast implants compared to other plastic surgery patients of the same age and similar demographic traits and health habits. This increase in cancer was attenuated but did not disappear when the researchers followed the women for 5 more years, with a 43% increase in brain cancer and a 63% increase in respiratory cancer compared to other plastic surgery patients. A study by Watad et al. evaluated the medical records of more than 24,000 women with breast implants compared to more than 98,000 women with the same demographic traits who did not have breast implants. The researchers found a statistically significant 22 percent increase in several diagnosed diseases, increasing to more than 60% for Sjogren's syndrome, multiple sclerosis, and sarcoidosis After investigating this issue, in 2021 the U.S. FDA revised its "black box warnings" on breast implants to acknowledge the association between breast implants and systemic autoimmune, rheumatologic, and neurological symptoms to state: "Patients receiving breast implants have reported a variety of systemic symptoms, such as joint pain, muscle aches, confusion, chronic fatigue, autoimmune diseases, and others. Individual patient risk for developing these symptoms has not been well established.
Sources: en.wikipedia.org
The colloidal gold protein assay is a highly sensitive biochemical assay for determining the total concentration of protein in a solution (~0.1 ng/μL to 200 ng/μL). It was first described in 1987 by two groups who used commercially available "Aurodye" colloidal gold solutions. Notably, the formulation of Aurodye changed between 1987 and 1990 such that it became incompatible with protein assays, however vendors such as Bio-Rad & Diversified Biotech starting offering colloidal gold formulations that were suitable for protein assays. These products have since been discontinued and there are no vendors that currently explicitly sell colloidal gold for the assay, however detailed synthetic procedures were published to produce the ~17-40 nm gold nanoparticles that are suitable for the assay, along with modifications to increase the shelf stability of the colloidal gold & adapt the assay to microplate format & increase its sensitivity. Gold nanoparticles in the ~17-40 nm size range that are presumably compatible with the assay are currently commercially available.
In a separate study of rehabilitative strength training following immobilization, creatine supplementation was associated with increased muscle MRF4 protein expression; however, whether changes in MRF4 directly mediate myonuclear accretion or hypertrophy remains uncertain.
Half shade device: It consist of two semicircular plates ACB and ADB. One half ACB is made of glass while other half is made of quartz. Both halves are cemented together. The quartz is cut parallel to the optic axis. Thickness of the quartz is selected in such a way that it introduces a path difference of ’A/2 between ordinary and extraordinary ray. The thickness of the glass is selected in such a way that it absorbs the same amount of light as is absorbed by the quartz half. Consider that the vibration of polarization is along OP. On passing through the glass half the vibrations remain along OP. But on passing through the quartz half these vibrations will split into 0- and £-components. The £-components are parallel to the optic axis while O- component is perpendicular to optic axis. The O-component travels faster in quartz and hence an emergence 0-component will be along OD instead of along OC. Thus components OA and OD will combine to form a resultant vibration along OQ which makes the same angle with optic axis as OP. Now if the Principal plane of the analyzing Nicol is parallel to OP then the light will pass through the glass half unobstructed. Hence the glass half will be brighter than the quartz half or we can say that the glass half will be bright and the quartz half will be dark. Similarly if the principal plane of the analyzing Nicol is parallel to OQ then the quartz half will be bright and the glass half will be dark. When the principal plane of the analyzer is along AOB then both halves will be equally bright.
== Bibliography == Ackerman, A. Bernard; Almut Böer; Bruce Bennin; Geoffrey J. Gottlieb (2005). Histologic Diagnosis of Inflammatory Skin Diseases An Algorithmic Method Based on Pattern Analysis. Ardor Scribendi. ISBN 978-1-893357-25-9. Archived from the original on 21 April 2011. Moore, Keith L. et al. (2010) Clinically Oriented Anatomy 6th Ed
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 solid is kept cold, dry and dark, typically at minus twenty degrees Celsius, in a sealed container with desiccant. Dissolved material is kept refrigerated and used promptly. Freezing and thawing a solution repeatedly is avoided because it accelerates degradation.