AEDG raises a handful of sensible questions. This page answers them in order, starting with the fundamentals and moving to applications.
This page was last updated on 2025-08-20 and is reviewed periodically as new material appears.
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.
The most widely cited claim is that epitalon activates telomerase and thereby extends telomere length. Supporting evidence comes largely from cultured human cells, where treatment was associated with increased telomerase activity and delayed replicative senescence. Telomerase activation is a biologically consequential effect, since the enzyme is largely silenced in most somatic cells. However, the route by which a short peptide would reach and act on the enzyme's regulatory machinery has not been established. Independent replication in human trials is scarce, so the link between cell-culture observations and whole-body aging remains an open question.
Human data are limited to small studies, often without the randomization, blinding, or control groups expected in contemporary clinical research. Reported outcomes have included changes in melatonin levels, immune markers, and subjective measures, but sample sizes were generally too small to support firm conclusions. Some reviews treat the peptide as promising while noting methodological weaknesses; others question whether the observed effects are specific. The compound is frequently discussed in longevity-focused communities, where enthusiasm often outpaces the published evidence. Separating established findings from speculation is therefore important when reading summaries of this research.
Epitalon emerged from research conducted in Saint Petersburg by Vladimir Khavinson and colleagues, who studied short peptides as potential regulators of aging. The work built on epithalamin, a pineal gland extract reported to influence neuroendocrine function. Epitalon was designed as a synthetic counterpart with a defined sequence, allowing reproducible experiments that extracts could not support. Early publications described effects on melatonin rhythms and lifespan in animal models. These findings circulated mainly in Russian-language journals during the 1990s, which limited their visibility among English-speaking researchers.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C14H22N4O9 | Computed for the free acid of Ala-Glu-Asp-Gly |
| Molecular mass | About 390.35 g/mol | Free peptide; salt forms shift the value |
| Appearance | White to off-white solid | Typical of short peptides after freeze-drying |
| Solubility class | Freely soluble in water | Aqueous buffers are also commonly used |
| Common synonyms | Epitalon, epithalone, AEDG | AEDG is the single-letter sequence |
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.
Epitalon is a synthetic tetrapeptide with the sequence alanine–glutamate–aspartate–glycine, commonly abbreviated AEDG. Its design traces to epithalamin, a peptide fraction prepared from bovine pineal gland extracts that researchers in Saint Petersburg began investigating in the 1970s. The compound has a molecular formula of C14H22N4O9 and a nominal molecular mass near 390 daltons. It holds no approved drug status in the United States or the European Union, and material sold under this name is generally offered as a research chemical rather than a finished pharmaceutical product.
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.
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.
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.
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.
There is a dose-dependent increase in the QT interval and the corrected QT interval (QTc). Because of this, many practitioners will initiate dofetilide therapy only on individuals under telemetry monitoring or if serial EKG measurements of QT and QTc can be performed.
Weighted Companion Cubes are variants of Weighted Storage Cubes that are used in the testing chambers. They are differentiated from regular Storage Cubes with small pink hearts on its external surface, instead of an Aperture Science logo. In Portal, during test chamber 17, Chell is given a Weighted Companion Cube by GLaDOS, told by her that it will be her faithful companion for the duration of the test. Chell must use the Cube to complete the chamber, at which point GLaDOS requires her to incinerate the Cube before being able to progress further. The requirement to incinerate the companion cube originates from test-play of Portal, during which players brought their companion cube with them to later levels, with unexpected impact on game play. Another Companion Cube is seen at the end of the game, standing next to the cake. In Portal 2, redesigned Weighted Companion Cubes appear in test chamber 7 in chapter 2. GLaDOS fizzles two of them at the start of the test to annoy Chell. Chell is given the option to take a Weighted Companion Cube with her at the end of the test, but if Chell does this, GLaDOS fizzles the Companion Cube before Chell can enter the lift leading to the next test chamber. A Companion Cube with the old design, supposedly the one from Portal, appears at the very end of the game, as it is ejected, charred and singed, from the shed (possibly at ground level) shortly after Chell's departure. Companion Cubes are also mentioned a lot in the Ratman dens in Portal. In the Lab Rat comic, Ratman is also accompanied by a Companion Cube, which he imagines talks to him.
Insulin icodec is a medication used to enhance glycemic control in individuals with diabetes. It is an ultralong-acting basal insulin analogue developed by Novo Nordisk. The analog has a plasma half-life exceeding eight days, which is significantly longer than the 25-hour half-life of insulin degludec, the previously longest-acting insulin analogue. Insulin icodec functions as a once-weekly basal insulin.
== Mobile corps == Mobile corps (Chinese: 机动总队; pinyin: jīdòng zǒngduì), often mistranslated as "Contingents" are large formations without fixed areas of responsibility. Two were created after the 2018 reforms; most of the subordinate units came from the 14 disbanded mobile divisions. Mobile corps are corps leader grade formations commanded by major generals. The mobile corps are mainly responsible for dealing with terrorism, violent crime, riots, and public security threats.
Sources: en.wikipedia.org
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== Clinical significance == Deletions and mutations in this gene are associated with supravalvular aortic stenosis (SVAS) and the autosomal dominant cutis laxa. Other associated defects in elastin include Marfan syndrome, emphysema caused by α1-antitrypsin deficiency, atherosclerosis, Buschke–Ollendorff syndrome, Menkes syndrome, pseudoxanthoma elasticum, and Williams syndrome.
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Curium is a common starting material for making higher transuranic and superheavy elements. Thus, bombarding 248Cm with neon (22Ne), magnesium (26Mg), or calcium (48Ca) yields isotopes of seaborgium (265Sg), hassium (269Hs and 270Hs), and livermorium (292Lv, 293Lv, and possibly 294Lv). Californium was discovered when a microgram-sized target of curium-242 was irradiated with 35 MeV alpha particles using the 60-inch (150 cm) cyclotron at Berkeley:
Rasburicase, sold under the brand name Elitek in the US and Fasturtec in the EU, is a medication that helps to clear uric acid from the blood. It is a recombinant version of urate oxidase, an enzyme that metabolizes uric acid to allantoin. Urate oxidase is known to be present in many mammals but does not naturally occur in humans. Rasburicase is produced by a genetically modified Saccharomyces cerevisiae strain. The complementary DNA (cDNA) coding for rasburicase was cloned from a strain of Aspergillus flavus. Rasburicase (Q00511) is a tetrameric protein with identical subunits. Each subunit is made up of a single 301 amino acid polypeptide chain with a molecular mass of about 34 kDa. The drug product is a sterile, white to off-white, lyophilized powder intended for intravenous administration following reconstitution with a diluent. Elitek (rasburicase) is supplied in 3 mL and 10 mL colorless, glass vials containing rasburicase at a concentration of 1.5 mg/mL after reconstitution. It is on the World Health Organization's List of Essential Medicines.
Sources: en.wikipedia.org
It is a four-amino-acid peptide with the sequence alanine-glutamate-aspartate-glycine. The chain is unmodified and contains only standard proteinogenic residues, which makes it straightforward to produce by solid-phase synthesis and to characterise by standard peptide methods.
Epitalon and epithalon both circulate, and the difference reflects transliteration of a name coined in Russian-language publications. Reference to the extract it derives from, epithalamin, explains the shared stem. Databases and suppliers are inconsistent, so a search for one spelling alone may miss relevant entries.
No. Epithalamin is a multi-component preparation obtained from pineal tissue, and its exact composition is not fully characterised. Epitalon is a single defined tetrapeptide described as a short synthetic counterpart of that extract, so the two are related in origin but not interchangeable in identity.
Vladimir Khavinson and colleagues at research institutes in Saint Petersburg developed and studied the peptide. Their program examined short peptides as regulators of aging and neuroendocrine function. Epitalon was one of several compounds produced by that group.