A practical reference on Tetrapeptide: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
Reviewed 2025-09-09. Anything still debated is marked as such rather than presented as settled.
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.
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.
The proposed relationship between epitalon and pineal function is a central part of its background. Khavinson's group reported that short peptides corresponding to regions of larger pineal proteins could influence gene expression in cells. Epitalon was framed as a synthetic analogue of an active fragment rather than a direct isolation product. Whether the tetrapeptide reproduces the effects of the parent extract is an open question, because comparative studies are limited and the parent extract itself is not a single defined substance.
Interest in epitalon is usually discussed within the broader field of short peptide bioregulators, a category that includes other synthetic di-, tri-, and tetrapeptides studied by the same research group. These compounds share a common rationale: that small fragments of tissue-derived proteins can retain biological activity and can be produced reproducibly. The category as a whole remains outside mainstream pharmacological consensus, and epitalon specifically has a limited presence in independent, non-Russian research literature, which shapes how its evidence base is described.
Epitalon is a synthetic tetrapeptide with the amino acid sequence alanine-glutamate-aspartate-glycine, abbreviated Ala-Glu-Asp-Gly or AEDG. It was developed by the Russian researcher Vladimir Khavinson and colleagues during work on peptide bioregulators derived from the pineal gland. The compound is short enough to be produced by standard solid-phase peptide synthesis and is typically handled as a lyophilized white powder. Its small size distinguishes it from larger pineal peptides such as epithalamin, a complex extract from which the tetrapeptide was conceptually derived.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C14H22N4O9 | Synthetic tetrapeptide, four residues |
| Nominal mass | Approximately 390 Da | Free peptide; salt forms differ |
| Appearance | White to off-white powder | Commonly supplied lyophilised |
| Solubility class | Freely soluble in water | Also dissolves in aqueous buffer |
| Typical storage | −20 °C, desiccated | Cold packs used during transport |
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.
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.
=== Collections and editions === Œuvres mêlées de Madame de Gomez:contenant ses tragedies & differens ouvrages en vers et en prose (1724 - English translation: Collected Works of Madame de Gomez: Containing her Tragedies and Various Works in Verse and Prose) Cent nouvelles nouvelles (published in multiple parts between 1732 and 1739 - English translation: The Hundred News)
Psilocybin and psilocin are listed as Schedule I drugs under the United Nations 1971 Convention on Psychotropic Substances. However, mushrooms containing psilocybin and psilocin are not unlawful in some parts of the world. For example, in Brazil they are legal, but extractions from the mushroom containing psilocybin and psilocin remain unlawful. In the United States, growing or possessing Psilocybe cubensis mushrooms is unlawful in all states, but it is legal to possess and buy the spores for microscopy purposes. However, Denver, Colorado, decriminalized them for those 21 and up on May 8, 2019. Oakland, California, followed suit, decriminalizing psilocybin-containing mushrooms as well as the peyote cactus on June 4, 2019. Santa Cruz, California, decriminalized naturally occurring psychedelics, including psilocybin mushrooms, on January 29, 2020. On November 3, 2020, the state of Oregon decriminalized possession of psilocybin mushrooms for recreational use and granted licensed practitioners permission to administer psilocybin mushrooms to individuals age 21 years and older. In 1978, the Florida Supreme Court ruled in Fiske vs Florida that possession of psilocybin mushrooms is not unlawful, in that the mushrooms cannot be considered a "container" for psilocybin based on how the law is written, i.e., it does not specifically state that psilocybin mushrooms themselves are unlawful, but that the hallucinogenic constituents in them are.
MALDI-TOF spectra are often used for the identification of microorganisms such as bacteria or fungi. A portion of a colony of the microbe in question is placed onto the sample target and overlaid with matrix. The mass spectra of expressed proteins generated are analyzed by dedicated software and compared with stored profiles for species determination in what is known as biotyping. It offers benefits to other immunological or biochemical procedures and has become a common method for species identification in clinical microbiological laboratories. Benefits of high resolution MALDI-MS performed on a Fourier transform ion cyclotron resonance mass spectrometry (also known as FT-MS) have been demonstrated for typing and subtyping viruses though single ion detection known as proteotyping, with a particular focus on influenza viruses. One main advantage over other microbiological identification methods is its ability to rapidly and reliably identify, at low cost, a wide variety of microorganisms directly from the selective medium used to isolate them. The absence of the need to purify the suspect or "presumptive" colony allows for a much faster turn-around times. For example, it has been demonstrated that MALDI-TOF can be used to detect bacteria directly from blood cultures. Another advantage is the potential to predict antibiotic susceptibility of bacteria. A single mass spectral peak can predict methicillin resistance of Staphylococcus aureus.
Mutation rates vary substantially across species, and the evolutionary forces that generally determine mutation are the subject of ongoing investigation. In humans, the mutation rate is about 50–90 de novo mutations per genome per generation, that is, each human accumulates about 50–90 novel mutations that were not present in their parents. This number has been established by sequencing thousands of human trios, that is, two parents and at least one child. The genomes of RNA viruses are based on RNA rather than DNA. The RNA viral genome can be double-stranded (as in DNA) or single-stranded. In some of these viruses (such as the single-stranded human immunodeficiency virus), replication occurs quickly, and there are no mechanisms to check the genome for accuracy. This error-prone process often results in mutations. The rate of de novo mutations, whether germline or somatic, vary among organisms. Individuals within the same species can even express varying rates of mutation. Overall, rates of de novo mutations are low compared to those of inherited mutations, which categorizes them as rare forms of genetic variation. Many observations of de novo mutation rates have associated higher rates of mutation correlated to paternal age. In sexually reproducing organisms, the comparatively higher frequency of cell divisions in the parental sperm donor germline drive conclusions that rates of de novo mutation can be tracked along a common basis.
Sources: en.wikipedia.org
At the mid-stage of gestation, the glucagon concentration is 6 μg/g, compared to 2 μg/g in adult humans. Just like insulin, fetal glucagon plasma levels do not change in response to an infusion of glucose. However, a study of an infusion of alanine into pregnant women was shown to increase the cord blood and maternal glucagon concentrations, demonstrating a fetal response to amino acid exposure. As such, while the fetal pancreatic alpha and beta islet cells have fully developed and are capable of hormone synthesis during the remaining fetal maturation, the islet cells are relatively immature in their capacity to produce glucagon and insulin. This is thought to be a result of the relatively stable levels of fetal serum glucose concentrations achieved via maternal transfer of glucose through the placenta. On the other hand, the stable fetal serum glucose levels could be attributed to the absence of pancreatic signaling initiated by incretins during feeding. In addition, the fetal pancreatic islets cells are unable to sufficiently produce cAMP and rapidly degrade cAMP by phosphodiesterase necessary to secrete glucagon and insulin. During fetal development, the storage of glycogen is controlled by fetal glucocorticoids and placental lactogen. Fetal insulin is responsible for increasing glucose uptake and lipogenesis during the stages leading up to birth. Fetal cells contain a higher amount of insulin receptors in comparison to adults cells and fetal insulin receptors are not downregulated in cases of hyperinsulinemia.
=== Leg === Lower limb amputations can be divided into two broad categories: minor and major amputations. Minor amputations generally refer to the amputation of digits. Major amputations are commonly below-knee- or above-knee amputations. Common partial foot amputations include the Chopart, Lisfranc, and ray amputations. Common forms of ankle disarticulations include Pyrogoff, Boyd, and Syme amputations. A less common major amputation is the Van Nes rotation, or rotationplasty, i.e. the turning around and reattachment of the foot to allow the ankle joint to take over the function of the knee. Types of amputations include:
In Australia, iced coffee may include syrup, cream, cocoa powder or coffee beans. The café style is something like an unblended milkshake, and may be made from espresso coffee or only coffee flavoring. Bushells has marketed a Coffee and Chicory Essence since the late 19th century, as has Bickfords since 1910. There are many brands of packaged iced coffee consisting of coffee, milk, and sweetener. In South Australia, Farmers Union Iced Coffee has outsold Coca-Cola and is one of the state's biggest brands. Pauls "Territory's Own" Iced Coffee is popular in the Northern Territory and Norco Real Iced Coffee is prominent in Northern New South Wales and South East Queensland. Other brands include Breaka, Big M, Brownes Chill, Moove, Masters, Dare, Max, Fleurieu, Rush, Oak and Ice Break.
In 1960 Dyson wrote a short paper for the journal Science titled "Search for Artificial Stellar Sources of Infrared Radiation". In it he speculated that a technologically advanced extraterrestrial civilization might surround its native star with artificial structures to maximize the capture of the star's energy. Eventually, the civilization would enclose the star, intercepting electromagnetic radiation with wavelengths from visible light downward and radiating waste heat outward as infrared radiation. One method of searching for extraterrestrial civilizations would be to look for large objects radiating in the infrared range of the electromagnetic spectrum.
=== Sodium bicarbonate === The administration of sodium bicarbonate solution to rapidly improve the acid levels in the blood is controversial. There is little evidence that it improves outcomes beyond standard therapy, and indeed some evidence that while it may improve the acidity of the blood, it may actually worsen acidity inside the body's cells and increase the risk of certain complications. Its use is therefore discouraged, although some guidelines recommend it for extreme acidosis (pH<6.9), and smaller amounts for severe acidosis (pH 6.9–7.0).
Sources: en.wikipedia.org
No. Epithalamin is a heterogeneous peptide fraction obtained from pineal gland extract and contains many components. Epitalon is a single synthetic tetrapeptide with the sequence Ala-Glu-Asp-Gly. Researchers synthesised the shorter peptide while attempting to identify active sequences within the extract.
No endogenous peptide with this exact sequence has been described as a circulating hormone or signalling molecule. The tetrapeptide was designed as a synthetic analogue based on fragments observed in pineal preparations. Any activity discussed in the literature therefore refers to administered material rather than to a natural pool of the compound.
It is not an approved medicine in major jurisdictions and does not appear in the major pharmacopoeias. Material is usually distributed as a research chemical or laboratory reagent. Such labelling places handling responsibility on the purchaser and does not indicate that a regulatory body has reviewed the substance.
Epitalon is a synthetic tetrapeptide composed of four amino acids: alanine, glutamate, aspartate, and glycine. It is written as Ala-Glu-Asp-Gly. The free peptide has a molecular weight of about 390 daltons and is normally supplied as a lyophilized powder.