AEDG tetrapeptide 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 2026-07-09 and is reviewed periodically as new material appears.
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.
（TG:@pojiaai）Epitalon is a synthetic linear tetrapeptide with the sequence alanine-glutamate-aspartate-glycine, abbreviated AEDG. It emerged from work on epithalamin, a peptide fraction prepared from bovine pineal tissue, and was designed as a short, chemically defined analogue of that extract. Early publications came mainly from Russian laboratories studying pineal peptides and aging-related endpoints. The compound appears in the literature under several spellings, including epithalon and epithalone, which complicates systematic searching. Its small size makes solid-phase assembly and routine analytical characterization straightforward.
Chemically, the molecule consists of four amino acid residues joined by three peptide bonds, with a free N-terminal amino group and a free C-terminal carboxyl group. Its molecular formula is C14H22N4O9, and its monoisotopic mass is approximately 390 daltons. The acidic glutamate and aspartate side chains give the peptide a net negative charge near neutral pH, a property that shapes its chromatographic behaviour and solubility profile. No disulfide bridges or other post-translational modifications are present, so the primary sequence alone defines the structure.
Most experimental work has been carried out in cell culture and animal models. Several reports describe changes in telomerase activity and proliferation in cultured cells, while rodent studies have examined lifespan, melatonin rhythm and reproductive endpoints. Human data remain limited, and much of the published clinical material consists of small trials with incomplete reporting of methods and controls. Whether the cell and animal findings translate into measurable effects in people is an open question, and the mechanistic basis of the reported telomerase changes is not fully established.
| 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 |
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.
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.
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 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.
The four residues give epitalon a molecular formula of C14H22N4O9 and a molecular weight near 390.35 daltons. The presence of two acidic residues, glutamate and aspartate, makes the free peptide strongly acidic, while the alanine and glycine ends provide neutral, nonpolar character. This combination produces a molecule with substantial water solubility. Because there are no cysteine, methionine, or tryptophan residues, the peptide lacks the most common oxidation-sensitive side chains, which simplifies handling compared with many longer peptides.
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.
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.
== History == BRD-6929 was first described in the scientific literature in 2005. Subsequently, it was described in greater detail in 2013 and thereafter. The drug's apparent lack of selectivity for HDAC1 and HDAC2 over HDAC3 was first described in 2022.
=== Grhl2 === Grhl2 is involved in lower jaw formation of mammals, among other craniofacial developmental processes. It is also evolutionarily closest to Grhl1, compared to Grhl3, while still exhibiting the highly conserved functions that all Grhl genes share. It also appears that Grhl2 is involved in the fusion of the facial bones and that disruption to the regulation of Grhl2 can lead to cranioschisis/split face during embryonic development, often causing death. Continuing with the trend of incomplete fusion, the formation of the neural tube and abdominal wall is also regulated by Grhl2, evident by observation of incomplete closure of these structures, leading to spina bifida and thoracoabdominoschisis, following loss of Grhl2 function in mutant mice models for Grhl2. Additionally, over-expression of Grhl2 can also lead to mice developing spina bifida, showing the delicate balance in regulation required for Grhl2. Grhl2 is also related to breast cancer progression due to its ability to regulate epithelial cells and other processes such as epithelial-mesenchymal transition (EMT), although it is not known if EMT is promoted or inhibited by Grhl2. However, tumour progression is more associated with the epithelial tissue phenotype. Interestingly, within zebrafish there are two separate orthologues, grhl2a and grhl2b. Comparing the homology of these two orthologues to the human and mice equivalent, Grhl2, showed that grhl2b had 36 out of 47 amino acids identical (77% identical), meaning it was slightly more conserved than grhl2a, which had 34 out of 47 (72% identical).
==== Recent advances ==== Since the early 2000s, advances in droplet-based microfluidics have made it a powerful technique for conducting directed evolution campaigns. Early developments in bulk production of single-emulsions (SEs; e.g. "water-in-oil" droplets) and double-emulsions (DEs; e.g. "water-in-oil-in-water" droplets) were followed by innovations in on-chip formation and sorting of SEs and DEs, which allow for greater ease and throughput of directed evolution experiments on microfluidic chips. An essential component of directed evolution is the maintenance of the linkage between enzymatic genotypes and phenotypes. The ability to form DEs on-chip and subsequently sort using fluorescence-activated cell sorting (FACS) pushed the field forward. In 2013, Yan et al. showed the use of FACS to sort DEs. In 2014, Zinchenko et al. published a system to formulate monodisperse DEs and to sort and quantitatively analyze them using a commercially available flow cytometer. The authors demonstrated the power of their system by enriching an active wild-type arylsulfatase from populations of 0.1% and 0.01% active cells by 800- to 2500-fold, respectively. In 2016, Larsen et al. developed a fluorescence-based optical sorting system to monitor polymerases activity inside a microfluidic device. Using their system, Larsen and colleagues showed approximately 1200-fold enrichment of an engineered polymerase.
==== Use in diagnostics ==== First cTnI and later cTnT were originally used as markers for cardiac cell death. Both proteins are now widely used to diagnose acute myocardial infarction (AMI), unstable angina, post-surgery myocardium trauma and some other related diseases with cardiac muscle injury. Both markers can be detected in patient's blood 3–6 hours after onset of the chest pain, reaching peak level within 16–30 hours. Elevated concentration of cTnI and cTnT in blood samples can be detected even 5–8 days after onset of the symptoms, making both proteins useful also for the late diagnosis of AMI.
Sources: en.wikipedia.org
== Appearance == C. brunneus are predominantly brown. However, they show a large variation in colour and can also be black, green, purple, or white. Wing patterns vary between individuals and can be mottled, striped, striped-mottled, or plain. Both green and purple grasshoppers tend to have plain forewing patterns while black grasshoppers primarily have mottled forewing patterns. Brown grasshoppers do not consistently have the same forewing pattern instead they have variable forewing patterns. At least two loci are responsible for pronotum color in C. brunneus. Green alleles are dominant to all other colors while brown alleles are recessive to all other colors. Wing pattern is determined by a separate locus than colour. The plain forewing pattern is dominant and the striped and mottled forewing patterns are codominant.
policy – the various forms, past and present, of the U.S. 'war on drugs'". Outside interests, including "racism, fear, economic interests, domestic and international politics, global trade, domestic protectionism, war, arms control initiatives, the Cold War, development aid, and various corporate agendas", significantly shaped the conventions. And certain individuals played an outsized role in forming the policies: "while in positions of power at opportune moments, their beliefs, morals, ambitions and single-minded determination enabled them to exert exceptional influence over the shape of the international drug control regime." The efforts of US drug control commissioner Harry Anslinger and his Canadian counterpart and policy ally, Charles Henry Ludovic Sharman, are particularly notable. While many scholars view the drug conventions as a US-engineered prohibitionist regime, others offer more nuanced analyses. Among them, John Collins finds that, though "a plurality of the policy literature maintains this narrative, the historiography has since moved on." He suggests that the conventions emerged from complex multilateral negotiations, "a triangulation between various state interests and blocs." Sebastien Scheerer finds that global drug policy "rests on a highly coercive consensus masterminded by ... the United States", yet the US relied on "other governments' prejudices, plans and interests" in drug prohibition; America may have to "share the credit (and blame)" with other parties.
==== Ribose aminooxazoline (RAO), a critical RNA precursor molecule ==== Ribose aminooxazoline (RAO) is a pentose aminooxazoline, first identified in 1970 as an important intermediate for ribonucleotide biosynthesis when it was shown to produce α-cytidine, a stereoisomer of the biologically-produced nucleoside β-cytidine. Over three decades later, the abiotic synthesis of RAO was achieved from the reaction of cyanamide and the simple 2- and 3-carbon compounds glycoaldehyde and glyceraldehyde, a demonstration of prebiotically feasible cyanosulfidic chemistry. Subsequent research additionally established an abiotic pathway from RAO to the pyrimidine ribonucleosides β-cytidine and β-uridine, revealing a plausible synthetic pathway to RNA monomers from simple chemical precursors that could have been available on the early Earth. Research into the synthesis of purine ribonucleosides is still underway, although a pathway from RAO to purine deoxyribonucleosides has been elucidated.
=== Route of administration === The most common route of administration at a methadone clinic is in a racemic oral solution, though in Germany, only the R enantiomer (the L optical isomer) has traditionally been used, as it is responsible for most of the desired opioid effects. The single-isomer form is becoming less common due to the higher production costs. Methadone is available in traditional pills, sublingual tablets, and two different formulations designed for the person to drink. Drinkable forms include ready-to-dispense liquid (sold in the United States as Methadose), and Diskets (known on the street as "wafers" or "biscuits") tablets which are dispersible in water for oral administration, used similarly to Alka-Seltzer. The liquid form is the most common as it allows for smaller dose changes. Methadone is almost as effective when administered orally as by injection. Oral medication is usually preferable because it offers safety, and simplicity and represents a step away from injection-based drug abuse in those recovering from addiction. U.S. federal regulations require the oral form in addiction treatment programs. Injecting methadone pills can cause collapsed veins, bruising, swelling, and possibly other harmful effects. Methadone pills often contain talc that, when injected, produces a swarm of tiny solid particles in the blood, causing numerous minor blood clots.
== Medical uses == Varicella vaccine is 70% to 90% effective for preventing varicella and more than 95% effective for preventing severe varicella. Follow-up evaluations have taken place in the United States of children immunized that revealed protection for at least 11 years. Studies were conducted in Japan which indicated protection for at least 20 years. People who do not develop enough protection when they get the vaccine may develop a mild case of the disease when in close contact with a person with chickenpox. In these cases, people show very little sign of illness. This has been the case of children who get the vaccine in their early childhood and later have contact with children with chickenpox. Some of these children may develop mild chickenpox also known as breakthrough disease. Another vaccine, known as zoster vaccine, is simply a larger-than-normal dose of the same vaccine used against chickenpox and is used in older adults to reduce the risk of shingles (also called herpes zoster) and postherpetic neuralgia, which are caused by the same virus. The recombinant zoster (shingles) vaccine is recommended for adults aged 50 years and older.
Sources: en.wikipedia.org
If the mixture produces bubbles or froth, the organism is said to be 'catalase-positive'. Staphylococci and Micrococci are catalase-positive. Other catalase-positive organisms include Listeria, Corynebacterium diphtheriae, Burkholderia cepacia, Nocardia, the family Enterobacteriaceae (Citrobacter, E. coli, Enterobacter, Klebsiella, Shigella, Yersinia, Proteus, Salmonella, Serratia), Pseudomonas, Mycobacterium tuberculosis, Aspergillus, Cryptococcus, and Rhodococcus equi. If not, the organism is 'catalase-negative'. Streptococcus and Enterococcus spp. are catalase-negative. While the catalase test alone cannot identify a particular organism, it can aid identification when combined with other tests such as antibiotic resistance. The presence of catalase in bacterial cells depends on both the growth condition and the medium used to grow the cells. Capillary tubes may also be used. A small sample of bacteria is collected on the end of the capillary tube, without blocking the tube, to avoid false negative results. The opposite end is then dipped into hydrogen peroxide, which is drawn into the tube through capillary action, and turned upside down, so that the bacterial sample points downwards. The hand holding the tube is then tapped on the bench, moving the hydrogen peroxide down until it touches the bacteria. If bubbles form on contact, this indicates a positive catalase result. This test can detect catalase-positive bacteria at concentrations above about 105 cells/mL, and is simple to use.
South Africa's defence establishment perceived this aspect of Cuban and to a lesser extent Soviet policy through the prism of the domino theory: if Havana and Moscow succeeded in installing a communist regime in Angola, it was only a matter of time before they attempted the same in South West Africa.
==== Asbestos fibers ==== Many common building materials (especially those manufactured in the United States before 1976) contain asbestos, such as some floor tiles, ceiling tiles, shingles, fireproofing, heating systems, pipe wrap, taping muds, mastics, and other insulation materials. Normally, significant releases of asbestos fiber do not occur unless the building materials are disturbed, such as by cutting, sanding, drilling, or building remodeling. Removal of asbestos-containing materials is not always optimal because the fibers can be spread into the air during the removal process. A management program for intact asbestos-containing materials is often recommended instead. When asbestos-containing material is damaged or disintegrates, microscopic fibers are dispersed into the air. Inhalation of asbestos fibers over long exposure times is associated with increased incidence of lung cancer, mesothelioma, and asbestosis. The risk of lung cancer from inhaling asbestos fibers is significantly greater for smokers. The symptoms of disease do not usually appear until about 20 to 30 years after the first exposure to asbestos. Although all asbestos is hazardous, products that are friable, e.g. sprayed coatings and insulation, pose a significantly higher hazard as they are more likely to release fibers to the air.
== Contamination and response in 2009–2010 == On 2 December 2009, China detained three employees of Shaanxi Jinqiao Dairy Company in northwest China suspected of selling 5.25 tons of melamine-laced powdered milk to Nanning Yueqian Food Additive Company, in Guangxi. On 30 December 2009, Xinhua reported continuing problems: powder and flavouring products sold by another company involved in the original scandal–the Shanghai Panda Dairy Company–were found to contain illegal levels of melamine; the dairy was closed and three of its executives arrested. On 25 January 2010, it was reported that three food companies from Hebei, Liaoning and Shandong provinces had produced melamine tainted products in March and April 2009 and that the three companies were banned from selling products in Guizhou. On 10 February 2010 China's state council announced a food safety commission, consisting of three vice premiers and a dozen minister-level officials, to address the nation's food regulatory problems. The group aims to improve government coordination and enforcement and to solve systemic food safety problems. As part of its ongoing effort to find and destroy any melamine-tainted milk remaining on the market, the Chinese government announced that it was recalling 170 tons of powdered milk laced with the industrial chemical which was supposed to have been destroyed or buried in 2008 but has recently found to have been repackaged and placed back into the marketplace.
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.
It is a synthetic tetrapeptide with the sequence alanine-glutamate-aspartate-glycine, often abbreviated AEDG. The molecule is linear and contains no modified residues, so it is fully described by its sequence.