The short version of AEDG fits in a sentence. The long version — which is the one that helps — is below.
This page was last updated on 2026-04-16 and is reviewed periodically as new material appears.
Epitalon is a synthetic tetrapeptide with the residue sequence alanine-glutamate-aspartate-glycine, commonly abbreviated AEDG. Its monoisotopic mass is approximately 390.35 daltons, and it is usually supplied as a lyophilised trifluoroacetate or acetate salt. The compound was derived from a pineal gland extract called epithalamin, a heterogeneous preparation investigated in the former Soviet Union. Researchers associated with the Saint Petersburg Institute of Bioregulation and Gerontology described the tetrapeptide as a constituent fragment of that extract. Commercial material is offered as a laboratory reagent rather than as a finished pharmaceutical product.
Literature searches for this compound must account for several spelling variants. Indexing databases contain epitalon, epithalon, epithalone, and AEDG, and relevant records are scattered across Russian-language and English-language journals that do not consistently cross-cite. Early publications describe the parent extract as a mixture of many peptides, whereas later work addresses the single synthetic tetrapeptide. That shift in nomenclature complicates comparison between studies, because extract data and tetrapeptide data are sometimes cited interchangeably. A search strategy omitting the alternate spellings will return an incomplete set of references.
Stability of the tetrapeptide follows ordinary peptide chemistry rather than any unusual structural feature. The aspartate-glycine pair is prone to aspartimide formation under mildly basic or neutral conditions, and deamidation can follow, altering both mass and chromatographic retention. Dry lyophilised powder kept at or below minus twenty degrees Celsius is the usual handling recommendation, with repeated freeze-thaw cycles avoided. Once dissolved in neutral aqueous buffer, degradation proceeds over days to weeks depending on pH and temperature, while acidic conditions generally slow the aspartimide route. A formal stability-indicating study has not been published in the indexed literature.
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.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic tetrapeptide | Four amino acid residues |
| Residue sequence | Ala-Glu-Asp-Gly | Abbreviated AEDG |
| Approximate mass | 390.35 Da | Monoisotopic, free base form |
| Parent preparation | Epithalamin extract | Derived from pineal tissue |
| Common spelling variants | Epithalon, epithalone, AEDG | Affects literature retrieval |
Discussions in the literature often conflate three distinct entities: the pineal extract epithalamin, the isolated tetrapeptide AEDG, and commercial preparations sold under similar names. Reviews citing older Russian-language studies sometimes omit detail on purity, route of administration and control groups, which makes cross-study comparison difficult. Researchers working with the compound generally note the need for independent replication, standardized enzyme assays, and clearer reporting of peptide identity. These caveats are relevant when weighing claims that appear in secondary sources rather than in primary reports.
（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.
Regulatory status varies by country and is not harmonized. Epitalon is not an approved drug in major Western jurisdictions. In some countries it is sold as a research chemical, and in others it has appeared in products marketed for other categories. This inconsistent status means that purity, labeling accuracy, and documentation differ widely between suppliers, and verification of identity and purity through independent analysis is the usual way buyers assess a given lot.
Epitalon appears in the literature primarily through a small number of research groups, most of them associated with the St. Petersburg Institute of Bioregulation and Gerontology. Publications describe cell culture experiments, animal studies, and a limited number of small human studies. Independent replication outside this network is sparse. As a result, reviews of the topic usually separate descriptive reports of observed effects from the question of whether those effects generalize, and they note the difficulty of comparing studies that use different preparations and endpoints.
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.
The compound is generally described as a synthetic analogue of a fragment isolated from a pineal gland extract. Researchers associated with the Saint Petersburg Institute of Bioregulation and Gerontology introduced it during the 1980s and 1990s while studying short peptides from animal tissue. The original extract, called epithalamin, is a heterogeneous mixture, whereas epitalon is a single defined sequence. That distinction matters because findings reported for the extract are not automatically findings about the pure tetrapeptide, and claims about broader biological effects remain a separate question from the chemical identity described here.
No national medicines regulator has approved epitalon as a therapeutic product. It is generally distributed as a research chemical, and in some jurisdictions selling peptides for human consumption without approval is restricted or prohibited. Certificates of analysis accompanying commercial material vary in which tests are performed, and independent verification of identity and purity is uncommon. Statements about anti-ageing or disease-prevention benefits on vendor pages are marketing claims rather than regulatory findings, a distinction that shapes how the compound is discussed in scientific and popular sources alike.
The most frequently cited laboratory finding is that AEDG increased telomerase activity and extended telomere length in cultured human somatic cells. That work used fetal fibroblast strains and reported changes in enzyme activity alongside altered division counts. Replication by unrelated groups has been limited, and the published record is largely a single-laboratory series rather than a multi-centre programme. The result supports a hypothesis about peptide influence on gene expression in cell culture; it does not by itself establish an effect on telomere length in living animals or in people.
Animal and clinical reports appear mainly in Russian-language journals from the 1990s and 2000s, covering endpoints such as melatonin rhythm, lifespan in aged rodents, and retinal function. Many of these papers involve small groups, lack blinding or placebo comparison, and are difficult to retrieve through indexed databases. Review articles published in English generally summarise the claims without reanalysing the underlying data. Because no large randomised trial exists, the clinical importance of these reported effects stays unresolved and is properly described as an open question.
=== 1979 === January 1: The United States and China normalize diplomatic relations. January 7: Vietnam deposes the Khmer Rouge and installs a pro-Vietnam, pro-Soviet government known as the People's Republic of Kampuchea. January 16: The Iranian Revolution ousts the pro-Western Shah, Mohammed Reza Pahlavi, and installs a theocracy under Grand Ayatollah Ruhollah Khomeini. The Central Treaty Organization dissolves as a result. February 17: Sino-Vietnamese War, China launches a punitive attack on Vietnam to punish it for invading Cambodia February 22: Saint Lucia becomes independent from the UK. February 24: A war broke out between Yemen Arab Republic and South Yemen. May 4: Margaret Thatcher is elected Prime Minister of the United Kingdom, becoming the first female to lead a major Western democracy. May 9: Civil war breaks out in El Salvador between Marxist-led insurgents and the U.S.-backed government. June 2: Pope John Paul II begins his first pastoral visit to his native Poland. June 18: U.S. President Jimmy Carter and Soviet leader Leonid Brezhnev sign the SALT II agreement, outlining limitations and guidelines for nuclear weapons. July 3: President Carter signs the first directive for financial aid to opponents of the pro-Soviet regime in Kabul, Afghanistan. July 16: Saddam Hussein becomes President of Iraq after Ahmed Hassan al-Bakr steps down. July 17: Marxist-led Sandinista revolutionaries overthrow the U.S.-backed Somoza dictatorship in Nicaragua. The Contra insurgency begins shortly thereafter.
Before the ghetto riot of 1967, Detroit's black population had the highest rate of home-ownership of any black urban population in the country, and their unemployment rate was just 3.4 percent. It was not despairing that fueled the riot. It was the riot which marked the beginning of the decline of Detroit to its current state of despair. Detroit's population today is only half of what it once was, and its most productive people have been the ones who fled. However, Thomas Sugrue argues that over 20% of Detroit's adult black population was out of work in the 1950s and 1960s, along with 30% of black youth between eighteen and twenty-four. Economist Edward L. Glaeser believes the riots were a symptom of the city's already downward trajectory:
Perforated septum – The reconstruction of a saddle nose caused by a (collapsed) perforated septum, or by autoimmune problems such as granulomatosis with polyangiitis (GPA), sarcoidosis, eosinophilic granulomatosis with polyangiitis (EGPA), relapsing polychondritis, by intranasal drug use, and by excessive nasal aerosol use. The saddle nose deformity resulting from lost dorsum support is reconstructed using autologous bone grafts and rib cartilage grafts. Rhinophyma – The correction of late-stage Rosacea, wherein the nasal skin is infected with acne rosacea that reddens, thickens, and enlarges the nose tip; an exemplar case is the American actor W.C. Fields. Although antibiotic acne treatments (e.g. Acutane) can halt the progression of Rosacea, the thickened skin and the fleshy obscuring of the nasal tip can only be corrected with rhinoplasty. Laser excision of abnormally thickened skin is the best rhinoplastic treatment for Rhinophyma; the CO2 laser and the infrared Erbium: YAG laser are the most effective treatments.
== Nomenclature == This enzyme belongs tois a hydrolase, specifically a glycosylase that hydrolyses N-glycosyl compounds. The systematic name of this enzyme class is NAD+ glycohydrolase. Other names in use include:
Sources: en.wikipedia.org
=== Fourier transform ion cyclotron resonance mass spectrometry === FT- ICR EI - MS can be used for analysis of three vacuum gas oil (VGO) distillation fractions in 295-319 °C, 319-456 °C and 456-543 °C. In this method, EI at 10 eV allows soft ionization of aromatic compounds in the vacuum gas oil range. The compositional variations at the molecular level were determined from the elemental composition assignment. Ultra-high resolving power, small sample size, high reproducibility and mass accuracy (<0.4ppm) are the special features in this method. The major product was aromatic hydrocarbons in all three samples. In addition, many sulfur-, nitrogen-, and oxygen-containing compounds were directly observed when the concentration of this heteroatomic species increased with the boiling point. Using data analysis it gave the information about compound types (rings plus double bonds), their carbon number distributions for hydrocarbon and heteroatomic compounds in the distillation fractions, increasing average molecular weight (or carbon number distribution) and aromaticity with increasing boiling temperature of the petroleum fractions.
=== Intracellular === Obligate intracellular parasites (e.g. Chlamydophila, Ehrlichia, Rickettsia) are only able to grow and replicate inside other cells. Infections due to obligate intracellular bacteria may be asymptomatic, requiring an incubation period. Examples of obligate intracellular bacteria include Rickettsia prowazekii (typhus) and Rickettsia rickettsii, (Rocky Mountain spotted fever). Chlamydia are intracellular parasites. These pathogens can cause pneumonia or urinary tract infection and may be involved in coronary heart disease. Other groups of intracellular bacterial pathogens include Salmonella, Neisseria, Brucella, Mycobacterium, Nocardia, Listeria, Francisella, Legionella, and Yersinia pestis. These can exist intracellularly, but can exist outside host cells.
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Aminoglycoside resistance is generally mediated by a resistance gene that inactivates the antibiotic via chemical modification. A wide range of such aminoglycoside modifying enzymes are known, including nucleotidyltranferases, phosphotransferases, or acetyltransferases: all enzymes that attach extra chemical groups to the molecule. New antibiotics have been developed based on the knowledge of some of these enzymes, incorporating structural changes that prevent specific groups of resistance enzymes from modifying the drug.
==== Nitrogen ==== The nitrogen stable isotope system is based on the relative enrichment/depletion of 15N in comparison to 14N in δ15N. Carbon and nitrogen stable isotope analyses are complementary in paleodiet studies. Nitrogen isotopes in bone collagen are ultimately derived from dietary protein, while carbon can be contributed by protein, carbohydrate, or fat. δ13C values help distinguish between dietary protein and plant sources while systematic increases in δ15N values as you move up in trophic level helps determine the position of protein sources in the food web. 15N increases 3-4% with each trophic step upward. It has been suggested that the relative difference between human δ15N values and animal protein values scales with the proportion of that animal protein in the diet, though this interpretation has been questioned due to contradictory views on the impact of nitrogen intake through protein consumption and nitrogen loss through waste release on 15N enrichment in the body. Variations in nitrogen values within the same trophic level are also considered. Nitrogen variations in plants, for example, can be caused by plant-specific reliance on nitrogen gas which causes the plant to mirror atmospheric values. Enriched or higher δ15N values can be achieved in plants that grew in soil fertilized by animal waste. Nitrogen isotopes have been used to estimate the relative contributions of legumes verses nonlegumes, as well as terrestrial versus marine resources.
Sources: en.wikipedia.org
It is based on epithalamin, a peptide-rich preparation obtained from pineal gland tissue and studied in the former Soviet Union. Researchers later identified the tetrapeptide AEDG as a constituent fragment of that material. Modern supplies are produced by chemical synthesis rather than tissue extraction.
No. Epithalamin is a heterogeneous extract containing many peptides, while epitalon is a single synthesised tetrapeptide. Publications sometimes treat findings from the two as equivalent, which is a common source of confusion. Their compositions differ and they are not interchangeable in analytical terms.
Most published work uses cell cultures or rodents because those models are faster and less costly to run. The few human trials that have been reported are small, and several lack control groups or blinding. This restricts what can reasonably be concluded about effects in people.
The molecule lacks aromatic residues, so it absorbs weakly near 280 nanometres, the wavelength applied to many other peptides. The peptide bond absorbs strongly below 220 nanometres, making 214 nanometres a practical compromise. Gradient methods must therefore use mobile phases with low ultraviolet absorbance to keep the baseline clean.