If you have been reading about epitalon and want a single page that covers the useful parts, this is it: definitions, context, how it is studied, and the questions that come up repeatedly.
Updated 2026-07-16. Numbers and descriptions here follow the published literature rather than marketing material.
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.
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.
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.
| 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 |
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.
Analytical characterization of epitalon relies on standard peptide methods. Reverse-phase high-performance liquid chromatography is used to assess purity, and mass spectrometry confirms identity by checking the observed mass against the expected value near 390 daltons. Amino acid analysis can verify composition. Because the peptide is short and hydrophilic, it elutes early on many reverse-phase columns, so method development often requires ion-pairing reagents to achieve adequate retention and resolution from related impurities.
Storage and handling follow conventional peptide practice. Lyophilized epitalon is typically kept refrigerated or frozen, protected from moisture and light, and allowed to equilibrate to room temperature before opening to avoid condensation. Once dissolved, aqueous solutions are usually stored cold and used within a short period, since dilute peptide solutions can support microbial growth and may slowly degrade. The absence of cysteine and methionine reduces, but does not eliminate, oxidation concerns during long-term storage.
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== Examples == Receptors for which inverse agonists have been identified include the GABAA, melanocortin, mu opioid, histamine, serotonin, and beta adrenergic receptors. Both endogenous and exogenous inverse agonists have been identified, as have drugs at ligand gated ion channels and at G protein-coupled receptors.
Once a male is able to retract his foreskin, penile hygiene should become an important feature of his routine body care. Although the American Academy of Pediatrics states there is "little evidence to affirm the association between circumcision status and optimal penile hygiene", various studies suggest that males be educated about the role of hygiene, including retracting the foreskin while urinating and rinsing under it and around the glans at each bathing opportunity. Regular washing under the foreskin was found by Krueger and Osborn (1986) to reduce the risk of numerous penile disorders, however Birley et al. (1993) reports excessive washing with soap should be avoided because it dries the oils out of the tissues and can cause non-specific dermatitis.
The narrower Russell Top 50 Mega Cap Index consists of the 50 largest companies in the Russell 3000 at the time of index reconstitution. As of April 30, 2026, the Russell Top 50 Mega Cap Index contained 51 constituents, with market caps ranging from $216.6 billion to $4.85 trillion. The even narrower Russell Top 10 Index consists of the 10 largest companies in the Russell 3000 at the time of index reconstitution. As of May 29, 2026, the Russell Top 10 Index contained 11 constituents, with market caps ranging from $873 billion to $4.93 trillion. A 2025 article by S&P Dow Jones Indices describes its own S&P 100, S&P 500 Top 50 (ticker: SP5T5), S&P 500 Top 20 (ticker: SP5T2), and S&P 500 Top 10 (ticker: SP5T1) indices as "mega-cap indices". As of May 29, 2026, the S&P 100 index's methodology required a minimum market cap of $22.7 billion, and the index's 101 constituents had actual market caps ranging from $55.1 billion to $5.13 trillion. As of May 29, 2026, the S&P 500 Top 50 Index contained 51 constituents, with market caps ranging from $92.3 billion to $5.13 trillion. Invesco issues an index ETF (NYSE Arca: XLG) that tracks the S&P 500 Top 50 Index. As of May 29, 2026, the S&P 500 Top 20 Index contained 21 constituents, with market caps ranging from $316 billion to $5.13 trillion. The S&P 500 Top 20 Select Index (ticker: SPXT2SUP) is a capped variant of the S&P 500 Top 20 Index, limiting any single company's weight in the index to a maximum of 22.5%, and limiting companies with weights above 4.5% to collectively constitute at most 48% of the index's weight.
Sources: en.wikipedia.org
English-language newspapers include The Moscow Times. Until its closure in 2014, The Moscow News was the oldest English-language weekly newspaper in Russia. Kommersant, Vedomosti, and Novaya Gazeta are Russian-language newspapers headquartered in Moscow. Kommersant and Vedomosti are among the country's oldest Russian-language business newspapers.
α2-Macroglobulin is known to bind zinc, as well as copper in plasma, even more strongly than albumin, and such it is also known as transcuprein. 10 to 15% of copper in human plasma is chelated by α2-macroglobulin.
=== Humans === The FPR3 gene was cloned and named based on the similarity of the amino acid sequence which it encodes to that encoded by the gene for FPR1 (see formyl peptide receptor 1 for details) The studies indicated that FPR3 is composed of 352 amino acids and its gene, similar to FPR1, has an intronless open reading frames which encodes a protein with the 7 transmembrane structure of G protein coupled receptors; FPR3 has 69% and 72% amino acid sequence identities with FPR1. All three genes localize to chromosome 19q.13.3 in the order of FPR1 (19q13.410), FPR2 (19q13.3-q13.4), and FPR3 (19q13.3-q13.4) to form a cluster which also includes the genes for another G protein-coupled chemotactic factor receptor, the C5a receptor (also termed CD88) and GPR77, and a second C5a receptor, C5a2 (C5L2), which has the structure of a G protein coupled receptor but fails to couple to G proteins and is of debated function.
The thoracic cavity is protected by the thoracic wall (comprising the rib cage and associated skin, muscle, and fascia), comprising the mediastinum, heart and great vessels, and the bulk of the respiratory tract. The abdominal cavity, lined by the peritoneum, contains the bulk of the gastrointestinal tract, the spleen and the kidneys. Abdominal organs may be classified as solid organs or hollow organs. The solid organs are the liver, pancreas, spleen, kidneys, and adrenal glands. The hollow organs of the abdomen are the stomach, intestines, gallbladder, bladder, and rectum. The pelvic cavity contains the urinary bladder, internal reproductive organs, and rectum. Viscera are the internal organs of the ventral cavity. The term "visceral" is contrasted with the term "parietal", meaning "of or relating to the wall of a body part, organ or cavity". The two terms are often used in describing a membrane or piece of connective tissue, referring to the opposing sides.
In the DSM-II, stressing the intensity and variability of moods, it was called cyclothymic personality (affective personality). While the term "borderline" was evolving to refer to a distinct category of disorder, psychoanalysts such as Otto Kernberg were using it to refer to a broad spectrum of issues, describing an intermediate level of personality organization between neurosis and psychosis. After standardized criteria were developed by John Gunderson to distinguish it from mood disorders and other Axis I disorders, BPD became a personality disorder diagnosis in 1980 with the publication of the DSM-III. The diagnosis was distinguished from sub-syndromal schizophrenia, which was termed "schizotypal personality disorder". The DSM-IV Axis II Work Group of the American Psychiatric Association finally decided on the name "borderline personality disorder", which is still in use by the DSM-5. However, the term "borderline" has been described as uniquely inadequate for describing the symptoms characteristic of this disorder. Psychodynamic theorists have historically offered the most comprehensive theoretical models of BPD. Gunderson emphasized the patient's fundamental interpersonal hypersensitivity, which he viewed as partially genetic. Kernberg sees the disorder as one involving disturbed object relations, marked by an excess of aggression and use of primitive defenses, such as splitting, projection, and projective identification.
Sources: en.wikipedia.org
== 1942: Battle of Stalingrad == On 1 January 1942, the 4th Panzer Group was redesignated 4th Panzer Army. The 4th Panzer Army held defensive positions in the spring of 1942 and then was reinforced, re-fit and transferred to Army Group South for Case Blue, its offensive in Southern Russia. Command was transferred to general Hermann Hoth in June. As the operation progressed, Hitler divided Army Group South into two army groups. Army Group A which was composed of the German 17th Army and 1st Panzer Army and Army Group B which was composed of 6th Army and the 4th Panzer Army. The 4th Panzer Army was on 1 Aug 1942 composed of:
=== Genetics === Two variants (G6PD A− and G6PD Mediterranean) are the most common in human populations. G6PD A− has an occurrence of 10% of Africans and African-Americans, while G6PD Mediterranean is prevalent in the Middle East. The known distribution of the mutated allele is largely limited to people of Mediterranean origins (Spaniards, Italians, Greeks, Armenians, Sephardi Jews, and other Semitic peoples). Both variants are believed to stem from a strongly protective effect against Plasmodium falciparum and Plasmodium vivax malaria. It is particularly frequent in the Kurdish Jewish population, wherein approximately 1 in 2 males have the condition, and the same rate of females are carriers. It is also common in African American, Saudi Arabian, Sardinian males, some African populations, and Asian groups. All mutations that cause G6PD deficiency are found on the long arm of the X chromosome, on band Xq28. The G6PD gene spans some 18.5 kilobases. The following variants and mutations are well-known and described:
The following year, Pauling published what he regarded as his most important paper, in which he first laid out the concept of hybridization of atomic orbitals and analyzed the tetravalency of the carbon atom. At Caltech, Pauling struck up a close friendship with theoretical physicist Robert Oppenheimer at the University of California, Berkeley, who spent part of his research and teaching schedule as a visitor at Caltech each year. Pauling was also affiliated with Berkeley, serving as a visiting lecturer in physics and chemistry from 1929 to 1934. Oppenheimer even gave Pauling a stunning personal collection of minerals. The two men planned to mount a joint attack on the nature of the chemical bond: apparently Oppenheimer would supply the mathematics and Pauling would interpret the results. Their relationship soured when Oppenheimer tried to pursue Pauling's wife, Ava Helen. When Pauling was at work, Oppenheimer came to their home and blurted out an invitation to Ava Helen to join him on a tryst in Mexico. She flatly refused, and reported the incident to Pauling. He immediately cut off his relationship with Oppenheimer. In the summer of 1930, Pauling made another European trip, during which he learned about gas-phase electron diffraction from Herman Francis Mark. After returning, he built an electron diffraction instrument at Caltech with a student of his, Lawrence Olin Brockway, and used it to study the molecular structure of a large number of chemical substances. Pauling introduced the concept of electronegativity in 1932.
When the U.S. government created the United States Agency for International Development (USAID) in November 1961, it built on a legacy of previous development-assistance agencies and their people, budgets, and operating procedures. USAID's predecessor agency was already substantial, with 6,400 U.S. staff in developing-country field missions in 1961. Except for the peak years of the Vietnam War, 1965–70, that was more U.S. field staff than USAID would have in the future, and triple the number USAID has had in field missions in the years since 2000. Although the size of the development-assistance effort was not new, the 1961 decision to reorganize the government's main development-assistance agency was a landmark in terms of institutional evolution, representing the culmination of twenty years' experience with different organizational forms and procedures, in changing foreign-policy environments. The new structure created in 1961 "proved to be sturdy and durable". In particular, the U.S. government has maintained since then "the unique American pattern of placing strong resident aid missions in countries that [the U.S. was] helping." The story of how the base for USAID's structure was built is described below, along with an account of changes that have been made since 1961.
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.
Small studies with human participants have been reported, chiefly in Russian-language journals, but they are limited in size and design. No large randomised controlled trial with published results is available.