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Structure, Naming And Discovery — Evidence Review

By Editorial Desk · published 2025-12-22 · last reviewed 2026-02-10 · Faq

Khavinson is one of those subjects where the details matter more than the headlines. This page pulls together the background, the mechanisms, and the practical points readers ask about most.

Last reviewed on 2026-02-10. Where a claim depends on a specific study, the study is described rather than over-claimed.

Structure, Naming and Discovery

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.

Epitalon Peptide Background and Structure

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 at a glance

PropertyValueNotes
Molecular formulaC14H22N4O9Derived from the four constituent residues
Molecular massAbout 390.35 DaMonoisotopic value, confirmed by mass spectrometry
Residue sequenceAla-Glu-Asp-GlyRead from the N-terminus to the C-terminus
Common synonymsEpithalon; AEDGBoth forms appear in reference catalogues
Net charge near neutral pHNegativeTwo acidic side chains give a low isoelectric point

Epitalon Background And Identification

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.

Reported biological findings come mainly from cell culture and rodent experiments. Those studies describe changes in telomerase catalytic subunit expression, melatonin rhythm amplitude, and antioxidant enzyme activity after peptide exposure. Human data are sparse and consist of small trials with limited blinding and inconsistent endpoints. The proposed mechanisms remain hypotheses rather than established facts, and there is no consensus on whether effects observed in animals carry over to people. Independent replication outside the original research groups is limited, which is a recognised gap in the published literature.

The parent extract epithalamin was characterised as a low-molecular-weight fraction of pineal tissue rather than a single defined chemical entity. Researchers fractionated it and tested successive fragments for activity, a screening approach typical of peptide discovery work in that era. Epitalon emerged from that process as one of the shorter sequences of interest. Because the original extract was never fully resolved into individual components, claims about which constituent drives a given effect rest on inference. This distinction matters when reading older reports that attribute extract observations to the tetrapeptide itself.

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Chemical Identity and Research Background

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.

Peptide Identity and Laboratory Handling

Epitalon is a synthetic tetrapeptide with the sequence alanine-glutamate-aspartate-glycine, abbreviated AEDG. Its molecular formula is C14H22N4O9 and its calculated monoisotopic mass is approximately 390.35 daltons. The compound does not occur naturally as a free peptide; it is produced by solid-phase peptide synthesis. Because it contains two acidic residues and no basic residues, the neutral form carries a net negative charge at physiological pH. This charge profile influences how the peptide behaves in solution and during chromatographic analysis.

Laboratory-grade epitalon is typically supplied as a lyophilized powder. Purity is commonly assessed with reverse-phase high-performance liquid chromatography, often paired with mass spectrometry to confirm molecular identity. Amino acid analysis and peptide mapping can provide additional confirmation of sequence. Certificates of analysis for research materials frequently report purity above 95 percent, although the methods behind such figures vary between suppliers. The absence of a pharmacopeial monograph means that no single standardized assay defines the compound, so reported results depend on the analytical protocol chosen.

Storage recommendations center on limiting moisture, heat, and light. The dry powder is generally kept at minus 20 degrees Celsius, and some suppliers recommend minus 80 degrees for long-term archival. Once dissolved, solutions are usually aliquoted and frozen to avoid repeated freeze-thaw cycles, which can promote aggregation or degradation. Aqueous stability depends on pH and concentration, and buffered saline is often preferred over plain water for biological work. Stability data specific to epitalon remain limited, so general peptide-handling practices are applied by analogy rather than from product-specific validation.

Epitalon Background and Nomenclature

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.

Reference notes

==== France ==== Rungis International Market in the Île-de-France region, created in 1969, is the largest market for fresh food in the whole of Europe, selling food from both within and without Île-de-France. The largest wholesale food market in the world, and perhaps even the largest fresh food market, various foods are offered, including sheep and eel. By 1972, 6000 tonnes of fruits and vegetables were shipped to the market daily.

=== Slaughter by the consumer === Insects may also be sold live for food purposes, and thus effectively slaughtered by the end human consumer prior to eating. Some "how to" guides for eating insects make no mention of freezing or other euthanasia methods. For example, Miles Olson's recommendations include:

Several screening and diagnostic tests have been used to look for high levels of glucose in plasma or serum in defined circumstances. One method is a stepwise approach where a suspicious result on a screening test is followed by a diagnostic test. Alternatively, a more involved diagnostic test can be used directly at the first prenatal visit for a woman with a high-risk pregnancy. (for example, in those with polycystic ovarian syndrome or acanthosis nigricans). Non-challenge blood glucose tests involve measuring glucose levels in blood samples without challenging the subject with glucose solutions. A blood glucose level is determined when fasting, two hours after a meal, or at any random time. In contrast, challenge tests involve drinking a glucose solution and measuring glucose concentration thereafter in the blood; in diabetes, they tend to remain high. The glucose solution has a very sweet taste, which some women find unpleasant; sometimes, therefore, artificial flavours are added. Some women may experience nausea during the test, and more so with higher glucose levels. There is currently not enough research to show which way is best at diagnosing gestational diabetes. Routine screening of women with a glucose challenge test may find more women with gestational diabetes than only screening women with risk factors. Hemoglobin A1c (HbA1c) is not recommended for diagnosing gestational diabetes, as it is a less reliable marker of glycemia during pregnancy than oral glucose tolerance testing (OGTT).

The nucleation of new actin filaments – the rate-limiting step in actin polymerization – is aided by actin-nucleating proteins such as formins (like formin-2) and the Arp2/3 complex. Formins help to nucleate long actin filaments. They bind two free actin-ATP molecules, bringing them together. Then as the filament begins to grow, formin moves along the (+) end of the growing filament, all the while recruiting actin-binding proteins that promote filament growth, and excluding capping proteins that would block filament extension. Branches in actin filaments are typically nucleated by the Arp2/3 complex in concert with nucleation promoting factors. Nucleation promoting factors bind two free G-actin molecules, then recruit and activate the Arp2/3 complex. The activated Arp2/3 complex attaches to an existing actin filament, and uses the two bound G-actin molecules to nucleate a new actin filament branching off of the old one at a 70° angle.

In 2018, she was awarded an Honorary Doctorate from Carnegie Mellon University In 2020, she was elected a Foreign Member of the Royal Society In 2023, she was awarded an Honorary Doctorate from the Jagiellonian University. In 2024, she was awarded an Honorary Doctorate from the Technion.

Sources: en.wikipedia.org

Reference notes

The fighter pilots claimed to have destroyed or damaged 1,062 aircraft and 254 ships, along with large numbers of buildings and railway rolling stock. American losses were 91 pilots killed and 157 Mustangs destroyed. Overall, P-51 pilots on Iwo Jima flew 51 missions (4,172 sorties) over Japan during their VLR campaign of 1945, including both bomber escort and independent ground-attack missions, encountering enemy aircraft on 33 occasions.

== EMAIL invention controversy == Ayyadurai is notable for his widely disputed claim of being the "inventor of email". His claim is based on an electronic mail software called EMAIL, an implementation of interoffice email system, which he wrote as a 14-year-old student at Livingston High School, New Jersey, in 1979. Initial reports that repeated Ayyadurai's assertion—from organizations such as The Washington Post and the Smithsonian Institution—were followed by public retractions. These corrections were triggered by objections from historians and ARPANET pioneers who cited the fact the history of email dated back to the early 1970s. Ayyadurai started a campaign in 2011 in which he rebranded himself as the "Inventor of Email"; according to a paper published in Information & Culture, he "provoked a dramatic succession of exaggerated claims, credulous reporters, retractions, and accusations that a cabal of industry insiders and corrupt Wikipedia editors are colluding to hide the truth." A November 2011 Time Techland interview by Doug Aamoth, entitled "The Man Who Invented Email", argued that EMAIL represented the birth of email "as we currently know it". In that interview, Ayyadurai recalled that Les Michelson, the former particle scientist at Brookhaven National Labs who assigned Ayyadurai the project, had the idea of creating an electronic mail system that uses the header conventions of a hardcopy memorandum. Ayyadurai recalled Michelson as saying: "Your job is to convert that into an electronic format.

At the end of 2014, there were almost 571,000 non-German citizens in Lower Saxony. At the end of 2023, there were almost 1,085,315 non-German citizens in Lower Saxony. The highest share of migrants to Germans in Lower Saxony is in the urban agglomeration of Braunschweig (44.8%) which consists the most populated parts of Salzgitter e.g Lebenstedt or Thiede, the town Wolfenbüttel, parts of the districts Landkreis Peine, Landkreis Gifhorn, Landkreis Helmstedt and Landkreis Wolfenbüttel. 57.5% of Salzgitter have a migration background, which has the highest percentage of people with a foreign background in Lower Saxony. The following table illustrates the largest minority groups in Lower Saxony:

== Appearances == The Headcrab debuted in Half-Life (1998) as an enemy that attacks protagonist Gordon Freeman and other surviving humans by leaping at them and biting them. Headcrabs first appear when a portal is opened, sending various interdimensional beings into the game's world and sending the Black Mesa lab into chaos. Throughout the game, the player encounters bodies with Headcrabs on their head, some of which becoming animated and attacking living people. In the sequel, Half-Life 2, the Headcrab and Headcrab Zombies return in a similar capacity. Headcrabs can be found in various environments, and the main antagonists, the Combine, who have taken control of the world post-invasion, have been attacking civilian and resistance groups by shooting rockets with Headcrabs in them to infect the population. Other Headcrabs appear, including a fast one and a poison one, the latter of which can put Gordon in serious danger if bitten. The character Isaac Kleiner manages to debeak a Headcrab, keeping it as a pet called Lamarr. Headcrabs also appear in Half-Life: Alyx, a virtual reality game. Fast-moving Headcrabs and Zombies were originally considered for inclusion, but were removed due to tests finding that they moved too fast for players to properly react. Outside of the Half-Life series, the Headcrab makes multiple cameo appearances. Multiple games, such as Vindictus and the Steam releases of Phantasy Star Online 2, Death Stranding, and Fall Guys featured accessories based on the Headcrab.

Sources: en.wikipedia.org

Reference notes

The pain in an osteoarthritic joint has been related to thickened synovium and to subchondral bone lesions. The inflammation of the joint lining (synovium) in osteoarthritis is characterized by involving macrophages via activation of the innate immune system (as compared to T-cell activation in the joint lining of people with rheumatoid arthritis). Pro-inflammation cytokines in osteoarthritis stimulate matrix metalloproteinases which leads to degradation and remodeling of the joint. Tissue damage or degradation of the articular cartilage or synovium leads to further release of inflammatory cytokines, driving the process.

Datura is a genus of nine species of highly poisonous, vespertine-flowering plants belonging to the nightshade family (Solanaceae). They are commonly known as thornapples or jimsonweeds, but are also known as devil's trumpets or mad apple (not to be confused with angel's trumpets, which are placed in the closely related genus Brugmansia). Other English common names include moonflower, devil's weed and hell's bells. All species of Datura are extremely poisonous and psychoactive, especially their seeds and flowers, which can cause respiratory depression, arrhythmias, fever, delirium, hallucinations, anticholinergic toxidrome, psychosis, and death if taken internally. The name Datura originates from the Sanskrit word for "thorn-apple," with historical and cultural significance in Ayurveda and Hinduism, while the American term "jimsonweed" derives from its prevalence in Jamestown, Virginia, where it was called "Jamestown-Weed." Datura species are herbaceous annual or short-lived perennial plants up to two meters tall with trumpet-shaped flowers and spiny fruit capsules, historically used in traditional medicine, especially in India, where they hold cultural and ritual significance. Datura species classification is complex due to high variability and overlapping traits among species, with many "new species" later reclassified as local varieties or subspecies; most species are native to Mexico, though some have disputed native ranges outside the Americas. Datura is closely related to Brugmansia and the recently established Trompettia.

== Test usage in the life insurance industry == The test has been widely used in the life insurance industry to screen applicants as part of the routine requirements when applying for a life insurance policy. It is also inexpensive and can be measured from blood samples routinely drawn as part of the application process. The test can be used to evaluate for a number of health conditions.

Sources: en.wikipedia.org

Frequently asked questions

What is epitalon made of?

It is a four-amino-acid peptide built from alanine, glutamate, aspartate and glycine in that order. Its formula is C14H22N4O9, and it is made by chemical synthesis rather than extracted from tissue. The synthetic peptide is a single defined molecule, unlike the pineal extracts it is often compared with.

Are epitalon and epithalon different compounds?

No. The two spellings refer to the same tetrapeptide, and the difference reflects transliteration from Russian. Laboratories and catalogues use both forms interchangeably. The material is also indexed as AEDG, taken from the one-letter codes of its residues.

How does epitalon differ from epithalamin?

Epithalamin is a mixed preparation derived from animal pineal tissue and contains many peptides. Epitalon is one synthetic sequence chosen for study from that broader mixture. Statements about one do not transfer directly to the other.

What is epitalon made of?

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.

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