epitalon 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 2026-06-29 and is reviewed periodically as new material appears.
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.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C14H22N4O9 | Derived from the four constituent residues |
| Molecular mass | About 390.35 Da | Monoisotopic value, confirmed by mass spectrometry |
| Residue sequence | Ala-Glu-Asp-Gly | Read from the N-terminus to the C-terminus |
| Common synonyms | Epithalon; AEDG | Both forms appear in reference catalogues |
| Net charge near neutral pH | Negative | Two acidic side chains give a low isoelectric point |
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.
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 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.
Pardaxin is a peptide produced by the Red Sea sole (P4, P5) and the Pacific Peacock sole (P1, P2, P3) that is used as a shark repellent. It causes lysis of mammalian and bacterial cells, similar to melittin.
6-Monoacetylmorphine (6-MAM, 6-acetylmorphine, or 6-AM) is an opioid and also one of three active metabolites of heroin (diacetylmorphine), the others being morphine and the much less active 3-monoacetylmorphine (3-MAM).
As such, it appears that there may be species differences in the central penetration of bicalutamide and that the medication does indeed cross the blood–brain barrier and affect central function in humans. This is supported by potential side effects of bicalutamide, in spite of increased testosterone levels, like hot flashes and decreased sexual interest in men. However, a clinical study comparing bicalutamide and flutamide in men found that bicalutamide had less influence on the HPG axis than flutamide, suggesting that bicalutamide might have a limited degree of peripheral selectivity, at least compared to other NSAAs, in humans. Bicalutamide has been identified as a substrate of P-glycoprotein and of the breast cancer resistance protein (BCRP), though not of the multidrug resistance-associated protein 1 (MRP1). This may be involved in tumor resistance to bicalutamide. P-Glycoprotein is also known to play a major role in excluding drugs from the brain due to efflux back across the blood–brain barrier. It is known that there are prominent species differences in the role of P-glycoprotein in limiting permeation of P-glycoprotein substrates across the blood–brain barrier.
=== Pituitary surgery === Transsphenoidal cryohypophysectomy is a difficult procedure that is only offered at specialised clinics. Few case reports of pituitary surgery in cats with hypersomatotropism have been published. In one case the procedure resulted in a 95% decrease to insulin requirement following the surgery and diabetic remission 3 weeks later. A follow up 18 months later showed normal growth hormone and IGF-1 levels. In another case there was a decreased insulin requirement, well-managed diabetes mellitus, and no acromegalic signs during an 18-month period of observation following the surgery. These cases and others with similar results showcase that beta cells have a potential to recover in hypersomatotropic cats with appropriate treatment.
==== Zebrafish ==== Being model organisms, zebrafish myomeres have been extensively studied. The tail-bending maneuver generated by myomeres in zebrafish requires innervation from motor neurons for both the hypaxial and epaxial muscle regions. It has been found that timing/intensity of neurons firing in these two regions varies, respectively. This process is mediated by a circuit that controls motor neuron activation during swimming behaviors, which, in turn, affects force generation. Similar to this idea, one study found that hypaxial and epaxial myomere activation did not always correlate with myomeric fibers closer to the horizontal septum itself.
Sources: en.wikipedia.org
The nitride anion (N3−) is the strongest π donor known among ligands (the second-strongest is O2−). Nitrido complexes are generally made by the thermal decomposition of azides or by deprotonating ammonia, and they usually involve a terminal {≡N}3− group. The linear azide anion (N−3), being isoelectronic with nitrous oxide, carbon dioxide, and cyanate, forms many coordination complexes. Further catenation is rare, although N4−4 (isoelectronic with carbonate and nitrate) is known.
== N-terminal modifications == Protein N-termini can be modified co - or post-translationally. Modifications include the removal of initiator methionine (iMet) by aminopeptidases, attachment of small chemical groups such as acetyl, propionyl and methyl, and the addition of membrane anchors, such as palmitoyl and myristoyl groups
It's possible that hackers have gotten into administrative computer systems of utility companies, but says those aren't linked to the equipment controlling the grid, at least not in developed countries. [Schmidt] has never heard that the grid itself has been hacked. In June 2019, Russia said that its electrical grid has been under cyber-attack by the United States. The New York Times reported that American hackers from the United States Cyber Command planted malware potentially capable of disrupting the Russian electrical grid.
== Example of use == Researchers often want to measure, say, medical compounds in the bodies of animals. It's hard to measure them directly, so it can be chemically joined to a radionuclide - by measuring the radioactivity, you can get a good idea of how the original medical compound is being processed. Samples may be collected and counted at short time intervals (ex: 1 and 4 hours). But they might be tested for radioactivity all at once. Decay correction is one way of working out what the radioactivity would have been at the time it was taken, rather than at the time it was tested. For example, the isotope copper-64, commonly used in medical research, has a half-life of 12.7 hours. If you inject a large group of animals at "time zero", but measure the radioactivity in their organs at two later times, the later groups must be "decay corrected" to adjust for the decay that has occurred between the two time points.
Sources: en.wikipedia.org
The IDF said that one in five rockets launched by Hezbollah had landed in Lebanese territory and published an infographic showing failed rocket launches into Israel. On 16 December, a soldier from the IDF's 129th Battalion was killed by a Hezbollah drone strike near Margaliot, which also caused a fire in a building. Two other soldiers were injured. Another drone was shot down by the IDF, which also responded to the infiltrations by shelling targets. The IAF later hit several Hezbollah targets inside Lebanon, including rocket launch sites and military infrastructure. On 22 December, two IDF soldiers of the 188th Armored Brigade were killed by a Hezbollah rocket attack in the Shtula area. On the morning of 23 December, IDF aircraft bombed a house in Kfar Kila and intense artillery fire also took place on the outskirts of Deir Mimas The IDF conducted a raid near a UNIFL center along the Khardali River. An Al-Manar cameraman was injured in the eye after an IDF attack on a road in the al-Khardali area where correspondents of MTV and the state-owned National News Agency were also passing. Hezbollah announced that two of their members were killed on that day. On 24 December, senior IRGC general Razi Mousavi was killed by an Israeli airstrike in Damascus. On 26 December, a Hezbollah anti-tank missile hit St. Mary's Greek Orthodox Church in Iqrit, northern Israel. A civilian suffered serious injuries, and when IDF responders arrived at the scene, another missile was fired, injuring nine soldiers.
Genetically modified organism History of biotechnology An Asilomar Moment Archived 10 July 2013 at the Wayback Machine Original Asilomar Genetics Guidelines “Asilomar Conference.” Provides another summary of the Asilomar Conference. The Basics of Recombinant DNA provides an introduction to the science behind recombinant DNA. The Recombinant DNA Debate Archived 31 March 2007 at the Wayback Machine provides more details about the history of the debate surrounding the use of recombinant DNA technology. “Paul Berg: The 1980 Nobel Prize in Chemistry – Autobiography.” Provides an autobiography about Paul Berg. Science History Institute: The story of the 1975 Asilomar Conference on Recombinant DNA
=== RTG (radioisotope thermoelectric generator) power generation === As 241Am has a roughly similar half-life to 238Pu (432.6 years Am-241, 87.7 years Pu-238, decay energies nearly the same), it has been proposed as an active isotope of radioisotope thermoelectric generators, for use in spacecraft. Even though americium-241 produces less heat and electricity than plutonium-238 (the power yield is 114.7 milliwatts per gram [3.25 watts per ounce] for 241Am vs. 570 mW/g [16 W/oz] for 238Pu) and its radiation poses a greater threat to humans owing to gamma emission, it has advantages for long duration missions with its significantly longer half-life. The European Space Agency is working on RTGs based on americium-241 for its space probes as a result of the global shortage of plutonium-238 and easy access to americium-241 in Europe from nuclear waste reprocessing. Its shielding requirements in an RTG are the second lowest of all possible isotopes: only 238Pu requires less. An advantage over 238Pu is that it is produced as nuclear waste already. Prototype designs of 241Am RTGs expect 2–2.2 We/kg for a 5–50 We design, putting 241Am RTGs at parity with 238Pu RTGs within that power range, as the vast majority of the mass of an RTG is not the radioisotope, but the thermoelectrics, radiators, and isotope containment mass.
Sources: en.wikipedia.org
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.
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.
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.
Epitalon is a synthetic four-amino-acid peptide with the sequence alanine–glutamate–aspartate–glycine, also written AEDG. It was developed in Russian gerontology research and is studied for proposed effects on telomerase, melatonin regulation, and neuroendocrine function. It is not an approved pharmaceutical in the United States or the European Union.