epithalamin 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 2026-02-24 and is reviewed periodically as new material appears.
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.
Dissolution is usually performed in water or a suitable aqueous buffer, and the resulting liquid is divided into single-use portions before freezing. Freeze-thaw cycling is a recognised source of loss for short peptides, since each cycle can encourage aggregation or adsorption onto container walls. Working solutions are generally kept cold and used within a short window, although published stability data specific to epitalon are thin. Containers should be marked with concentration and date, and solutions examined for cloudiness before use.
Identity is normally established by reversed-phase high-performance liquid chromatography combined with mass spectrometry, a pairing that separates components and confirms molecular mass at once. Purity is quoted as a percentage from the chromatogram, and figures above ninety-five percent are a frequent commercial specification. Amino acid analysis or sequencing supplies further confirmation when required. Because many short peptides behave similarly under chromatography, retention time alone does not establish sequence; the mass measurement is what separates one tetrapeptide from another, and certificates should report both.
Short peptides such as AEDG are normally supplied as a freeze-dried solid and are kept dry, cold, and shielded from light. Holding at minus twenty degrees Celsius is common for the long term, while a refrigerator suffices for brief periods before use. The material takes up moisture to some degree, so containers should stay sealed and be allowed to reach room temperature before opening, which limits condensation on the contents. Repeated warming and cooling of a single container is discouraged because it admits water and can lower the amount of intact peptide.
| 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 studies on epitalon are dominated by a small number of research groups, and independent replication in other laboratories remains limited. Proposed mechanisms include activation of telomerase and modulation of melatonin rhythms, but the evidence for either rests mainly on cell cultures and animal models. Whether the peptide produces comparable effects in humans is an open question, and the absence of large controlled trials means the literature is best read as exploratory rather than settled.
Epitalon is a synthetic four-amino-acid peptide with the sequence alanine-glutamate-aspartate-glycine, commonly abbreviated AEDG. Its molecular formula is C14H22N4O9, and its calculated molar mass is approximately 390.35 grams per mole. The compound is a short fragment related to a peptide fraction isolated from bovine pineal gland extracts, and it is normally supplied as a lyophilised powder intended for laboratory research. It is not a registered pharmaceutical product in most countries.
Lyophilised epitalon is generally held at minus twenty degrees Celsius in a sealed container kept dry and dark. Cooler conditions are sometimes recommended for long-term archives. The solid takes up moisture readily enough that repeated opening of a vial introduces water, so dividing a batch into smaller portions before storage lowers degradation risk. Aqueous solutions are less durable than the dry powder and are usually prepared shortly before use, then kept cold and shielded from light to slow hydrolysis and oxidation.
Verification of research-grade material involves comparing a supplier chromatogram against an in-house reference, checking the observed mass against the calculated value, and where possible confirming residue order by tandem mass spectrometry or enzymatic peptide mapping. Purity claims should be read alongside the method used to obtain them, because detection wavelength and integration settings alter the result. Batch-specific data, rather than a generic grade statement, is the informative part of a certificate.
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.
Laboratory handling begins with dissolution of the lyophilized powder in water or a suitable aqueous buffer. The dry solid is the more stable form, so stock solutions are generally prepared only when required and kept cold afterwards. Repeated freezing and thawing of a solution is avoided because it encourages aggregation and gradual loss of the intact chain. Diluents and containers are selected to limit adsorption of a short peptide onto plastic surfaces and to reduce microbial growth in aqueous preparations.
Stability depends strongly on pH, temperature and the presence of oxygen and trace metals. Cleavage of the backbone proceeds faster under neutral to alkaline conditions, whereas acidic solutions tend to slow that reaction. The aspartate and glutamate side chains can undergo deamidation or imide formation over time, generating closely related impurities. Published stability data specific to epitalon are sparse, so the usable life of a given solution is best regarded as an open question that depends on buffer composition, concentration and storage temperature.
Identity and purity are usually assessed by reversed-phase high-performance liquid chromatography with ultraviolet detection, frequently near 214 nanometers where the peptide bond absorbs. Mass spectrometry, most often with electrospray ionization, confirms the observed molecular mass and helps separate the intact peptide from truncated or modified forms. Amino acid analysis or tandem mass spectrometry can establish residue order. Purity is commonly quoted as an area percentage, yet such values are method-dependent, and comparisons between laboratories require matching column, gradient and detection wavelength.
For services to Child Road Safety. Kenneth Fitzpatrick. Lifeboat Operations Manager, Porthdinllaen Lifeboat Station, Royal National Lifeboat Institution. For services to Maritime Safety. Barry Flack. For services to the Jewish Community in the London Borough of Barnet. Margaret Elizabeth Flanagan. Member, Inner Wheel Club of Ballymena. For voluntary services to the community in Ballymena, County Antrim. John Campbell Forrester. President and Poppy Appeal Organiser, Driffield Branch, Royal British Legion. For voluntary service to Veterans in East Yorkshire. Claire Forsythe. Duke of Edinburgh's Award Officer, Probation Board for Northern Ireland. For services to the Rehabilitation of Offenders. Susan Joan Foster. For voluntary service in Hampshire. Richard Charles Fowler. Library Lead, Harbury Community Library, Warwickshire. For services to Libraries. Dr Jennifer Ann Frow. Volunteer, Bewdley Tennis Club. For services to Lawn Tennis in Worcestershire. Robert Francis Fyfe. Chair and Director, Runway Theatre Company. For services to the Arts and to the community in Glasgow. Melanie Jane Gardner. Fine and Decorative Arts Curator, Tullie House Museum, Carlisle. For services to Arts and Culture in Cumbria. Joseph William Garvey. For services to the community in County Armagh. Peter William Garwood. For services to the community in Barrow-in-Furness, Cumbria. Christine Frances Gatfield. Founder, Dove Cottage Day Hospice. For services to the Terminally Ill. Patricia Mary Gaywood. Membership Secretary, The Forty Club. For voluntary service to Cricket. Andrew Gell.
Mass change = (unbound system calculated mass) − (measured mass of system) e.g. (sum of masses of protons and neutrons) − (measured mass of nucleus) After a nuclear reaction occurs that results in an excited nucleus, the energy that must be radiated or otherwise removed as binding energy in order to decay to the unexcited state may be in one of several forms. This may be electromagnetic waves, such as gamma radiation; the kinetic energy of an ejected particle, such as an electron, in internal conversion decay; or partly as the rest mass of one or more emitted particles, such as the particles of beta decay. No mass deficit can appear, in theory, until this radiation or this energy has been emitted and is no longer part of the system. When nucleons bind together to form a nucleus, they must lose a small amount of mass, i.e. there is a change in mass to stay bound. This mass change must be released as various types of photon or other particle energy as above, according to the relation E = mc2. Thus, after the binding energy has been removed, binding energy = mass change × c2. This energy is a measure of the forces that hold the nucleons together. It represents energy that must be resupplied from the environment for the nucleus to be broken up into individual nucleons. For example, an atom of deuterium has a mass defect of 0.0023884 Da, and its binding energy is nearly equal to 2.23 MeV. This means that energy of 2.23 MeV is required to disintegrate an atom of deuterium.
== Estimation methods == The basic reproduction number can be estimated through examining detailed transmission chains or through genomic sequencing. However, it is most frequently calculated using epidemiological models. During an epidemic, typically the number of diagnosed infections
=== October === 1 October – The Government confirms it will not sell its shares in the electrical generation sector but will instead increase capital investments and the enforcement powers of the Electricity Authority. 2 October: The Police and Serious Fraud Office (SFO) end their criminal investigation into alleged electoral misconduct at the Manurewa Marae during the 2023 New Zealand general election, citing insufficient evidence of corruption. Māori activist group Toitū Te Tiriti, led by Eru Kapa-Kingi, severs its formal relationship with Te Pāti Māori, citing leadership differences and a desire for independence. Three new measles cases are reported in the Northland Region, bringing the total number of cases nationwide to ten. 4 October — The Presbyterian Church of Aotearoa New Zealand issues its second apology to survivors of historical abuse in Auckland. 6 October: Mike Davidson is elected as a list MP for the Green Party following the resignation of Benjamin Doyle. The New Zealand government agrees to pay Samoa 10 million tala ($3.6 million) in compensation for the sinking of HMNZS Manawanui in 2024. 7 October — ASB Bank agrees to pay NZ$135.6 million to settle a lawsuit relating to alleged breaches of the Credit Contracts and Consumer Finance Act. ANZ Bank New Zealand declines to settle the lawsuit with plaintiffs. 8 October — Over 100 pro-Palestinian protesters attempt to disrupt the New Zealand Aerospace Summit 2025 at Christchurch's Te Pae Convention Centre. Police arrest 22 protesters.
Sources: en.wikipedia.org
Dundee becomes the second city in Scotland to introduce a low emission zone. 30 May – Police searching for a father and son missing after hillwalking in Glen Coe confirm they have found two bodies. 31 May – Scotland's UEFA Women's Euro 2025 qualifier match against Israel is delayed after a protestor padlocks himself to the goalposts at Hampden Park. A 24-year-old man is subsequently charged over the incident.
There are three types of muscles—cardiac, skeletal, and smooth. Smooth muscles are used to control the flow of substances within the lumens of hollow organs, and are not consciously controlled. Skeletal and cardiac muscles have striations that are visible under a microscope due to the components within their cells. Only skeletal and smooth muscles are part of the musculoskeletal system and only the muscles can move the body. Cardiac muscles are found in the heart and are used only to circulate blood; like the smooth muscles, these muscles are not under conscious control. Skeletal muscles are attached to bones and arranged in opposing groups around joints. Muscles are innervated, whereby nervous signals are communicated by nerves, which conduct electrical currents from the central nervous system and cause the muscles to contract.
The Bible may contain an early account of rhabdomyolysis. The Book of Numbers says that while traveling in the desert, people ate large quantities of quail meat, after which an illness killed numerous people. Rhabdomyolysis after consuming quail was described in more recent times and called coturnism (after Coturnix, the main quail genus). Migrating quail consume large amounts of hemlock, a known cause of rhabdomyolysis. In modern times, early reports from the 1908 Messina earthquake and World War I on kidney failure after injury were followed by studies by London physicians Eric Bywaters and Desmond Beall, working at the Royal Postgraduate Medical School and the National Institute for Medical Research, on four victims of the Blitz in 1941. Myoglobin was demonstrated in the urine of victims by spectroscopy, and it was noted that the kidneys of victims resembled those of patients who had hemoglobinuria (hemoglobin rather than myoglobin being the cause of the kidney damage). In 1944, Bywaters demonstrated experimentally that the kidney failure was mainly caused by myoglobin. Already during the war, teams of doctors traveled to bombed areas to provide medical support, chiefly with intravenous fluids, as dialysis was not yet available. The prognosis of acute kidney failure improved markedly when dialysis was added to supportive treatment, which first happened during the 1950–1953 Korean War.
The four substrates of this enzyme are anthranilic acid, reduced nicotinamide adenine dinucleotide (NADH), oxygen, and a proton. Its products are catechol, carbon dioxide, oxidised NAD+, and ammonia. The enzyme can also use nicotinamide adenine dinucleotide phosphate as a cofactor. This enzyme is an oxidoreductase which uses molecular oxygen as oxidant and incorporates its atoms into the product. The systematic name of this enzyme class is anthranilate,NAD(P)H:oxygen oxidoreductase (1,2-hydroxylating, deaminating, decarboxylating). Other names in common use include anthranilate hydroxylase, anthranilic hydroxylase, and anthranilic acid hydroxylase. It participates in three metabolic pathways: benzoate degradation via hydroxylation, carbazole degradation, and nitrogen metabolism. It requires ferrous iron.
== Function == The high-temperature requirement (HtrA) family are conserved evolutionarily and these oligomeric serine proteases has been classified in family S1B of the PA protease clan in the MEROPS protease database. The protease activity of the HtrA member HtrA2/Omi is required for mitochondrial homeostasis in mice and humans and inactivating mutations associated with neurodegenerative disorders such as Parkinson's disease. Moreover, HtrA2/Omi is released in the cytosol from the mitochondria during apoptosis and uses its four most N-terminal amino acids to mimic a caspase and be recruited by inhibitor of apoptosis protein (IAP) caspase inhibitors such as XIAP and CIAP1/2. Once bound, the serine protease cleaves the IAP, reducing the cell's inhibition to caspase activation. In summary, HTRA2/Omi contributes to apoptosis through both caspase-dependent and -independent pathways.
Sources: en.wikipedia.org
Required a retrievable record of all purchases, identifying the name and address of each party, to be kept for two years Required verification of proof of identity of all purchasers Required protection and disclosure methods in the collection of personal information Required reports to the Attorney General of any suspicious payments or disappearances of the regulated products Required training of employees with regard to the requirements of the CMEA. Retailers must self-certify as to training and compliance. The non-liquid dose form of regulated products may only be sold in unit dose blister packs Regulated products must be stored behind the counter or in a locked cabinet in such a way as to restrict public access Sales limits (per customer): Daily sales limit—must not exceed 3.6 grams of pseudoephedrine base without regard to the number of transactions 30-day (not monthly) sales limit—must not exceed 7.5 grams of pseudoephedrine base if sold by mail order or "mobile retail vendor" 30-day purchase limit—must not exceed 9 grams of pseudoephedrine base. (A misdemeanor possession offense under 21 U.S.C. § 844a for the person who buys it.) The requirements were revised in the Methamphetamine Production Prevention Act of 2008 to require that a regulated seller of scheduled listed chemical products may not sell such a product unless the purchaser:
To meet the NADPH and ATP demands in the mesophyll and bundle sheath, light needs to be harvested and shared between two distinct electron transfer chains. ATP may be produced in the bundle sheath mainly through cyclic electron flow around Photosystem I, or in the mesophyll mainly through linear electron flow, depending on the light available in the bundle sheath or in the mesophyll. The relative requirement of ATP and NADPH in each type of cell will depend on the photosynthetic subtype. The apportioning of excitation energy between the two cell types will influence the availability of ATP and NADPH in the mesophyll and bundle sheath. For instance, green light is not strongly adsorbed by mesophyll cells and can preferentially excite bundle sheath cells, or vice versa for blue light. Because bundle sheaths are surrounded by mesophyll, light harvesting in the mesophyll will reduce the light available to reach bundle sheath cells. Also, the bundle sheath size limits the amount of light that can be harvested.
Waters joined UNC-Chapel Hill as an assistant professor in 1999. As of 2018, she is the Glen H. Elder, Jr. Distinguished Professor. Waters' research began with studies of non-covalent interactions in peptide beta-hairpin model systems, specifically, how pi-pi and cation-pi system interactions could influence peptide folding and function. This research can also extend to molecular recognition, in which specific peptide cavities can be designed to "host" selected organic molecules. Waters' group also studies protein and peptide methylation patterns and their biophysical interactions, which can relate to epigenetic disease mechanisms. She collaborated with faculty colleague Nancy Albritton to study degrons of proteolytically cleaved ubiquitins.
=== Other chalcogenide derivatives === Technetium forms a dioxide, disulfide, diselenide, and ditelluride. An ill-defined Tc2S7 forms upon treating pertechnate with hydrogen sulfide. It thermally decomposes into disulfide and elemental sulfur. Similarly the dioxide can be produced by reduction of the Tc2O7. Unlike the case for rhenium, a trioxide has not been isolated for technetium. However, TcO3 has been identified in the gas phase using mass spectrometry.
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.
Reversed-phase high-performance liquid chromatography is run alongside mass spectrometry. The chromatogram separates components and gives a purity figure, while the mass spectrum confirms that the measured molecular mass matches the expected sequence. Neither measurement on its own is treated as sufficient.