epithalamin comes up often in conversation and rarely with the context attached. Here we lay out the basics in order, then work through the practical considerations.
Updated 2026-03-17. 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.
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 |
|---|---|---|
| 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 |
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 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.
Material sold for research use varies widely in documented quality. A useful verification package includes a certificate of analysis that states peptide content rather than only net weight, the chromatographic method and column used, and a mass spectrum consistent with the expected mass. Independent testing by a third-party laboratory is occasionally reported. Statements of identity resting only on a supplier label provide little assurance, and the gap between nominal mass and actual peptide content can be substantial once counterions and residual water are counted.
Peptides of this size are generally stable as dry solids but degrade in solution over time. The principal routes are hydrolysis of the peptide backbone and oxidation, with hydrolysis favoured by elevated temperature and extreme pH. Aqueous solutions held at room temperature can show measurable loss of purity within days, while frozen aliquots are considerably more durable. Because the sequence contains neither cysteine nor methionine, oxidation is less of a concern than for many other peptides, but pH control during handling still matters.
The Enhanced Games (TEG) is a multi-sport event. Founded by Australian businessman Aron D'Souza, it allows athletes to use performance-enhancing substances without being subject to drug tests; organizers claim these substances must be FDA-approved and used under medical supervision. D'Souza stated that he founded the Games based on the principle of bodily autonomy for athletes, further alleging that the International Olympic Committee (IOC) maintains an exploitative relationship with competitors. Reactions from the sporting world, scientific community, and media outlets have generally been negative, with commentators highlighting the safety risks of encouraging performance-enhancing drug use. The first event took place on 24 May 2026 in Las Vegas, and included competitions in swimming, athletics, and weightlifting.
The acceptor stem is a 7- to 9-base pair (bp) stem made by the base pairing of the 5′-terminal nucleotide with the 3′-terminal nucleotide (which contains the CCA tail used to attach the amino acid). The acceptor stem may contain non-Watson-Crick base pairs. The CCA tail is a cytosine-cytosine-adenine sequence at the 3′ end of the tRNA molecule. The amino acid loaded onto the tRNA by aminoacyl tRNA synthetases, to form aminoacyl-tRNA, is covalently bonded to the 3′-hydroxyl group on the CCA tail. This sequence is important for the recognition of tRNA by enzymes and critical in translation. In prokaryotes, the CCA sequence is transcribed in some tRNA sequences. In most prokaryotic tRNAs and eukaryotic tRNAs, the CCA sequence is added during processing and therefore does not appear in the tRNA gene. The D loop is a 4- to 6-bp stem ending in a loop that often contains dihydrouridine. The anticodon loop is a 5-bp stem whose loop contains the anticodon. The TΨC loop is named so because of the characteristic presence of the unusual base Ψ in the loop, where Ψ is pseudouridine, a modified uridine. The modified base is often found within the sequence 5'-TΨCGA-3', with the T (ribothymidine, m5U) and A forming a base pair. The variable loop or V loop sits between the anticodon loop and the ΨU loop and, as its name implies, varies in size from 3 to 21 bases. In some tRNAs, the "loop" is long enough to form a rigid stem, the variable arm. tRNA with a V loop more than 10 bases long is classified as "class II" and the rest is called "class I".
=== Peace committees === Among those Burghers who had stopped fighting, it was decided to form peace committees to persuade those fighting to desist. In December 1900, Lord Kitchener gave permission that a central Burgher Peace Committee be inaugurated in Pretoria. By the end of 1900 thirty envoys were sent out to the districts to form peace committees to persuade burghers to give up. Previous leaders of the Boers, like Generals Piet de Wet and Andries Cronjé were involved in the organisation. Meyer de Kock was an emissary of a peace committee, but he was arrested, convicted of high treason, and executed by firing squad.
=== Tenure === Upon the opening of the 118th United States Congress on January 3, 2023, Schmitt was sworn in by Senate president and Vice President Kamala Harris. He tweeted that he was honored to be the 2,000th senator to hold office in the history of the Senate. Schmitt was among the 31 Senate Republicans who voted against final passage of the Fiscal Responsibility Act of 2023, a bill to raise the debt ceiling. In February 2025, when NBC's Kristen Welker asked Schmitt the same question posed to Tulsi Gabbard during her Director of National Intelligence confirmation hearing—whether he would call Edward Snowden a traitor—he said many asking this oppose Gabbard because she would "reform and curb the excesses and the worst instincts of the intelligence community that at times has gone after presidential candidates". Later that month, after Trump called Ukrainian president Volodymyr Zelenskyy a "dictator" and said Ukraine was at fault for the Ukraine war, Schmitt said Zelenskyy should not be "openly criticizing" Trump and should "stop lecturing" him. Schmitt said Trump had spoken "a lot on the campaign trail" about "trying to negotiate a peace deal between Russia and Ukraine. ... He's a master negotiator, and I think he's going to get to a lasting peace." According to ABC News, Schmitt was the only Republican senator "to seemingly offer both support for Trump and the premise of his statements on Ukraine and Russia". At the start of the 119th Congress in 2025, Schmitt hired Nate Hochman as a staffer.
Sources: en.wikipedia.org
=== Accumulation in buildings === Measurement of radon levels in the first decades of its discovery was mainly done to determine the presence of radium and uranium in geological surveys. In 1956, most likely the first indoor survey of radon decay products was performed in Sweden, with the intent of estimating the public exposure to radon and its decay products. From 1975 up until 1984, small studies in Sweden, Austria, the United States and Norway aimed to measure radon indoors and in metropolitan areas.
The variance is infinite. In a real reactor, diffusion will eventually mix the layers so that the tail of the RTD becomes exponential and the variance finite; but laminar flow reactors can have variance greater than 1, the maximum for CTSD reactors.
Tom Kempinski, playwright and screenwriter Peter Kosminsky (born 21 April 1956); writer, playwright, scriptwriter and screenwriter director and producer; has directed Hollywood movies White Oleander and television films, Warriors, The Government Inspector, The Promise, Wolf Hall and The State; born in London in 1956 to Jewish parents. Hyam Maccoby (Hebrew: חיים מכובי, 1924–2004) was a Jewish-British scholar, dramatist, playwright and author of over fifteen scholarly books, specialising in the study of the Jewish and Christian religious traditions. He was known for his theories of the historical Jesus and the origins of Christianity. Maccoby's play The Disputation has been widely performed, and was broadcast by Channel 4 starring Christopher Lee and Toyah Willcox. Hyam Maccoby's daughter is the anti-Zionist BDS activist, organiser of Jews for Justice for Palestinians and author, Deborah Maccoby, acknowledged for her monograph on Isaac Rosenberg. Patrick Marber, playwright and comedian Laurence Marks (British writer) (born 8 December 1948), producer, scriptwriter, screenwriter and one half of writing duo Marks and Gran (with Maurice Gran). Harold Pinter, Nobel prize-winning playwright; Pinter signed the mission statement of Jews for Justice for Palestinians in 2005 and its full-page advertisement, "What Is Israel Doing? A Call by Jews in Britain", published in The Times on 6 July 2006, and he was a patron of the Palestine Festival of Literature. In April 2008, Pinter signed the statement "We're not celebrating Israel's anniversary".
== Method == The RAST is a radioimmunoassay test to detect specific IgE antibodies to suspected or known allergens for the purpose of guiding a diagnosis about allergy. IgE is the antibody associated with Type I allergic response: for example, if a person exhibits a high level of IgE directed against pollen, the test may indicate the person is allergic to pollen (or pollen-like) proteins. A person who has outgrown an allergy may still have a positive IgE years after exposure. The suspected allergen is bound to an insoluble material and the patient's serum is added. If the serum contains antibodies to the allergen, those antibodies will bind to the allergen. Radiolabeled anti-human IgE antibody is added where it binds to those IgE antibodies already bound to the insoluble material. The unbound anti-human IgE antibodies are washed away. The amount of radioactivity is proportional to the serum IgE for the allergen. RASTs are often used to test for allergies when:
{\displaystyle {\hat {H}}=\hbar \omega _{+}\left({\hat {a}}_{+}^{\dagger }{\hat {a}}_{+}+{\frac {1}{2}}\right)-\hbar \omega _{-}\left({\hat {a}}_{-}^{\dagger }{\hat {a}}_{-}+{\frac {1}{2}}\right)+\hbar \omega _{z}\left({\hat {a}}_{z}^{\dagger }{\hat {a}}_{z}+{\frac {1}{2}}\right)}
Sources: en.wikipedia.org
Nicotinamide mononucleotide adenylyltransferase 3 (NMNAT3) is an enzyme that in humans is encoded by the NMNAT3 gene. NMNAT3 is the third of three protein isoforms of nicotinamide-nucleotide adenylyltransferase (NMNAT) found in humans. As with the other NMNATs, NMNAT3 is an enzyme that catalyzes nicotinamide adenine dinucleotide (NAD) synthesis. NMNAT3 levels are highest in liver, heart, skeletal muscle, and erythrocytes.
=== Nitric oxide === Nitric oxide (NO) is a major source of immunomodulation in rodents, and is produced by enzyme nitric oxide synthetase type 2 (NOS2) in the alveolar macrophage. NO inhibits tyrosine phosphorylation of the kinases involved in production of the interleukin-2 (IL-2) receptor, the expression of which is fundamental for T cell proliferation. In humans, however, NOS2 activity has been difficult to verify. There are two explanations for the lack of responsiveness in the promoter of human inducible nitric oxide synthetase (iNOS) to NO activation by lipopolysaccharides (LPS) + interferon gamma (IFNγ). The first is that there are various inactivating nucleotide variations in the human counterpart of the enhancer element that regulates LPS/IFNγ induced expression of the mouse NOS2 gene. The second is because of the absence of a nuclear factor in human macrophages that is required for optimum expression of gene NOS2 (LPS-inducible nuclear factor-kappa B/Rel complex). It is assumed that the difficulty in verifying NOS2 is due to a much more tightly controlled expression in human AMs as compared to that in the rodent AMs. NOS2 is part of an autoregulatory feedback loop, wherein an allergen or provoker stimulates inflammatory cytokine production, which in turn stimulates NO production, and NO down-regulates cytokine production.
NMR spectroscopy is one of the principal techniques used to obtain physical, chemical, electronic and structural information about molecules due to the chemical shift of the resonance frequencies of the nuclear spins in the sample. Peak splittings due to J- or dipolar couplings between nuclei are also useful. NMR spectroscopy can provide detailed and quantitative information on the functional groups, topology, dynamics and three-dimensional structure of molecules in solution and the solid state. Since the area under an NMR peak is usually proportional to the number of spins involved, peak integrals can be used to determine composition quantitatively. A common methodology involves an extended delay time between each spectral scan (generally, 5 times the longest T1 in a complex mixture for a 90 degree pulsing angle, where T1 can be calculated using techniques such as FLIPS). This lets nuclei relax completely, allowing integrals to be more accurate for quantitation. Structure and molecular dynamics can be studied (with or without "magic angle" spinning (MAS)) by NMR of quadrupolar nuclei (that is, with spin S > 1/2) even in the presence of magnetic "dipole-dipole" interaction broadening (or simply, dipolar broadening), which is always much smaller than the quadrupolar interaction strength because it is a magnetic vs. an electric interaction effect. Additional structural and chemical information may be obtained by performing double-quantum NMR experiments for pairs of spins or quadrupolar nuclei such as 2H.
=== Prokaryotic === Although sterol biosynthesis is rare in prokaryotes, certain bacteria, including Methylococcus capsulatus, specific methanotrophs, myxobacteria, and the planctomycete Gemmata obscuriglobus, are capable of producing sterols. In G. obscuriglobus, sterols are essential for cell viability, but their roles in other bacteria remain poorly understood. Prokaryotic sterol synthesis involves the tetracyclic steroid framework, as found in myxobacteria, as well as hopanoids, pentacyclic lipids that regulate bacterial membrane functions. These sterol biosynthetic pathways may have originated in bacteria or been transferred from eukaryotes. Sterol synthesis depends on two key enzymes: squalene monooxygenase and oxidosqualene cyclase. Phylogenetic analyses of oxidosqualene cyclase (Osc) suggest that some bacterial Osc genes may have been acquired via horizontal gene transfer from eukaryotes, as certain bacterial Osc proteins closely resemble their eukaryotic homologs.
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.
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.