Mass spectrometry 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.
Updated 2026-07-24. Numbers and descriptions here follow the published literature rather than marketing material.
The four residues give epitalon a molecular formula of C14H22N4O9 and a molecular weight near 390.35 daltons. The presence of two acidic residues, glutamate and aspartate, makes the free peptide strongly acidic, while the alanine and glycine ends provide neutral, nonpolar character. This combination produces a molecule with substantial water solubility. Because there are no cysteine, methionine, or tryptophan residues, the peptide lacks the most common oxidation-sensitive side chains, which simplifies handling compared with many longer peptides.
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.
Identity testing for epitalon relies on reversed-phase high-performance liquid chromatography for purity and mass spectrometry for mass confirmation. Because the sequence contains no tryptophan or tyrosine, ultraviolet detection at 280 nanometres is insensitive, so chromatographic methods usually monitor absorbance near 214 nanometres, where the peptide backbone absorbs. Electrospray ionisation or matrix-assisted laser desorption/ionisation then checks the intact mass against the expected value near 390 daltons. Peptide mapping or amino acid analysis after acid hydrolysis can supplement these measurements, although such confirmatory work is seldom reported on commercial certificates of analysis.
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 |
|---|---|---|
| Amino acid sequence | Ala-Glu-Asp-Gly | Tetrapeptide, often abbreviated AEDG |
| Molecular formula | C14H22N4O9 | Free peptide, unmodified termini |
| Molecular weight | ~390.35 Da | Calculated for the free acid form |
| Appearance | White to off-white powder | Typical lyophilized product form |
| Solubility class | Freely soluble in water | Two acidic residues dominate ionic character |
Epitalon is a synthetic tetrapeptide with the sequence alanine–glutamate–aspartate–glycine, commonly abbreviated AEDG. Its design traces to epithalamin, a peptide fraction prepared from bovine pineal gland extracts that researchers in Saint Petersburg began investigating in the 1970s. The compound has a molecular formula of C14H22N4O9 and a nominal molecular mass near 390 daltons. It holds no approved drug status in the United States or the European Union, and material sold under this name is generally offered as a research chemical rather than a finished pharmaceutical product.
Proposed mechanisms centre on cell-culture observations rather than a defined receptor interaction. Several reports describe increased expression of the telomerase catalytic subunit after exposure of cultured human cells, and the authors attributed the effect to short peptide fragments entering the nucleus and influencing gene transcription. No receptor for the tetrapeptide has been identified, and the free peptide is expected to be degraded rapidly by plasma peptidases. Whether any measurable fraction reaches intact tissues after administration remains an unresolved question rather than an established finding.
The published literature is dominated by a small number of research groups, much of it in Russian-language journals, and independent replication outside those groups is limited. Studies are typically small, use cultured cells or rodent models, and report endpoints that differ between papers, which makes comparison difficult. Large randomised human trials have not appeared in the indexed literature. Questions about absorption, distribution and clearance are therefore still treated as open in reviews that mention the compound.
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.
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.
In its supplied form epitalon is a white to off-white powder, usually lyophilized and often hygroscopic. It dissolves readily in water and in aqueous buffers, and it is commonly handled as the acetate or trifluoroacetate salt to improve stability during purification and drying. The amide backbone is labile in aqueous media, so solutions are less durable than the dry solid. Handling notes in the chemical literature therefore emphasize keeping the powder dry, cool and shielded from light until it is dissolved.
== External links == "Ghrelin Receptor". IUPHAR Database of Receptors and Ion Channels. International Union of Basic and Clinical Pharmacology. Archived from the original on 2015-07-11. Retrieved 2007-10-25. growth+hormone+secretagogue+receptor at the U.S. National Library of Medicine Medical Subject Headings (MeSH) Ghrelin Archived 2008-05-12 at the Wayback Machine at Colorado State University This article incorporates text from the United States National Library of Medicine, which is in the public domain.
=== Sources === Print Bosco, David (2009). Five to Rule Them All: The UN Security Council and the Making of the Modern World. Oxford University Press. ISBN 978-0-19-532876-9. Dallek, Robert (1995). Franklin D. Roosevelt and American Foreign Policy, 1932–1945: With a New Afterword. Oxford University Press. ISBN 978-0-19-982666-7. Gaddis, John Lewis (1972). The United States and the Origins of the Cold War, 1941–1947. Columbia University Press. ISBN 978-0-231-12239-9. Hoopes, Townsend; Brinkley, Douglas (1997). FDR and the Creation of the U.N.. Yale University Press. ISBN 978-0-300-08553-2. Kimball, Warren F. (1991). The Juggler: Franklin Roosevelt as Wartime Statesman. Princeton University Press. ISBN 0-691-03730-2. Ma, Xiaohua (2003). The Sino-American alliance during World War II and the lifting of the Chinese exclusion acts. New York: Routledge. pp. 203–204. ISBN 0-415-94028-1. United States Department of State (1942). "Union of Soviet Socialist Republics". Foreign relations of the United States diplomatic papers, 1942. Europe Volume III. U.S. Government Printing Office. pp. 406–771. Welles, Sumner (January 1951). "Two Roosevelt Decisions: One Debit, One Credit". Foreign Affairs. Vol. 29, no. 2. pp. 182–204. Online "1942: Declaration of The United Nations". United Nations. Archived from the original on May 13, 2016. Retrieved April 21, 2016. "1945: The San Francisco Conference". United Nations. 1945. Archived from the original on October 30, 2015. Retrieved May 16, 2015. Urquhart, Brian (July 16, 1998). "Looking for the Sheriff". New York Review of Books.
== Chemical properties == Copper(II) sulfate pentahydrate decomposes before melting. It loses two water molecules upon heating at 63 °C (145 °F), followed by two more at 109 °C (228 °F) and the final water molecule at 200 °C (392 °F). The chemistry of aqueous copper sulfate is simply that of copper aquo complex, since the sulfate is not bound to copper in such solutions. Thus, such solutions react with concentrated hydrochloric acid to give tetrachlorocuprate(II):
Sources: en.wikipedia.org
=== Marketing === The marketing of the Claritin brand is important in the history of direct-to-consumer advertising of drugs. The first television commercial for a prescription drug was broadcast in the United States in 1983, by Boots. It caused controversy. The federal Food and Drug Administration responded with strong regulations requiring disclosure of side effects and other information. These rules made pharmaceutical manufacturers balk at spending money on ads that had to highlight negative aspects. In the mid-1990s, the marketing team for Claritin at Schering-Plough found a way around these rules. They created brand awareness commercials that never actually said what the drug was for, but instead showed sunny images, and the voiceover said such things as "At last, a clear day is here" and "It's time for Claritin" and repeatedly told viewers "Ask your doctor [about Claritin]." The first ads made people aware of the brand and increased prescriptions, which led Schering-Plough and others to aggressively pursue the advertising strategy. In 1998, a 12-page one-shot comic based on the Batman: The Animated Series was given away to advertise Claritin. The book, written by PRIEST, penciled by Joe Staton, and inked by Mike DeCarlo, sees Tim Drake unable to perform his crime-fighting duties because hay fever and antihistamines make him drowsy. After being given a prescription for Claritin, he saved Batman from Poison Ivy.
28 July DeepMind announces that its AlphaFold program has uncovered the structures of more than 200 million folded proteins, essentially all of those known to science. Researchers report the development of a wearable bioadhesive stretchable high-resolution ultrasound imaging patch for days-long continuous imaging of diverse organs which may enable novel diagnostic and monitoring tools. First reported discovery of an animal helping algae reproduce after pollination in the sea was first reported in 2016. Researchers report the development of nanoscale brain-inspired artificial synapses, using the ion proton (H+), for 'analog deep learning'. Scientists report the discovery of chemical reactions by potential primordial soup components that produced amino acids and may be part of the origin of life on Earth. 29 July In a preprint, scientists from the Galileo Project describe a planned expedition to retrieve small fragments of interstellar meteor CNEOS 2014-01-08, which "appears to be rare both in composition and in speed" and is not ruled out to be "extraterrestrial equipment", using a magnetic sled on the seafloor of the impact region. A study, that reanalyzes data used in a study by DeSilva et al. (2021), indicates that human brain size did not decrease over the last three thousand years as suggested by this study nor within 300 ka as suggested by other studies. It concludes that "the samples need to be specific enough to test the hypothesis across different times and populations".
=== Solvent choice === An eluotropic series, which orders solvents by how much they move compounds, can help select a mobile phase. Solvents are divided into solvent selectivity groups. Using solvents with different elution strengths or different selectivity groups can often give very different results. While single-solvent mobile phases can sometimes give good separation, some cases may require solvent mixtures. In normal-phase TLC, the most common solvent mixtures include ethyl acetate/hexanes (EtOAc/Hex) for less-polar compounds and methanol/dichloromethane (MeOH/DCM) for more polar compounds. Different solvent mixtures and solvent ratios can help give better separation. In reverse-phase TLC, solvent mixtures are typically water with a less-polar solvent: Typical choices are water with tetrahydrofuran (THF), acetonitrile (ACN), or methanol.
Sources: en.wikipedia.org
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.
No. Epitalon is chemically synthesized, not extracted. It was designed as a short synthetic fragment conceptually related to larger pineal peptides studied in the same research tradition, particularly the extract known as epithalamin. The two are distinct materials with different compositions.
The term bioregulator is used in this research tradition for short peptides proposed to influence gene expression or cell function. Epitalon is grouped with other synthetic short peptides under this label. The term reflects a proposed mechanism rather than an established drug classification.
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.