mass spectrometry 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 2026-05-11. Numbers and descriptions here follow the published literature rather than marketing material.
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.
The peptide is a synthetic analogue of epithalamin, a preparation extracted from bovine pineal glands. Investigators sought a short, chemically defined molecule that would reproduce some of the endocrine and gerontological observations attributed to the glandular extract. Proposed mechanisms centre on induction of telomerase activity, an effect reported in cultured human somatic cells in the early 2000s, together with influences on melatonin secretion and neuroendocrine regulation. Those mechanisms remain incompletely characterised, and the reported telomerase response has not been consistently reproduced by independent groups working in comparable systems.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Peptide sequence | Ala-Glu-Asp-Gly | Often abbreviated AEDG in research literature |
| Common synonyms | Epithalon, epitalon, AEDG | Spelling variants refer to the same tetrapeptide |
| Molecular formula | C14H22N4O9 | Theoretical monoisotopic mass near 390.35 Da |
| Appearance | White to off-white powder | Typically supplied as a lyophilised solid |
| Solubility class | Freely soluble in water | Hydrophilic peptide; dissolves in aqueous buffer |
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 linear tetrapeptide with the sequence alanine–glutamate–aspartate–glycine, abbreviated AEDG. Its molecular formula is C14H22N4O9 and the calculated mass is approximately 390.35 g/mol. The compound is made by solid-phase peptide synthesis rather than extracted from tissue, although early work described it as a short fragment of a peptide fraction obtained from bovine pineal extract. In the research literature the spelling epitalon and the variant epithalone both appear, while AEDG is the standard code used in peptide nomenclature.
Identity confirmation uses mass spectrometry, usually electrospray ionisation in positive mode or matrix-assisted laser desorption. The protonated free peptide produces a signal near three hundred and ninety-one daltons, while salt adducts shift that value slightly. Tandem mass spectrometry or amino acid analysis supplies sequence-level confirmation, which a single mass measurement cannot. Peptides containing aspartate can cyclise into succinimide intermediates that hydrolyse to isoaspartate isomers of identical mass. Because those isomers are difficult to separate chromatographically, identity and purity results carry more weight when interpreted together.
Storage practice centres on limiting moisture, oxygen, and repeated temperature cycling. Freeze-dried powder is generally held desiccated at minus twenty degrees Celsius or colder and protected from light. Reconstituted solutions are markedly less stable, and the aspartate-glycine junction is prone to succinimide formation at neutral to mildly alkaline pH. Portioning material into single-use aliquots reduces degradation compared with repeated freeze-thaw cycles. Stability data specific to this tetrapeptide remain scarce, so most handling guidance is extrapolated from general peptide chemistry rather than measured directly.
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.
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.
Identity and purity are checked by reversed-phase high-performance liquid chromatography, usually with ultraviolet detection near 214 nanometres, where the peptide bond absorbs. Mass spectrometry confirms the expected mass and reveals whether truncation products or adducts are present. Acid hydrolysis followed by amino acid analysis gives the residue ratio, which should approximate one alanine, one glutamate, one aspartate and one glycine. Counter-ions such as acetate or trifluoroacetate remain in the dried product and lower net peptide content, so a stated purity figure on a label does not by itself describe how much peptide a vial holds.
Regulatory treatment differs by country. No formulation of epitalon holds a marketing authorisation as a medicine in the United States or the European Union, where material sold for laboratory use is handled as a research chemical and is not intended for human consumption. In Russia, several short peptide preparations from the same institute's peptide series are registered medicinal products, and epitalon appears in that national context. Elsewhere it is frequently offered as a cosmetic ingredient, a category with lighter requirements. Advertising claims about longevity or disease prevention are restricted in most jurisdictions, which limits how sellers describe the compound.
Freeze-dried epitalon is normally kept at minus twenty degrees Celsius in a sealed, desiccated container, protected from light. Short excursions at ambient temperature during shipping are generally tolerated, but repeated warming and cooling cycles encourage moisture uptake, which shortens shelf life. Once dissolved, the peptide is far less stable than the solid: aqueous solutions are subject to hydrolysis and to deamidation at the aspartate and glutamate residues. Working solutions are therefore held refrigerated and used within days, and repeated freezing and thawing of the same vial is best avoided.
=== Excitotoxicity in Stroke and Neurodegeneration === Excessive activation of AMPARs, particularly those lacking the GluA2 subunit, leads to increased calcium permeability, contributing to neuronal injury and death—a phenomenon known as excitotoxity. This mechanism in involved in acute events such as stroke and in chronic neurodegenerative diseases. For instance, in ALS, motor neurons exhibit elevated levels of calcium-permeable AMPARs, rendering them more susceptible to excitotoxic damage.
Сорокин) "Rugby" (Регби) in English translation of Great Soviet Encyclopedia (Progress Publishers, Moscow, 1978) Starmer-Smith, Nigel (ed) Rugby - A Way of Life, An Illustrated History of Rugby (Lennard Books, 1986 ISBN 0-7126-2662-X) Thau, Chris Soviet Rugby in Starmer-Smith, Nigel & Robertson, Ian (eds) The Whitbread Rugby World '89 (Lennard Books, 1988 ISBN 1-85291-038-0) Thau, Chris Soviet Students in Starmer-Smith, Nigel & Robertson, Ian (eds) The Whitbread Rugby World '90 (Lennard Books, 1989 ISBN ) The Ultimate Encyclopaedia of Rugby, (Carlton Books, 1997 ISBN 1-85868-076-X) Dancing On Our Bones: New Zealand, South Africa, Rugby and Racism by Trevor Richards (Bridget Williams Books, 1999). The author was one of a small group of people who founded Halt All Racist Tours (HART) in Auckland in 1969 and worked for the organisation for many years, serving as chair (1969–1980) and international secretary (1980–1985).
Initially, Owens believed the Wests had been sincere in their apologies and obliged, believing she had simply mistaken their earlier intentions. Rose joined her in the back seat, with the explanation she wanted a "girls' chat" as Fred drove. Shortly thereafter, Rose began to fondle Owens, as Fred questioned whether she had had sex with her boyfriend that evening. When Owens began to protest, Fred stopped the car, referred to Owens as a "bitch" and punched her into unconsciousness before he and Rose bound and gagged her with a scarf and duct tape. In her subsequent statement to police, Owens stated that, at Cromwell Street, she was given a drugged cup of tea to drink before being again gagged and subjected to a prolonged sexual assault from the Wests. When Owens screamed, Rose smothered her with a pillow, further restrained her about the neck and performed cunnilingus on her. Realising the gravity of her situation, Owens ceased resisting their sexual assaults. The following morning, having noted Owens' screaming when one of his children had knocked on the door of the room in which she was restrained, Fred threatened that he and his wife would keep her locked in the cellar and allow his "black friends" to abuse her, and that when they had finished he would bury her body beneath "the paving stones of Gloucester." Fred then claimed he had killed hundreds of young girls, adding that Owens had primarily been brought to the house for "Rose's pleasure." He and Rose then calmly asked Owens whether she would consider returning to work as their nanny.
== See also == Crick, Brenner et al. experiment – DNA structure discoveryPages displaying short descriptions of redirect targets Crick's wobble hypothesis – RNA base pair that does not follow Watson–Crick base pair rules History of RNA biology List of RNA biologists Molecular structure of Nucleic Acids – 1953 scientific paper on DNAPages displaying short descriptions of redirect targets Neural correlates of consciousness – Neuronal events sufficient for a specific conscious percept
This marks the beginning of a long period of submission to, initially the Third International, and, after its dissolution, to the political leadership of the Communist Party of the Soviet Union. This decade also marked two cycles on the party's history: one of increasing influence, until 1935, and one of decline, until 1942. Both cycles are comprehensible when seen in the context of the Vargas era.
Sources: en.wikipedia.org
== Transmutation of technetium to stable ruthenium-100 == Technetium (Tc) can be completely transformed into ruthenium-100 by coating the inner cladding of fuel rods with Tc. This works with conventional pressurized water reactors and does not require specialized transmutation facilities. An alternative disposal method, transmutation, has been demonstrated at CERN and NIIAR for technetium-99. This transmutation process bombards the technetium (99Tc as a metal target) with neutrons, forming the short-lived 100Tc (half-life 16 seconds), which decays by beta decay to stable ruthenium (100Ru). Given the relatively high market value of ruthenium and the particularly undesirable properties of technetium, this type of nuclear transmutation appears particularly promising.
=== Marijuana legalization === President Jimmy Carter was an advocate for legalization of marijuana at the national level. Carter argued that possession of less than 28 g of marijuana should be decriminalized. Carter believed in a more treatment-based approach to the addiction problems, with softer penalties for cocaine but was as opposed to heroin as his predecessors. In a speech to Congress in 1977, Carter stated that "penalties against possession of a drug should not be more damaging to an individual than the use of the drug itself." Rather than legalization, congressional lawmakers passed a bill that would criminalize only marijuana "open to public view." Scholars would later criticize the abuse of that bill when they debated stop-and-frisk laws. In 1967, the US Supreme Court ruled in Terry v. Ohio that a "stop-and-frisk" search does not violate the Fourth Amendment if the officer executing the search bears a "reasonable suspicion" that the person being searched has committed or is about to commit a crime. As a result, "stop-and-frisk" searches became much more common during the war on drugs and were generally conducted in minority communities. "Stop-and-frisk" searches have been criticized for being disproportionately carried out against minorities as a result of racial bias, but empirical literature on that count is inconclusive. Certain authors have found that even after controlling for location and crime participation rates, blacks and Hispanics are stopped more frequently than whites.
== Academic achievements == In 1942, Drew became the first African-American surgeon selected to serve as an examiner on the American Board of Surgery. Drew had a lengthy research and teaching career, returning to Freedman's Hospital and Howard University as a surgeon and professor of medicine in 1942. He was awarded the Spingarn Medal by the NAACP in 1944 for his work. He was given honorary doctor of science degrees by Virginia State College in 1945 and by Amherst College in 1947.
=== Mechanism of action === Chlorambucil produces its anti-cancer effects by interfering with DNA replication and damaging the DNA in a cell. The DNA damage induces cell cycle arrest and cellular apoptosis via the accumulation of cytosolic p53 and subsequent activation of Bcl-2-associated X protein, an apoptosis promoter. Chlorambucil alkylates and cross-links DNA during all phases of the cell cycle, inducing DNA damage via three different methods of covalent adduct generation with double-helical DNA:
Sources: en.wikipedia.org
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.
No. Epithalamin is a peptide-rich extract prepared from bovine pineal glands, while epitalon is a short synthetic peptide designed as a defined analogue of it. The synthetic version was intended to provide a reproducible molecule with some of the same proposed biological activity.
Telomere elongation and telomerase activation have been reported in cultured human somatic cells, but evidence from living human subjects is limited and has not been independently confirmed at scale. Reported findings come largely from small studies with differing designs, so the question remains open rather than settled.
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.