If you have been reading about reversed-phase HPLC and want a single page that covers the useful parts, this is it: definitions, context, how it is studied, and the questions that come up repeatedly.
Last reviewed on 2025-08-31. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
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.
Typical storage for the lyophilized powder is −20 °C or lower, in a sealed container protected from light and moisture. Hygroscopic material should be allowed to equilibrate to room temperature before the vial is opened, which limits condensation on the contents. Working solutions are commonly divided into single-use aliquots and frozen to avoid repeated freeze-thaw cycles. Dilute solutions are more prone to adsorption onto plastic surfaces and to loss during filtration, so procedures that minimize transfers and use low-binding labware are preferable.
| 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 |
The peptide emerged from research carried out in Saint Petersburg from the late 1980s onward, where investigators searched for shorter active fragments of a pineal preparation known as epithalamin. The name epitalon was chosen to reflect that parent extract. Early reports described effects on neuroendocrine markers and on the lifespan of laboratory animals. Much of that work appeared in Russian-language journals, with English translations following later, which affects how readily the original protocols can be assessed by outside groups.
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.
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.
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.
In radio and telecommunications, the frequency spectrum can be shared among many different broadcasters. The radio spectrum is the part of the electromagnetic spectrum corresponding to frequencies lower below 300 GHz, which corresponds to wavelengths longer than about 1 mm. The microwave spectrum corresponds to frequencies between 300 MHz (0.3 GHz) and 300 GHz and wavelengths between one meter and one millimeter. Each broadcast radio and TV station transmits a wave on an assigned frequency range, called a channel. When many broadcasters are present, the radio spectrum consists of the sum of all the individual channels, each carrying separate information, spread across a wide frequency spectrum. Any particular radio receiver will detect a single function of amplitude (voltage) vs. time. The radio then uses a tuned circuit or tuner to select a single channel or frequency band and demodulate or decode the information from that broadcaster. If we made a graph of the strength of each channel vs. the frequency of the tuner, it would be the frequency spectrum of the antenna signal. In astronomical spectroscopy, the strength, shape, and position of absorption and emission lines, as well as the overall spectral energy distribution of the continuum, reveal many properties of astronomical objects. Stellar classification is the categorisation of stars based on their characteristic electromagnetic spectra. The spectral flux density is used to represent the spectrum of a light-source, such as a star.
The band was advised Kinney's health issue needed "immediate attention" and he was unfit to perform the scheduled dates, though they stated "his long-term prognosis is positive." In a September 2025 interview with Cleveland.com, Cantrell stated that Alice in Chains "had a tour planned for, like, right now that kind of fell through", adding, "So we had some bad luck; we planned on doing much more this year, but it just didn't work out." He also commented on the possibility of the band touring or recording a new album in 2026: "We'll take a look at it again probably early next year and figure out what we're gonna do, whether go in and make another record or do some shows—or both."
Eventually, the kidnapping of drug cartel family members by guerrillas led to the creation in 1981 of the Muerte a Secuestradores ("Death to Kidnappers") death squad (MAS). The Medellín Cartel and other cartels came under pressure from the U.S. government and from critical sectors of Colombian society who supported the extradition of suspected Colombian cartel members to the U.S. The cartels responded by bribing or murdering numerous public officials, politicians, and others. Their victims included Justice Minister Rodrigo Lara Bonilla, whose assassination in 1984 led the Betancur administration to confront the drug lords directly. The first negotiated cease-fire with the M-19 ended when the guerrillas resumed fighting in 1985. The M-19 claimed that the cease-fire had not been fully respected by official security forces, alleged that several of its members had suffered threats and assaults, and questioned the reality of the government's willingness to implement any accords. The Betancur administration in turn criticized the M-19's actions and questioned its commitment to the peace process, while at the same time continuing to advance high-profile negotiations with the FARC. These negotiations led to the creation of the Patriotic Union (Unión Patriótica, UP), a legal and non-clandestine political organization. On November 6, 1985, the M-19 stormed the Colombian Palace of Justice and held the Supreme Court magistrates hostage, intending to put President Betancur on trial.
== Family == The Hoffmann-La Roche family is Switzerland's richest and one of the most secretive families. Many members of the family don't carry the last name Hoffmann anymore. Some are known as Oeri, Michalski, Faber-Castell, Fabre, Schmid or Duschmalé.
The first total synthesis of phalloidin was achieved through a combination of solid phase and solution phase synthesis (Baosheng Liu and Jianheng Zhang, United States Patent, US 8,569,452 B2). The physical and chemical properties of the synthetic phalloidin are the same as the naturally occurring phalloidin.
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Octreotide is used in nuclear medicine imaging by labeling with indium-111 (Octreoscan) to noninvasively image neuroendocrine and other tumours expressing somatostatin receptors. It has been radiolabeled with carbon-11 as well as gallium-68 (using edotreotide), enabling imaging with positron emission tomography (PET).
APUD cells (DNES cells) constitute a group of apparently unrelated endocrine cells, which were named by the scientist A.G.E. Pearse, who developed the APUD concept in the 1960s based on calcitonin-secreting parafollicular C cells of dog thyroid. These cells share the common function of secreting a low molecular weight polypeptide hormone. There are several different types which secrete the hormones secretin, cholecystokinin and several others. The name is derived from an acronym, referring to the following:
=== Molecular machinery === Molecular machines are molecules or molecular assemblies that can perform functions such as linear or rotational movement, switching, and entrapment. These devices exist at the boundary between supramolecular chemistry and nanotechnology, and prototypes have been demonstrated using supramolecular concepts. Jean-Pierre Sauvage, Sir J. Fraser Stoddart and Bernard L. Feringa shared the 2016 Nobel Prize in Chemistry for the 'design and synthesis of molecular machines'.
=== Intrastromal corneal ring segments === In corneal disorders where vision correction is not possible by using contact lenses, intrastromal corneal ring segments may be used to flatten the cornea, which is intended to relieve the nearsightedness and astigmatism. In this procedure, an ophthalmologist makes an incision in the cornea of the eye, and inserts two crescent or semi-circular shaped ring segments between the layers of the corneal stroma, one on each side of the pupil. Intrastromal corneal rings were approved in 2004 by the Food and Drug Administration for people with keratoconus who cannot adequately correct their vision with glasses or contact lenses. They were approved under the Humanitarian Device Exemption, which means the manufacturer did not have to demonstrate effectiveness.
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.
The powder is normally kept at −20 °C or below in a sealed, moisture-protected container. Letting the vial reach room temperature before opening helps prevent condensation on the contents.