If you have been reading about freeze-drying 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.
Updated 2026-08-01. Numbers and descriptions here follow the published literature rather than marketing material.
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.
| 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.
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.
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.
There are three types of protein microarrays that are currently used to study the biochemical activities of proteins. Analytical microarrays are also known as capture arrays. In this technique, a library of antibodies, aptamers or affibodies is arrayed on the support surface. These are used as capture molecules since each binds specifically to a particular protein. The array is probed with a complex protein solution such as a cell lysate. Analysis of the resulting binding reactions using various detection systems can provide information about expression levels of particular proteins in the sample as well as measurements of binding affinities and specificities. This type of microarray is especially useful in comparing protein expression in different solutions. For instance the response of the cells to a particular factor can be identified by comparing the lysates of cells treated with specific substances or grown under certain conditions with the lysates of control cells. Another application is in the identification and profiling of diseased tissues. Reverse phase protein microarray (RPPA) involve complex samples, such as tissue lysates. Cells are isolated from various tissues of interest and are lysed. The lysate is arrayed onto the microarray and probed with antibodies against the target protein of interest. These antibodies are typically detected with chemiluminescent, fluorescent or colorimetric assays. Reference peptides are printed on the slides to allow for protein quantification of the sample lysates.
Evidence of effects of heroin maintenance compared to methadone are unclear as of 2010. A Cochrane review found some evidence in opioid users who had not improved with other treatments. In Switzerland, Germany, the Netherlands, and the United Kingdom, long-term injecting drug users who do not benefit from methadone and other medication options may be treated with injectable heroin that is administered under the supervision of medical staff. Other countries where it is available include Spain, Denmark, Belgium, Canada, and Luxembourg. Dihydrocodeine in both extended-release and immediate-release form is also sometimes used for maintenance treatment as an alternative to methadone or buprenorphine in some European countries. Dihydrocodeine is an opioid agonist. It may be used as a second-line treatment. A 2020 systematic review found low-quality evidence that dihydrocodeine may be no more effective than other routinely used medication interventions in reducing illicit opiate use. An extended-release morphine confers a possible reduction of opioid use and with fewer depressive symptoms but overall more adverse effects compared to other forms of long-acting opioids. Retention in treatment was not found to be significantly different. It is used in Switzerland and Canada.
== Applications == Due to its contribution to fibrinolysis, tissue plasminogen activator is used medically to treat blood clot-related disorders including thrombotic or embolic stroke, myocardial infarction, and pulmonary embolism. It is manufactured using recombinant techniques and is sold as alteplase, reteplase, and tenecteplase. Alteplase was the first of these versions to go on the market, and has the same structure as tPA. Reteplase and tenecteplase both received FDA approval after alteplase, and have nonidentical structures to tPA. These recombinant forms of tPA have been shown to have a longer half-life in the blood and greater resistance to inhibition, resulting in an increased capacity to treat thrombolytic diseases. Urokinase is similarly used in the medical field, specifically for the treatment of pulmonary embolism.
5-Fluorowillardiine – a synthetic modification of willardiine AMPATooltip α-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid – a synthetic agonist after which the receptor is named Domoic acid – a naturally occurring agonist that causes amnesic shellfish poisoning Glutamic acid (glutamate) – the endogenous agonist Ibotenic acid – a naturally occurring agonist found in Amanita muscaria Quisqualic acid – a naturally occurring agonist found in certain species Willardiine – a naturally occurring agonist
Sources: en.wikipedia.org
O-GlcNAc transferase OGTase O-linked N-acetylglucosaminyltransferase Uridine diphospho-N-acetylglucosamine:polypeptide β-N-acetylglucosaminyltransferase Systematic name: UDP-N-α-acetyl-d-glucosamine:[protein]-3-O-N-acetyl-β-d-glucosaminyl transferase
=== Mitigation measures === Several strategies have been proposed as a way to protect people at the greatest risk of occupational exposure to PFAS, including exposure monitoring, regular blood testing, and the use of PFAS-free alternatives such as fluorine-free firefighting foam and plant-based ski wax.
Russia claimed to have taken the villages of Hatyshche, Krasne, Morokhovets, and Oliinykove in Kharkiv Oblast. In Russia, the governor of Volgograd Oblast, Andrey Bocharov, claimed that a Ukrainian drone started a fire at an oil refinery, which was put out without any casualties. In Belgorod, officials claimed that 16 people were killed and 27 others were injured when a fragment of a Tochka-U struck an apartment building, according to the Russian Defence Ministry, which also claimed to have shot down several missiles over Belgorod Oblast. Ukrainian media later reported that the HUR carried out drone strikes in Volgograd, Lipetsk and Kaluga Oblasts. One person was killed by Russian shelling in Sumy Oblast. Officials reported that Ukraine's seaborne grain exports had recovered to close to their prewar level. The Kremlin announced the appointment of economist and Deputy Prime Minister Andrey Belousov as Defence Minister, replacing Sergei Shoigu who was transferred to become secretary of the Security Council of Russia.
in medicine, forming nouns with the sense "swelling, tumour" in botany or zoology, forming nouns in the sense "a part of an animal or plant with a specified structure" in cellular and molecular biology, forming nouns with the sense "all constituents considered collectively" The -ome suffix originated as a variant of -oma, and became productive in the last quarter of the 19th century. It originally appeared in terms like sclerome or rhizome. All of these terms derive from Greek words in -ωμα, a sequence that is not a single suffix, but analyzable as -ω-μα, the -ω- belonging to the word stem (usually a verb) and the -μα being a genuine Greek suffix forming abstract nouns. The OED suggests that its third definition originated as a back-formation from mitome, Early attestations include biome (1916) and genome (first coined as German Genom in 1920). The association with chromosome in molecular biology is by false etymology. The word chromosome derives from the Greek stems χρωμ(ατ)- "colour" and σωμ(ατ)- "body". While σωμα "body" genuinely contains the -μα suffix, the preceding -ω- is not a stem-forming suffix but part of the word's root. Because genome refers to the complete genetic makeup of an organism, a neo-suffix -ome suggested itself as referring to "wholeness" or "completion". Bioinformaticians and molecular biologists figured amongst the first scientists to apply the "-ome" suffix widely.
Center of Bhiwandi North of Kalyan North of Ulhasnagar South of Shahapur South of Igatpuri (Nashik) South of Sinnar South of Kopargaon North of Shirdi South of Vaijapur North of Aurangabad Caves North of Shendra North of Jalna North of Sindkhed Raja North of Mehkar North of Malegaon Jahangir North of Karanja Lad South of Dhamangaon North of Pulgaon North of Wardha South of Seloo West of Butibori Power Plant South of MIHAN SEZ (Nagpur)
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.