Deamidation 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.
Last reviewed on 2026-02-26. Where a claim depends on a specific study, the study is described rather than over-claimed.
Epitalon is a synthetic tetrapeptide with the amino acid sequence alanine-glutamate-aspartate-glycine, abbreviated Ala-Glu-Asp-Gly or AEDG. It was developed by the Russian researcher Vladimir Khavinson and colleagues during work on peptide bioregulators derived from the pineal gland. The compound is short enough to be produced by standard solid-phase peptide synthesis and is typically handled as a lyophilized white powder. Its small size distinguishes it from larger pineal peptides such as epithalamin, a complex extract from which the tetrapeptide was conceptually derived.
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.
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.
| 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 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.
Reference material is normally supplied as a lyophilised powder in a sealed vial. Product literature typically recommends storage at minus twenty degrees Celsius or colder, protected from light and moisture. Freeze-thaw cycling is usually avoided because repeated condensation can introduce water into the vial. Working solutions are commonly prepared fresh, aliquoted, and kept cold for short periods rather than stored at ambient temperature. Labelling the date of opening helps track how long a vial has been in use.
Solubility is high in water, phosphate-buffered saline and normal saline, a pattern that follows from the two acidic residues in the chain. The peptide dissolves poorly in non-polar solvents such as hexane or chloroform. Stock solutions are often prepared in water first and then diluted into the buffer of interest. Because the molecule is small and hydrophilic, filtration through a low-protein-binding membrane is usually straightforward, and visible particulates are uncommon in freshly made solutions.
Discussions in the literature often conflate three distinct entities: the pineal extract epithalamin, the isolated tetrapeptide AEDG, and commercial preparations sold under similar names. Reviews citing older Russian-language studies sometimes omit detail on purity, route of administration and control groups, which makes cross-study comparison difficult. Researchers working with the compound generally note the need for independent replication, standardized enzyme assays, and clearer reporting of peptide identity. These caveats are relevant when weighing claims that appear in secondary sources rather than in primary reports.
（TG:@pojiaai）Epitalon is a synthetic linear tetrapeptide with the sequence alanine-glutamate-aspartate-glycine, abbreviated AEDG. It emerged from work on epithalamin, a peptide fraction prepared from bovine pineal tissue, and was designed as a short, chemically defined analogue of that extract. Early publications came mainly from Russian laboratories studying pineal peptides and aging-related endpoints. The compound appears in the literature under several spellings, including epithalon and epithalone, which complicates systematic searching. Its small size makes solid-phase assembly and routine analytical characterization straightforward.
Russian media reported an attack by Ukrainian drones on the Afipsky oil refinery in Krasnodar Krai, as well as in oil depots in Tambov Oblast and Enem, Adygea. Authorities also claimed that drones were shot down over Bryansk, Rostov, Belgorod and Oryol Oblasts. One person was killed in a drone strike in Slavyansk-on-Kuban. Russia withdrew 80% of its soldiers from the Finnish border and redeployed them to Ukraine, according to an investigation by Finnish media. The Romanian government pledged to deliver a Patriot battery to Ukraine in exchange for a replacement unit from the US. John Kirby, National Security Council Coordinator for Strategic Communications, confirmed that the US government was to “reprioritise” all foreign exports of Patriot and NASAMS missiles in favour of Ukraine. Russia claimed that it used for the first time, a FAB-3000 modified with a guidance wing kit near Lyptsi, Kharkiv Oblast.
According to various regulations, such as the international ISO 15189 norm, all pathological laboratory results must be verified by a competent professional. In some countries, staffs composed of clinical scientists do the majority of this work inside the laboratory with certain abnormal results referred to the relevant pathologist. Doctor Clinical Laboratory scientists have the responsibility for limited interpretation of testing results in their discipline in many countries. Interpretation of results can be assisted by some software in order to validate normal or non-modified results. In other testing areas, only professional medical staff (pathologist or clinical Laboratory) is involved with interpretation and consulting. Medical staff are sometimes also required in order to explain pathology results to physicians. For a simple result given by phone or to explain a technical problem, often a medical technologist or medical lab scientist can provide additional information. Medical laboratory departments in some countries are exclusively directed by a specialized Doctor laboratory Science. In others, a consultant, medical or non-medical, may be the head the department. In Europe and some other countries, Clinical Scientists with a Masters level education may be qualified to head the department. Others may have a PhD and can have an exit qualification equivalent to medical staff (e.g., FRCPath in the UK). In France, only medical staff (Pharm.D. and M.D. specialized in anatomical pathology or clinical Laboratory Science) are authorized to discuss laboratory results.
=== Potency === For equianalgesic dosing, when used sublingually, the potency of buprenorphine is about 40 to 70 times more potent than morphine. When used as a transdermal patch, the potency of buprenorphine may be 100 to 115 times greater than that of morphine.
Sources: en.wikipedia.org
=== Plants, climate and environmental change === Plant responses to climate and other environmental changes can inform one's understanding of how these changes affect ecosystem function and productivity. For example, plant phenology can be a useful proxy for temperature in historical climatology, and the biological impact of climate change and global warming. Palynology, the analysis of fossil pollen deposits in sediments from thousands or millions of years ago allows the reconstruction of past climates. Estimates of atmospheric CO2 concentrations since the Palaeozoic have been obtained from stomatal densities and the leaf shapes and sizes of ancient land plants. Ozone depletion can expose plants to higher levels of ultraviolet radiation-B (UV-B), resulting in lower growth rates. Moreover, information from studies of community ecology, plant systematics, and taxonomy is essential to understanding vegetation change, habitat destruction and species extinction.
== Further reading == Hassan, Muntaha M. Rapid Immunochrotographic Techniques. Ramadi, Al Anbar, Iraq: University of Anbar. Didactic presentation (lab notes for students). Retrieved 12 January 2022. Porex Clinical Sciences (manufacturer) "Sample Collection & Transport | Sample Preparation | Sample Analysis".
== Uses == Pure ammonium formate decomposes into formamide and water when heated, and this is its primary use in industry. Formic acid can also be obtained by reacting ammonium formate with a dilute acid, and since ammonium formate is also produced from formic acid, it can serve as a way of storing formic acid. Ammonium formate can also be used in palladium on carbon (Pd/C) reduction of functional groups. In the presence of Pd/C, ammonium formate decomposes to hydrogen, carbon dioxide, and ammonia. This hydrogen gas is adsorbed onto the surface of the palladium metal, where it can react with various functional groups. For example, alkenes can be reduced to alkanes, formaldehyde to methanol, and nitro compounds to amines. Activated single bonds to heteroatoms can also be replaced by hydrogens (hydrogenolysis). Ammonium formate can be used for reductive amination of aldehydes and ketones (Leuckart reaction), by the following reaction:
Sources: en.wikipedia.org
In 1946, Freeman performed this procedure for the first time on a patient, who was subdued before the operation with electroshock treatment. The transorbital lobotomy procedure, which Freeman performed very quickly, sometimes in less than 10 minutes, was used on many patients with relatively minor mental disorders that Freeman believed did not warrant traditional lobotomy surgery, in which the skull itself was opened. A large proportion of such lobotomized patients exhibited reduced tension or agitation. Many also showed other effects, such as apathy, passivity, lack of initiative, poor concentration, and a generally decreased depth and intensity of their emotional response to life. Some died as a result of the procedure. However, those effects were not widely reported in the 1940s, and at that time, the long-term effects were largely unknown. Because the procedure met with seemingly widespread success, Moniz was awarded the 1949 Nobel Prize for Physiology or Medicine (along with Swiss physiologist Walter Rudolf Hess). Lobotomies were performed on a wide scale during the 1940s; Freeman himself performed or supervised more than 3,500 lobotomies by the late 1960s. Freeman performed his first transorbital lobotomy on Ellen Ionesco, a woman who suffered from bouts of manic depression and suicidal ideation. Freeman utilized media coverage and penned editorials for numerous interviews promoting the procedure and achieving accolades for his work in psychiatric care.
The plantar fascia contributes to support of the arch of the foot by acting as a tie-rod, where it undergoes tension when the foot bears weight. One biomechanical model estimated it carries as much as 14% of the total load of the foot. In an experiment using cadavers, it was found that failure of the plantar fascia averaged at loads of 118±244 newtons (12 ± 25 kilograms-force; 27 ± 55 pounds-force). Failure most often occurred at the proximal attachment to the calcaneus, which is consistent with the usual location of symptoms (i.e., in plantar fasciitis). Complete rupture or surgical release of the plantar fascia leads to a decrease in arch stiffness and a significant collapse of the longitudinal arch of the foot. By modeling it was predicted such conditions would result in a 17% increase in vertical displacement and a 15% increase in horizontal elongation of the foot when it was loaded at 683 newtons (70 kgf; 154 lbf). Surgical release also significantly increases both stress in the plantar ligaments and plantar pressures under the metatarsal heads. Although most of the figures mentioned above are from either cadaver studies or investigations using models, they highlight the relatively large load the plantar fascia is subjected to while contributing to the structural integrity of the foot.
=== April === 1 April – The Hate Crime and Public Order (Scotland) Act 2021, which creates a new crime of "stirring up hatred" relating to age, disability, religion, sexual orientation, transgender identity or being intersex, comes into force in Scotland. Twenty Labour Party councillors serving on Pendle Borough Council, Nelson Town Council and Brierfield Town Council resign from the party in protest at Sir Keir Starmer's leadership, which they say no longer reflects their views. This included the leader of Pendle Borough Council Asjad Mahmood. 2 April – Education Secretary Gillian Keegan says that proposed homelessness legislation will not be used against "excessive smells". The Criminal Justice Bill, which is currently making its way through Parliament, will replace the 1824 Vagrancy Act. 3 April – Labour commits to the Conservatives' childcare expansion plans if it wins the next general election. MP Johnny Mercer announces his intention to challenge a court order to reveal names of those who had told him about alleged war crimes by British special forces in Afghanistan. 4 April – Conservative MP William Wragg tells The Times he shared the phone numbers of fellow MPs with someone he met on a dating app after sending the person intimate pictures of himself. 5 April – Veterans' Minister Johnny Mercer is given until 8 May to present his argument as to why he should not reveal the identity of those who told him about alleged war crimes committed in Afghanistan by British Special Forces.
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 dry powder is typically held at -20 degrees Celsius or lower, protected from light and moisture. Allowing a sealed vial to reach room temperature before opening reduces condensation on its contents. Conditions stated on a supplier certificate of analysis take precedence over general guidance.