A practical reference on Deamidation: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
This page was last updated on 2026-07-09 and is reviewed periodically as new material appears.
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 and purity are usually assessed by reversed-phase high-performance liquid chromatography with ultraviolet detection, frequently near 214 nanometers where the peptide bond absorbs. Mass spectrometry, most often with electrospray ionization, confirms the observed molecular mass and helps separate the intact peptide from truncated or modified forms. Amino acid analysis or tandem mass spectrometry can establish residue order. Purity is commonly quoted as an area percentage, yet such values are method-dependent, and comparisons between laboratories require matching column, gradient and detection wavelength.
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.
| Property | Value | Notes |
|---|---|---|
| Amino acid sequence | Ala-Glu-Asp-Gly | Linear tetrapeptide, also written AEDG |
| Molecular mass | About 390.35 g/mol | Value calculated from the sequence |
| Appearance | White to off-white powder | Lyophilised material forms a loose cake |
| Solubility | Freely soluble in water | Also dissolves in isotonic saline |
| Storage | -20 °C, desiccated | Aliquot solutions to avoid freeze–thaw cycling |
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.
Laboratory work has examined effects on telomerase activity in cultured cells, on melatonin rhythms in animals, and on markers of oxidative stress. Some experiments report measurable changes while others show none, and the reported findings rest largely on small studies. The absence of large independent trials means the generality of these results is unresolved rather than settled. Review articles occasionally apply the label geroprotector, a term that reflects a research hypothesis about ageing rather than an established clinical finding.
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.
Laboratory-grade epitalon is typically supplied as a lyophilized powder. Purity is commonly assessed with reverse-phase high-performance liquid chromatography, often paired with mass spectrometry to confirm molecular identity. Amino acid analysis and peptide mapping can provide additional confirmation of sequence. Certificates of analysis for research materials frequently report purity above 95 percent, although the methods behind such figures vary between suppliers. The absence of a pharmacopeial monograph means that no single standardized assay defines the compound, so reported results depend on the analytical protocol chosen.
Storage recommendations center on limiting moisture, heat, and light. The dry powder is generally kept at minus 20 degrees Celsius, and some suppliers recommend minus 80 degrees for long-term archival. Once dissolved, solutions are usually aliquoted and frozen to avoid repeated freeze-thaw cycles, which can promote aggregation or degradation. Aqueous stability depends on pH and concentration, and buffered saline is often preferred over plain water for biological work. Stability data specific to epitalon remain limited, so general peptide-handling practices are applied by analogy rather than from product-specific validation.
Epitalon is a synthetic tetrapeptide with the sequence alanine-glutamate-aspartate-glycine, abbreviated AEDG. Its molecular formula is C14H22N4O9 and its calculated monoisotopic mass is approximately 390.35 daltons. The compound does not occur naturally as a free peptide; it is produced by solid-phase peptide synthesis. Because it contains two acidic residues and no basic residues, the neutral form carries a net negative charge at physiological pH. This charge profile influences how the peptide behaves in solution and during chromatographic analysis.
Storage and handling follow conventional peptide practice. Lyophilized epitalon is typically kept refrigerated or frozen, protected from moisture and light, and allowed to equilibrate to room temperature before opening to avoid condensation. Once dissolved, aqueous solutions are usually stored cold and used within a short period, since dilute peptide solutions can support microbial growth and may slowly degrade. The absence of cysteine and methionine reduces, but does not eliminate, oxidation concerns during long-term storage.
Regulatory status varies by country and is not harmonized. Epitalon is not an approved drug in major Western jurisdictions. In some countries it is sold as a research chemical, and in others it has appeared in products marketed for other categories. This inconsistent status means that purity, labeling accuracy, and documentation differ widely between suppliers, and verification of identity and purity through independent analysis is the usual way buyers assess a given lot.
Epitalon appears in the literature primarily through a small number of research groups, most of them associated with the St. Petersburg Institute of Bioregulation and Gerontology. Publications describe cell culture experiments, animal studies, and a limited number of small human studies. Independent replication outside this network is sparse. As a result, reviews of the topic usually separate descriptive reports of observed effects from the question of whether those effects generalize, and they note the difficulty of comparing studies that use different preparations and endpoints.
=== Amino acid metabolism === Clostridium scindens also has the genetic potential to perform Stickland fermentation, or the generation of ATP through the fermentation of amino acids. C. scindens pairs amino acid fermentation with bile acid metabolism by using amino acids as electron donors and primary bile acids as acceptors. The presence of glycine and proline reductase enzymes in the Clostridium scindens ATCC35704 genome indicates that glycine and proline may be commonly fermented amino acids by this organism.
=== Research === Many aspects of academic research and industrial research such as in pharmaceuticals, health products, and many others relies on accurate water analysis to identify substances of potential use, to refine those substances and to ensure that when they are manufactured for sale that the chemical composition remains consistent. The analytical methods used in this area can be very complex and may be specific to the process or area of research being conducted and may involve the use of bespoke analytical equipment.
In Asia, this has expanded their range to include an area from southern China to India and Sri Lanka, and in other continents they are now found in Australia, Mauritius, Réunion, Madagascar and elsewhere. Translocations within Southeast Asia likely started in ancient times. Even Europeans recognized its value as a food fish several hundred years ago. For example, Georges Cuvier (1769–1832) suggested that it should be introduced to the French colonies.
An independent body (a review board or a committee, institutional, regional, national, or supranational), constituted of medical/scientific professionals and nonmedical/nonscientific members, whose responsibility it is to ensure the protection of the rights, safety, and well-being of human subjects involved in a trial and to provide public assurance of that protection, by, among other things, reviewing and approving/providing favorable opinion on the trial protocol, the suitability of the investigator(s), facilities, and the methods and material to be used in obtaining and documenting informed consent of the trial subjects. The legal status, composition, function, operations, and regulatory requirements pertaining to Independent Ethics Committees may differ among countries, but should allow the Independent Ethics Committee to act in agreement with GCP as described in this guidance. (ICH E6) Indication
Soy was most likely domesticated 6,000–9,000 years ago in the region between the Yellow River and the Huai River in China. The earliest documented evidence for the use of Glycine of any kind comes from charred plant remains of wild soybean recovered from Jiahu in Henan province, a Neolithic site occupied between 9,000 and 7,800 years ago. An abundance of archaeological charred soybean specimens have been found accumulated around this region. Soybeans became an important crop by the Zhou dynasty (c. 1046–256 BC) in China. According to an ancient Chinese myth, in 2853 BC, the legendary Emperor Shennong of China proclaimed that five plants were sacred: soybeans, rice, wheat, barley, and millet. Early Chinese records mention that soybeans were a gift from the region of the Yangtze River delta and Southeast China. However, there is no archaeological evidence that soybeans were domesticated in southern China, and it appears that soy was unknown there prior to the Han dynasty. The oldest preserved soybeans resembling modern varieties in size and shape were found in archaeological sites in Korea dated about 1000 BC. Radiocarbon dating of soybean samples recovered through flotation during excavations at the Early Mumun period Okbang site in Korea indicated soybeans were cultivated as a food crop in around 1000–900 BC. Soybeans from the Jōmon period in Japan from 3000 BC are also significantly larger than wild varieties. The earliest Japanese textual reference to the soybean is in the classic Kojiki (Records of Ancient Matters), which was completed in 712 CE.
Sources: en.wikipedia.org
== Growth hormone deficiency == In a study of children with growth hormone deficiency, ibutamoren performed better than other growth hormone secretagogues at improving growth hormone levels. An ongoing study compares ibutamoren directly to injectable hGH in terms of height velocity in this population. Topline data from Phase 2 OraGrowtH210 and OraGrowtH212 Trials of LUM-201 in PGHD met all primary and secondary endpoints.
In the early 20th century, the number of patients residing in mental hospitals increased significantly while little in the way of effective medical treatment was available. Lobotomy was one of a series of radical and invasive physical therapies developed in Europe at this time that signaled a break with the psychiatric culture of therapeutic nihilism which had prevailed since the mid-nineteenth century. The new "heroic" physical therapies devised during this experimental era, including malarial therapy for general paresis of the insane (1917), deep sleep therapy (1920), insulin shock therapy (1933), cardiazol shock therapy (1934), and electroconvulsive therapy (1938), served to galvanize a profession which had been both therapeutically moribund and systemically demoralized. Unlike other medical disciplines (e.g., cardiology, dermatology, orthopedics, etc.), which applied surgical and pharmacological treatments that were both apparent and measurable regarding their efficacy, psychiatry had often struggled with quantification. These novel remedial methodologies, however, meant that (at the time) modern psychiatric treatments were no longer relegated to the metaphysical or abstract, and this increased the popularity of the field among clinicians and prospective patients alike. Suddenly, conditions like insanity, psychosis, and others felt less like incurable afflictions and more like surmountable diagnoses, emboldening psychiatrists to attempt new procedures.
== Features == The purpose of ModDB is to list the mods, files, tutorials and information of any games that are capable of being modded with user-made content. The website allows users to create pages for mods, upload screenshots and files, publish news, and request help from the community. Scott's intentions, from the beginning, were to get the community heavily involved in the creation and development of the website. To this end, the most active members were chosen as moderators and administrators. The core staff generally remain the same, while lower positions are heavily rotated among trainee moderators, and administrator candidates. ModDB's terms of use prohibit certain types of content, including pornographic, defamatory, and obscene content, as well as material that incites crime or hatred, violates intellectual property law under the terms of the copyright law of Australia and the Digital Millennium Copyright Act, or otherwise "brings [the website] into disrepute." Nevertheless, the website received mainstream media attention when in early 2011 it hosted School Shooter: North American Tour 2012, a Half-Life 2 mod. The mod's premise led to a number complaints accusing the website of being involved in the project, prompting the website to shut it down in March.
Bob Stewart, MP for Beckenham, has his conviction for a racially aggravated public order offence quashed following an appeal. 24 February – Lee Anderson is suspended from the Conservative Party after "refusing to apologise" for saying "Islamists" had "got control" of London Mayor Sadiq Khan during an edition of his GB News show the previous day. 25 February – Sunak warns of the dangers of polarisation and hatred in politics following a week of political friction at Westminster. Preet Gill, Labour MP for Birmingham Edgbaston, tells BBC Politics Midlands that receiving death threats appears to have become the "norm" and that her job worries her "in a way I've never been worried before". The SNP announces plans to apply for another parliamentary debate on Gaza in the coming week. The Scottish Government confirms that Economy Secretary Màiri McAllan, who is pregnant, will take maternity leave during the summer, becoming the second Scottish Government minister to do so. 26 February – House of Commons Speaker Sir Lindsay Hoyle rejects the SNP's request for an emergency debate on Gaza. Lee Anderson says that his words were clumsy, but refuses to apologise for his comments about Sadiq Khan. 27 February – A statement from 10 Downing Street says that the prime minister believed Lee Anderson's comments were wrong because they conflated "all Muslims with Islamist extremism". Conservative MP and former minister Paul Scully apologises for suggesting there are "no-go" areas in parts of the London Borough of Tower Hamlets.
Sources: en.wikipedia.org
It is a synthetic tetrapeptide. Its sequence was derived from research on peptide fractions of bovine pineal extract, and the intact AEDG sequence has not been demonstrated as an abundant free peptide in human tissue.
AEDG is the one-letter code for the four amino acids alanine, glutamate, aspartate and glycine in that order. The same molecule is written in three-letter form as Ala-Glu-Asp-Gly.
Identity is normally confirmed by mass spectrometry against the calculated mass of roughly 390.35 g/mol. Purity is then estimated by reversed-phase high-performance liquid chromatography with ultraviolet detection.
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.