AEDG is one of those subjects where the details matter more than the headlines. This page pulls together the background, the mechanisms, and the practical points readers ask about most.
Updated 2026-07-28. Numbers and descriptions here follow the published literature rather than marketing material.
（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.
Chemically, the molecule consists of four amino acid residues joined by three peptide bonds, with a free N-terminal amino group and a free C-terminal carboxyl group. Its molecular formula is C14H22N4O9, and its monoisotopic mass is approximately 390 daltons. The acidic glutamate and aspartate side chains give the peptide a net negative charge near neutral pH, a property that shapes its chromatographic behaviour and solubility profile. No disulfide bridges or other post-translational modifications are present, so the primary sequence alone defines the structure.
Most experimental work has been carried out in cell culture and animal models. Several reports describe changes in telomerase activity and proliferation in cultured cells, while rodent studies have examined lifespan, melatonin rhythm and reproductive endpoints. Human data remain limited, and much of the published clinical material consists of small trials with incomplete reporting of methods and controls. Whether the cell and animal findings translate into measurable effects in people is an open question, and the mechanistic basis of the reported telomerase changes is not fully established.
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.
Stability of the tetrapeptide follows ordinary peptide chemistry rather than any unusual structural feature. The aspartate-glycine pair is prone to aspartimide formation under mildly basic or neutral conditions, and deamidation can follow, altering both mass and chromatographic retention. Dry lyophilised powder kept at or below minus twenty degrees Celsius is the usual handling recommendation, with repeated freeze-thaw cycles avoided. Once dissolved in neutral aqueous buffer, degradation proceeds over days to weeks depending on pH and temperature, while acidic conditions generally slow the aspartimide route. A formal stability-indicating study has not been published in the indexed literature.
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.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Linear tetrapeptide | Four residues joined by three peptide bonds |
| Sequence | Ala-Glu-Asp-Gly | Commonly abbreviated AEDG |
| Molecular formula | C14H22N4O9 | Free acid form |
| Monoisotopic mass | Approximately 390 Da | Matches values reported from mass spectrometry |
| Net charge near neutral pH | Negative | Contributed by glutamate and aspartate side chains |
Epitalon is a synthetic tetrapeptide with the residue sequence alanine-glutamate-aspartate-glycine, commonly abbreviated AEDG. Its monoisotopic mass is approximately 390.35 daltons, and it is usually supplied as a lyophilised trifluoroacetate or acetate salt. The compound was derived from a pineal gland extract called epithalamin, a heterogeneous preparation investigated in the former Soviet Union. Researchers associated with the Saint Petersburg Institute of Bioregulation and Gerontology described the tetrapeptide as a constituent fragment of that extract. Commercial material is offered as a laboratory reagent rather than as a finished pharmaceutical product.
Literature searches for this compound must account for several spelling variants. Indexing databases contain epitalon, epithalon, epithalone, and AEDG, and relevant records are scattered across Russian-language and English-language journals that do not consistently cross-cite. Early publications describe the parent extract as a mixture of many peptides, whereas later work addresses the single synthetic tetrapeptide. That shift in nomenclature complicates comparison between studies, because extract data and tetrapeptide data are sometimes cited interchangeably. A search strategy omitting the alternate spellings will return an incomplete set of references.
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.
31 May: David Seymour succeeds Winston Peters as deputy prime minister, under the terms of the coalition agreement in 2023. Strong winds cause power outages in parts of Otago and the Southland Region.
Ernst on developing the first two-dimensional NMR experiments, and established the nuclear Overhauser effect as a convenient way of measuring distances within proteins. This research later led to the complete assignment of resonances for among others the bovine pancreatic trypsin inhibitor and glucagon. In October 2010, Wüthrich participated in the USA Science and Engineering Festival's Lunch with a Laureate program where middle and high school students will get to engage in an informal conversation with a Nobel Prize–winning scientist over a brown-bag lunch. Wüthrich is also a member on the USA Science and Engineering Festival's Advisory Board and a supporter of the Campaign for the Establishment of a United Nations Parliamentary Assembly, an organisation which campaigns for democratic reform in the United Nations. Wüthrich is a member of the Executive Advisory Board of the World.Minds Foundation, where he contributes to international dialogue on science, research, and innovation policy.
In total ten Venera probes achieved a soft landing on the surface of Venus. In 1984, the Soviet Vega programme began and ended with the launch of two crafts launched six days apart, Vega 1 and Vega 2. Both crafts deployed a balloon in addition to a lander, marking a first in spaceflight. The US never caught up or matched the Soviet efforts to explore the surface of Venus, but did claim the title of the first successful probe to have flown by the planet and had notable success with the Pioneer atmospheric probes.
Sources: en.wikipedia.org
Other bridged 2,5-diketopiperazines include bicyclomycin, an antibacterial agent used as food additives to prevent diarrhea in animals while the thio derivatives such as the cytotoxic bridged epipolythiodioxopiperazine are represented by gliotoxin. The unsaturated derivatives are illustrated by phenylahistin the anti-cancer microtubule binding agent, and the mycotoxin roquefortine C found in blue cheeses.
These complexes are often laid out in a similar fashion, and they can contain many different modules to perform a diverse set of chemical manipulations on the developing product. These peptides are often cyclic and can have highly complex cyclic structures, although linear nonribosomal peptides are also common. Since the system is closely related to the machinery for building fatty acids and polyketides, hybrid compounds are often found. The presence of oxazoles or thiazoles often indicates that the compound was synthesized in this fashion. Peptones are derived from animal milk or meat digested by proteolysis. In addition to containing small peptides, the resulting material includes fats, metals, salts, vitamins, and many other biological compounds. Peptones are used in nutrient media for growing bacteria and fungi. Peptide fragments refer to fragments of proteins that are used to identify or quantify the source protein. Often these are the products of enzymatic degradation performed in the laboratory on a controlled sample, but can also be forensic or paleontological samples that have been degraded by natural effects.
== Treatment == Although feline cutaneous asthenia is not curable, there are treatment and management options for the disease. Affected animals must be kept away from others, and sharp corners on tables and other furniture must be padded. Cats should have their claws regularly trimmed so that they cannot injure themselves while scratching, and it is often advised that males be neutered, both because of the heritability of the disease and because there is a chance of injury during mating. If something causes the skin to tear, it should be sutured if possible, and the wound should be treated with antibiotics as needed. Vitamin C is also given to cats in controlled doses, to assist with the translation of collagen. Given proper care, cats with feline cutaneous asthenia can live long lives, although the prognosis is not as positive if joint hypermobility is present.
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Admiral Brad Cooper said that the US military had struck more than 8,000 Iranian military targets, including 130 vessels. On 21 March, the US conducted strikes on the Natanz Nuclear Facility using bunker buster bombs to target the site. Russia condemned the strikes on Natanz as a "blatant violation of international law" while the IAEA urged military restraint "to avoid any risk of a nuclear accident". In response, Iran struck the southern Israeli town of Dimona, injuring at least 78 people. Iran said that it targeted the Shimon Peres Negev Nuclear Research Center. Citing unnamed US officials, CNN and The Wall Street Journal reported that Iran unsuccessfully attempted to strike the joint US–UK military base at Diego Garcia on the Chagos Islands in the British Indian Ocean Territory. The report said one of the missiles broke apart mid-flight, while another was intercepted by a SM-3 air defense missile launched by a US warship. Israel said that Iran used a two-stage intercontinental ballistic missile to target the island. Iran denied launching missiles towards Diego Garcia, saying that it was an Israeli false flag attack. In response the UK foreign secretary confirmed and denounced the Iranian attack on their end, and additionally expanded permission for the United States to bomb certain targets using their bases. No evidence has been presented that the alleged Iranian missiles neared Diego Garcia or that one was intercepted.
Chumming (American English from Powhatan) is the blue water fishing practice of throwing meat-based groundbait called "chum" into the water in order to lure various marine animals (usually large game fish) to a designated fishing ground, so the target animals are more easily caught by hooking or spearing. Chums typically consist of fresh chunks of fish meat with bone and blood, the scent of which attracts predatory fish, particularly sharks, billfishes, tunas and groupers. In the past, the chum contents have also been made from "offal", the otherwise rejected or unwanted parts of slaughtered animals such as internal organs.
concentrated table salt is toxic to many slugs and snails). Bioaccumulation of chemically-prepared agricultural insecticides is a matter of concern for the many species, especially birds, which consume insects as a primary food source. Selective toxicity, controlled application, and controlled biodegradation are major challenges in herbicide and pesticide development and in chemical engineering generally, as all lifeforms on earth share an underlying biochemistry; organisms exceptional in their environmental resilience are classified as extremophiles, these for the most part exhibiting radically different susceptibilities.
Sources: en.wikipedia.org
It is a synthetic tetrapeptide with the sequence alanine-glutamate-aspartate-glycine, often abbreviated AEDG. The molecule is linear and contains no modified residues, so it is fully described by its sequence.
The compound came out of work on epithalamin, a peptide preparation derived from pineal tissue, conducted largely in Russian laboratories. Later studies in other countries examined it mainly in cell cultures and animal models.
The tetrapeptide sequence is a synthetic construct rather than a described circulating peptide. It was derived by analogy to peptide fractions obtained from tissue extracts, not isolated from blood or tissue as such.
The molecule lacks aromatic residues, so it absorbs weakly near 280 nanometres, the wavelength applied to many other peptides. The peptide bond absorbs strongly below 220 nanometres, making 214 nanometres a practical compromise. Gradient methods must therefore use mobile phases with low ultraviolet absorbance to keep the baseline clean.