The short version of Research chemical fits in a sentence. The long version — which is the one that helps — is below.
Reviewed 2025-12-18. Anything still debated is marked as such rather than presented as settled.
Regulatory treatment differs by country. No formulation of epitalon holds a marketing authorisation as a medicine in the United States or the European Union, where material sold for laboratory use is handled as a research chemical and is not intended for human consumption. In Russia, several short peptide preparations from the same institute's peptide series are registered medicinal products, and epitalon appears in that national context. Elsewhere it is frequently offered as a cosmetic ingredient, a category with lighter requirements. Advertising claims about longevity or disease prevention are restricted in most jurisdictions, which limits how sellers describe the compound.
Freeze-dried epitalon is normally kept at minus twenty degrees Celsius in a sealed, desiccated container, protected from light. Short excursions at ambient temperature during shipping are generally tolerated, but repeated warming and cooling cycles encourage moisture uptake, which shortens shelf life. Once dissolved, the peptide is far less stable than the solid: aqueous solutions are subject to hydrolysis and to deamidation at the aspartate and glutamate residues. Working solutions are therefore held refrigerated and used within days, and repeated freezing and thawing of the same vial is best avoided.
Identity and purity are checked by reversed-phase high-performance liquid chromatography, usually with ultraviolet detection near 214 nanometres, where the peptide bond absorbs. Mass spectrometry confirms the expected mass and reveals whether truncation products or adducts are present. Acid hydrolysis followed by amino acid analysis gives the residue ratio, which should approximate one alanine, one glutamate, one aspartate and one glycine. Counter-ions such as acetate or trifluoroacetate remain in the dried product and lower net peptide content, so a stated purity figure on a label does not by itself describe how much peptide a vial holds.
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.
| Property | Value | Notes |
|---|---|---|
| Storage temperature, solid | Approximately -20 C | Sealed, desiccated, protected from light |
| Typical identity method | Electrospray mass spectrometry | Protonated ion expected near 391 |
| Typical purity method | Reversed-phase HPLC | Ultraviolet detection near 214 nm |
| Common synonyms | Epithalon, epithalone, AEDG | Spelling variants appear in supplier catalogues |
| Solution stability | Days at 2-8 C | Hydrolysis and deamidation limit shelf life |
Purity assessment of peptide reagents normally relies on reversed-phase high-performance liquid chromatography. A gradient of acetonitrile in water with trifluoroacetic acid, paired with a C18 stationary phase, separates the target tetrapeptide from truncated sequences and deletion analogues. Detection at 214 nanometres exploits absorbance of the peptide backbone, since the molecule contains no aromatic residue. Results are expressed as a percentage of total peak area. Values above ninety-five percent are typical for research-grade material, although reporting conventions vary between suppliers.
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.
The compound is generally described as a synthetic analogue of a fragment isolated from a pineal gland extract. Researchers associated with the Saint Petersburg Institute of Bioregulation and Gerontology introduced it during the 1980s and 1990s while studying short peptides from animal tissue. The original extract, called epithalamin, is a heterogeneous mixture, whereas epitalon is a single defined sequence. That distinction matters because findings reported for the extract are not automatically findings about the pure tetrapeptide, and claims about broader biological effects remain a separate question from the chemical identity described here.
Residue composition is the property that most cleanly separates verified material from mislabelled samples. Alanine, glutamate, aspartate and glycine appear in that order from the N-terminus, and the two acidic residues sit in the middle of the chain. Because the peptide is short, it can be produced by solid-phase synthesis and characterised by mass spectrometry without ambiguity. Any reported sample whose measured mass departs substantially from 390 daltons is a different compound or a degraded mixture rather than epitalon.
Epitalon is a synthetic tetrapeptide whose four residues are alanine, glutamate, aspartate and glycine, commonly abbreviated AEDG. Its molecular formula is C14H22N4O9 and its monoisotopic mass is near 390.35 daltons. The peptide carries two acidic side chains, so it is neutral to negatively charged in most aqueous buffers. Published reference summaries usually list it under both spellings, epitalon and epithalon, and treat the two names as the same material.
== Function == Due to its diverse nature and composition, the ECM can serve many functions, such as providing support, segregating tissues from one another, and regulating intercellular communication. The extracellular matrix regulates a cell's dynamic behavior. In addition, it sequesters a wide range of cellular growth factors and acts as a local store for them. Changes in physiological conditions can trigger protease activities that cause local release of such stores. This allows the rapid local growth-factor-mediated activation of cellular functions without de novo synthesis. Formation of the extracellular matrix is essential for processes like growth, wound healing, and fibrosis. An understanding of ECM structure and composition also helps in comprehending the complex dynamics of tumor invasion and metastasis in cancer biology as metastasis often involves the destruction of extracellular matrix by enzymes such as serine proteases, threonine proteases, and matrix metalloproteinases. The stiffness and elasticity of the ECM has important implications in cell migration, gene expression, and differentiation. Cells actively sense ECM rigidity and migrate preferentially towards stiffer surfaces in a phenomenon called durotaxis. They also detect elasticity and adjust their gene expression accordingly, which has increasingly become a subject of research because of its impact on differentiation and cancer progression. The biochemical and biomechanical properties of tumor ECM differ from those of normal tissues, and could be used for cancer diagnosis and therapy.
== External links == "Connective Tissue Disorders". National Library of Medicine. 2017-09-15. Dunkin, Mary Anne (2023-10-10). "Connective Tissue Disease: Types, Symptoms, Causes". WebMD. "Connective tissue diseases". DermNet®. 2023-10-26.
Tendon (in particular, beef tendon) is used as a food in some Asian cuisines (often served at yum cha or dim sum restaurants). One popular dish is suan bao niu jin, in which the tendon is marinated in garlic. It is also sometimes found in the Vietnamese noodle dish phở.
==== Ultrastructure and collagen synthesis ==== Collagen fibres coalesce into macroaggregates. After secretion from the cell, cleaved by procollagen N- and C-proteases, the tropocollagen molecules spontaneously assemble into insoluble fibrils. A collagen molecule is about 300 nm long and 1–2 nm wide, and the diameter of the fibrils that are formed can range from 50–500 nm. In tendons, the fibrils then assemble further to form fascicles, which are about 10 mm in length with a diameter of 50–300 μm, and finally into a tendon fibre with a diameter of 100–500 μm. The collagen in tendons are held together with proteoglycan (a compound consisting of a protein bonded to glycosaminoglycan groups, present especially in connective tissue) components including decorin and, in compressed regions of tendon, aggrecan, which are capable of binding to the collagen fibrils at specific locations. The proteoglycans are interwoven with the collagen fibrils – their glycosaminoglycan (GAG) side chains have multiple interactions with the surface of the fibrils – showing that the proteoglycans are important structurally in the interconnection of the fibrils. The major GAG components of the tendon are dermatan sulfate and chondroitin sulfate, which associate with collagen and are involved in the fibril assembly process during tendon development. Dermatan sulfate is thought to be responsible for forming associations between fibrils, while chondroitin sulfate is thought to be more involved with occupying volume between the fibrils to keep them separated and help withstand deformation.
== Bibliography == Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. doi:10.1016/C2009-0-30414-6. ISBN 978-0-08-037941-8. Penneman, R. A. and Keenan T. K. The radiochemistry of americium and curium, University of California, Los Alamos, California, 1960 Wiberg, Nils (2007). Lehrbuch Der Anorganischen Chemie. De Gruyter. ISBN 978-3-11-017770-1.
Sources: en.wikipedia.org
In 1838, France enacted a law to regulate both the admissions into asylums and asylum services across the country. In the United States, the erection of state asylums began with the first law for the creation of one in New York, passed in 1842. The Utica State Hospital was opened around 1850. Many state hospitals in the United States were built in the 1850s and 1860s on the Kirkbride Plan, an architectural style meant to have curative effect. At the turn of the century, England and France combined had only a few hundred individuals in asylums. By the late 1890s and early 1900s, this number had risen to the hundreds of thousands. However, the idea that mental illness could be ameliorated through institutionalization ran into difficulties. Psychiatrists were pressured by an ever-increasing patient population, and asylums again became almost indistinguishable from custodial institutions. In the early 1800s, psychiatry made advances in the diagnosis of mental illness by broadening the category of mental disease to include mood disorders, in addition to disease level delusion or irrationality. The 20th century introduced a new psychiatry into the world, with different perspectives of looking at mental disorders. For Emil Kraepelin, the initial ideas behind biological psychiatry, stating that the different mental disorders are all biological in nature, evolved into a new concept of "nerves", and psychiatry became a rough approximation of neurology and neuropsychiatry.
At the beginning of July 2024, Santiago Peña expressed his opposition to the flexibilization of Mercosur, arguing that it is more advantageous to negotiate as a bloc, and questioned Uruguay's position of moving forward with bilateral agreements. Although in the first days of his term he had shown a willingness toward extra-bloc agreements, at that time he adopted the opposite stance. Prior to the transfer of the rotating presidency of Mercosur to Uruguay, Peña pointed to the need to continue efforts to strengthen regional integration, acknowledging that the bloc is going through a period of challenges. In October 2024, Peña lowered expectations regarding an imminent trade agreement between Mercosur and the European Union, underscoring that, although the bloc has shown interest in moving toward a free trade agreement, it has not found an equivalent willingness in Europe. He described as "unacceptable" the lack of recognition by Brussels of Paraguay's sanitary certification institutions. In December of that same year, he aligned himself with the position of the president of Brazil, Luiz Inácio Lula da Silva, reaffirming that Paraguay will not support unilateral negotiations that could fragment Mercosur's cohesion.
Another review on the surgical management of cystocele describes a more successful treatment that more strongly attaches the ligaments and fascia to the vagina to lift and stabilize it. Post-surgical complications can develop. The complications following surgical treatment of cystocele are:
=== Proposed Treatment Plan === Early diagnosis is important for improving patient outcomes. Patients with delayed diagnoses experienced decreased growth compared to those diagnosed earlier in life. Long-term treatment plans center around dietary management, but because long term results have not been documented due to a lack of thorough research, careful monitoring of the disease is required. Yearly check-ups are recommended to track the growth of children affected by the disease. Evaluations tracking liver function that involve the use of ultrasounds to monitor liver growth, are recommended to be administered every three years. At about ten years of age (pre-puberty), neurological and ophthalmological exams may be required every three years to track muscle and eye activity/strength. In adulthood, past eighteen years of age, echocardiograms are recommended to track heart activity. Thorough and vigorous testing warrant themselves to the treatment of a disease of which we know so little.
The Parliament of Trinidad and Tobago is the legislative branch of the government of Trinidad and Tobago. The Parliament is bicameral. It consists of the elected House of Representatives, which has 41 members elected for a five-year term in single-seat constituencies, and the Senate which has 31 members appointed by the president: 16 government senators appointed on the advice of the prime minister, 6 opposition senators appointed on the advice of the leader of the opposition and 9 independent senators appointed by the president to represent other sectors of civil society.
Sources: en.wikipedia.org
The solid is kept cold, dry and dark, typically at minus twenty degrees Celsius, in a sealed container with desiccant. Dissolved material is kept refrigerated and used promptly. Freezing and thawing a solution repeatedly is avoided because it accelerates degradation.
Reversed-phase chromatography with ultraviolet detection gives a purity percentage, while mass spectrometry confirms identity. Amino acid analysis checks the residue composition. Buyers typically request a certificate of analysis showing these measurements for the specific lot.
It is not authorised as a medicine in the United States or the European Union. Material is sold there as a research chemical or cosmetic ingredient. Some related short peptides are registered drugs in Russia, which is a distinct national situation rather than a general approval.
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.