This is a working overview of epitalon, written for readers who want more than a one-paragraph summary but less than a textbook.
This page was last updated on 2026-05-20 and is reviewed periodically as new material appears.
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.
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.
In its supplied form epitalon is a white to off-white powder, usually lyophilized and often hygroscopic. It dissolves readily in water and in aqueous buffers, and it is commonly handled as the acetate or trifluoroacetate salt to improve stability during purification and drying. The amide backbone is labile in aqueous media, so solutions are less durable than the dry solid. Handling notes in the chemical literature therefore emphasize keeping the powder dry, cool and shielded from light until it is dissolved.
Epitalon is a synthetic tetrapeptide whose sequence is alanine-glutamate-aspartate-glycine, written in single-letter code as AEDG. The four residues are joined by three peptide bonds, giving a linear backbone with no branching and no disulfide bridges. Its calculated molecular mass for the free form is approximately 390.3 daltons, a figure that rises when the compound is supplied as an acetate or trifluoroacetate salt. Because the chain is short, the molecule is defined entirely by its residue order rather than by any folded three-dimensional structure.
| Property | Value | Notes |
|---|---|---|
| Analytical method | Reversed-phase HPLC | Purity determination, typically 214 nm |
| Mass confirmation | ESI or MALDI mass spectrometry | Compared with mass near 390 Da |
| Common synonyms | Epitalon, epithalon, AEDG | Naming differs between suppliers |
| Storage temperature | −20 °C or lower | Lyophilised powder, kept desiccated |
| Solution stability | Limited in neutral aqueous buffer | Aspartimide and hydrolysis pathways |
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.
Short peptides such as AEDG are normally supplied as a freeze-dried solid and are kept dry, cold, and shielded from light. Holding at minus twenty degrees Celsius is common for the long term, while a refrigerator suffices for brief periods before use. The material takes up moisture to some degree, so containers should stay sealed and be allowed to reach room temperature before opening, which limits condensation on the contents. Repeated warming and cooling of a single container is discouraged because it admits water and can lower the amount of intact peptide.
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.
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.
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.
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.
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.
Molybdenum-99 is produced commercially by intense neutron-bombardment (i.e. fission) of a highly purified uranium-235 target, followed rapidly by extraction. It is used as a parent radioisotope in technetium-99m generators to produce the even shorter-lived daughter isotope technetium-99m, which is used in approximately 40 million medical procedures annually. A common misunderstanding or misnomer is that 99Mo is used in these diagnostic medical scans, when actually it has no role in the imaging agent or the scan itself. In fact, 99Mo co-eluted with the 99mTc (also known as breakthrough) is considered a contaminant and is minimised to adhere to the appropriate USP (or equivalent) regulations and standards. The IAEA recommends that 99Mo concentrations exceeding more than 0.15 μCi/mCi 99mTc or 0.015% should not be administered for usage in humans. Typically, quantification of 99Mo breakthrough is performed for every elution when using a 99Mo/99mTc generator during QA-QC testing of the final product. There are alternative routes for generating 99Mo that do not require a fissionable target, such as high or low enriched uranium (i.e., HEU or LEU). Some of these include accelerator-based methods, such as proton bombardment or photoneutron reactions on enriched 100Mo targets. Historically, 99Mo generated by neutron capture on natural isotopic molybdenum or enriched 98Mo targets was used for the development of commercial 99Mo/99mTc generators. The neutron-capture process was eventually superseded by fission-based 99Mo that could be generated with much higher specific activities.
=== Rehabilitation === Professor Cathy Schnieder of International Service at American University noted that in 1989, blacks, representing 12-15% of all drug use in the United States, made up 41% of all arrests. That was a noted increase from 38% in 1988. Whites were 47% of those in state-funded treatment centers but fewer than 10% of those committed to prison.
Drew was born in 1904 into an African-American middle-class family in Washington, D.C. His father, Richard, was a carpet layer, and his mother, Nora Burrell, trained as a teacher. Drew and three (two sisters, one brother) of his four younger siblings (three sisters and one brother) grew up in Washington's largely middle-class and interracial Foggy Bottom neighborhood. From a young age Drew began work as a paperboy in his neighborhood, daily helping deliver over a thousand newspapers to his neighbors. Drew attended Washington's Dunbar High School which was well-known for its equality and opportunities for all, despite the racial climate at the time. From 1920 until his marriage in 1939, Drew's permanent address was in Arlington County, Virginia, although he graduated from Washington's Dunbar High School in 1922 and resided elsewhere during that period of time.
Many essential biological processes involve redox reactions. Before some of these processes can begin, iron must be assimilated from the environment. Aerobic cellular respiration, for instance, is the oxidation of substrates (in this case, glucose [C6H12O6]) and the reduction of oxygen to water. The summary equation for aerobic respiration is:
==== Agriculture ==== On 3 October 2021, the 53rd anniversary of Juan Velasco's rise to power via a military coup d'état, Castillo announced the start of the Second Agrarian Reform with the aim of helping small farmers and ending abuse and inequality. This was a tacit acknowledgement of the original Agrarian Reform carried out by Velasco. Castillo stated that the Second Agrarian Reform will respect property rights and will not involve the expropriation of land. However, Castillo also stated "Let's end with the bosses and the landowners. They will no longer eat thanks to the sweat of the poor and of the peasants." Castillo signaled that he would adjust the price bands to protect domestic agriculture from subsidized foreign products. Price bands for agriculture were created in 2001 for select goods, such as "hard yellow corn, milled rice, white sugar, and whole milk powder." However, over the years the price bands became increasingly liberalized, and by 2015 the price bands became nonexistent in practice. Castillo also spoke about his plan to industrialize coca leaf production and build an airport in Pichari so that goods can go directly to the national market. In a speech before a crowd, then Prime Minister Guido Bellido threatened Congress to approve the agrarian reform. "If Congress does not approve it, let the congressmen go and let the people choose other congressmen." Afterward, the attendees shouted: "Close the Congress!" Peru's Congress has been accused of obstructionism by supporters of the Castillo Administration.
Sources: en.wikipedia.org
Unlike spectroscopic methods, X-ray crystallography always allows for unambiguous structure determination and provides precise bond angles and lengths totally unavailable through spectroscopy. It is often used in physical organic chemistry to provide an absolute molecular configuration and is an important tool in improving the synthesis of a pure enantiomeric substance. It is also the only way to identify the position and bonding of elements that lack an NMR active nucleus such as oxygen. Indeed, before x-ray structural determination methods were made available in the early 20th century all organic structures were entirely conjectural: tetrahedral carbon, for example, was only confirmed by the crystal structure of diamond, and the delocalized structure of benzene was confirmed by the crystal structure of hexamethylbenzene. While crystallography provides organic chemists with highly satisfying data, it is not an everyday technique in organic chemistry because a perfect single crystal of a target compound must be grown. Only complex molecules, for which NMR data cannot be unambiguously interpreted, require this technique. In the example below, the structure of the host–guest complex would have been quite difficult to solve without a single crystal structure: there are no protons on the fullerene, and with no covalent bonds between the two halves of the organic complex spectroscopy alone was unable to prove the hypothesized structure.
=== Food distribution in Latin America === Food distribution in Latin America is mainly dominated by large distributors and chains. Efforts have been made to compete with the industrialization of the food distribution system through the establishment of four types of organizations: consumer purchasing organizations, consumer cooperatives, voluntary chains, and retailer purchasing associations. Consumer purchasing organizations are groups of families who buy food together. The benefits of joining one of these organizations are the reduced cost and improved variety in diet that comes from purchasing food with other families. Consumer cooperatives differ from consumer purchasing organizations in that they are constituted by groups of individuals who work together to secure high quality food for low prices. The cooperatives are analogous to a food union that actively works to secure the rights of its consumers. Voluntary chains are organizations of privately owned retailers and food wholesalers who operate as one economic body. These groups form contracts to work under, but are economically independent of one another. Retailer purchasing organizations are groups of retailers who purchase products as though they were a single buyer. Members within these organizations are all involved in the purchasing of goods, but do not form contracts.
It propped up friendly puppet politicians and supported right-wing militias to maintain power. Workers often organized and went on strike against these conditions, forming local militias against the United Fruit Company. This would usually lead to conflict between the two sides, which culminated in a strike in November 1928 by farmers in Ciénaga for better working conditions. The striking workers called for an end to temporary contracts, the creation of mandatory worker insurance, the creation of compensation for work accidents, the creation of hygienic dormitories, a 6-day work week, the implementation of a minimum wage, the abolishment of wages through company coupons and office stores, and the recognition of farmers and tenants as employees with legal rights. The strike quickly grew, becoming the largest in Colombia's history, with many socialists, anarchists, Marxists, and leftists joining and organizing the strike. The United Fruit Company demanded that the workers and the union disband. Following several weeks of failed negotiations, the Colombian government of Miguel Abadía Méndez sent the Colombian Army to Ciénaga. After a standoff with the strikers, the Army shot into the crowd of strikers, killing between 68 and 2,000 people, in what became known as the Banana Massacre. This led to an outrage in the Colombian public, creating an explosion of leftist and revolutionary organizations. In Bogotá, leftist students protested and organized against the Colombian government, eventually hoping to overthrow it. This opposition exploded in 1948.
Bovista – various species, including: Bovista aestivalis Bovista dermoxantha Bovista nigrescens Bovista plumbea Calvatia – various species, including: Calvatia bovista Calvatia craniiformis Calvatia cyathiformis Calvatia gigantea Calvatia booniana Calvatia fumosa Calvatia lepidophora Calvatia pachyderma Calvatia sculpta Calvatia subcretacea – edible Calbovista subsculpta Handkea – various species, including: Handkea utriformis Lycoperdon – various species, including: Lycoperdon candidum Lycoperdon echinatum Lycoperdon fusillum Lycoperdon umbrinum Scleroderma – various species, including: Scleroderma auratium Scleroderma geaster – not edible
== History == In 1999 it became a wholly owned subsidiary of the publicly held Cracker Barrel. On December 6, 2006, Logan's Roadhouse was sold to affiliates of Bruckmann, Rosser, Sherrill & Co., Canyon Capital Advisors LLC, and Black Canyon Capital LLC for $486 million. In 2010, private equity firm Kelso & Company acquired the company. On February 20, 2013, Mike Andres, a former McDonald's vice-president and former chief executive officer of Boston Market, replaced Tom Vogel as chief executive officer. On January 12, 2017, Hazem Ouf, former chief executive officer of American Blue Ribbon Holdings, was named president and chief executive officer. On August 8, 2016, Logan's Roadhouse filed for bankruptcy and announced plans to close eighteen of its 256 locations that are under-performing. The chain was reported to be struggling with heavy debt and falling sales. Locations closing in late September 2016, include, in Florida, two each in Kissimmee and Orlando, and one each in Mary Esther, Tampa, and Tallahassee; one in each of those cities: Macon, Georgia; Houston, Texas; Lafayette, Louisiana and Waynesboro, Virginia. On December 1, 2016, Logan's Roadhouse formally exited bankruptcy with a debt load reduced from about $400 million to $100 million. On November 1, 2018, Logan's Roadhouse announced that it was acquired by CraftWorks Restaurants & Breweries. On March 3, 2020, Craftworks filed for Chapter 11 Bankruptcy protection. On March 19, 2020, all open Logan's locations were temporarily closed amid the COVID-19 pandemic.
Sources: en.wikipedia.org
When dried for eating, pine nuts are 2% water, 13% carbohydrates, 14% protein, and 68% fat (table). In a 100-gram (3+1⁄2-ounce) reference serving, dried pine nuts supply 2,815 kilojoules (673 kilocalories) of food energy and are a rich source (20% or more of the Daily Value, DV) of numerous dietary minerals, particularly manganese, copper, magnesium, and zinc, with substantial amounts of vitamin E, vitamin K, and the B vitamins, thiamin and niacin (table).
Maturity-onset diabetes of the young (MODY) is a rare autosomal dominant inherited form of diabetes, due to one of several single-gene mutations causing defects in insulin production. It is significantly less common than the three main types, constituting 1–2% of all cases. The name of this disease refers to early hypotheses as to its nature. Being due to a defective gene, this disease varies in age at presentation and in severity according to the specific gene defect; thus, there are at least 14 subtypes of MODY. People with MODY often can control it without using insulin.
== People == Maxim (given name) Maxim (surname) Maxim (musician) Maxim., taxonomic author abbreviation of Karl Maximovich (1827–1891), Russian botanist Maksim, Metropolitan of all Rus, Metropolitan of Kiev (1283–1305) Maksim, Bulgarian Patriarch (1914–2012), Patriarch of the Bulgarian Orthodox Church Maksim, Serbian Patriarch (d. 1680), Patriarch of the Serbian Orthodox Church (1655-1674) Maksim Branković (d. 1516), Serbian Orthodox Metropolitan of Belgrade and Syrmia
=== Recreational drug use === Subcutaneous injection may also be used by people to (self-) administer recreational drugs. This can be referred to as skin popping. In some cases, the administration of illicit drugs in this way is associated with unsafe practices leading to infections and other adverse effects. In rare cases, this results in serious side effects such as AA amyloidosis. Recreational drugs reported to be administered subcutaneously have included cocaine, mephedrone, and amphetamine derivatives such as PMMA.
== External links == Osteocalcin at the U.S. National Library of Medicine Medical Subject Headings (MeSH) Overview of all the structural information available in the PDB for UniProt: Q8HYY9 (Pig Osteocalcin) at the PDBe-KB.
Sources: en.wikipedia.org
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.
Neutral and slightly basic aqueous conditions promote aspartimide formation at the aspartate-glycine step, often followed by deamidation. Elevated temperature and repeated freeze-thaw cycles accelerate the loss. Acidic solutions and dry lyophilised powder are comparatively stable over short periods.
No monograph exists in the United States Pharmacopeia or the European Pharmacopoeia, and no widely distributed certified reference standard is available. Purity and identity therefore rest on supplier methods that are not harmonised. This absence is the main reason reported purities are difficult to compare between sources.
The peptide contains four residues in the order alanine, glutamate, aspartate and glycine, abbreviated AEDG. The chain is linear and held together by three peptide bonds. Its calculated mass for the uncharged free form is about 390.3 daltons.