This is a working overview of HPLC purity, written for readers who want more than a one-paragraph summary but less than a textbook.
Reviewed 2026-07-09. Anything still debated is marked as such rather than presented as settled.
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.
Epitalon is a synthetic tetrapeptide with the sequence alanine–glutamate–aspartate–glycine, commonly abbreviated AEDG. Its design traces to epithalamin, a peptide fraction prepared from bovine pineal gland extracts that researchers in Saint Petersburg began investigating in the 1970s. The compound has a molecular formula of C14H22N4O9 and a nominal molecular mass near 390 daltons. It holds no approved drug status in the United States or the European Union, and material sold under this name is generally offered as a research chemical rather than a finished pharmaceutical product.
Proposed mechanisms centre on cell-culture observations rather than a defined receptor interaction. Several reports describe increased expression of the telomerase catalytic subunit after exposure of cultured human cells, and the authors attributed the effect to short peptide fragments entering the nucleus and influencing gene transcription. No receptor for the tetrapeptide has been identified, and the free peptide is expected to be degraded rapidly by plasma peptidases. Whether any measurable fraction reaches intact tissues after administration remains an unresolved question rather than an established finding.
The published literature is dominated by a small number of research groups, much of it in Russian-language journals, and independent replication outside those groups is limited. Studies are typically small, use cultured cells or rodent models, and report endpoints that differ between papers, which makes comparison difficult. Large randomised human trials have not appeared in the indexed literature. Questions about absorption, distribution and clearance are therefore still treated as open in reviews that mention the compound.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C14H22N4O9 | Derived from the four-residue sequence |
| Molar mass | About 390.35 g/mol | Free peptide, counter-ion not included |
| Appearance | White to off-white powder | Lyophilised solid from aqueous solution |
| Water solubility | Freely soluble | Short, polar peptide chain |
| Common synonyms | AEDG; epithalone | Catalogues use the names interchangeably |
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.
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.
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.
The parent extract epithalamin was characterised as a low-molecular-weight fraction of pineal tissue rather than a single defined chemical entity. Researchers fractionated it and tested successive fragments for activity, a screening approach typical of peptide discovery work in that era. Epitalon emerged from that process as one of the shorter sequences of interest. Because the original extract was never fully resolved into individual components, claims about which constituent drives a given effect rest on inference. This distinction matters when reading older reports that attribute extract observations to the tetrapeptide itself.
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.
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.
A seroma is a pocket of clear serous fluid (filtered blood plasma). They may sometimes develop in the body after surgery, particularly after breast surgery, abdominal surgery, and reconstructive surgery. They can be diagnosed by physical signs, and with a CT scan. Seromas can be difficult to manage. Serous fluid may leak out naturally, and a persistent leak can cause problems. Fluid can be drained, including by inserting a drain surgically. Seromas can be prevented through careful surgery, and drains can be inserted before they form. Patient posturing and position can reduce risk, as well as breast binding after breast surgery.
=== Defining agrifood systems resilience === The resilience of agrifood systems builds on the concept of resilience, which originated in the study of ecosystems and evolved over 50 years into an object of study across an array of disciplines, including engineering, agriculture, economics and psychology. Although there is little agreement today as to a precise definition across disciplines, broadly speaking, resilience can be defined as the dynamic capacity to continue to achieve goals despite disturbances. In a call for cross-sectoral collaboration to prevent, anticipate, absorb, adapt and transform in the face of shocks and stresses across all sectors of society, the United Nations has developed and adopted the UN Common Guidance on Helping Build Resilient Societies. Since there is a wide variety of risks relating to understanding resilience, the UN offers the following definition: "the ability of individuals, households, communities, cities, institutions, systems and societies to prevent, anticipate, absorb, adapt, and transform positively, efficiently and effectively when faced with a wide range of risks, while maintaining an acceptable level of functioning and without compromising long-term prospects for sustainable development, peace and security, human rights and well-being for all." Resilience building is a system-wide multi-risk, multi-actor and multisectoral effort.
A fluorescence microscopy-based assay reveals that the relative number of SeV virions bound to the receptor can be defined as 0.5 for GM3, as 1 for GD1a, and as 2 for Gq1b. The structures of some of these receptors are available for visualization through SugarBindDB – a resource of glycan-mediated host–pathogen interactions. Others are available through KEGG Glycan Database, PubChem compound database, and TOXNET database (toxicology data network) of US National Library of Medicine.
Sources: en.wikipedia.org
All major powers engaged in espionage, using a great variety of spies, double agents, moles, and new technologies such as the tapping of telephone cables. The Soviet KGB ("Committee for State Security"), the bureau responsible for foreign espionage and internal surveillance, was famous for its effectiveness. The most famous Soviet operation involved its atomic spies that delivered crucial information from the United States' Manhattan Project, leading the USSR to detonate its first nuclear weapon in 1949, four years after the American detonation and much sooner than expected. A massive network of informants throughout the Soviet Union was used to monitor dissent from official Soviet politics and morals. Although to an extent disinformation had always existed, the term itself was invented, and the strategy formalized by a black propaganda department of the Soviet KGB. Based on the amount of top-secret Cold War archival information that has been released, historian Raymond L. Garthoff concludes there probably was parity in the quantity and quality of secret information obtained by each side. However, the Soviets probably had an advantage in terms of HUMINT (human intelligence or interpersonal espionage) and "sometimes in its reach into high policy circles." In terms of decisive impact, however, he concludes:
== Public reception == The discovery of Lindow Man in 1984 at Lindow Moss in Cheshire, England, received worldwide news coverage. Newspapers adopted the nickname "Pete Marsh", while scientists investigating his remains called him Lindow Man. In April 1985, a documentary about the investigation in the BBC television series Q.E.D. was watched by more than 10 million people. His first temporary exhibition at Manchester Museum in 1987 attracted up to 2,000 visitors a day. During the exhibition, local resident Barbara O'Brien led a campaign for his remains to stay permanently in North West England. The campaign gained support from local members of Parliament and attracted coverage in local and national newspapers. In November 1987, pupils at Lindow Primary School recorded O'Brien's song, "Lindow Man We Want You Back Again". The campaign was unsuccessful, and the British Museum retained the remains. The Manchester Museum exhibition of 2008–2009 presented different perspectives on Lindow Man through personal accounts from people involved in his discovery and study, museum curators, a local resident and a pagan contributor. According to museum curator Bryan Sitch, public responses were mixed but broadly favourable. Some visitors questioned the inclusion of a pagan viewpoint alongside scientific interpretations, while others criticised the design or wanted more factual information. Visitors left thousands of comment cards and personal offerings, which the museum collected for further study. The exhibition also contributed to debate about whether human remains should be displayed.
=== Mass spectrometry === Quantitative mass spectrometry (MS) (or quantitative proteomics) can be used to discover RNA-binding proteins (RBPs) bound to RNA. Labeling MS methods involve the differential use of stable isotope labels or chemical tagging of proteins in samples and controls. This is used to obtain enrichment scores and true binding partners through the ratio of labeled peptides. Label-free MS methods are able to identify proteins in samples and controls. In order to distinguish true binding partners for nonspecific proteins, analytical tools used alongside spectral count data from non-quantitative MS are used to score the probability of a true RBP-RNA interaction
Sources: en.wikipedia.org
Governor King had been requesting a replacement, for at least a year. In 1805, Governor William Bligh was appointed. Although the economy had developed and diversified somewhat by 1806, Bligh arrived determined to bring the Corps, and especially John Macarthur, to heel, and stop their trading in rum. This led to the Rum Rebellion, the deposing of Bligh, and the eventual recall of the New South Wales Corps. In 1808, the New South Wales Corps was renamed the 102d Regiment of Foot. Having arrived in the colony in December 1809 with the 73rd Regiment of Foot, which was to take over from the 102d Regiment of Foot, Governor Lachlan Macquarie was able to control the rum trade more effectively, introducing and enforcing a licensing system. Due to the lack of currency, he was still forced to pay for public works in rum. The construction of Sydney Hospital was entirely funded by granting a monopoly on the import of rum to the contractors, who were the merchants Alexander Riley and Garnham Blaxcell. The colonial surgeon D'Arcy Wentworth, and troops were used to prohibit the landing of rum anywhere but at the hospital dock. A few of the officers and long-serving privates in the 102d Regiment were transferred to Macquarie's 73rd regiment, bringing it up to near full strength. About 100 veterans and invalids were retained for garrison duty in New South Wales.
== Research == In 2018, the World Health Organization listed snakebite envenoming as a neglected tropical disease. In 2019, they launched a strategy to prevent and control snakebite envenoming, which involved a program targeting affected communities and their health systems. A policy analysis however found that the placement of snakebite in the global health agenda of WHO is fragile due to reluctance to accept the disease in the neglected tropical disease community and the perceived colonial nature of the network driving the agenda. Key institutions conducting snakebite research on snakebite are the George Institute for Global Health, the Liverpool School of Tropical Medicine, and the Indian Institute of Science.
=== April === 1 April The cost of an average annual energy bill falls by £238 to £1,690 under the latest Ofgem price cap, its lowest for two years. The cost of a TV licence increases by £10.50 from £159 to £169.50. The National Living Wage rises from £10.42 to £11.44 per hour, and is extended to workers over 21. 2 April Royal Mail stamp increases – 1st class standard stamp goes up by 10p to £1.35 and 2nd class standard increases by 10p to 85p. Other postage has increased too. Three Britons, named as John Chapman, James Henderson and James Kirby, are identified as being among seven people working for the food charity World Central Kitchen, who were killed during air strikes in Gaza the previous day. Data compiled by the British Retail Consortium indicates falling prices of sugar, jam and chocolate helped to reduce food inflation to its lowest level for two years in March. 3 April – The Liberal Democrats, Scottish National Party and former UK national security adviser Lord Ricketts call for an immediate suspension of the sale of arms to Israel following the World Central Kitchen air strikes. 4 April Three former Supreme Court justices and more than 600 legal experts call for the UK government to end weapons sales to Israel, saying the UK risks breaking international law over a "plausible risk of genocide" in Gaza. Foreign Secretary David Cameron rules out sending western troops to Ukraine since it would provide Russia with a "target".
=== Medication === Management often includes the use of beta blockers such as propranolol or if not tolerated calcium channel blockers, ACE inhibitors, and/or angiotensin receptor blockers (ARBs). Beta blockers are used to reduce the stress exerted on the aorta and to decrease aortic dilation.
Sources: en.wikipedia.org
It is a synthetic tetrapeptide built from alanine, glutamate, aspartate and glycine. The four residues are joined by standard peptide bonds, giving a linear chain rather than a branched structure.
The name derives from epithalamin, a pineal gland extract studied in the former Soviet Union. Researchers proposed that short fragments of that extract carried the biological activity of interest.
No major regulatory agency has approved it as a medicine. It is handled as a research chemical, and products sold under this name are not standardised drugs with defined clinical labelling.
No. Epithalamin is a heterogeneous peptide fraction obtained from pineal gland extract and contains many components. Epitalon is a single synthetic tetrapeptide with the sequence Ala-Glu-Asp-Gly. Researchers synthesised the shorter peptide while attempting to identify active sequences within the extract.