If you have been reading about epitalon and want a single page that covers the useful parts, this is it: definitions, context, how it is studied, and the questions that come up repeatedly.
Last reviewed on 2026-07-08. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C14H22N4O9 | Derived from the four constituent residues |
| Molecular mass | About 390.35 Da | Monoisotopic value, confirmed by mass spectrometry |
| Residue sequence | Ala-Glu-Asp-Gly | Read from the N-terminus to the C-terminus |
| Common synonyms | Epithalon; AEDG | Both forms appear in reference catalogues |
| Net charge near neutral pH | Negative | Two acidic side chains give a low isoelectric point |
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.
=== Reversed-phase chromatography === A popular stationary phase is an octadecyl carbon chain (C18)-bonded silica (USP classification L1). Such materials are produced by reaction of silica gel with trimethoxyoctadecylsilane. The individual links involve silanol groups displacing the methoxy groups, forming an Si-O-Si bonds. This reaction changes the hydrophilic silanol groups into hydrophobic coatings. Other silanizing groups install C8-bonded silica (L7), pure silica (L3), cyano-bonded silica (L10) and phenyl-bonded silica (L11). Note that C18, C8 and phenyl are dedicated reversed-phase resins, while cyano columns can be used in a reversed-phase mode depending on analyte and mobile phase conditions.
Unlike global alignment approaches, local structural alignment approaches are suited to detection of locally conserved patterns of functional groups, which often appear in binding sites and have significant involvement in ligand binding. As an example, comparing G-Losa, a local structure alignment tool, with TM-align, a global structure alignment based method. While G-Losa predicts drug-like ligands' positions in single-chain protein targets more precisely than TM-align, the overall success rate of TM-align is better. However, as algorithmic improvements and computer performance have erased purely technical deficiencies in older approaches, it has become clear that there is no one universal criterion for the 'optimal' structural alignment. TM-align, for instance, is particularly robust in quantifying comparisons between sets of proteins with great disparities in sequence lengths, but it only indirectly captures hydrogen bonding or secondary structure order conservation which might be better metrics for alignment of evolutionarily related proteins. Thus recent developments have focused on optimizing particular attributes such as speed, quantification of scores, correlation to alternative gold standards, or tolerance of imperfection in structural data or ab initio structural models. An alternative methodology that is gaining popularity is to use the consensus of various methods to ascertain proteins structural similarities.
=== Criminal forensics === GC–MS can analyze the particles from a human body in order to help link a criminal to a crime. The analysis of fire debris using GC–MS is well established, and there is even an established American Society for Testing and Materials (ASTM) standard for fire debris analysis. GCMS/MS is especially useful here as samples often contain very complex matrices, and results used in court need to be highly accurate.
==== Pat Farrell's Alpha-Angle Freeze Mark ==== A specialized brand system is required to mark many animals such that each can be individually identified. Arabic numerals are difficult to brand much smaller than 4 inches (10 cm) tall. Further, conventional numbers can be altered, with a branded "3" easily turned into an "8," potentially shifting apparent ownership of the horse. It is also inconvenient to carry a dozen or more unique brands into the field if animals must be branded there.
== Summary table for each class of nuclides == This is a summary table for the 987 nuclides with half-lives longer than one hour, given in List of nuclides. Note that that number, while exact to present knowledge, will likely change slightly in the future, as some "stable" nuclides are observed to be radioactive with very long half-lives, and some half-lives or known radioactive ones are revised.
Sources: en.wikipedia.org
Found under the patio at Cromwell Street was the body of the Wests' daughter, Heather, who had been murdered in June 1987 after being abused by her parents all her life. It is said that Heather had begun to tell her friends about her abuse. Barry, her younger brother, would later describe watching, as a seven-year-old, his mother kick Heather repeatedly about the head until she was no longer moving. The Wests had told friends and concerned parties that Heather left home to work at a Devonshire holiday village and on one occasion fabricated a phone call, supposedly from Heather, to allay her siblings' suspicions about her disappearance. Fred would even taunt his children when they misbehaved by jokingly stating, "If you don't behave, you'll end up under the patio like Heather." This was the last known murder that the pair committed. While on remand at HM Prison Birmingham, Fred died by suicide by hanging on 1 January 1995.
=== Retinol esters have been used as markers === Retinyl esters can be distinguished from retinol in serum and other tissues and quantified with the use of methods such as high-performance liquid chromatography. Elevated amounts of retinyl ester (i.e., >10% of total circulating vitamin A) in the fasting state have been used as markers for chronic hypervitaminosis A in humans and monkeys. This increased retinyl ester may be due to decreased hepatic uptake of vitamin A and the leaking of esters into the bloodstream from saturated hepatic stellate cells.
autosome Any chromosome that is not an allosome and hence is not involved in the determination of the sex of an organism. Unlike the sex chromosomes, the autosomes in a diploid cell exist in pairs, with the members of each pair having the same structure, morphology, and genetic loci.
In the United States, the New Deal liberalism of President Franklin D. Roosevelt won mass support leaving socialists unable to gain significant ground. Norman Thomas of the Socialist Party of America (SPA) attracted nearly 188,000 votes in his 1936 run for president, but performed poorly in historic strongholds of the party and the Socialist Party of America's membership had begun to decline. Meanwhile, the Trotskyist movement, followed a policy known as the French Turn, a strategy of entryism in democratic socialist parties such as the SPA, SFIO and ILP, pulling these to the left in some places. However, fascism was also advancing. In Germany, it was the fascists of Adolf Hitler's Nazi Party who successfully exploited the Depression to win power, in January 1933. Hitler's regime swiftly destroyed both the German Communist Party and the Social Democratic Party, the worst blow the world socialist movement had ever suffered. This forced Stalin to reassess his strategy, and after its 7th World Congress in 1935 the Comintern began urging a popular front against fascism. The socialist parties were at first suspicious, given the bitter hostility of the 1920s, but eventually effective Popular Fronts were formed in both France and Spain. In Italy, the Italian Socialist Party (PSI) established an alliance with the Communists and it gradually cooperated with conservative reformists, revolutionaries, and syndicalists. In France, the Popular Front, headed by the SFIO's Léon Blum, won the 3 May 1936 election, leading to a government composed of Radical and Socialist ministers.
Sources: en.wikipedia.org
It is a four-amino-acid peptide built from alanine, glutamate, aspartate and glycine in that order. Its formula is C14H22N4O9, and it is made by chemical synthesis rather than extracted from tissue. The synthetic peptide is a single defined molecule, unlike the pineal extracts it is often compared with.
No. The two spellings refer to the same tetrapeptide, and the difference reflects transliteration from Russian. Laboratories and catalogues use both forms interchangeably. The material is also indexed as AEDG, taken from the one-letter codes of its residues.
Epithalamin is a mixed preparation derived from animal pineal tissue and contains many peptides. Epitalon is one synthetic sequence chosen for study from that broader mixture. Statements about one do not transfer directly to the other.
Identity is normally confirmed by mass spectrometry, which checks the measured mass against the expected value near 390 daltons. Reverse-phase high-performance liquid chromatography is used alongside it to assess purity. Amino acid analysis can provide additional composition data.