This is a working overview of AEDG, written for readers who want more than a one-paragraph summary but less than a textbook.
This page was last updated on 2026-02-02 and is reviewed periodically as new material appears.
Verification of a sample usually begins with reversed-phase high-performance liquid chromatography, which resolves the peptide from truncated sequences and other impurities and expresses purity as a percentage of total peak area. Mass spectrometry by electrospray ionisation or matrix-assisted laser desorption supplies an independent check, because the measured mass can be compared against the theoretical value for AEDG. Amino acid analysis or tandem mass spectrometry sequencing can confirm residue order. Each of these methods answers a different question: a purity figure does not establish identity, and an identity match does not establish how much of the material is intact peptide.
The molecule is a short, linear, hydrophilic peptide that dissolves readily in water or aqueous buffer. Its principal chemical liabilities are hydrolytic rather than oxidative, since it contains no cysteine, methionine, or tryptophan residues. The aspartate–glycine step is a recognised site for aspartimide formation under mildly acidic or basic conditions, generating isoaspartate and succinimide-related products over time. Desiccated lyophilised powder held at −20 °C is comparatively stable, whereas dilute solutions degrade faster and are best frozen as single-use aliquots rather than thawed repeatedly.
No pharmacopoeial monograph exists for this peptide, so quality rests on the supplier's internal specifications and on whatever independent testing a purchaser arranges. Certificates of analysis differ widely in which tests they report and in the limits applied. The counter-ion introduced during purification, commonly acetate or trifluoroacetate, changes the net peptide content of a given mass of powder, so two samples of equal weight may not contain equal amounts of the active sequence. Third-party laboratories can verify purity, identity, residual solvents, and counter-ion content for a fee, which makes documentation more informative than labelling.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Identity confirmation | Electrospray or MALDI mass spectrometry | Observed mass compared with theoretical 390.35 Da |
| Purity specification | 95 percent or greater by RP-HPLC | Common convention for research-grade peptide |
| Counter-ion | Acetate or trifluoroacetate | Affects net peptide content of a weighed sample |
| Solution storage | −80 °C as single-use aliquots | Repeated freeze–thaw cycles accelerate loss |
| Main degradation route | Aspartimide formation at Asp-Gly | Produces isoaspartate and related species |
Lyophilised epitalon is generally held at minus twenty degrees Celsius in a sealed container kept dry and dark. Cooler conditions are sometimes recommended for long-term archives. The solid takes up moisture readily enough that repeated opening of a vial introduces water, so dividing a batch into smaller portions before storage lowers degradation risk. Aqueous solutions are less durable than the dry powder and are usually prepared shortly before use, then kept cold and shielded from light to slow hydrolysis and oxidation.
Verification of research-grade material involves comparing a supplier chromatogram against an in-house reference, checking the observed mass against the calculated value, and where possible confirming residue order by tandem mass spectrometry or enzymatic peptide mapping. Purity claims should be read alongside the method used to obtain them, because detection wavelength and integration settings alter the result. Batch-specific data, rather than a generic grade statement, is the informative part of a certificate.
Interest in epitalon is usually discussed within the broader field of short peptide bioregulators, a category that includes other synthetic di-, tri-, and tetrapeptides studied by the same research group. These compounds share a common rationale: that small fragments of tissue-derived proteins can retain biological activity and can be produced reproducibly. The category as a whole remains outside mainstream pharmacological consensus, and epitalon specifically has a limited presence in independent, non-Russian research literature, which shapes how its evidence base is described.
Epitalon is a synthetic tetrapeptide with the amino acid sequence alanine-glutamate-aspartate-glycine, abbreviated Ala-Glu-Asp-Gly or AEDG. It was developed by the Russian researcher Vladimir Khavinson and colleagues during work on peptide bioregulators derived from the pineal gland. The compound is short enough to be produced by standard solid-phase peptide synthesis and is typically handled as a lyophilized white powder. Its small size distinguishes it from larger pineal peptides such as epithalamin, a complex extract from which the tetrapeptide was conceptually derived.
The four residues give epitalon a molecular formula of C14H22N4O9 and a molecular weight near 390.35 daltons. The presence of two acidic residues, glutamate and aspartate, makes the free peptide strongly acidic, while the alanine and glycine ends provide neutral, nonpolar character. This combination produces a molecule with substantial water solubility. Because there are no cysteine, methionine, or tryptophan residues, the peptide lacks the most common oxidation-sensitive side chains, which simplifies handling compared with many longer peptides.
A systematic review and meta-analysis has shown that cabergoline and quinagolide are more effective in the treatment of hyperprolactinemia compared to bromocriptine, this is because evidence had suggested fewer side effects, rapid titration and offers better dosing interval in medication like quinagolide compared to bromocriptine. Similar studies have been conducted regarding the safety and efficacy of dopamine agonists. According to SUCRA (Surface Under the Cumulative Ranking) and SMAA (Stochastic Multicriteria Acceptability Analysis), quinagolide was found to be the best treatment for women since it can help reduce menstrual irregularities, in addition bromocriptine was shown to be more effective in the treatment for galactorrhea (breast milk production unrelated to pregnancy), and cabergoline was the safest medication as it did not show any alarming side effects. Other dopamine agonists that have been used less commonly to suppress prolactin include dihydroergocryptine, ergoloid, lisuride, metergoline, pergolide, and terguride. If the prolactinoma does not initially respond to dopamine agonist therapy, such that prolactin levels are still high or the tumor is not shrinking as expected, the dose of the dopamine agonist can be increased in a stepwise fashion to the maximum tolerated dose. Another option is to consider switching between dopamine agonists. The prolactinoma can be resistant to bromocriptine but respond well to cabergoline or other dopamine agonists, and vice versa.
=== Class I: Cys-based PTPs === Class I PTPs constitute the largest family. They contain the well-known classical receptor (a) and non-receptor PTPs (b), which are strictly tyrosine-specific, and the DSPs (c) which target Ser/Thr as well as Tyr and are the most diverse in terms of substrate specificity.
When naming a complex ion, the ligands are named before the metal ion. The ligands' names are given in alphabetical order. Numerical prefixes do not affect the order. Multiple occurring monodentate ligands receive a prefix according to the number of occurrences: di-, tri-, tetra-, penta-, or hexa-. Multiple occurring polydentate ligands (e.g., ethylenediamine, oxalate) receive bis-, tris-, tetrakis-, etc. Anions end in o. This replaces the final 'e' when the anion ends with '-ide', '-ate' or '-ite', e.g. chloride becomes chlorido and sulfate becomes sulfato. Formerly, '-ide' was changed to '-o' (e.g. chloro and cyano), but this rule has been modified in the 2005 IUPAC recommendations and the correct forms for these ligands are now chlorido and cyanido. Neutral ligands are given their usual name, with some exceptions: NH3 becomes ammine; H2O becomes aqua or aquo; CO becomes carbonyl; NO becomes nitrosyl. Write the name of the central atom/ion. If the complex is an anion, the central atom's name will end in -ate, and its Latin name will be used if available (except for mercury). The oxidation state of the central atom is to be specified (when it is one of several possible, or zero), and should be written as a Roman numeral (or 0) enclosed in parentheses. Name of the cation should be preceded by the name of anion. (if applicable, as in last example) Examples:
Sources: en.wikipedia.org
Acute lymphoblastic leukemia (ALL) cells are CD10+. Follicular lymphoma (follicle centre cell lymphoma) are CD10+. Burkitt Lymphoma cells are CD10+. CD10+ diffuse large B cell lymphoma (CD10+ DLBCL) Marker for germinal center phenotype (CD10, HGAL, BCL6, CD38) are considered a favorable prognostic factor, but CD10+, BCL2+ tumors could have poorer survival. For some authors, CD10 expression in DLBCL does not influence survival. Angioimmunoblastic T cell lymphoma (AITL) are CD10+ and distinguishes AITL from other T cell lymphomas (CD10−) Some benign T cells can be CD10+
1. Fußballclub Lokomotive Leipzig e.V. is a German football club based in Probstheida in the Südost borough of Leipzig, Saxony. The club was previously known as VfB Leipzig and was the first national champion of Germany. It has also been known as SC Leipzig. The club won four titles in the FDGB-Pokal and the 1965–66 Intertoto Cup during the East German era. It also finished runner-up in the 1986–87 European Cup Winners' Cup. 1. FC Lokomotive Leipzig was renamed VfB Leipzig after German re-unification and managed to qualify for the Bundesliga in 1993. However, like many clubs of the former DDR-Oberliga, VfB Leipzig faced financial difficulties in reunified Germany and a steady decline soon followed. 1. FC Lokomotive Leipzig was relaunched in 2003 and began climbing through the divisions. As of 2021, the team competes in the fourth-tier division, Regionalliga Nordost. The 1. in front of the club's name indicates that it was the first to be founded in the city.
It is a member of the family of heme-containing peroxidases. Heme peroxidases catalyse the hydrogen peroxide-dependent oxidation of a wide range of different, usually organic, substrates in biology. This enzyme belongs to the family of oxidoreductases, specifically those acting on a peroxide as acceptor (peroxidases). The systematic name of this enzyme class is L-ascorbate:hydrogen-peroxide oxidoreductase. Other names in common use include L-ascorbic acid peroxidase, L-ascorbic acid-specific peroxidase, ascorbate peroxidase, and ascorbic acid peroxidase. This enzyme participates in the ascorbate and aldarate metabolism. APXs are important in cellular antioxidant networks in photosynthetic organisms; they are the primary component of the ascorbate-glutathione cycle and are important for peroxide scavenging and redox signaling.
The 1970s saw a shift in audience tastes to high concept films, with five such films made by either George Lucas or Steven Spielberg topping the chart during the 1980s. The 21st century has seen an increasing dependence on franchises and adaptations, with the box-office dominance of films based on pre-existing intellectual property at record levels. Steven Spielberg (1975, 1981, 1982, 1989 and 1993) and Cecil B. DeMille (1932, 1947, 1949, 1952 and 1956) tie as the most represented directors on the chart with five films apiece occupying the annual top spot. William Wyler (1942, 1946, 1959 and 1968) and James Cameron (1991, 1997, 2009 and 2022) are each represented by four films, whilst D. W. Griffith (1915, 1916 and 1920), George Roy Hill (1966, 1969 and 1973) and the Russo brothers (2016, 2018 and 2019) all feature heavily with three films apiece. George Lucas directed three chart-toppers in 1977, 1999 and 2005, but also served in a strong creative capacity as a producer and writer in 1980, 1981, 1983, and 1989 as well. The following directors have also all directed two films on the chart: Frank Lloyd, King Vidor, Frank Capra, Michael Curtiz, Leo McCarey, Alfred Hitchcock, David Lean, Stanley Kubrick, Guy Hamilton, Mike Nichols, William Friedkin, Peter Jackson, Gore Verbinski, and Michael Bay; Mervyn LeRoy, Ken Annakin and Robert Wise are each represented by one solo credit and one shared credit, and John Ford co-directed two films.
Sources: en.wikipedia.org
Mass spectrometry provides the identity check, because the observed mass is compared with the theoretical mass of the AEDG sequence. Chromatography separates and quantifies impurities but does not by itself prove which peptide is present. The two techniques are normally used together.
Yes. Trifluoroacetate and acetate ions remain associated with the peptide after purification, so a weighed quantity of powder contains less peptide than the nominal mass suggests. Certificates that report net peptide content rather than raw weight are more directly comparable between suppliers.
Dilute aqueous solutions are less stable than the dry powder and are usually aliquoted and frozen to avoid repeated freeze–thaw cycles. Lyophilised material is best stored desiccated at −20 °C, protected from light. Working solutions are typically prepared fresh from a frozen aliquot.
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.