A practical reference on Epitalon: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
This page was last updated on 2026-08-01 and is reviewed periodically as new material appears.
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.
Published studies on epitalon are dominated by a small number of research groups, and independent replication in other laboratories remains limited. Proposed mechanisms include activation of telomerase and modulation of melatonin rhythms, but the evidence for either rests mainly on cell cultures and animal models. Whether the peptide produces comparable effects in humans is an open question, and the absence of large controlled trials means the literature is best read as exploratory rather than 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.
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.
| 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 tetrapeptide with the sequence alanine-glutamate-aspartate-glycine, commonly abbreviated AEDG. It was designed at the St. Petersburg Institute of Bioregulation and Gerontology as a short, chemically defined analogue of epithalamin, a fraction obtained from bovine pineal tissue. Small peptide bioregulators of this type formed a long-running line of work there from the 1980s onward. Because the molecule is produced by solid-phase synthesis rather than extraction, its composition is exact and its purity can be measured directly.
The most frequently cited proposed action is induction of telomerase, the enzyme that adds repeat sequences to chromosome ends. Cell-culture work from the originating group reported higher telomerase reverse transcriptase expression and measurable telomere elongation in human somatic cells after exposure. How a four-residue peptide would reach nuclear gene regulation is not established, and no cell-surface receptor or uptake route has been identified. Additional reports describe changes in melatonin secretion, antioxidant enzyme activity and lipid peroxidation in aged animals, but these findings remain mechanistically unconnected to the telomerase observation.
Published evidence comes mainly from Russian-language journals and from a single research group, with small sample sizes and limited independent replication. A few laboratories outside that group have examined related peptides and reported weaker or absent telomerase effects, so the central claim is best described as contested rather than settled. Rodent studies report modest changes in some ageing markers and in survival, but designs vary and control conditions are often sparse. No large randomised trial in humans has been published, and long-term safety data in healthy populations are correspondingly thin.
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.
Identity and purity of epitalon samples are normally established by reversed-phase high-performance liquid chromatography with ultraviolet detection near 214 nanometres, combined with mass spectrometry. The mass spectrum confirms the expected molecular ion and can reveal truncated or oxidised by-products. Amino acid analysis after acid hydrolysis verifies that the four residues are present in the expected ratio. Certificates typically report a purity figure taken from chromatographic peak area, expressed as a percentage of total integrated signal.
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.
=== Chemical constituents === About 140 chemical compounds are in the subterranean portions of R. rosea. Rhodiola roots contain phenols, rosavin, rosin, rosarin, organic acids, terpenoids, phenolic acids and their derivatives, flavonoids, anthraquinones, alkaloids, tyrosol, and salidroside. The chemical composition of the essential oil from R. rosea root growing in different countries varies. For example, rosavin, rosarin, and rosin at their highest concentration according to many tests can be found only in R. rosea of Russian origin; the main components of the essential oil from Rhodiola growing in Bulgaria are geraniol and myrtenol; in China the main components are geraniol and 1-octanol; and in India the main component is phenethyl alcohol. Cinnamyl alcohol was discovered only in the sample from Bulgaria. Rosavin, rosarin, rosin, and salidroside (and sometimes p-tyrosol, rhodioniside, rhodiolin, and rosiridin) are mostly polyphenols, and have no evidence of a physiological effect in humans. Although these phytochemicals are typically mentioned as specific to Rhodiola rosea extracts, rosea and other Rhodiola species contain many other constituent polyphenols, including proanthocyanidins, quercetin, gallic acid, chlorogenic acid, and kaempferol.
=== Glycogenesis === Glycogenesis refers to the process of synthesizing glycogen. In humans, glucose can be converted to glycogen via this process. Glycogen is a highly branched structure, consisting of the core protein Glycogenin, surrounded by branches of glucose units, linked together. The branching of glycogen increases its solubility, and allows for a higher number of glucose molecules to be accessible for breakdown at the same time. Glycogenesis occurs primarily in the liver, skeletal muscles, and kidney. The Glycogenesis pathway consumes energy, like most synthetic pathways, because an ATP and a UTP are consumed for each molecule of glucose introduced.
The protein kinase domain is a structurally conserved protein domain containing the catalytic function of protein kinases. Protein kinases are a group of enzymes that move a phosphate group onto proteins, in a process called phosphorylation. This functions as an on/off switch for many cellular processes, including metabolism, transcription, cell cycle progression, cytoskeletal rearrangement and cell movement, apoptosis, and differentiation. They also function in embryonic development, physiological responses, and in the nervous and immune system. Abnormal phosphorylation causes many human diseases, including cancer, and drugs that affect phosphorylation can treat those diseases. Protein kinases possess a catalytic subunit which transfers the gamma phosphate from nucleoside triphosphates (almost always ATP) to the side chain of an amino acid in a protein, resulting in a conformational and/or dynamic changes affecting protein function. These enzymes fall into two broad classes, characterised with respect to substrate specificity: serine/threonine specific and tyrosine specific.
Sources: en.wikipedia.org
The bioavailability of spironolactone when taken by mouth is 60 to 90%. The bioavailability of spironolactone and its metabolites increases significantly (+22–95% increases in levels) when spironolactone is taken with food, although it is uncertain whether this further increases the therapeutic effects of the medication. The increase in bioavailability is thought to be due to promotion of the gastric dissolution and absorption of spironolactone, as well as due to a decrease of the first-pass metabolism. The relationship between a single dose of spironolactone and plasma levels of canrenone, a major active metabolite of spironolactone, has been found to be linear across a dose range of 25 to 200 mg spironolactone. Steady-state concentrations of spironolactone are achieved within 8 to 10 days of treatment initiation. Little or no systemic absorption has been observed with topical spironolactone.
=== Score of the BLOSUM matrices === A scoring matrix or a table of values is required for evaluating the significance of a sequence alignment, such as describing the probability of a biologically meaningful amino-acid or nucleotide residue-pair occurring in an alignment. Typically, when two nucleotide sequences are being compared, all that is being scored is whether or not two bases are the same at one position. All matches and mismatches are respectively given the same score (typically +1 or +5 for matches, and -1 or -4 for mismatches). But it is different for proteins. Substitution matrices for amino acids are more complicated and implicitly take into account everything that might affect the frequency with which any amino acid is substituted for another. The objective is to provide a relatively heavy penalty for aligning two residues together if they have a low probability of being homologous (correctly aligned by evolutionary descent). Two major forces drive the amino-acid substitution rates away from uniformity: substitutions occur with the different frequencies, and lessen functionally tolerated than others. Thus, substitutions are selected against. Commonly used substitution matrices include the blocks substitution (BLOSUM) and point accepted mutation (PAM) matrices. Both are based on taking sets of high-confidence alignments of many homologous proteins and assessing the frequencies of all substitutions, but they are computed using different methods.
"[...] we commend the Anti-Eugenics Project for their essential work to understand[...] the harmful legacies of eugenicist ideologies. [...] examine the role that philanthropies played in developing and perpetuating eugenics policies and practices. The Rockefeller Foundation is currently reckoning with our own history in relation to eugenics. This requires uncovering the facts and confronting uncomfortable truths, [...] The Rockefeller Foundation is putting equity and inclusion at the center of all our work: [...] confronting the hateful legacies of the past [...] we understand that the work we engage in today does not absolve us of yesterday's mistakes. [...]"
Sources: en.wikipedia.org
Bektashis believe in God and follow all Islamic prophets. Bektashis claim the heritage of Haji Bektash Veli, who was a descendant of Ali, Husayn ibn Ali, Ali al-Sajjad and other Imams. In contrast to many Twelver Shia, Bektashis respect all companions of Muhammad, including Abu Bakr, Umar, Uthman, Talha, Mu'awiya, and Ali who is considered the greatest of them. Bektashis follow the teachings of Haji Bektash, who preached about the Twelve Imams. Bektashis differ from other Muslims by also following the Fourteen Innocents, who either died in infancy or were martyred with Husayn. Abbas ibn Ali is also an important figure in Bektashism, and Bektashis visit Mount Tomorr to honor him in an annual pilgrimage to the Abbas Ali Türbe on August 20–25. In addition to the Muslim five daily prayers, Bektashis have two specific prayers, one at dawn and another at dusk for the welfare of all humanity. Bektashism places much emphasis on the concept of Wahdat al-Wujud (Arabic: وحدة الوجود, romanized: Unity of Being) that was formulated by Ibn Arabi. Malakat is an important Bektashi text, perhaps written by Haji Bektash. Some scholars question whether the Malakat was actually authored by Haji Bektash. Resultingly, those scholars question whether the presentation of Haji Bektash and Bektashism as orthoprax in Islam (practicing orthodox Islam). There remains dispute as to whether Bektashis have historically followed the shariah law of Islam.
== Career and research == In 1997, Sereti came to the National Institute of Allergy and Infectious Diseases as a clinical associate in the laboratory of immunoregulation. She became a staff clinician in 2003. Sereti was appointed to a clinical tenure-track position in 2009 and received tenure in 2015. She is chief of the HIV pathogenesis section. Sereti researches the pathogenesis of HIV infection emphasizing mechanisms of immune reconstitution inflammatory syndrome in advanced HIV infection and of serious non-AIDS events in treated HIV-infected patients. She also investigates the pathogenesis of idiopathic CD4 lymphocytopenia (ICL) and immune-based therapeutic strategies of HIV infection and ICL.
=== With phosphorus species === Thionyl chloride converts phosphonic acids and phosphonates into phosphoryl chlorides. It is for this type of reaction that thionyl chloride is listed as a Schedule 3 compound, as it can be used in the "di-di" method of producing G-series nerve agents. For example, thionyl chloride converts dimethyl methylphosphonate into methylphosphonic acid dichloride, which can be used in the production of sarin and soman.
=== Proximity and orientation === Enzyme-substrate interactions align the reactive chemical groups and hold them close together in an optimal geometry, which increases the rate of the reaction. This reduces the entropy of the reactants and thus makes addition or transfer reactions less unfavorable, since a reduction in the overall entropy when two reactants become a single product. However this is a general effect and is seen in non-addition or transfer reactions where it occurs due to an increase in the "effective concentration" of the reagents. This is understood when considering how increases in concentration leads to increases in reaction rate: essentially when the reactants are more concentrated, they collide more often and so react more often. In enzyme catalysis, the binding of the reagents to the enzyme restricts the conformational space of the reactants, holding them in the 'proper orientation' and close to each other, so that they collide more frequently, of an with the correct geometry, to facilitate the desired reaction. The "effective concentration" is the concentration the reactant would have to be, free in solution, to experiences the same collisional frequency. Often such theoretical effective concentrations are unphysical and impossible to realize in reality – which is a testament to the great catalytic power of many enzymes, with massive rate increases over the uncatalyzed state.
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.
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.