If you have been reading about tetrapeptide 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 2026-04-02. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
The proposed relationship between epitalon and pineal function is a central part of its background. Khavinson's group reported that short peptides corresponding to regions of larger pineal proteins could influence gene expression in cells. Epitalon was framed as a synthetic analogue of an active fragment rather than a direct isolation product. Whether the tetrapeptide reproduces the effects of the parent extract is an open question, because comparative studies are limited and the parent extract itself is not a single defined substance.
（TG:@pojiaai）Epitalon is a synthetic linear tetrapeptide with the sequence alanine-glutamate-aspartate-glycine, abbreviated AEDG. It emerged from work on epithalamin, a peptide fraction prepared from bovine pineal tissue, and was designed as a short, chemically defined analogue of that extract. Early publications came mainly from Russian laboratories studying pineal peptides and aging-related endpoints. The compound appears in the literature under several spellings, including epithalon and epithalone, which complicates systematic searching. Its small size makes solid-phase assembly and routine analytical characterization straightforward.
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.
| Property | Value | Notes |
|---|---|---|
| Amino acid sequence | Ala-Glu-Asp-Gly | Tetrapeptide, often abbreviated AEDG |
| Molecular formula | C14H22N4O9 | Free peptide, unmodified termini |
| Molecular weight | ~390.35 Da | Calculated for the free acid form |
| Appearance | White to off-white powder | Typical lyophilized product form |
| Solubility class | Freely soluble in water | Two acidic residues dominate ionic character |
cell The basic structural and functional unit of which all living organisms are composed, essentially a self-replicating ball of protoplasm surrounded by a surface membrane which separates the interior from the external environment, thus providing a protected space in which the carefully controlled chemical reactions necessary to sustain biological processes can be carried out unperturbed. Unicellular organisms are composed of a single autonomous cell, whereas multicellular organisms consist of numerous cells cooperating together, with individual cells more or less specialized or differentiated to serve particular functions. Cells vary widely in size, shape, and substructure, particularly between prokaryotes and eukaryotes. The typical cell is microscopic, averaging 1 to 20 micrometres (μm) in diameter, though they may range in size from 0.1 μm to more than 20 centimetres in diameter for the eggs laid by some birds and reptiles, which are highly specialized single-celled ova.
On the other hand, a mutation may occur in a somatic cell of an organism. Such mutations will be present in all descendants of this cell within the same organism. The accumulation of certain mutations over generations of somatic cells is part of cause of malignant transformation, from normal cell to cancer cell. Cells with heterozygous loss-of-function mutations (one good copy of gene and one mutated copy) may function normally with the unmutated copy until the good copy has been spontaneously somatically mutated. This kind of mutation happens often in living organisms, but it is difficult to measure the rate. Measuring this rate is important in predicting the rate at which people may develop cancer. Point mutations may arise from spontaneous mutations that occur during DNA replication. The rate of mutation may be increased by mutagens. Mutagens can be physical, such as radiation from UV rays, X-rays or extreme heat, or chemical (molecules that misplace base pairs or disrupt the helical shape of DNA). Mutagens associated with cancers are often studied to learn about cancer and its prevention.
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Sources: en.wikipedia.org
=== Works cited === Army Techniques Publication 7-100.3: Chinese Tactics (PDF). Washington, D.C.: Headquarters, United States Army. 2021. ISBN 9798457607118. Goldstein, Melvyn C. (1997). The Snow Lion and the Dragon: China, Tibet, and the Dalai Lama. University of California Press. ISBN 978-0-520-21254-1. International Institute for Strategic Studies (12 February 2025). The Military Balance 2025. London: Routledge. doi:10.4324/9781003630760. ISBN 978-1-003-63076-0. Kaufman, Alison A.; Mackenzie, Peter W. (2009). The Culture of the Chinese People's Liberation Army (Report). Marine Corps Intelligence Activity. Archived from the original on 23 June 2024. Retrieved 23 June 2024. Pollpeter, Kevin; Allen, Kenneth W., eds. (14 June 2012). The PLA as Organization v2.0 (Report). China Aerospace Studies Institute. Saunders, Phillip C.; Ding, Arthur S.; Scobell, Andrew; Yang, Andrew N.D.; Joel, Wuthnow, eds. (2019). Chairman Xi Remakes the PLA: Assessing Chinese Military Reforms. Washington, D.C.: National Defense University Press. ISBN 978-1070233420. International Institute for Strategic Studies (2025). The Military Balance 2025. London: Routledge. ISBN 978-1-041-04967-8.
== Oligomerization == Glutathione S-transferases form homodimers, but in eukaryotes can also form heterodimers of the A1 and A2 or YC1 and YC2 subunits. The homodimeric enzymes display a conserved structural fold. Each monomer is composed of a distinct N-terminal sub-domain, which adopts the thioredoxin fold, and a C-terminal all-helical sub-domain. This entry is the C-terminal domain.
=== Routes of exposure === Antineoplastic drugs are usually given through intravenous, intramuscular, intrathecal, or subcutaneous administration. In most cases, before the medication is administered to the patient, it needs to be prepared and handled by several workers. Any worker who is involved in handling, preparing, or administering the drugs, or with cleaning objects that have come into contact with antineoplastic drugs, is potentially exposed to hazardous drugs. Health care workers are exposed to drugs in different circumstances, such as when pharmacists and pharmacy technicians prepare and handle antineoplastic drugs and when nurses and physicians administer the drugs to patients. Additionally, those who are responsible for disposing antineoplastic drugs in health care facilities are also at risk of exposure. Dermal exposure is thought to be the main route of exposure due to the fact that significant amounts of the antineoplastic agents have been found in the gloves worn by healthcare workers who prepare, handle, and administer the agents. Another noteworthy route of exposure is inhalation of the drugs' vapors. Multiple studies have investigated inhalation as a route of exposure, and although air sampling has not shown any dangerous levels, it is still a potential route of exposure. Ingestion by hand to mouth is a route of exposure that is less likely compared to others because of the enforced hygienic standard in the health institutions. However, it is still a potential route, especially in the workplace, outside of a health institute.
Sources: en.wikipedia.org
Epitalon is a synthetic tetrapeptide composed of four amino acids: alanine, glutamate, aspartate, and glycine. It is written as Ala-Glu-Asp-Gly. The free peptide has a molecular weight of about 390 daltons and is normally supplied as a lyophilized powder.
No. Epitalon is chemically synthesized, not extracted. It was designed as a short synthetic fragment conceptually related to larger pineal peptides studied in the same research tradition, particularly the extract known as epithalamin. The two are distinct materials with different compositions.
The term bioregulator is used in this research tradition for short peptides proposed to influence gene expression or cell function. Epitalon is grouped with other synthetic short peptides under this label. The term reflects a proposed mechanism rather than an established drug classification.
It is a synthetic tetrapeptide with the sequence alanine-glutamate-aspartate-glycine, often abbreviated AEDG. The molecule is linear and contains no modified residues, so it is fully described by its sequence.