AEDG tetrapeptide comes up often in conversation and rarely with the context attached. Here we lay out the basics in order, then work through the practical considerations.
Last reviewed on 2025-08-20. Where a claim depends on a specific study, the study is described rather than over-claimed.
Laboratory work has examined effects on telomerase activity in cultured cells, on melatonin rhythms in animals, and on markers of oxidative stress. Some experiments report measurable changes while others show none, and the reported findings rest largely on small studies. The absence of large independent trials means the generality of these results is unresolved rather than settled. Review articles occasionally apply the label geroprotector, a term that reflects a research hypothesis about ageing rather than an established clinical finding.
Epitalon is the common name for a synthetic tetrapeptide with the sequence alanine-glutamate-aspartate-glycine, usually abbreviated AEDG. All four residues are proteinogenic amino acids, and the free peptide has a calculated mass near 390 grams per mole. Because the chain is short and carries no modifications, it is assembled readily by solid-phase synthesis and is distributed mainly as a freeze-dried solid for laboratory work. Catalogue listings use the spellings epitalon, epithalone, and simply AEDG, and the three refer to the same sequence.
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.
Material supplied for laboratory use is normally a lyophilised white to off-white powder that dissolves readily in water and in isotonic saline. Lyophilised cakes are hygroscopic and should be equilibrated to room temperature before opening to limit condensation on the solid. Solutions are typically prepared at milligram-per-millilitre concentrations and divided into single-use aliquots, because repeated freeze–thaw cycles degrade short peptides. Aqueous solutions are far less stable than the dry powder, and identity is usually verified by mass spectrometry alongside purity estimation from reversed-phase high-performance liquid chromatography.
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.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C14H22N4O9 | Computed for the free acid of Ala-Glu-Asp-Gly |
| Molecular mass | About 390.35 g/mol | Free peptide; salt forms shift the value |
| Appearance | White to off-white solid | Typical of short peptides after freeze-drying |
| Solubility class | Freely soluble in water | Aqueous buffers are also commonly used |
| Common synonyms | Epitalon, epithalone, AEDG | AEDG is the single-letter sequence |
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.
Discussions in the literature often conflate three distinct entities: the pineal extract epithalamin, the isolated tetrapeptide AEDG, and commercial preparations sold under similar names. Reviews citing older Russian-language studies sometimes omit detail on purity, route of administration and control groups, which makes cross-study comparison difficult. Researchers working with the compound generally note the need for independent replication, standardized enzyme assays, and clearer reporting of peptide identity. These caveats are relevant when weighing claims that appear in secondary sources rather than in primary reports.
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.
Epitalon is a synthetic tetrapeptide whose sequence is alanine–glutamate–aspartate–glycine, commonly abbreviated AEDG. It was developed in Russia during the 1980s and 1990s by investigators associated with the St. Petersburg Institute of Bioregulation and Gerontology, who studied short peptides as regulators of gene expression and tissue function. The alternative spelling epithalon appears interchangeably in the literature, and the two names refer to the same molecule. Outside Russia it is encountered chiefly as a research chemical rather than a licensed medicine, and it holds no approval from the United States Food and Drug Administration or the European Medicines Agency.
The peptide is a synthetic analogue of epithalamin, a preparation extracted from bovine pineal glands. Investigators sought a short, chemically defined molecule that would reproduce some of the endocrine and gerontological observations attributed to the glandular extract. Proposed mechanisms centre on induction of telomerase activity, an effect reported in cultured human somatic cells in the early 2000s, together with influences on melatonin secretion and neuroendocrine regulation. Those mechanisms remain incompletely characterised, and the reported telomerase response has not been consistently reproduced by independent groups working in comparable systems.
As of the direct-to-video anniversary special Tokusou Sentai Dekaranger: 10 Years After, he has joined S.P.D.'s Earth unit and married Jasmine, with whom they have a son named Taiga. Hikaru Hiwatari is portrayed by Yuto Uemura (上村 祐翔, Uemura Yūto). Zamuzan Myra (ザムザ星人マイラ, Zamuza Seijin Maira): A young woman from Planet Zamuza who was the subject of a stakeout conducted by the Dekarangers due to her ex-boyfriend, an Alienizer named Sheik, having recently escaped from prison. However, Ban becomes enamored by her and goes undercover as her apartment building's plumber to socialize with her. After Sheik attacks Myra and the Dekarangers delete him, Myra loses respect for Ban for lying to her, but chooses to remain friends with him since he kept his promise to protect her. Myra is portrayed by Nana Nakamoto (中本 奈奈, Nakamoto Nana). Ocarnan Amy (オカーナ星人エイミー, Okāna Seijin Eimī): A giant alien baby from planet Ocarna who possesses currently uncontrollable size-changing capabilities limited by a special pacifier and shockwave-inducing cries. After Amy's cradle pod lands on Earth, Umeko is assigned to protect her until the former's parents can come for her. Agent Abrella sends an Igaroid to pilot a Kaijuki called Devil Capture 3 (デビルキャプチャー3, Debiru Kyapuchā Surī) and capture Amy, but Umeko destroys them with Dekaranger Robo before Amy's parents arrive and take their daughter back. Amy is voiced by Sara Nakayama (中山 さら, Nakayama Sara).
The metabolome is the complete set of small-molecule chemicals found within a biological sample. The biological sample can be a cell, a cellular organelle, an organ, a tissue, a tissue extract, a biofluid or an entire organism. The small molecule chemicals found in a given metabolome may include both endogenous metabolites that are naturally produced by an organism (such as amino acids, organic acids, nucleic acids, fatty acids, amines, sugars, vitamins, co-factors, pigments, antibiotics, etc.) as well as exogenous chemicals (such as drugs, environmental contaminants, food additives, toxins and other xenobiotics) that are not naturally produced by an organism. In other words, there is both an endogenous metabolome and an exogenous metabolome. The endogenous metabolome can be further subdivided to include a "primary" and a "secondary" metabolome (particularly when referring to plant or microbial metabolomes). A primary metabolite is directly involved in the normal growth, development, and reproduction. A secondary metabolite is not directly involved in those processes, but usually has important ecological function. Secondary metabolites may include pigments, antibiotics or waste products derived from partially metabolized xenobiotics. The study of the metabolome is called metabolomics.
== Types of nuclear warfare == Nuclear warfare scenarios are usually divided into two groups, each with different effects and potentially fought with different types of nuclear armaments. The first, a limited nuclear war (sometimes attack or exchange), refers to the controlled use of nuclear weapons, whereby the implicit threat exists that a nation can still escalate their use of nuclear weapons. For example, using a small number of nuclear weapons against strictly military targets could be escalated through increasing the number of weapons used, or escalated through the selection of different targets. Limited attacks are thought to be a more credible response against attacks that do not justify all-out retaliation, such as an enemy's limited use of nuclear weapons. The second, a full-scale nuclear war, could consist of large numbers of nuclear weapons used in an attack aimed at an entire country, including military, economic, and civilian targets. Such an attack would almost certainly destroy the entire economic, social, and military infrastructure of the target nation, and would likely have a devastating effect on Earth's biosphere. Some Cold War strategists such as Henry Kissinger argued that a limited nuclear war could be possible between two heavily armed superpowers (such as the United States and the Soviet Union). Some predict, however, that a limited war could potentially "escalate" into a full-scale nuclear war.
His research article on a systems approach to prion diseases in 2009 was one of the first to thoroughly explore the use of systems biology to interrogate the dynamic network changes in disease models. These studies are the first to explain the dynamics of diseased-perturbed networks and have expanded to include frontal temporal dementia and Huntington's disease. Hood is also studying glioblastoma in mice and humans from the systems viewpoint. Hood advocates several practices in the burgeoning field of systems medicine, including: (1) The use of family genome sequencing, integrating genetics and genomics, to identify genetic variants associated with health and disease (2) The use of targeted proteomics and biomarkers as a window into health and disease. He has pioneered the discovery of biomarker panels for lung cancer and posttraumatic stress syndrome. (3) The use of systems biology to stratify disease into its different subtypes allowing for more effective treatment. (4) The use of systems strategies to identify new types of drug targets to facilitate and accelerate the drug discovery process.
Sources: en.wikipedia.org
Hitchens stated, "[an] unborn child seems to me to be a real concept. It's not a growth or an appendix. You can't say the rights question doesn't come up. I don't think a woman should be forced to choose, or even can be", and, "as a materialist, I think it has been demonstrated that an embryo is a separate body and entity". Showing a desire to recognise the unborn as a life, he also affirmed a need for the right to abortion, stating, "the second-best fallback solution, which may sometimes be desirable for other reasons, is termination of pregnancy... all thinking people recognise a painful conflict of rights and interest in this question". Hitchens opposed an overturning of Roe v. Wade and instead hoped for science to develop new solutions to unwanted pregnancies "that will make abortion more like a contraceptive procedure than a surgical one." He strongly criticized the encouragement of sexual abstinence within the anti-abortion movement of the Christian right, and the equating of contraceptives to abortion, as expressed by Mother Teresa and representatives of the Roman Catholic Church.
Platelets are either isolated from collected units of whole blood and pooled to make a therapeutic dose, or collected by platelet apheresis: blood is taken from the donor, passed through a device which removes the platelets, and the remainder is returned to the donor in a closed loop. The industry standard is for platelets to be tested for bacteria before transfusion to avoid septic reactions, which can be fatal. Recently the AABB Industry Standards for Blood Banks and Transfusion Services (5.1.5.1) has allowed use of pathogen reduction technology as an alternative to bacterial screenings in platelets. Pooled whole-blood platelets, sometimes called "random" platelets, are separated by one of two methods. In the US, a unit of whole blood is placed into a large centrifuge in what is referred to as a "soft spin". At these settings, the platelets remain suspended in the plasma. The platelet-rich plasma (PRP) is removed from the red cells, then centrifuged at a faster setting to harvest the platelets from the plasma. In other regions of the world, the unit of whole blood is centrifuged using settings that cause the platelets to become suspended in the "buffy coat" layer, which includes the platelets and the white blood cells. The "buffy coat" is isolated in a sterile bag, suspended in a small amount of red blood cells and plasma, then centrifuged again to separate the platelets and plasma from the red and white blood cells.
The enzyme characterised from liver converts the riboside, nicotinamide riboside, to the ribonucleotide, nicotinamide mononucleotide, by transferring a phosphate group from the cofactor, adenosine triphosphate (ATP), which is converted to adenosine diphosphate (ADP). This reaction is part of one of the biosynthesis pathways for the coenzyme, nicotinamide adenine dinucleotide. The other major one instead involves the enzyme nicotinamide phosphoribosyltransferase. This enzyme is a transferase, specifically one transferring phosphorus-containing groups (phosphotransferases) with an alcohol group as acceptor. The systematic name of this enzyme class is ATP:N-ribosylnicotinamide 5'-phosphotransferase. This enzyme is also called ribosylnicotinamide kinase (phosphorylating).
Descended from Howard Fisher of the Fisher Brothers, owners of Fisher Body, from 1919 a part of General Motors, she has served as president of the General Motors Foundation and as executive director of global community relations and government relations at GM. She married Representative John Dingell in 1981. She had grown up as a Republican, but became a Democrat soon after marrying Dingell. Their marriage lasted 38 years until her husband's death on February 7, 2019, at the age of 92. Like her husband, she is a Catholic. She is a member of the Democratic National Committee from Michigan and chaired Vice President Al Gore's campaign in Michigan in 2000. In 2004, she also helped secure the Michigan Democratic primary and general election vote for John Kerry in Michigan. In November 2006, Dingell was elected to Wayne State University's board of governors. Dingell and Senator Carl Levin were proponents of moving up Michigan's presidential primary before February 5 in an attempt to garner greater political influence for Michigan during the 2008 Democratic primaries. This resulted in Michigan almost losing its delegates' votes in the Democratic National Convention. When Carl Levin announced his retirement from the U.S. Senate at the end of his term in 2015, Dingell indicated that she was interested in running for his seat. When former Michigan Governor Jennifer Granholm declined to run for the seat, a Politico writer declared Dingell to be one of the front-runners for the Democratic nomination, alongside Representative Gary Peters. She chose not to run, and Peters won the seat.
It is hypothesized that the various introductions led to multiple genotypes which are adapted to either oaks or conifers. Californian specimens of A. phalloides frequently display yellowish to mustard-yellow caps, a coloration that can closely resemble the edible species Amanita velosa and Amanita calyptroderma, both of which are commonly foraged and consumed in California. This deceptive appearance is the result of environmental homoplasy with Asian cousin Amanita subjunquillea: the fungus expresses a phylogenetically conserved pigment palette (derived from the shikimate pathway) under the particular microclimatic conditions of coastal California oak woodlands. Prolonged high humidity from summer fog drip, followed by intense sunlight and oxidative stress once the fog burns off, upregulates polyphenolic compounds and causes oxidative bleaching of the originally greener or olive tones, producing the characteristic yellowish hues. Such similarity poses a significant risk of fatal misidentification for foragers, as the highly toxic death cap may be mistaken for these otherwise edible look-alikes. A. phalloides were conveyed to new countries across the Southern Hemisphere with the importation of hardwoods and conifers in the late twentieth century. Introduced oaks appear to have been the vector to Australia and South America; populations under oaks have been recorded from Melbourne, Canberra (where two people died in January 2012, of four who were poisoned), Adelaide, and further observed by citizen scientists in Beechworth, Sydney and Albury.
Sources: en.wikipedia.org
Overview of the RNAi process, from Cambridge University's The Naked Scientists Animation of the RNAi process, from Nature NOVA scienceNOW explains RNAi – A 15-minute video of the Nova broadcast that aired on PBS, 26 July 2005 Silencing Genomes Archived 10 August 2019 at the Wayback Machine RNA interference (RNAi) experiments and bioinformatics in C. elegans for education. From the Dolan DNA Learning Center of Cold Spring Harbor Laboratory. RNAi screens in C. elegans in a 96-well liquid format and their application to the systematic identification of genetic interactions (a protocol) 2 American 'Worm People' Win Nobel for RNA Work, from NY Times Molecular Therapy web focus: "The development of RNAi as a therapeutic strategy", a collection of free articles about RNAi as a therapeutic strategy. GenomeRNAi: a database of phenotypes from RNA interference screening experiments in Drosophila melanogaster and Homo sapiens RNAi tools Archived 19 June 2018 at the Wayback Machine Pre-designed and custom RNA Interference tools
== Clinical significance == Immunohistochemistry analysis of human myocytes has shown greater immunoreactivity of Ucn2 in myocytes of the failing heart compared to those of the healthy heart. This is a result of an innate mechanism in which Ucn2 acts to improve function of the failing heart. The pathophysiology of heart failure is often a consequence of improper calcium handling and relaxation resulting in a lower cardiac output, decreased blood flow and overall decreased heart function. Infusion of Ucn2 in healthy humans has shown a dose dependent increase in cardiac output, heart rate and left ventricle ejection fraction and a decrease in systemic vascular resistance. Ucn2 has been studied as potential treatment for individuals with heart failure.
=== Leadership under Brian L. Halla === National Semiconductor announced the appointment of Brian L. Halla as its chairman, president and CEO on May 3, 1996. Halla was then the head of LSI logic products division. Prior to LSI, he had been with Intel for 14 years. Halla reinforced Amelio's emphasis on the expertise of National Semiconductor in analog technology. He also was, on occasions, an evangelist for analog technology. However, he found that National Semiconductor under Amelio had too few product offerings. Halla embarked on a diversification into personal computer and graphics business. He advocated PC-on-a-chip (aka system-on-a-chip) as a business direction for National Semiconductor. During his tenure at LSI, LSI had successfully applied similar concepts. However, LSI had steered clear of getting involved with PC technologies that would make it a competitor with Intel. Halla held the vision that information appliances (IAs) would succeed the personal computer as a trend. He predicted that IAs would overtake sales of PCs by the year 2000. To achieve the goal, National Semiconductor started acquiring companies that would provide the needed technological complements. Among the acquisitions were Cirrus Logic Inc's PicoPower business, for its specialised expertise in small form factor devices; Mediamatics Inc, which makes multimedia connectivity products; Future Integrated Systems Inc, a PC graphics company; Gulbransen Inc, a digital audio technology maker; ComCore Semiconductor Inc, a maker of digital signal processing for LANs; Cyrix, the maker of Intel x86 clones.
== Signs and symptoms == Symptoms of this disease include deterioration of motor functions and speech, seizures, and other involuntary movement. Other symptoms are headaches, dementia, and vision impairment. Characteristics of Parkinson's Disease are also similar to PFBC. The disease usually manifests itself in the third to fifth decade of life but may appear in childhood or later in life. It usually presents with clumsiness, fatigability, unsteady gait, slow or slurred speech, difficulty swallowing, involuntary movements or muscle cramping. Seizures of various types are common. Neuropsychiatric symptoms, which may be the first or the most prominent manifestations, range from mild difficulty with concentration and memory to changes in personality and/or behavior, to psychosis and dementia.
Sources: en.wikipedia.org
It is a four-amino-acid peptide with the sequence alanine-glutamate-aspartate-glycine. The chain is unmodified and contains only standard proteinogenic residues, which makes it straightforward to produce by solid-phase synthesis and to characterise by standard peptide methods.
Epitalon and epithalon both circulate, and the difference reflects transliteration of a name coined in Russian-language publications. Reference to the extract it derives from, epithalamin, explains the shared stem. Databases and suppliers are inconsistent, so a search for one spelling alone may miss relevant entries.
No. Epithalamin is a multi-component preparation obtained from pineal tissue, and its exact composition is not fully characterised. Epitalon is a single defined tetrapeptide described as a short synthetic counterpart of that extract, so the two are related in origin but not interchangeable in identity.
It is a synthetic tetrapeptide. Its sequence was derived from research on peptide fractions of bovine pineal extract, and the intact AEDG sequence has not been demonstrated as an abundant free peptide in human tissue.