Everything below concerns counterion. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Last reviewed on 2025-10-23. Where a claim depends on a specific study, the study is described rather than over-claimed.
Published work on this compound consists mainly of in vitro experiments, animal studies, and small clinical investigations, a substantial share of which appeared in Russian-language journals. Sample sizes are generally small, control conditions differ between studies, and several endpoints rely on markers whose clinical meaning is itself debated. Reviews of the longevity field treat the peptide as an early example of telomerase-directed research rather than an established intervention. Regulatory treatment varies by country: some jurisdictions place it under prescription controls, others treat it as a laboratory material, and importation may be restricted regardless of local status.
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.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Peptide sequence | Ala-Glu-Asp-Gly | Often abbreviated AEDG in research literature |
| Common synonyms | Epithalon, epitalon, AEDG | Spelling variants refer to the same tetrapeptide |
| Molecular formula | C14H22N4O9 | Theoretical monoisotopic mass near 390.35 Da |
| Appearance | White to off-white powder | Typically supplied as a lyophilised solid |
| Solubility class | Freely soluble in water | Hydrophilic peptide; dissolves in aqueous buffer |
Reported biological findings come mainly from cell culture and rodent experiments. Those studies describe changes in telomerase catalytic subunit expression, melatonin rhythm amplitude, and antioxidant enzyme activity after peptide exposure. Human data are sparse and consist of small trials with limited blinding and inconsistent endpoints. The proposed mechanisms remain hypotheses rather than established facts, and there is no consensus on whether effects observed in animals carry over to people. Independent replication outside the original research groups is limited, which is a recognised gap in the published literature.
The parent extract epithalamin was characterised as a low-molecular-weight fraction of pineal tissue rather than a single defined chemical entity. Researchers fractionated it and tested successive fragments for activity, a screening approach typical of peptide discovery work in that era. Epitalon emerged from that process as one of the shorter sequences of interest. Because the original extract was never fully resolved into individual components, claims about which constituent drives a given effect rest on inference. This distinction matters when reading older reports that attribute extract observations to the tetrapeptide itself.
Epitalon is a synthetic tetrapeptide with the residue sequence alanine-glutamate-aspartate-glycine, commonly abbreviated AEDG. Its monoisotopic mass is approximately 390.35 daltons, and it is usually supplied as a lyophilised trifluoroacetate or acetate salt. The compound was derived from a pineal gland extract called epithalamin, a heterogeneous preparation investigated in the former Soviet Union. Researchers associated with the Saint Petersburg Institute of Bioregulation and Gerontology described the tetrapeptide as a constituent fragment of that extract. Commercial material is offered as a laboratory reagent rather than as a finished pharmaceutical product.
Documentation accompanying research peptides usually includes a certificate of analysis listing the batch number, purity figure, and test methods applied. Buyers comparing suppliers should check whether the reported purity refers to chromatographic area or to a mass-balance calculation, because the two are not equivalent. Counter-ion content, residual solvents, and water content are sometimes omitted from such certificates even though they affect the actual peptide mass present. Independent verification through a second laboratory is the most direct way to confirm that a supplied material matches its label.
Purity assessment of peptide reagents normally relies on reversed-phase high-performance liquid chromatography. A gradient of acetonitrile in water with trifluoroacetic acid, paired with a C18 stationary phase, separates the target tetrapeptide from truncated sequences and deletion analogues. Detection at 214 nanometres exploits absorbance of the peptide backbone, since the molecule contains no aromatic residue. Results are expressed as a percentage of total peak area. Values above ninety-five percent are typical for research-grade material, although reporting conventions vary between suppliers.
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.
Reversed-phase high-performance liquid chromatography is the standard approach for assessing purity, usually with ultraviolet detection near 214 nm, where the peptide bond absorbs. Mass spectrometry, most often with electrospray ionization, confirms the molecular mass and helps reveal truncation or deletion byproducts. Amino acid analysis can verify composition, and counterion content is sometimes measured because peptides purified with trifluoroacetic acid retain variable amounts of that salt. Purity figures reported without a stated method and detection wavelength are difficult to interpret.
Material sold for research use varies widely in documented quality. A useful verification package includes a certificate of analysis that states peptide content rather than only net weight, the chromatographic method and column used, and a mass spectrum consistent with the expected mass. Independent testing by a third-party laboratory is occasionally reported. Statements of identity resting only on a supplier label provide little assurance, and the gap between nominal mass and actual peptide content can be substantial once counterions and residual water are counted.
Peptides of this size are generally stable as dry solids but degrade in solution over time. The principal routes are hydrolysis of the peptide backbone and oxidation, with hydrolysis favoured by elevated temperature and extreme pH. Aqueous solutions held at room temperature can show measurable loss of purity within days, while frozen aliquots are considerably more durable. Because the sequence contains neither cysteine nor methionine, oxidation is less of a concern than for many other peptides, but pH control during handling still matters.
Proper nutrition is important after delivery to help the mother recover, and to provide enough food energy and nutrients for a woman to breastfeed her child. Women having serum ferritin less than 70 μg/L may need iron supplements to prevent iron deficiency anaemia during pregnancy and postpartum. During lactation, water intake may need to be increased. Human milk is made of 88% water, and the IOM recommends that breastfeeding women increase their water intake by about 300 mL/day to a total volume of 3000 mL/day (from food and drink), approximately 2,400 mL/day from fluids. Fetal alcohol spectrum disorder Prenatal nutrition Smoking and pregnancy "Nutrition During Pregnancy Resource List for Consumers" (PDF). USDA NAL Food and Nutrition Information Center. Archived from the original (PDF) on 2007-07-14. Retrieved 2007-10-17. Health Education Authority (1996) Folic acid - what all women should know (leaflet) London:HEA
This reaction is relatively slow, so even after significant exposure, the 239Pu is still mixed with a great deal of 238U (and possibly other isotopes of uranium), oxygen, other components of the original material, and fission products. Only if the fuel has been exposed for a few days in the reactor, can the 239Pu be chemically separated from the rest of the material to yield high-purity 239Pu metal. 239Pu has a higher probability for fission than 235U and a larger number of neutrons produced per fission event, so it has a smaller critical mass. Pure 239Pu also has a reasonably low rate of neutron emission due to spontaneous fission (10 fission/s·kg), making it feasible to assemble a mass that is highly supercritical before a detonation chain reaction begins. In practice, however, reactor-bred plutonium will invariably contain a certain amount of 240Pu due to the tendency of 239Pu to absorb an additional neutron during production. 240Pu has a high rate of spontaneous fission events (415,000 fission/s-kg), making it an undesirable contaminant. As a result, plutonium containing a significant fraction of 240Pu is not well-suited to use in nuclear weapons; it emits neutron radiation, making handling more difficult, and its presence can lead to a "fizzle" in which a small explosion occurs, destroying the weapon but not causing fission of a significant fraction of the fuel. It is because of this limitation that plutonium-based weapons must be implosion-type, rather than gun-type.
reuteri-and-tryptophan-diet for checkpoint inhibitor potentiation (6 Apr), doxycycline post-exposure prophylaxis against STIs (6 Apr), an engineered probiotic against alcohol-induced damage (11 Apr), phase 2 trialed AXA1125 against long COVID fatigue (14 Apr), review finds cranberry products useful against UTIs in women (17 Apr) (but is not suggested for older people, those have trouble emptying their bladder, or people who are pregnant), and macaques-tested low-intensity focus ultrasound delivery of AAV into brain regions against brain diseases (19 Apr). Progress in screening: an α-synuclein SAA (assay) against Parkinson's disease (12 Apr), and exogenously administered bioengineered sensors that amplify urinary cancer biomarkers for detection (24 Apr). Promising innovations relating to global challenges are reported: a laser-using drone-based methane plume localization method, approval of the first yeast-based cow-free dairy (Remilk), a Tor browser-equivalent Web browser for privacy-protected browsing when using a VPN (Mullvad browser), a concentrated solar-to-hydrogen device approaching viability, a method for fat tissue cultured meat, flexible organic solar cells on balloons in the 35 km stratosphere.
The Ewe in Ghana speak three principal dialects: Anlo (along the coast), Tongu (along the Volta River) and Ewedome (in the hill country side). The Ga-Dangme occupy the Greater Accra Region and parts of the Eastern Region, while the Ewe are found in the Volta Region and the neighbouring Togo, Benin Republic and Nigeria (around Badagry area).
== Disorders == Platelet disorders can occur because there are not enough platelets, too many platelets, or the platelets do not function properly. Low platelet concentration is called thrombocytopenia, and is due to either decreased production, increased destruction of platelets, or platelets being sequestered in another part of the body. Elevated platelet concentration is called thrombocytosis, and is either congenital, reactive (to cytokines), or due to unregulated production: one of the myeloproliferative neoplasms or certain other myeloid neoplasms. Normal platelets can respond to an abnormality on the vessel wall rather than to hemorrhage, resulting in inappropriate platelet adhesion/activation and thrombosis: the formation of a clot within an intact vessel. This type of thrombosis arises by mechanisms different from those of a normal clot: extending the fibrin of venous thrombosis; extending an unstable or ruptured arterial plaque, causing arterial thrombosis; and microcirculatory thrombosis. An arterial thrombus may partially obstruct blood flow, causing downstream ischemia, or may completely obstruct it, causing downstream tissue death.:
Sources: en.wikipedia.org
Economic failings in the Communist system were becoming more obvious across eastern Europe during the 1980s, as for instance, the yearly per capita GDP of East Germans was barely half that of those in West Germany. Infrastructure investments were also deficient in countries like Poland, Hungary, and Czechoslovakia, while at the same time, eastern bloc countries were losing their share of world trade. Meanwhile, countries throughout western Europe continued to prosper. By the mid-1980s, historian John W. Young observes, this contrast had become stark and rather than an integrated economic community at the technological frontier, Eastern Europe remained heavily indebted, inefficient, and unable to compete in world markets—a burden the Soviet economy itself had to help sustain through subsidized oil and raw materials. In 1985, Reagan and Gorbachev held their first of four "summit" meetings, beginning in Geneva, Switzerland. After discussing policy, facts, etc., Reagan invited Gorbachev to go with him to a small house near the beach. The two leaders spoke in that house well over their time limit, but came out with the news that they had planned two more (soon three more) summits. The second summit took place the following year, in 1986 on October 11, in Reykjavík, Iceland. The meeting was held to pursue discussions about scaling back their intermediate-range ballistic missile arsenals in Europe.
CBS News said, "The moderates viewed the deal — after Republicans leaders refused Schumer's offer — as the best possible offer they could secure, arguing that continuing the shutdown would only inflict more pain without any hopes of a better deal." In addition, Senator Tim Kaine (D-Virginia) was won over by a new continuing resolution coming from the White House which reversed the October layoffs.
==== GSK–Pfizer joint venture ==== In December 2018, GSK announced that it, along with Pfizer, had reached an agreement to merge and combine their consumer healthcare divisions into a single entity. The combined entity would have sales of around £9.8 billion ($12.7 billion), with GSK maintaining a 68% controlling stake in the joint venture. Pfizer would own the remaining 32% shareholding. The deal builds on an earlier 2018 deal where GSK bought out Novartis' stake in the GSK-Novartis consumer healthcare joint business.
=== Pyrolysis–mass spectrometry === Pyrolysis mass spectrometry (Py-MS) is an new technique that combines pyrolysis with DART-MS or Ambient Corona Discharge Ionization-mass spectrometry for Thermal Desorption and Pyrolysis to determine the structure of small molecules and polymers.
Sources: en.wikipedia.org
Epitalon is a synthetic four-amino-acid peptide with the sequence alanine–glutamate–aspartate–glycine, also written AEDG. It was developed in Russian gerontology research and is studied for proposed effects on telomerase, melatonin regulation, and neuroendocrine function. It is not an approved pharmaceutical in the United States or the European Union.
No. Epithalamin is a peptide-rich extract prepared from bovine pineal glands, while epitalon is a short synthetic peptide designed as a defined analogue of it. The synthetic version was intended to provide a reproducible molecule with some of the same proposed biological activity.
Telomere elongation and telomerase activation have been reported in cultured human somatic cells, but evidence from living human subjects is limited and has not been independently confirmed at scale. Reported findings come largely from small studies with differing designs, so the question remains open rather than settled.
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.