epithalamin 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 2025-08-05. 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.
（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.
| 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 |
The compound is generally presented as a synthetic fragment of epithalamin, a pineal gland extract investigated in the former Soviet Union from the 1970s onward. Vladimir Khavinson and colleagues in Saint Petersburg developed short peptides modelled on such extracts, and epitalon became the most widely cited of those sequences. Most primary reports appeared in Russian-language journals or in proceedings with limited international circulation. Independent replication in laboratories outside that network remains sparse, and much repeated secondary material traces back to a small number of originating groups.
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.
In its supplied form epitalon is a white to off-white powder, usually lyophilized and often hygroscopic. It dissolves readily in water and in aqueous buffers, and it is commonly handled as the acetate or trifluoroacetate salt to improve stability during purification and drying. The amide backbone is labile in aqueous media, so solutions are less durable than the dry solid. Handling notes in the chemical literature therefore emphasize keeping the powder dry, cool and shielded from light until it is dissolved.
Epitalon is a synthetic tetrapeptide whose sequence is alanine-glutamate-aspartate-glycine, written in single-letter code as AEDG. The four residues are joined by three peptide bonds, giving a linear backbone with no branching and no disulfide bridges. Its calculated molecular mass for the free form is approximately 390.3 daltons, a figure that rises when the compound is supplied as an acetate or trifluoroacetate salt. Because the chain is short, the molecule is defined entirely by its residue order rather than by any folded three-dimensional structure.
== Pores == The pore media of the resin particles is one of the most important parameters for the efficiency of the product. These pores make different functions depending on their sizes and are the main feature responsible for the mass transfer between phases making the whole ion exchange process possible. There are three main types of pore sizes:
centrifuge A device used to separate substances based on size, shape, and density by centrifugation, or the rotation of vessels containing the substances around a centred axis at extremely high velocities.
=== Cysteine aminopeptidase === Cysteine aminopeptidases, on the other hand, rely on a cysteine amino acid to perform catalysis. These enzymes are part of a broader group of cysteine proteases, all of which carve up proteins by using a nucleophilic cysteine thiol along with one or two other catalytic amino acids in a diad or triad. The triad typically consists of cysteine, histidine, and aspartate amino acids, where the cysteine acts as a nucleophile, the histidine acts as a chemical base, and the aspartate stabilizes the histidine. Examples of cysteine aminopeptidases include cathepsin H and aminopeptidase B.
==== Operation bootstrap (1948) ==== Operation Bootstrap was enacted in 1948 and was the result of Puerto Rico's desire to attract outside capital by inviting U.S. private funds. Therefore, a tax arrangement was made by the U.S. to improve the industrial production on the island in an effort to increase profits and funnel money to the mainland. This economic development program enticed industries within the U.S. that were in search of "cheap labor, tax exemptions, and free trade between Puerto Rico and the mainland". This rapid foreign investment provided promise for disadvantaged Puerto Rican women who were struggling to navigate through domestic working conditions and limited job opportunities. Operation Bootstrap was marketed and believed to be an advantageous new service sector for women in search of white collar jobs. However, Puerto Rican women and the vast majority of the island experienced the exact opposite. Operation Bootstrap resulted in "high unemployment, increased migration, exacerbated poverty", and most importantly, economic colonization.
== Factors == First-pass metabolism may occur in the liver (for propranolol, lidocaine, clomethiazole, and nitroglycerin) or in the gut (for benzylpenicillin and insulin). The four primary systems that affect the first pass effect of a drug are the enzymes of the gastrointestinal lumen, gastrointestinal wall enzymes, bacterial enzymes and hepatic enzymes.
Sources: en.wikipedia.org
Even though YAN can be added into juice before fermentation, there are other ways to affect the levels of nitrogen in the juice before pressing, like the maturity of the orchard or what type of fertiliser is used. Using a fertiliser with a good amount of nitrogen will help the roots of apple trees; nitrogen fixing bacteria on the roots will be able to provide the tree with more nitrogen that will be able to make its way into the fruit. A low crop load can also yield juices with more YAN than a high crop load because the nitrogen in more concentrated in the low number of apples instead of being distributed to many apples. While a sufficient amount of YAN is good for the yeast and ensures fermentation of the sugars in the juice to alcohol, some cider makers may choose to limit nitrogen because it is the limiting factor. When the yeast are starved for nitrogen, they stop fermenting and die off. This can be desirable if cider makers prefer their cider to have some more sugar than alcohol in their cider. However, limiting YAN should be done in moderation because too little nitrogen can lead to an increase in hydrogen sulfide (H2S) production which is responsible for a rotten egg-like smell. Primary cider fermentation can be initiated by inoculating the cider must with selected yeast strains or by permitting indigenous yeast strains present on the fruit and in the cider production equipment to spontaneously commence fermentation without inoculation.
== History == Historically, ligand binding assay techniques were used extensively to quantify hormone or hormone receptor concentrations in plasma or in tissue. The ligand-binding assay methodology quantified the concentration of the hormone in the test material by comparing the effects of the test sample to the results of varying amounts of known protein (ligand). The foundations for which ligand binding assay have been built are a result of Karl Landsteiner, in 1945, and his work on immunization of animals through the production of antibodies for certain proteins. Landsteiner's work demonstrated that immunoassay technology allowed researchers to analyze at the molecular level. The first successful ligand binding assay was reported in 1960 by Rosalyn Sussman Yalow and Solomon Berson. They investigated the binding interaction for insulin and an insulin-specific antibody, in addition to developing the first radioimmunoassay (RIA) for insulin. These discoveries provided precious information regarding both the sensitivity and specificity of protein hormones found within blood-based fluids. Yalow and Berson received the Nobel Prize in Medicine as a result of their advancements. Through the development of RIA technology, researchers have been able to move beyond the use of radioactivity, and instead, use liquid- and solid-phase, competitive, and immunoradiometric assays. As a direct result of these monumental findings, researchers have continued the advancement of ligand binding assays in many facets in the fields of biology, chemistry, and the like.
Cuban Assets Control Regulations of 1963 Cuban Democracy Act of 1992 Helms–Burton Act of 1996 (Cuba) Iran and Libya Sanctions Act of 1996 Trade Sanction Reform and Export Enhancement Act of 2000 (Cuba) Iran Freedom and Support Act of 2006 Comprehensive Iran Sanctions, Accountability, and Divestment Act of 2010
=== Criteria for a cleansing agent === Wound cleansing forms an integral part of wound management and generally suggests the application of a fluid to aid the removal of surface contaminants, bacteria, and debris from the wound surface and surrounding skin. Water as a cleansing agent, especially in chronic wounds has been proposed and is widely used especially in the management of infected wounds. Despite the plethora of work focussing on the value of water/saline in wound cleansing there is no current consensus as to whether water has an active role to play in the promotion of healing. With this unclear position in mind, alternative cleansing agents such as antiseptics that possess the potential to improve clinical outcomes should be considered. The use of antiseptics on open wounds is justified in terms of prevention/treatment of infection and improved healing outcomes. Criteria by which a wound cleansing agent could be deemed suitable for use on wounds include:
Sources: en.wikipedia.org
On average, groups of people with "obese" BMIs may have a higher risk of developing illnesses like diabetes, hypertension, dyslipidemia (high cholesterol), liver disease, and some cancers. "Underweight" BMIs may indicate malnutrition or other health problems. However, BMI has limitations when used to describe individual health rather than describing populations of people.
The major benefit of the indirect methodology is that conventional achiral stationary phase/mobile phase system may be used for the separation of the generated diastereomers. Thus, considerable flexibility in chromatographic conditions is available to achieve the desired separation and to eliminate interferences from metabolites and endogenous substances. Moreover, the sensitivity of the method can be enhanced by sensible choice of the CDA and the chromatographic detection system. But this indirect approach to enantiomeric analysis has some potential problems. These include availability of a suitable functional group on the enantiomer for derivatization, enantiomeric purity of the CDA, racemization of the CDA during derivatization, and racemization of the analyte during the derivatization. Currently, however, the application of indirect analytical approaches is in decline.
=== Absorbed dose and dose equivalent === The British physicist and radiologist and founder of radiobiology Louis Harold Gray (1905-1965) introduced the unit Rad (acronym for radiation absorbed dose) in the 1930s, which was renamed Gray (Gy) after him in 1978. One gray is a mass-specific quantity and corresponds to the energy of one joule absorbed by one kilogram of body weight. Acute whole-body exposures in excess of four Gy are usually fatal to humans. The different types of radiation ionize to different degrees. Ionization is any process in which one or more electrons are removed from an atom or molecule, leaving the atom or molecule as a positively charged ion (cation). Each type of radiation is therefore assigned a dimensionless weighting factor that expresses its biological effectiveness. For X-rays, gamma and beta radiation, the factor is one, alpha radiation reaches a factor of twenty, and for neutron radiation it is between five and twenty, depending on the energy. Multiplying the absorbed dose in Gy by the weighting factor gives the equivalent dose, expressed in Sievert (Sv). It is named after the Swedish physician and physicist Rolf Maximilian Sievert (1896-1966). Sievert was the founder of radiation protection research and developed the Sievert chamber in 1929 to measure the intensity of X-rays. He founded the International Commission on Radiation Units and Measurements (ICRU) and later became chairman of the International Commission on Radiological Protection (ICRP).
==== McLean v. Arkansas ==== In 1981, Kenyon was recruited to be an expert witness for the creationist side in the McLean v. Arkansas case that tested the constitutionality of Arkansas' Equal Time Legislation that mandated equal time for "creation science" and "evolution science". Kenyon flew to Arkansas to be deposed and testify during the trial. However, apparently under the influence of creationist attorney Wendell Bird (who was displeased with the defense of the creationist position by the Arkansas attorney general Steve Clark), Kenyon left town just before he was to testify:
In 2000, the chapter on Vitamin C in the North American Dietary Reference Intake was updated to give the Recommended Dietary Allowance (RDA) as 90 milligrams per day for adult men, 75 mg/day for adult women, and setting a tolerable upper intake level (UL) for adults of 2,000 mg/day. The table here shows RDAs for the United States and Canada for children, and for pregnant and lactating women, as well as the ULs for adults. For the European Union, the EFSA set higher recommendations for adults, and also for children: 20 mg/day for ages 1–3, 30 mg/day for ages 4–6, 45 mg/day for ages 7–10, 70 mg/day for ages 11–14, 100 mg/day for males ages 15–17, 90 mg/day for females ages 15–17. For pregnancy 100 mg/day; for lactation 155 mg/day. Cigarette smokers and people exposed to secondhand smoke have lower serum vitamin C levels than nonsmokers. The reasoning is that inhalation of smoke causes oxidative damage, depleting this antioxidant vitamin. The US Institute of Medicine estimated that smokers need 35 mg more vitamin C per day than nonsmokers, but did not formally establish a higher RDA for smokers. The US National Center for Health Statistics conducts biannual National Health and Nutrition Examination Survey (NHANES) to assess the health and nutritional status of adults and children in the United States. Some results are reported as What We Eat In America. The 2013–2014 survey reported that for adults ages 20 years and older, men consumed on average 83.3 mg/d and women 75.1 mg/d. This means that half the women and more than half the men are not consuming the RDA for vitamin C.
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.
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.