Everything below concerns telomerase. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Updated 2026-04-25. Numbers and descriptions here follow the published literature rather than marketing material.
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.
=== Biosynthetic pathway === Plants exclusively of the genus Capsicum produce capsaicinoids, which are alkaloids. Capsaicin is believed to be synthesized in the interlocular septum of chili peppers and depends on the gene AT3, which resides at the pun1 locus, and which encodes a putative acyltransferase. Biosynthesis of the capsaicinoids occurs in the glands of the pepper fruit where capsaicin synthase condenses vanillylamine from the phenylpropanoid pathway with an acyl-CoA moiety produced by the branched-chain fatty acid pathway. Capsaicin is the most abundant capsaicinoid found in the genus Capsicum, but at least ten other capsaicinoid variants exist. Phenylalanine supplies the precursor to the phenylpropanoid pathway while leucine or valine provide the precursor for the branched-chain fatty acid pathway. To produce capsaicin, 8-methyl-6-nonenoyl-CoA is produced by the branched-chain fatty acid pathway and condensed with vanillylamine. Other capsaicinoids are produced by the condensation of vanillylamine with various acyl-CoA products from the branched-chain fatty acid pathway, which is capable of producing a variety of acyl-CoA moieties of different chain length and degrees of unsaturation. All condensation reactions between the products of the phenylpropanoid and branched-chain fatty acid pathway are mediated by capsaicin synthase to produce the final capsaicinoid product.
=== Shortenings === Shortenings, because they are widely used, are of particular concern. Baking shortenings, unless reformulated, contain around 30% trans fats compared to their total fats. High-fat dairy products such as butter contain about 4%. Margarines not reformulated to reduce trans fats may contain up to 15% trans fat by weight, but some reformulated ones are less than 1% trans fat. Shortenings for deep-frying in restaurants can be used for longer than most conventional oils before becoming rancid. In the early 21st century, non-hydrogenated vegetable oils that have lifespans exceeding that of the frying shortenings became available.
=== 13 August === Three people were killed in an RSF drone strike on an event organized by the Sudan Shield Forces in Tambul, Gezira State. The RSF accused the SAF of carrying out an airstrike that destroyed the Ministry of Urban Planning building in Ed Daein and injured several people.
=== Adults === The widely used rule calculating normal maximum ESR values in adults (98% confidence limit) is given by a formula devised in 1983 from a study of ≈1000 individuals over the age of 20: The normal values of ESR in men is age (in years) divided by 2; for women, the normal value is age (in years) plus 10, divided by 2.
In the flaxseed variety Linum usitatissimum, a precursor peptide was found using Blast searching that potentially contains five core peptides separated by putative recognition sequences. Proteusins are named after "Proteus", a Greek shape-shifting sea god. Until now, the only known members in the family of Proteusins are called polytheonamides. They were originally presumed to be nonribosomal natural products due to the presence of many D-amino acids and other non-proteinogenic amino acids. However, a metagenomic study revealed the natural products as the most extensively modified class of RiPPs known to date. Six enzymes are responsible for installing a total of 48 posttranslational modifications onto the polytheonamide A and B precursor peptides, including 18 epimerizations. Polytheonamides are exceptionally large, as a single molecule is able to span a cell membrane and form an ion channel. Sactipeptides contain intramolecular linkages between the sulfur of Cys residues and the α-carbon of another residue in the peptide. A number of nonribosomal peptides bear the same modification. In 2003, the first RiPP with a sulfur-to-α-carbon linkage was reported when the structure of subtilosin A was determined using isotopically enriched media and NMR spectroscopy.
Sources: en.wikipedia.org
Collagen alpha-1(XXV) chain is a protein that in humans is encoded by the COL25A1 gene. COL25A1 is a brain-specific membrane-bound collagen. Proteolytic processing releases CLAC, a soluble form of COL25A1 containing the extracellular collagen domains that associates with senile plaques in Alzheimer disease (AD; MIM 104300) brains (Osada et al., 2005).[supplied by OMIM]
Dyspigmentation, the formation of wrinkles and other symptoms appear around regions of skin commonly exposed to the sun, mostly the eyes, mouth, and forehead. The lips may be affected. In Canadian women, the upper chest is commonly affected. Spider veins on face and neck Loss of color and fullness in the lips Symptoms of photoaging attributed to prolonged exposure to UV:
Plutonium-244 (244Pu) is an isotope of plutonium that has a half-life of 81.3 million years. This is longer than any other isotope of plutonium and longer than any other known isotope of an element beyond bismuth, except for the three naturally abundant ones: uranium-235 (704 million years), uranium-238 (4.463 billion years), and thorium-232 (14.0 billion years). Given the half-life of 244Pu, an exceedingly small amount should still be present on Earth, making plutonium a likely but unproven candidate as the shortest-lived primordial element.
Weight gain is also less of a concern with ziprasidone compared to other atypical antipsychotics. In fact, in a trial of long term therapy with ziprasidone, overweight patients (BMI > 27) actually had a mean weight loss overall. According to the manufacturer insert, ziprasidone caused an average weight gain of 2.2 kg (4.8 lbs), which is significantly lower than other atypical antipsychotics, making this medication better for patients that are concerned about their weight. In December 2014, the FDA warned that ziprasidone could cause a potentially fatal skin reaction, Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS), although this was believed to occur only rarely.
Sources: en.wikipedia.org
The research assistant's job can include some or all of the following: providing the local institutional review board (IRB) with the documentation necessary to obtain its permission to conduct the study, assisting with study start-up, identifying eligible patients, obtaining consent from them or their families, administering study treatment(s), collecting and statistically analyzing data, maintaining and updating data files during followup, and communicating with the IRB, as well as the sponsor and CRO.
==== Mixed ==== A mixed inhibitor binds to an allosteric site and the binding of the substrate and the inhibitor affect each other. The enzyme's function is reduced but not eliminated when bound to the inhibitor. This type of inhibitor does not follow the Michaelis–Menten equation.
== Structure == Lumican is a proteoglycan Class II member of the small leucine-rich proteoglycan (SLRP) family that includes decorin, biglycan, fibromodulin, keratocan, epiphycan, and osteoglycin. Like the other SLRPs, lumican has a molecular weight of about 40 kilodaltons and has four major intramolecular domains:
One penicillin unit was defined as 0.5988 micrograms of the Second International Standard. There is an older unit for penicillin V that is not equivalent to the current penicillin V unit. The reason is that the US FDA incorrectly assumed that the potency of penicillin V is the same mole-for-mole as penicillin G. In fact, penicillin V is less potent than penicillin G, and the current penicillin V unit reflects that fact.
The heavy chain contains domains with several functions; it has the domain responsible for binding specifically to presynaptic nerve terminals, as well as the domain responsible for mediating translocation of the light chain into the cell cytoplasm as the vacuole acidifies. The light chain is a M27-family zinc metalloprotease and is the active part of the toxin. It is translocated into the host cell cytoplasm where it cleaves the host protein SNAP-25, a member of the SNARE protein family, which is responsible for fusion. The cleaved SNAP-25 cannot mediate fusion of vesicles with the host cell membrane, thus preventing the release of the neurotransmitter acetylcholine from axon endings. This blockage is slowly reversed as the toxin loses activity and the SNARE proteins are slowly regenerated by the affected cell. The seven toxin serotypes (A–G) are traditionally separated by their antigenicity. They have different tertiary structures and sequence differences. While the different toxin types all target members of the SNARE family, different toxin types target different SNARE family members. The A, B, and E serotypes cause human botulism, with the activities of types A and B enduring longest in vivo (from several weeks to months). Existing toxin types can recombine to create "hybrid" (mosaic, chimeric) types. Examples include BoNT/CD, BoNT/DC, and BoNT/FA, with the first letter indicating the light chain type and the latter indicating the heavy chain type.
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.