Everything below concerns telomerase. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Updated 2025-11-07. Numbers and descriptions here follow the published literature rather than marketing material.
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.
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.
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.
| 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 |
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.
=== Analogues === Although several related compounds are disclosed in the original patent, no activity data are provided and it was unclear whether these share tianeptine's unique pharmacological effects. More recent structure-activity relationship studies have since been conducted, providing some further insight on μ-opioid, δ-opioid, and pharmacokinetic activity. Derivatives where the aromatic chlorine substituent is replaced by bromine, iodine or methylthio, and/or the heptanoic acid tail is varied in length or replaced with other groups such as 3-methoxypropyl, show similar or increased opioid receptor activity relative to tianeptine, with up to 13x higher potency than tianeptine itself. Amineptine, the most closely related drug to have been widely studied, is a dopamine reuptake inhibitor with no significant effect on serotonin levels, nor opioid agonist activity. Tianeptinaline and tianeptinostat, analogues of tianeptine, are potent histone deacetylase (HDAC) inhibitors.
In the afternoon of 23 September, Xi Jinping boarded an Air China plane and left Beijing for Washington, D.C. He was accompanied by his wife Peng Liyuan, as well as Chinese Communist Party General Office director Cai Qi and Central Foreign Affairs Commission Office director and foreign minister Wang Yi. President Trump and First Lady Melania Trump left the White House at 16:39 EDT (UTC-4:00), and later arrived at Joint Base Andrews in Maryland. Xi's Air China plane landed at the base at 17:39, and a red carpet was placed for the Chinese delegation, who were also greeted by battery salute, three color teams carrying American and Chinese flags, and platoons from each military service. Trump personally greeted Xi, the first time the US President has greeted a foreign leader except the Pope at the base since John F. Kennedy met British prime minister Harold Macmillan in 1962. The United States Air Force Band played the national anthems of China and the United States and a 21-gun salute was fired on site. Two Rockwell B-1 Lancer bombers flew overhead to celebrate Xi's arrival. Trump walked Xi to his car, and afterwards departed to the Marine One by the presidential state car for a flight back to the White House.
=== Hospitals === Most clinical teaching takes place in facilities operated by UNC Health, primarily within the UNC Medical Center complex at the southern tip of the UNC campus. The complex comprises five healthcare facilities collectively known as UNC Hospitals, including North Carolina Memorial Hospital, North Carolina Children’s Hospital, North Carolina Women’s Hospital, North Carolina Neurosciences Hospital, and North Carolina Cancer Hospital. In 2024, the North Carolina Surgical Hospital was opened, featuring 26 new surgical spaces and 80 inpatient rooms. Together, these facilities offer over 1,000 inpatient beds and are ranked as the 2nd best hospital in the state of North Carolina. Additional hospitals and outpatient clinics in the area are also used for training, including the Ambulatory Care Center, the Family Medicine Building, UNC Hillsborough, and UNC Chatham. During the Application Phase (third year) of the school's MD program, students will be matched into one of six regions located across the state of North Carolina to complete their clinical clerkships at local facilities, including:
== Preparation == EDC is commercially available. It may be prepared by coupling ethyl isocyanate to N,N-dimethylpropane-1,3-diamine to give a urea, followed by a dehydration reaction mediated by TsCl and TEA:
Sources: en.wikipedia.org
The word is derived from the Ancient Greek χηλή, chele, meaning "crab pincers", and the suffix -oid, meaning "like". In the 19th century it was known as the "Keloid of Alibert" as opposed to "Addison's keloid" (Morphea). The famous American Civil War-era photograph "Whipped Peter" depicts an escaped former slave with extensive keloid scarring as a result of numerous brutal beatings from his former overseer. Intralesional corticosteroid injections were introduced as a treatment in the mid-1960s as a method to attenuate scarring. Pressure therapy has been used for the prophylaxis and treatment of keloids since the 1970s. Topical silicone gel sheeting was introduced as a treatment in the early 1980s.
== Properties == The S−S bond dissociation energy is 305±21 kJ/mol, about 80 kJ/mol stronger than the S−S bond in diphenyldisulfide. At temperatures above 150 °C (302 °F), S2F10 decomposes slowly (disproportionation) into SF6 and sulfur tetrafluoride (SF4):
On the broader subject of Communism, Lindemann wrote that Peukert's book was flawed by what the reviewer considered his moral blind spot, writing that for Peukert fascism was "a convenient absolute evil; anti-fascism, however flawed in its particulars is thus in some ultimate sense heroic". Lindemann wrote that "the author [Peukert] appears to consider it absurd to suggest the KPD and the NSDAP morally resembled each other. Yet Stalinism in the 1930s was at least as brutish in form as Hitlerism and was responsible, at least until 1939, for many more deaths, indeed for organized murder on an unparalleled scale. The KPD enthusiastically associated itself with the nightmarish inhumanities of Stalin's rule". Lindemann ended his review that Peukert's approach in considering Communist resistance in Nazi Germany to be "heroic" was wrong as the subject of "Communist heroism" in Nazi Germany was more morally nuanced than what Peukert would consider.
Neopentalenolactone D synthase (EC 1.14.13.171, ptlE (gene)) is an enzyme with systematic name 1-deoxy-11-oxopentalenate,NADH:oxygen oxidoreductase (neopentalenolactone-D forming). This enzyme catalyses the following chemical reaction
In December 1940, Franz Simon at Oxford wrote his Estimate of the size of an actual separation plant." Simon proposed gaseous diffusion as the best method for uranium isotope separation. On 28 March 1941, Emilio Segré and Glen Seaborg reported on the "strong indications that 239Pu undergoes fission with slow neutrons." This meant chemical separation was an alternative to uranium isotope separation. Instead, a nuclear reactor fueled with ordinary uranium could produce a plutonium isotope as a nuclear explosive substitute for 235U. In May, they demonstrated the cross section of plutonium was 1.7 times that of U235. When plutonium's cross section for fast fission was measured to be ten times that of U238, plutonium became a viable option for a bomb. In October 1941, MAUD released its final report to the U.S. Government. The report stated, "We have now reached the conclusion that it will be possible to make an effective uranium bomb...The material for the first bomb could be ready by the end of 1943..." In November 1941, John Dunning and Eugene T. Booth were able to demonstrate the enrichment of uranium through gaseous barrier diffusion. On 27 November, Bush delivered to third National Academy of Sciences report to Roosevelt. The report, amongst other things, called for parallel development of all isotope-separation systems. On 6 December, Bush and Conant reorganized the Uranium Committee's tasks, with Harold Urey developing gaseous diffusion, Lawrence developing electromagnetic separation, Eger V.
Sources: en.wikipedia.org
==== Monoamine oxidase B (MAO-B) inhibitors ==== Rasagiline (Agilect; AGN-1135; Azilect; Elbrus; Lu-00-773; TV-1030; TVP-101; TVP-1012) – monoamine oxidase B (MAO-B) inhibitor [338] Safinamide (EMD-1195686; Equfina; FCE-26743; ME-2125; NW-1015; Onstryv; PNU-151774; Xadago; ZP-034) – reversible monoamine oxidase B (MAO-B) inhibitor and other actions [339] Selegiline (Eldepryl, Jumex) – monoamine oxidase B (MAO-B) inhibitor and other actions Selegiline orally disintegrating tablet (Efupi; FPF-1100-NW; selegiline ODT) – monoamine oxidase B (MAO-B) inhibitor and other actions [340]
=== Dehydration of amides and others === Nitriles can be prepared by the dehydration of primary amides. Common reagents for this include phosphorus pentoxide (P2O5) and thionyl chloride (SOCl2). In a related dehydration, secondary amides give nitriles by the von Braun amide degradation. In this case, one C-N bond is cleaved.
=== Apoptosis === During DNA damage or cellular stress PARPs are activated, leading to an increase in the amount of poly(ADP-ribose) and a decrease in the amount of NAD+. For over a decade it was thought that PARP1 was the only poly(ADP-ribose)polymerase in mammalian cells, therefore this enzyme has been the most studied. Caspases are a family of cysteine proteases that are known to play an essential role in programmed cell death. This protease cleaves PARP-1 into two fragments, leaving it completely inactive, to limit poly(ADP-ribose) production. One of its fragments migrates from the nucleus to the cytoplasm and is thought to become a target of autoimmunity. During caspase-independent apoptosis, also called parthanatos, poly(ADP-ribose) accumulation can occur due to activation of PARPs or inactivation of poly(ADP-ribose)glycohydrolase, an enzyme that hydrolyses poly(ADP-ribose) to produce free ADP-ribose. Studies have shown poly(ADP-ribose) drives the translocation of the apoptosis inducing factor protein to the nucleus where it will mediate DNA fragmentation. It has been suggested that if a failure of caspase activation under stress conditions were to occur, necroptosis would take place. Overactivation of PARPs has led to a necrotic cell death regulated by the tumor necrosis factor protein. Though the mechanism is not yet understood, PARP inhibitors have been shown to affect necroptosis.
Kimon Georgiev Stoyanov (Bulgarian: Кимон Георгиев Стоянов; August 11, 1882 – September 28, 1969) was a Bulgarian general who was the Prime Minister of the Kingdom of Bulgaria from 1934 to 1935 and again from 1944 to 1946. He was considered a "master in the art of coup d'états".
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.
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.