A practical reference on AEDG: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
Reviewed 2025-07-15. Anything still debated is marked as such rather than presented as settled.
The compound is described in the literature as a derivative of epithalamin, a preparation obtained from bovine pineal tissue. Work on this peptide family was carried out mainly by a research group in Saint Petersburg beginning in the 1980s, and the substance was later registered for clinical use in Russia under the name Epitalon. Outside that region it is generally treated as a research chemical rather than an approved medicine. Statements about its biological activity rest on a relatively small number of studies, and independent replication remains limited.
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.
Residue composition is the property that most cleanly separates verified material from mislabelled samples. Alanine, glutamate, aspartate and glycine appear in that order from the N-terminus, and the two acidic residues sit in the middle of the chain. Because the peptide is short, it can be produced by solid-phase synthesis and characterised by mass spectrometry without ambiguity. Any reported sample whose measured mass departs substantially from 390 daltons is a different compound or a degraded mixture rather than epitalon.
Epitalon is a synthetic tetrapeptide whose four residues are alanine, glutamate, aspartate and glycine, commonly abbreviated AEDG. Its molecular formula is C14H22N4O9 and its monoisotopic mass is near 390.35 daltons. The peptide carries two acidic side chains, so it is neutral to negatively charged in most aqueous buffers. Published reference summaries usually list it under both spellings, epitalon and epithalon, and treat the two names as the same material.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic tetrapeptide | Four residues, linear chain |
| Residue sequence | Ala-Glu-Asp-Gly | Single-letter form AEDG |
| Calculated mass | 390.3 daltons | Value for the free, uncharged form |
| Appearance | White to off-white powder | Usually supplied lyophilized |
| Solubility | Freely soluble in water | Often handled as a salt form |
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.
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.
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.
==== Ion exchange chromatography ==== Ion exchange chromatography is often employed in the first step, or capturing step, for the separation of PEGylated proteins as PEGylation may affect the charges of target proteins by neutralizing electrostatic interaction, changing the isoelectric point (pI), and increasing the pKa value. Due to the high pI of lysozyme (pI = 10.7), cation exchange chromatography is used. As the increased degree of PEGylation decreases the ion strength of the protein, the poly-PEGylated proteins tend to bind to the cation resin weaker than the mono-PEGylated protein or the intact form does. Thus, the poly-PEGylated proteins elute faster and the intact protein eludes last in the cation exchange chromatography. As mono-PEGylated is widely investigated and described as a protection of target proteins, the target eluate in the cation exchange chromatography is usually the mono-PEGylated proteins.
== Operational history == In 2006 and 2007, the Stiletto participated in Trident Warrior exercises, as well as a number of other naval exercises. This included three days of mine-clearing experimentation during Exercise Howler in 2006, when the vessel was operated by the Naval Special Clearance Team-1 (NSCT-1) from the Naval Amphibious Base in Coronado. A key feature of this vessel is that it can set up a network between a special forces team by launching an unmanned aerial vehicle (UAV) that relays information between the team and boat. The Stiletto can also carry surveillance UAVs to provide reconnaissance for the SEAL team, and, using a clustered supercomputer on board, will be able to send real-time images to the team on shore. The Stiletto was selected by Time magazine as one of the Best Inventions of 2006 and one of two inventions in the Armed Forces category. In 2008, the Stiletto deployed on a 70-day mission for USSOUTHCOM as part of a joint agency operation that included the Drug Enforcement Administration and U.S. Coast Guard. In July 2012, the US Navy deployed the Stiletto to retrieve the NASA Inflatable Reentry Vehicle Experiment 3 (IRVE-3) test article, a 3 m (9.8 ft) diameter heat shield, which splashed down in the Atlantic Ocean off North Carolina after being launched on July 23 by a sounding rocket from NASA's Wallops Flight Facility. The Stiletto is referenced as a maritime demonstration craft operated by the Naval Surface Warfare Center Carderock, Combatant Craft Division, and based at Joint Expeditionary Base Little Creek-Ft Story, Va.
=== Pharmacotherapy === Sodium thiosulfate is commonly prescribed for treatment in patients with calciphylaxis. The actual mechanism of the drug is unknown, but several explanations have been proposed, including chelation of calcium, vasodilation, antioxidant properties, and restoration of endothelial function. Adverse effects of sodium thiosulfate include high anion gap metabolic acidosis and high sodium levels (hypernatremia). Bisphosphonates are a popular choice for the treatment of osteoporosis, but they have also been used to treat calciphylaxis even though the exact mechanism in calciphylaxis is unknown. They are most beneficial in patients who have a genetic ENPP1 deficiency and have been shown to slow development of calciphylaxis lesions in a small prospective study. Cinacalcet (medication parathyroidectomy) is an oral medication that can be used to suppress the parathyroid glands for patients who may not be able to undergo surgical parathyroidectomy. Vitamin K supplementation has also been shown to slow development of calcification in coronary arteries and the aortic valve in older patients. The ability of vitamin K supplementation to slow calcification of blood vessels in calciphylaxis is not well-studied. Warfarin, a vitamin K antagonist discussed above, should be discontinued if possible. Other acceptable treatments may include one or more of the following:
The three substrates of this enzyme are saccharopine, oxidised nicotinamide adenine dinucleotide (NAD+), and water. Its products are L-glutamic acid, L-allysine, reduced NADH, and a proton. This enzyme belongs to the family of oxidoreductases, specifically those acting on the CH-NH group of donors with NAD+ or NADP+ as acceptor. The systematic name of this enzyme class is N6-(L-1,3-dicarboxypropyl)-L-lysine:NAD+ oxidoreductase (L-glutamate-forming). Other names in common use include dehydrogenase, saccharopine (nicotinamide adenine dinucleotide,, glutamate-forming), saccharopin dehydrogenase, NAD+ oxidoreductase (L-2-aminoadipic-delta-semialdehyde and, glutamate forming), aminoadipic semialdehyde synthase, saccharopine dehydrogenase (NAD+, L-glutamate-forming), 6-N-(L-1,3-dicarboxypropyl)-L-lysine:NAD+ oxidoreductase, and (L-glutamate-forming). This enzyme participates in lysine degradation.
=== Industrial applications === Casein proteins, which are about 80% of the proteins in cow milk and between 20% and 60% in human milk. Xylanases, enzymes which degrade the linear polysaccharide xylan into xylose, thus breaking down hemicellulose, one of the major components of plant cell walls Proteases, an enzyme which catalyze proteolysis, breaking down proteins into smaller polypeptides or single amino acids. They have found applications in both the industrial (such as the food industry). and domestic settings. Whey proteins, which are about 20% of the proteins in cow milk and 60% in human milk.
Sources: en.wikipedia.org
The pelycosaurs are synapsids (more closely related to mammals) while the ctenosauriscids are archosaurs (closely related to crocodilians, pterosaurs and dinosaurs). Also, the spinosaurids had sail-like fins on their backs, when they were not closely related to either. Also, Acrocanthosaurus and Ouranosaurus, which are not closely related to either pelycosaurs, ctenosauriscids or spinosaurids, also had similar, but thicker, spines on their vertebrae. Noasaurus, Baryonyx, and Megaraptor, all unrelated, all had an enlarged hand claw that were originally thought to be placed on the foot, as in dromaeosaurs. A similarly modified claw (or in this case, finger) is on the hand of Iguanodon. The ornithopods had feet and beaks that resembled that of birds, but are only distantly related. Three groups of dinosaurs, the Tyrannosauridae, Ornithomimosauria, and the Troodontidae, all evolved an arctometatarsus, independently. Some placodonts (like Cyamodus, Psephoderma, Henodus and especially Placochelys) bear striking resemblance to sea turtles (and turtles in general) in terms of size, shell, beak, mostly toothless jaws, paddle-shaped limbs and possibly other adaptations for aquatic lifestyle.
The NHS Grampian health board announcing it is to divert ambulance patients to hospitals outside its area because of "critical" pressure on its largest hospital. 29 November – Finlay MacDonald, who carried out a series of shootings on the Isle of Skye and the Scottish mainland, which included the fatal shooting of his brother-in-law, is sentenced to life imprisonment with a minimum term of 28 years. GP leaders in Scotland vote in favour of a motion to ballot workers on industrial action over pay, following what they describe as "years of disinvestment in general practice". 30 November – The Proclaimers perform at a memorial service for former first minister Alex Salmond, held at Edinburgh's St Giles' Cathedral.
Adiponectin Resistin Plasminogen activator inhibitor-1 (PAI-1) TNFα IL-6 Leptin Estradiol (E2) Adipose tissues also secrete a type of cytokines (cell-to-cell signalling proteins) called adipokines (adipose cytokines), which play a role in obesity-associated complications. Perivascular adipose tissue releases adipokines such as adiponectin that affect the contractile function of the vessels that they surround.
==== Parkinson's disease ==== Creatine's impact on mitochondrial function has led to research on its efficacy and safety for slowing Parkinson's disease. As of 2014, the evidence did not provide a reliable foundation for treatment decisions, due to risk of bias, small sample sizes, and the short duration of trials.
Sources: en.wikipedia.org
The peptide contains four residues in the order alanine, glutamate, aspartate and glycine, abbreviated AEDG. The chain is linear and held together by three peptide bonds. Its calculated mass for the uncharged free form is about 390.3 daltons.
Epithalamin refers to a crude preparation derived from bovine pineal tissue, which contains many components. Epitalon is a single synthetic tetrapeptide identified from that material and produced by chemical synthesis. The two names are sometimes confused because early reports treated the synthetic peptide as an active fragment of the extract.
It has been registered for clinical use in Russia, where it is associated with a small family of short peptides. In most other jurisdictions it is not an approved medicine and is traded as a research chemical. Regulatory status varies by country and changes over time.
It is a four-amino-acid peptide built from alanine, glutamate, aspartate and glycine in that order. Its formula is C14H22N4O9, and it is made by chemical synthesis rather than extracted from tissue. The synthetic peptide is a single defined molecule, unlike the pineal extracts it is often compared with.