epitalon raises a handful of sensible questions. This page answers them in order, starting with the fundamentals and moving to applications.
This page was last updated on 2025-11-10 and is reviewed periodically as new material appears.
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.
| 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 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.
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.
=== Epstein's coefficient of difference === Epstein's coefficient of difference is based on the differences in polarity and size between replaced pairs of amino acids. This index that distincts the direction of exchange between amino acids, described by 2 equations:
== External links == The History of the Darcy–Weisbach Equation Archived 2011-07-20 at the Wayback Machine Darcy–Weisbach equation calculator Pipe pressure drop calculator Archived 2019-07-13 at the Wayback Machine for single phase flows. Pipe pressure drop calculator for two phase flows. Archived 2019-07-13 at the Wayback Machine Open source pipe pressure drop calculator. Web application with pressure drop calculations for pipes and ducts ThermoTurb – A web application for thermal and turbulent flow analysis
Combating Terrorism Center: 20–23. Hitti, Philip K. (1966). The Origins of the Druze People: With Extracts from Their Sacred Writings. AMS Press. Kratschkowsky, I. & Halm, Heinz (1993). "al-Muḳtanā". In Bosworth, C. E.; van Donzel, E.; Heinrichs, W. P. & Pellat, Ch. (eds.). The Encyclopaedia of Islam, Second Edition. Volume VII: Mif–Naz. Leiden: E. J. Brill. p. 544. doi:10.1163/1573-3912_islam_SIM_5483. ISBN 978-90-04-09419-2. Van Leeuwen, Richard (1994). Notables and Clergy in Mount Lebanon: The Khāzin Sheikhs and the Maronite Church, 1736–1840. BRILL. ISBN 978-90-04-09978-4. Levi Della Vida, G. (2000). "Taym Allah". In Bearman, P. J.; Bianquis, Th.; Bosworth, C. E.; van Donzel, E. & Heinrichs, W. P. (eds.). The Encyclopaedia of Islam, Second Edition. Volume X: T–U. Leiden: E. J. Brill. pp. 400–401. ISBN 978-90-04-11211-7. Makarim, Sami Nasib (1974). The Druze Faith. Caravan Books. ISBN 978-0-88206-003-3. McGrath, Alister E. (2006). Christianity: An Introduction. John Wiley & Sons. pp. 4–6. ISBN 978-1-4051-0899-7. Archived from the original on September 10, 2015. Retrieved August 14, 2015. Mishaqa, Mikhail (1988). Thackston, Wheeler McIntosh (ed.). Murder, Mayhem, Pillage, and Plunder: The History of the Lebanon in the 18th and 19th Centuries by Mikhayil Mishaqa (1800-1873). State University of New York Press. ISBN 978-0-88706-712-9. Morgenstern, Julian (1966). The Rites of Birth, Marriage, Death, and Kindred Occasions Among the Semites. Hebrew Union College Press. Olsaretti, Alessandro (December 2008). "Political Dynamics in the Rise of Fakhr al-Din, 1590-1633".
=== Priority review voucher (PRV) === The priority review voucher is a provision of the Food and Drug Administration Amendments Act of 2007, which awards a transferable "priority review voucher" to any company that obtains approval for a treatment for a neglected tropical diseases. The system was first proposed by Duke University faculty David Ridley, Henry Grabowski, and Jeffrey Moe in their 2006 Health Affairs paper: "Developing Drugs for Developing Countries". President Obama signed into law the Food and Drug Administration Safety and Innovation Act of 2012, which extended the authorization until 2017. In April 2026, the scope of the voucher system was expanded through an executive order aimed at accelerating the approval of mental health treatments that have received Breakthrough Therapy designations. This order established non-transferable National Priority Vouchers (NPV), specifically designed for psychedelic-assisted therapies and psychoplastogens.
=== Production === Polystyrene is an addition polymer that results when styrene monomers polymerize (interconnect). This can be started by applying heat or benzoyl peroxide to styrene as initiators. As a liquid or a gas, pure styrene will polymerise spontaneously to polystyrene, without the need of external initiators. In the polymerization, the carbon–carbon π bond of the vinyl group is broken, and a new carbon–carbon σ bond is formed, attaching to the carbon of another styrene monomer to the chain. Since only one kind of monomer is used in its preparation, it is a homopolymer. The newly formed σ bond is stronger than the π bond that was broken, thus it is difficult to depolymerize polystyrene. About a few thousand monomers typically comprise a chain of polystyrene, giving a molar mass of 100,000–400,000 g/mol.
Sources: en.wikipedia.org
=== Depression === A variety of meta-analyses have been conducted to evaluate the efficacy of paroxetine in depression. They have variously concluded that paroxetine is superior to placebo and that it is equivalent to other antidepressants. Despite this, there was no clear evidence that paroxetine was better or worse compared with other antidepressants at increasing response to treatment at any point in time.
== Manufacturing == Remdesivir requires "70 raw materials, reagents, and catalysts" to make, and approximately "25 chemical steps." Some of the ingredients are extremely dangerous to humans, especially trimethylsilyl cyanide. The original end-to-end manufacturing process required 9 to 12 months to go from raw materials at contract manufacturers to finished product, but after restarting production in January 2020, Gilead Sciences was able to find ways to reduce the production time to six months. In January 2020, Gilead began working on restarting remdesivir production in glass-lined steel chemical reactors at its manufacturing plant in Edmonton, Alberta. On 2 February 2020, the company flew its entire stock of remdesivir, 100 kilograms in powder form (left over from Ebola research), to its filling plant in La Verne, California, to start filling vials. The Edmonton plant finished its first new batch of remdesivir in April 2020. Around the same time, fresh raw materials began to arrive from contract manufacturers reactivated by Gilead in January. Another challenge is getting remdesivir into patients despite the drug's "poor predicted solubility and poor stability." In June 2020, Ligand Pharmaceuticals revealed that Gilead has been managing those issues by mixing Ligand's proprietary excipient Captisol (based on University of Kansas research into cyclodextrin) with remdesivir at a 30:1 ratio.
=== FDA Warning === On February 12, 2007, after an advisory committee discussion and vote in December 2006, the FDA announced a revision to the labeling of Ketek. The changes included the removal of two of the three previously approved indications: acute bacterial sinusitis and acute bacterial exacerbations of chronic bronchitis. The agency determined that the balance of benefits and risks no longer supported approval of the drug for these indications. Ketek remained on the market for the treatment of community acquired bacterial pneumonia of mild to moderate severity (acquired outside of hospitals or long-term care facilities). In addition, the FDA worked with the manufacturer to update the product labeling with a "black box warning," their strongest form of warning. Ketek's warning states that it should not be used in patients with myasthenia gravis, a disease that causes muscle weakness. Following this decision, Sanofi-Aventis withdrew the drug from active sales in the United States.
== Academic and professional activities == Throughout 37 years of activity, Mendes published some 150 articles, During this time, he created various inventions and innovations in the field of Implant Surgery, Bio materials, Orthopedic instruments and surgical techniques. As a result, he is the owner of several international patents. Mendes introduced the Total Knee Arthroplasty operation for the first time in Israel, a technology he studied in the USA. By combining materials developed in Germany and France, he was able to extend the service life of the implant. As part of his activities in the Center for Implant Surgery, Mendes created a platform for cooperation with researchers from the Technion, the Hebrew University and the high tech industry. These efforts were directed at the investigation of influence of different types of energy on bone restructure and fracture healing, development of new implants and replacement parts for joints and ligaments and contributed to the arising field of Computed Tomography. Together with International teams financed by the German-Israel Foundation, Mendes managed several research efforts into the replacement of ligaments with synthetic fibers and the design of artificial replacement of the bony patella.
Sources: en.wikipedia.org
== Side effects == The most concerning side effects, as with other aminoglycosides, are kidney toxicity and ear toxicity. Transient or permanent deafness may result. The vestibular portion of cranial nerve VIII (the vestibulocochlear nerve) can be affected, resulting in tinnitus, vertigo, ataxia, kidney toxicity, and can potentially interfere with diagnosis of kidney malfunction. Common side effects include vertigo, vomiting, numbness of the face, fever, and rash. Fever and rashes may result from persistent use. Use is not recommended during pregnancy. Congenital deafness has been reported in children whose mothers received streptomycin during pregnancy. Use appears to be okay while breastfeeding. It is not recommended in people with myasthenia gravis.
=== Photothermal agents === Gold nanorods are being investigated as photothermal agents for in-vivo applications. Gold nanorods are rod-shaped gold nanoparticles whose aspect ratios tune the surface plasmon resonance (SPR) band from the visible to near-infrared wavelength. The total extinction of light at the SPR is made up of both absorption and scattering. For the smaller axial diameter nanorods (~10 nm), absorption dominates, whereas for the larger axial diameter nanorods (>35 nm) scattering can dominate. As a consequence, for in-vivo studies, small diameter gold nanorods are being used as photothermal converters of near-infrared light due to their high absorption cross-sections. Since near-infrared light transmits readily through human skin and tissue, these nanorods can be used as ablation components for cancer, and other targets. When coated with polymers, gold nanorods have been observed to circulate in-vivo with half-lives longer than 6 hours, bodily residence times around 72 hours, and little to no uptake in any internal organs except the liver. Despite the unquestionable success of gold nanorods as photothermal agents in preclinical research, they have yet to obtain the approval for clinical use because the size is above the renal excretion threshold. In 2019, the first NIR-absorbing plasmonic ultrasmall-in-nano architecture has been reported, and jointly combine: (i) a suitable photothermal conversion for hyperthermia treatments, (ii) the possibility of multiple photothermal treatments and (iii) renal excretion of the building blocks after the therapeutic action.
The three substrates of this enzyme are santonin, reduced nicotinamide adenine dinucleotide (NADH), and a proton. Its products are 1,2-dihydrosantonin and oxidised NAD+. The enzyme can also use nicotinamide adenine dinucleotide phosphate as an alternative cofactor. This enzyme belongs to the family of oxidoreductases, specifically those acting on the CH-CH group of donor with NAD+ or NADP+ as acceptor. The systematic name of this enzyme class is 1,2-dihydrosantonin:NAD(P)+ 1,2-oxidoreductase.
Pulp degeneration Increasing age Orthodontic treatment Traumatic occlusion Dental caries Pulp stones usually consist of circular layers of mineralised tissues. These layers are made up of blood clots, dead cells and collagen fibres. Occasionally, pulp stones appear surrounded by odontoblast-like cells that contain tubules. Pulp stones can reach as high as 50% in surveyed samples. Pulp stones are estimated to typically range from 8–9%. Pulpal calcifications are more common in females and more frequent in maxillary teeth compared to mandibular teeth. The reason is uncertain. They are more common in molar teeth, especially first molars compared to second molars and premolars. A review suggested this was because the first molars are the first teeth to be located in the mandible (lower jaw) and have longer exposure to degenerative changes. They also have a larger blood supply. In general, pulp stones do not require treatment. Depending on the stones' size and location, they may interfere with endodontic treatment and should be removed.
RNA-targeted therapies are being explored for severe genetic epilepsies; for example, ASO-mediated knockdown of KCNT1 has been investigated as an experimental approach for KCNT1-associated epileptic encephalopathy in humans, as well as in prenatal models. Non-viral vectors, virus vectors and liposomes have been used to deliver the antisense RNA through the cell membrane into the cytoplasm and nucleus. It has been found that the viral vector based delivery is the most advantageous among different delivery systems because it has a high transfection efficacy. However, it is difficult to deliver antisense RNA only to the targeted sites. Also, due to the size and the stability issues of antisense RNA, there are some limitations to its use. To improve the delivery issues, chemical modifications, and new oligonucleotide designs have been studied to enhance the drug distribution, side effects, and tolerability.
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. Its sequence was derived from research on peptide fractions of bovine pineal extract, and the intact AEDG sequence has not been demonstrated as an abundant free peptide in human tissue.