A practical reference on telomerase: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
This page was last updated on 2026-02-27 and is reviewed periodically as new material appears.
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.
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.
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.
| 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 |
== Further reading == Albert, A.; Serjeant, E.P. (1971). The Determination of Ionization Constants: A Laboratory Manual. Chapman & Hall. ISBN 0-412-10300-1. (Previous edition published as Ionization constants of acids and bases. London (UK): Methuen. 1962.) Atkins, P.W.; Jones, L. (2008). Chemical Principles: The Quest for Insight (4th ed.). W.H. Freeman. ISBN 978-1-4292-0965-6. Housecroft, C. E.; Sharpe, A. G. (2008). Inorganic Chemistry (3rd ed.). Prentice Hall. ISBN 978-0-13-175553-6. (Non-aqueous solvents) Hulanicki, A. (1987). Reactions of Acids and Bases in Analytical Chemistry. Horwood. ISBN 0-85312-330-6. (translation editor: Mary R. Masson) Perrin, D.D.; Dempsey, B.; Serjeant, E.P. (1981). pKa Prediction for Organic Acids and Bases. Chapman & Hall. ISBN 0-412-22190-X. Reichardt, C. (2003). Solvents and Solvent Effects in Organic Chemistry (3rd ed.). Wiley-VCH. ISBN 3-527-30618-8. Chapter 4: Solvent Effects on the Position of Homogeneous Chemical Equilibria. Skoog, D.A.; West, D.M.; Holler, J.F.; Crouch, S.R. (2004). Fundamentals of Analytical Chemistry (8th ed.). Thomson Brooks/Cole. ISBN 0-03-035523-0.
Thomas Powers, "The Nuclear Worrier" (review of Daniel Ellsberg, The Doomsday Machine: Confessions of a Nuclear War Planner, New York, Bloomsbury, 2017, ISBN 9781608196708, 420 pp.), The New York Review of Books, vol. LXV, no. 1 (18 January 2018), pp. 13–15. "Presidency in the Nuclear Age", conference and forum at the JFK Library, Boston, October 12, 2009. Four panels: "The Race to Build the Bomb and the Decision to Use It", "Cuban Missile Crisis and the First Nuclear Test Ban Treaty", "The Cold War and the Nuclear Arms Race", and "Nuclear Weapons, Terrorism, and the Presidency". Tom Stevenson, "A Tiny Sun" (review of Fred Kaplan, The Bomb: Presidents, Generals, and the Secret History of Nuclear War, Simon and Schuster, 2021, 384 pp.; and Keir A. Lieber and Daryl G. Press, The Myth of the Nuclear Revolution: Power Politics in the Atomic Age, Cornell, 2020, 180 pp.), London Review of Books, vol. 44, no. 4 (24 February 2022), pp. 29–32. "Nuclear strategists systematically underestimate the chances of nuclear accident... [T]here have been too many close calls for accidental use to be discounted." (p. 32.) Jacobsen, Annie (2024). Nuclear War: A Scenario. Hypothetical minute-by-minute examination of how a nuclear first strike could escalate to global thermonuclear war within 72 minutes, based on interviews with military officials and declassified documents. Lee Billings, "The Quest for a Theory of Everything: A Breakthrough Prize winner warns nuclear war could prevent reaching the holy grail of physics", Scientific American, vol. 335, no. 2 (September 2026), pp. 90–93.
Kenan Christopher Garcia (also known as K. Christopher Garcia) is an American scientist known for his research on the molecular and structural biology of cell surface receptors. Garcia is a professor in the Departments of Molecular and Cellular Physiology and Structural Biology at the Stanford University School of Medicine, an Investigator of the Howard Hughes Medical Institute and a member of the National Academies of Science and Medicine. In addition to his role at Stanford, Garcia is a co-founder of several biotechnology companies, including Alexo Therapeutics, Surrozen, and 3T Biosciences.
== History of adipose-derived hormones == It had been shown that adipose tissue secreted some unknown factor that influenced appetite. However, the importance of adipose tissue as an endocrine organ was only fully appreciated in 1995 with the discovery of leptin, the protein product of the Ob gene. Leptin is a strong appetite suppressant that, when depleted, causes early onset severe obesity in humans and in animal models. Low levels of leptin in the blood plasma have been heavily associated with people who have moderate to severe forms of depression. Leptin is known to influence moods and cognition by inducing some structural and functional changes within the hippocampus and prefrontal cortex. Also, leptin has been shown to activate signal transduction pathways associated with dopamine and mTOR, which can increase synaptogenesis. Leptin's role in neuroplasticity is currently still being elucidated, but it has been proven to be active in regions of the brain closely linked to depression. It was found that leptin has antidepressant-like effects similar to that of selective serotonin reuptake inhibitors (SSRIs). The discovery of leptin and its effects on appetite led to hopes of a treatment for obesity and type 2 diabetes, a major disease in the developed world. Unfortunately, clinical studies using leptin as a treatment for obesity in humans failed to show improvement, leading some scientists to conclude that the brain can become resistant to leptin, even at supra-physiological levels (the so-called "ceiling effect"), rendering treatment with leptin ineffective.
== Concrete fracture analysis == Concrete fracture analysis is part of fracture mechanics that studies crack propagation and related failure modes in concrete. As it is widely used in construction, fracture analysis and modes of reinforcement are an important part of the study of concrete, and different concretes are characterized in part by their fracture properties. Common fractures include the cone-shaped fractures that form around anchors under tensile strength.
Sources: en.wikipedia.org
Early undiagnosed rheumatic diseases such as preclinical rheumatoid arthritis, early stages of inflammatory spondyloarthritis, polymyalgia rheumatica, myofascial pain syndromes and hypermobility syndrome. Neurological diseases that can have important pain and fatigue components include multiple sclerosis, Parkinson's disease and peripheral neuropathy. Other medical illnesses that should be ruled out are endocrine disease or metabolic disorder (hypothyroidism, hyperparathyroidism, acromegaly, vitamin D deficiency), gastro-intestinal disease (celiac and non-celiac gluten sensitivity), infectious diseases (Lyme disease, hepatitis C and immunodeficiency disease) and the early stages of a malignancy such as multiple myeloma, metastatic cancer and leukemia/lymphoma. Other systemic, inflammatory, endocrine, rheumatic, infectious, and neurologic disorders may cause fibromyalgia-like symptoms, such as systemic lupus erythematosus, Sjögren's disease, ankylosing spondylitis, Ehlers-Danlos syndromes, psoriatic-related polyenthesitis, a nerve compression syndrome (such as carpal tunnel syndrome), and myasthenia gravis. Several medications can evoke pain (statins, aromatase inhibitors, bisphosphonates, and opioids).
In continuum mechanics, viscosity is a property of a fluid that quantifies the resistance force acting on fluids when there is relative motion between fluid parcels. This resistance force is caused by the stress in fluid parcels, which ideally is directly proportional to the strain rate (the time derivative of strain) that arises when fluid parcels are in relative motion, and the relative speed between the boundary between adjacent fluid parcels is zero. In liquids, viscosity arises from cohesive molecular forces, while in gases it results from molecular collisions. Except for the case of superfluidity, there is no fluid with zero viscosity, and thus all fluid flows involve viscous effects to some degree. For liquids, it corresponds to the informal concept of thickness; for example, syrup has a higher viscosity than water. Viscosity is defined scientifically as a force multiplied by a time divided by an area. Thus its SI units are newton-seconds per metre squared, or pascal-seconds. For instance, when a viscous fluid is forced through a tube, it flows more quickly near the tube's center line than near its walls. Some stress (such as a pressure difference between the two ends of the tube) is needed to sustain the flow. This is because a force is required to overcome the friction between the layers of the fluid which are in relative motion. For a tube with a constant rate of flow, the strength of the compensating force is proportional to the fluid's viscosity. In general, viscosity depends on a fluid's state, such as its temperature, pressure, and rate of deformation.
Martinez (1977), 8th Virginia secretary of transportation and deputy administrator of the United States Maritime Administration David Paterson (1977), first African-American governor of New York Karl Dean (1978), mayor of Nashville Christopher Dell (1978), career diplomat, former US ambassador to Zimbabwe, Angola, and Kosovo Martin J. Dunn (1979), former mayor of Holyoke, Massachusetts and member of the Massachusetts Senate Jim McGreevey (1978), 53rd governor of New Jersey Andres Alonso (1979), former CEO of Baltimore City Public Schools Timothy Horrigan (1979), member of the New Hampshire House of Representatives Randal Quarles (1981), 15th under secretary of the treasury for domestic finance, chair of the Financial Stability Board and vice chairman of the Federal Reserve Andrew C. McCarthy (1981), assistant U.S. attorney and columnist for National Review Charles J. O'Byrne (1981), secretary to the governor of New York Michael Waldman (1982), speechwriter for president Clinton; president of the Brennan Center for Justice John Solecki (1982), U.S. official for the United Nations high commissioner for Refugees, kidnapped in Pakistan by the Balochistan Liberation United Front in 2009 Barack Obama (1983), 44th president of the United States and first African-American to hold the office; former senator from Illinois; winner of the 2009 Nobel Peace Prize Victor Cha (1983), foreign policy expert; President Bush's top advisor on North Korean affairs Jay Lefkowitz (1984), George W.
=== Other routes === Small amounts are formed by electrolysis, photochemistry, electric arc, and related methods. A commercially viable route for hydrogen peroxide via the reaction of hydrogen with oxygen favours production of water but can be stopped at the peroxide stage. One economic obstacle has been that direct processes give a dilute solution uneconomic for transportation. None of these has yet reached a point where it can be used for industrial-scale synthesis. The electrochemical reduction of oxygen allows for the generation of hydrogen peroxide from oxygen and water.
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.
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.