This is a working overview of AEDG, written for readers who want more than a one-paragraph summary but less than a textbook.
This page was last updated on 2026-06-26 and is reviewed periodically as new material appears.
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.
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 |
|---|---|---|
| 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.
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.
As of 2019, there were an estimated 72,000 centenarians living in the U.S.; the 2020 census officially counted 80,139, and the 2010 census had 53,364. However, the U.S. Census Bureau claimed in 1999 that as many as a third of people stating their age as over 100 might be exaggerating. In the United States, centenarians may request a letter of congratulation from the president of the United States to mark their longevity. Strom Thurmond became the first sitting Senator to reach 100 on 5 December 2002. Jimmy Carter became the first former president to reach the age of 100 on 1 October 2024. Today also presents a segment honoring centenarians and older, sponsored by Smuckers. The tradition was created in 1983 by weather presenter Willard Scott, and is now presented by his successor Al Roker. In the state of New Mexico, centenarians have been exempt from state income tax since tax year 2002, if they are not dependents of another taxpayer.
Xanthoria parietina's extreme resilience has made it a focus of astrobiology and space-exposure research. Lichens are among the most stress-tolerant life forms, and X. parietina, with its strong UV defenses, has been tested for survivability in space and Mars-like conditions. Laboratory experiments simulating outer space conditions (high vacuum, cosmic UV radiation) exposed the lichen to 10–14 days of extreme stress. The lichen survived, remained metabolically active, and resumed growth after treatment, proving its short-term viability in space environments. Laboratory tests have further demonstrated the lichen's extraordinary cold tolerance, with dry samples surviving immersion in liquid nitrogen at temperatures below −182 °C (−295.6 °F). Building on these findings, X. parietina was tested under simulated Martian conditions in a 2023 study. Samples were exposed for 30 days to low pressure, a CO2-rich atmosphere, extreme temperature shifts, and high UV radiation. The lichen's health was monitored using chlorophyll fluorescence and structural analysis. It survived the full 30 days, retained photosynthetic ability, and maintained structural integrity, though UV-exposed samples showed reduced efficiency and some pigment degradation. Given this resilience, researchers suggested X. parietina as a candidate for long-term space exposure, such as on the International Space Station or satellites. A 2024 study further examined X. parietina's physiological resilience under simulated Martian conditions.
==== Elimination ==== Pseudoephedrine is excreted primarily via the kidneys in urine. Its urinary excretion is highly influenced by urinary pH and is increased when the urine is acidic and is decreased when it is alkaline. The elimination half-life of pseudoephedrine on average is 5.4 hours and ranges from 3 to 16 hours depending on urinary pH. At a pH of 5.6 to 6.0, the elimination half-life of pseudoephedrine was 5.2 to 8.0 hours. In one study, a more acidic pH of 5.0 resulted in a half-life of 3.0 to 6.4 hours, whereas a more alkaline pH of 8.0 resulted in a half-life of 9.2 to 16.0 hours. Substances that influence urinary acidity and are known to affect the excretion of amphetamine derivatives include urinary acidifying agents like ascorbic acid and ammonium chloride as well as urinary alkalinizing agents like acetazolamide. A majority of an oral dose of pseudoephedrine is excreted unchanged in urine within 24 hours of administration. This has been found to range from 43 to 96%. The amount excreted unchanged is dependent on urinary pH similarly to the drug's half-life, as a longer half-life and duration in the body allows more time for the drug to be metabolized. The duration of action of pseudoephedrine, which is dependent on its elimination, is 4 to 12 hours. Pseudoephedrine has been reported to accumulate in people with renal impairment.
=== Acute effects === The median lethal dose (LD50) for acute radiation exposure is about 4.5 Sieverts (Sv). The committed effective dose equivalent 210Po is 0.51 μSv/Becquerel (Bq) if ingested, and 2.5 μSv/Bq if inhaled. A fatal 4.5 Sv dose can be caused by ingesting 8.8 MBq (240 μCi), about 50 nanograms (ng), or inhaling 1.8 MBq (49 μCi), about 10 ng. One gram of 210Po could thus in theory poison 20 million people, of whom 10 million would die. The actual toxicity of 210Po is lower than these estimates because radiation exposure that is spread out over several weeks (the biological half-life of polonium in humans is 30 to 50 days) is less damaging than an instantaneous dose. It has been estimated that a median lethal dose of 210Po is 15 megabecquerels (0.41 mCi), or 0.89 micrograms (μg). For comparison, one grain of table salt is about 0.06 mg = 60 μg.
Amarasate is a supplement developed to trigger the "Bitter Brake" satiety mechanism, whereby bitter foods targeted to the small intestine trigger the release of the same appetite suppressing gut hormones that are typically elevated after a meal. The Bitter Brake concept was developed based on a combination of historical data supporting the use of bitter foods as a means to suppress appetite, and the discovery of bitter taste receptors (TAS2Rs) in appetite regulating enteroendocrine cells of the gastrointestinal tract. In vitro and biopsy research had identified TAS2Rs throughout the gastrointestinal tract and over 900 plant compounds were tested, with amarasate found to be a potent TAS2R activator. The role of gastrointestinal taste receptors has been examined in animal and human trials and a 2021 meta-analysis determined that pre-meal treatment with bitter compounds reduced energy intake, concluding that "bitter stimuli are most potent to influence eating behaviour".
Sources: en.wikipedia.org
They set out to determine whether or not the 13-minute isotope was indeed an isotope of protactinium. Between 1934 and 1938, Hahn, Meitner and Strassmann found a great number of radioactive transmutation products, all of which they regarded as transuranic. At that time, the existence of actinides was not yet established, and uranium was wrongly believed to be a group 6 element similar to tungsten. It followed that the first transuranic elements would be similar to group 7 to 10 elements, i.e. rhenium and platinoids. They established the presence of multiple isotopes of at least four such elements, and (mistakenly) identified them as elements with atomic numbers 93 through 96. They were the first scientists to measure the 23-minute half-life of uranium-239 and to establish chemically that it was an isotope of uranium, but were unable to continue this work to its logical conclusion and identify the real element 93. They identified ten different half-lives, with varying degrees of certainty. To account for them, Meitner had to hypothesise a new class of reaction and the alpha decay of uranium, neither of which had ever been reported before, and for which physical evidence was lacking. Hahn and Strassmann refined their chemical procedures, while Meitner devised new experiments to shine more light on the reaction processes.
A systemic disease is one that affects a number of organs and tissues, or affects the body as a whole. It differs from a localized disease, which is a disease affecting only part of the body (e.g., a mouth ulcer).
Biodistribution of 14C-labelled docetaxel in three patients showed the bulk of the drug to be metabolised and excreted in bile to the faeces. Of the radioactively labelled docetaxel administered, 80% was eliminated to the faeces with 5% in the urine over seven days, an indication that urinary excretion of docetaxel is minimal. Saliva contributed minimal excretion and no excretion was detected through pulmonary means. The terminal half-life of docetaxel was determined as approximately 86 hours, through prolonged plasma sampling, contrary to the clinically stated terminal half-life of 10–18 hours.
=== Arts critics === Gustav Kobbé (1877), opera scholar and music critic of the New York Herald Clifton Fadiman (1925), book critic for The New Yorker and judge for the Book of the Month Club Edward Downes (1933), music critic, former host on the Metropolitan Opera radio broadcasts, son of music critic Olin Downes Ralph J.
Sources: en.wikipedia.org
Hypertension treated with a β-blocker such as atenolol, alone or in conjunction with a thiazide diuretic, is associated with a higher incidence of new onset type 2 diabetes mellitus compared to those treated with an ACE inhibitor or angiotensin receptor blocker. β-blockers, of which atenolol is mainly studied, provides weaker protection against stroke and mortality in patients over 60 years old compared to other antihypertensive medications. Diuretics may be associated with better cardiovascular and cerebrovascular outcomes than β-blockers in the elderly. Rarely, atenolol has been associated with induction of acute delirium.
=== Mechanism of action === Bisoprolol is cardioprotective because it selectively and competitively blocks catecholamine (adrenaline) stimulation of β1 adrenergic receptors (adrenoreceptors), which are mainly found in the heart muscle cells and heart conduction tissue (cardiospecific), but also found in juxtaglomerular cells in the kidney. Normally, adrenaline and noradrenaline stimulation of the β1 adrenoreceptor activates a signalling cascade (Gs protein and cAMP) which ultimately leads to increased myocardial contractility and increased heart rate of the heart muscle and heart pacemaker, respectively. Bisoprolol competitively blocks the activation of this cascade, so decreases the adrenergic tone/stimulation of the heart muscle and pacemaker cells. Decreased adrenergic tone shows less contractility of heart muscle and lowered heart rate of pacemakers.
== Function == In KYNU reaction, PLP facilitates Cβ-Cγ bond cleavage. The reaction follows the same steps as the transamination reaction but does not hydrolyze the tautomerized Schiff base. The proposed reaction mechanism involves an attack of an enzyme nucleophile on the carbonyl carbon (Cγ) of the tautomerized 3hKyn-PLP Schiff base. This is followed by Cβ-Cγ bond cleavage to generate an acyl-enzyme intermediate together with a tautomerized Ala-PLP adduct. Hydrolysis of the acyl-enzyme then yields 3hAnt.
The unsanitary conditions engendered by the war, severe overcrowding in barracks, wartime propaganda interfering with public health warnings, and migration of so many soldiers around the world helped the outbreak become a pandemic. Ultimately, World War I created a decisive break with the old world order that had emerged after the Napoleonic Wars, which was modified by the mid-19th century's nationalistic revolutions. The results of World War I would be important factors in the development of World War II approximately 20 years later.
== Early life and education == Milan Mrksich (Serbian Cyrillic: Милан Мркшић) was born on August 15, 1968, to Serbian immigrants and raised in Justice, Illinois. He graduated from University of Illinois at Urbana-Champaign in 1989 with a B.S. in chemistry working in the laboratory of Steven Zimmerman on molecular tweezers. He completed his PhD in organic chemistry in 1994 from Caltech under chemist Peter B. Dervan. After graduate school, he was an American Chemical Society postdoctoral fellow at Harvard University under chemist George M. Whitesides before joining the faculty at the University of Chicago in 1996. He worked there for 15 years before joining the faculty at Northwestern University in 2011.
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 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.