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 2026-07-14 and is reviewed periodically as new material appears.
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.
Stability depends strongly on pH, temperature and the presence of oxygen and trace metals. Cleavage of the backbone proceeds faster under neutral to alkaline conditions, whereas acidic solutions tend to slow that reaction. The aspartate and glutamate side chains can undergo deamidation or imide formation over time, generating closely related impurities. Published stability data specific to epitalon are sparse, so the usable life of a given solution is best regarded as an open question that depends on buffer composition, concentration and storage temperature.
Identity and purity are usually assessed by reversed-phase high-performance liquid chromatography with ultraviolet detection, frequently near 214 nanometers where the peptide bond absorbs. Mass spectrometry, most often with electrospray ionization, confirms the observed molecular mass and helps separate the intact peptide from truncated or modified forms. Amino acid analysis or tandem mass spectrometry can establish residue order. Purity is commonly quoted as an area percentage, yet such values are method-dependent, and comparisons between laboratories require matching column, gradient and detection wavelength.
| 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 |
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.
Several names circulate for the same molecule, including epitalon, epithalone, epithalamin tetrapeptide, and the sequence code AEDG. A CAS registry number, 307297-39-8, is commonly cited for it, though catalogue entries should be checked against supplier documentation because mislabelled records occur. In its usual form the peptide carries free amino and carboxyl termini and is neither glycosylated nor lipidated. Researchers distinguish the defined tetrapeptide from epithalamin itself, a crude pineal preparation containing many peptides that is not chemically characterised.
The most widely cited claim is that epitalon activates telomerase and thereby extends telomere length. Supporting evidence comes largely from cultured human cells, where treatment was associated with increased telomerase activity and delayed replicative senescence. Telomerase activation is a biologically consequential effect, since the enzyme is largely silenced in most somatic cells. However, the route by which a short peptide would reach and act on the enzyme's regulatory machinery has not been established. Independent replication in human trials is scarce, so the link between cell-culture observations and whole-body aging remains an open question.
Human data are limited to small studies, often without the randomization, blinding, or control groups expected in contemporary clinical research. Reported outcomes have included changes in melatonin levels, immune markers, and subjective measures, but sample sizes were generally too small to support firm conclusions. Some reviews treat the peptide as promising while noting methodological weaknesses; others question whether the observed effects are specific. The compound is frequently discussed in longevity-focused communities, where enthusiasm often outpaces the published evidence. Separating established findings from speculation is therefore important when reading summaries of this research.
Uranium is pyrophoric when finely divided. It will corrode under the influence of air and water producing insoluble uranium(IV) and soluble uranium(VI) salts. Soluble uranium salts are toxic. Uranium slowly accumulates in several organs, such as the liver, spleen, and kidneys. The World Health Organization has established a daily "tolerated intake" of soluble uranium salts for the general public of 0.5 micrograms per kilogram (3.5×10−6 gr/lb) body weight, or 35 micrograms (0.00054 gr) for a 70 kilograms (150 lb) adult. Epidemiological studies and toxicological tests on laboratory animals point to it as being immunotoxic, teratogenic, neurotoxic, with carcinogenic and leukemogenic potential. A 2005 report by epidemiologists concluded: "the human epidemiological evidence is consistent with increased risk of birth defects in offspring of persons exposed to DU." Early studies of depleted uranium aerosol exposure assumed that uranium combustion product particles would quickly settle out of the air and thus could not affect populations more than a few kilometers from target areas, and that such particles, if inhaled, would remain undissolved in the lung for a great length of time and thus could be detected in urine. Violently burning uranium droplets produce a gaseous vapor comprising about half of the uranium in their original mass. Uranyl ion contamination in uranium oxides has been detected in the residue of DU munitions fires. Approximately 90 micrograms (0.0014 gr) of natural uranium, on average, exist in the human body as a result of normal intake of water, food and air.
This excretion of glucose in the urine, which does not seem to disturb other blood electrolytes, is accompanied by some diuresis which may be what contributes to many other physiological functions, potentially explaining its place in heart failure treatment. Empagliflozin was approved for medical use in the United States and in the European Union in 2014. It is on the World Health Organization's List of Essential Medicines. In 2023, it was the 34th most commonly prescribed medication in the United States, with more than 16 million prescriptions. It received approval as a generic medication from the US Food and Drug Administration (FDA) in 2022.
Tempeh can also be differentiated according to its degrees of maturity (i.e. the mycelium's growth/age). Tempe mondhol is a tempeh that is not fully fermented, that is, the mycelium has not fully covered the surface. The taste of the beans is more solid and profound. Sometimes tempeh is left to ferment further, creating more pungent varieties: tempe wayu (day-old tempeh), i.e. when the tempeh starts to age; tempe semangit (a few-days old tempeh), i.e. when the tempeh becomes yellowish, a bit slimy, and the smell becomes more potent; and tempe bosok (lit. 'rotten tempeh'), when the mycelium has acquired a blackened coloration and the product has a putrid smell. Some types of tempeh are made of ingredients that would be otherwise wasted if not used. According to traditional Javanese customs, wasting food is deemed as a sign of disrespect to Nature and other beings, and encourages efforts to use every part of an ingredient. The wrappings used in tempeh making can contribute to its flavor and aroma. Though some prefer the traditional banana, waru or teak leaf, readily available plastic sheet wrappings have been increasingly widely used.
Little Caesars produces a variety of pizzas. Several core menu items are part of the HOT-N-READY menu, designed to make popular items available for immediate carry-out, while others are considered either specialty pizzas or custom pizzas. In 2013, they added the Deep! Deep! Dish Pizza, a Detroit-style pizza, to the menu. Additional entrée options include flavored Caesar Wings and bread, such as Crazy Bread and Italian Cheese Bread. Select locations offer salads. All Little Caesars locations carry Pepsi products. Little Caesars also sells brownies. In 1996, they introduced Pizza by the Foot, a three-foot-long rectangular pizza. The product has since been discontinued; however, its equivalent, Pizza by the Meter, has been sold in the Saudi Arabian market since the 90s and is a top-rated product. On occasion, Little Caesars releases limited time offers. In 2014, they introduced the Soft Pretzel Crust Pizza, and in 2015, the "Bacon Wrapped Deep! Deep! Dish Pizza." In May 2019, Little Caesars began testing a pizza with meatless sausage made by Impossible Foods. In June 2020, Little Caesars reintroduced Stuffed Crazy Bread. They first introduced it in 1995. The original Crazy Bread was first introduced in 1982. As of May 15, 2023, Little Caesars introduced Crazy Puffs in Canada as a handheld snack made with pizza dough filled with cheese, pepperoni, and sauce, topped with garlic sauce and herbs. They later launched in the U.S. on March 11, 2024, offering both pepperoni and cheese varieties.
Sources: en.wikipedia.org
end-group A constitutional unit that occupies a terminal position within or is at an extremity of a macromolecule or polymer, and thus by definition is connected to only one other constitutional unit of the molecule.
==== Groups and labels ==== AAA (band), Triple A, or Attack All Around, a Japanese pop band The AAA Girls or The American Apparel Ad Girls, a drag queen trio Against All Authority (-AAA-), an American ska-punk band Acid Angel from Asia (AAA), the first sub-unit of K-pop girl group TripleS American Accordionists' Association
== Research == In supramolecular chemistry, cyclodextrins are precursors to mechanically interlocked molecular architectures, such as rotaxanes and catenanes. Illustrative, α-cyclodextrin form second-sphere coordination complex with tetrabromoaurate anion ([AuBr4]-). β-Cyclodextrin complexes with certain carotenoid food colorants have been shown to intensify color, increase water solubility and improve light stability. Complexes formed between β-cyclodextrin and adamantane derivatives have been used to make self-healing materials, such as hydrogels and low-friction surfaces. Using the host-guest interaction between β-Cyclodextrin and Perfluorohexane, acoustically active nanoparticles were created. These nanoparticles were combined with histotripsy, leading to the development of Nanoparticle-Mediated Histotripsy (NMH). NMH addresses limitations of traditional histotripsy, such as non-selectivity and the requirement for high pressure. This promising new method has potential applications in cell ablation for various purposes, including cancer treatment.
Antiparasitics are a class of medications indicated for the treatment of infectious diseases such as leishmaniasis, malaria and Chagas disease, which are caused by parasites such as nematodes, cestodes, trematodes and infectious protozoa. Antiparasitic medications include metronidazole, iodoquinol and albendazole. Like all therapeutic antimicrobials, they must kill the infecting organism without serious damage to the host.
In Greece, during a civil war involving the communist-led partisan movement ELAS-EAM, British Special Forces terminated arms supplies to the ELA-ELAM, pro-monarchist armed forces were strengthened. On the political front, Americans, with British encouragement, attempted to dismantle ELAS-EAM socialist structures in the countryside, and an anti-communist swing gradually occurred. Western Allies conducted meetings in Italy in March 1945 with German representatives to forestall a takeover by Italian communist resistance forces in northern Italy and to hinder the potential there for post-war influence of the civilian Italian Communist Party. The affair caused a major rift between Stalin and Churchill, and in a letter to Roosevelt on 3 April Stalin complained that the secret negotiations did not serve to "preserve and promote trust between our countries".
Sources: en.wikipedia.org
=== Gastrointestinal === CCK is synthesized and released by enteroendocrine cells in the mucosal lining of the small intestine (mostly in the duodenum and jejunum), called I cells, neurons of the enteric nervous system, and neurons in the brain. It is released rapidly into the circulation in response to a meal. The greatest stimulator of CCK release is the presence of fatty acids and/or certain amino acids in the chyme entering the duodenum. In addition, release of CCK is stimulated by monitor peptide (released by pancreatic acinar cells), CCK-releasing protein (via paracrine signalling mediated by enterocytes in the gastric and intestinal mucosa), and acetylcholine (released by the parasympathetic nerve fibers of the vagus nerve). Once in the circulatory system, CCK has a relatively short half-life.
=== DNA repair === Repair of DNA double-strand breaks can occur by either of two processes, non-homologous end joining (NHEJ) or homologous recombination (HR). A-type lamins promote genetic stability by maintaining levels of proteins that have key roles in NHEJ and HR. Mouse cells deficient for maturation of prelamin A show increased DNA damage and chromosome aberrations and have increased sensitivity to DNA damaging agents. In progeria, the inability to adequately repair DNA damages due to defective A-type lamin may cause aspects of premature aging (also see DNA damage theory of aging).
Potassium salts such as carnallite, langbeinite, polyhalite, and sylvite form extensive evaporite deposits in ancient lake bottoms and seabeds, making extraction of potassium salts in these environments commercially viable. The principal source of potassium – potash – is mined in Canada, Russia, Belarus, Kazakhstan, Germany, Israel, the U.S., Jordan, and other places around the world. The first mined deposits were located near Staßfurt, Germany, but the deposits span from Great Britain over Germany into Poland. They are located in the Zechstein and were deposited in the Middle to Late Permian. Canada leads the world production of potash; the easiest deposits to mine lie 1,000 meters (3,300 feet) below the surface of the Canadian province of Saskatchewan. The water of the Dead Sea is used by Israel and Jordan as a source of potash, while the concentration in normal oceans is too low for commercial production at current prices.
First generation cephalosporins were the first cephalosporins on the market. They have good antimicrobial activity against gram-positive bacteria but limited activity against gram-negative species. The chemical structures of the first generation cephalosporins are fairly simple. As an example three drugs from this class (cefalexin, cefradine and cefadroxil) all have a single methyl group at position C-3. The common side groups at C-3 for first class cephalosporins are small uncharged groups like methyl. The methyl group at position C-3 gives low affinity for common PBP which can in part explain the relatively low activity of these first drugs. Cefaclor however has a Cl group at position C-3 which gives it better binding to PBP and thus better antimicrobial activity. There is not an agreement on classifying cefaclor as a first generation cephalosporin because of the Cl group at the C-3 position and therefore its improved activity, but it is often classified as such because of its C-7 side chain which is more related to the first generation than the second. All of the first generation cephalosporins have an α-amino group at position C-7. This structure makes them vulnerable to hydrolysis by β-lactamases.
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.
The dry powder is typically held at -20 degrees Celsius or lower, protected from light and moisture. Allowing a sealed vial to reach room temperature before opening reduces condensation on its contents. Conditions stated on a supplier certificate of analysis take precedence over general guidance.