epithalamin comes up often in conversation and rarely with the context attached. Here we lay out the basics in order, then work through the practical considerations.
Updated 2026-04-16. Numbers and descriptions here follow the published literature rather than marketing material.
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.
Thiamine was the first of the water-soluble vitamins to be isolated. The earliest observations in humans and in chickens had shown that diets of primarily polished white rice caused beriberi, but did not attribute it to the absence of a previously unknown essential nutrient. In 1884, Takaki Kanehiro, a surgeon general in the Imperial Japanese Navy, rejected the previous germ theory for beriberi and suggested instead that the disease was due to insufficiencies in the diet. Switching diets on a navy ship, he discovered that replacing a diet of white rice only with one also containing barley, meat, milk, bread, and vegetables, nearly eliminated beriberi on a nine-month sea voyage. However, Takaki had added many foods to the successful diet and he incorrectly attributed the benefit to increased protein intake, as vitamins were unknown at the time. The Navy was not convinced of the need for such an expensive program of dietary improvement, and many men continued to die of beriberi, even during the Russo-Japanese War of 1904–05. Not until 1905, after the anti-beriberi factor had been discovered in rice bran (removed by polishing into white rice) and in barley bran, was Takaki's experiment rewarded. He was made a baron in the Japanese peerage system, after which he was affectionately called "Barley Baron". The specific connection to grain was made in 1897 by Christiaan Eijkman, a military doctor in the Dutch East Indies, who discovered that fowl fed on a diet of cooked, polished rice developed paralysis that could be reversed by discontinuing rice polishing.
Only four days after making this proclamation, the great announcement of the Independence of Argentina took place, with a large majority of the assembly members opting for the suggested monarchical form that, in addition, should have its headquarters in the city of Cuzco, the capital of the projected New Kingdom. Only Godoy Cruz and part of his collaborators demanded that said capital be in Buenos Aires. According to this "Plan del Inca", it would be an effective and constitutional parliamentary-style government, similar to the British one, to achieve prompt international recognition of Argentine independence. His proposal to establish a parliamentary Inca monarchy was ridiculed by his contemporaries who supported the formation of a republic, the original project was rejected mainly for reasons of anti-Peruvian racism. The Buenos Aires delegates expressed their total rejection of the delusional idea, almost without being heard. It is said that one of them came to shout there: "I'd rather be dead than serve a king with flip flops!"; and that the journalists from Buenos Aires mocked the decision, assuring that now he would have to go look for "a dirty-legged king in some grocery store or tavern in the Altiplano". The Congress of Tucumán finally decided to reject the Inca's plan because anti-Peruvian fellings, creating in its place a republican and centralist state with its capital in Buenos Aires.
=== Karyotyping === The routine chromosome analysis (Karyotyping) refers to analysis of metaphase chromosomes which have been banded using trypsin followed by Giemsa, Leishmanns, or a mixture of the two. This creates unique banding patterns on the chromosomes. The molecular mechanism and reason for these patterns are unknown, although it's likely related to replication timing and chromatin packing. Several chromosome-banding techniques are used in cytogenetics laboratories. Quinacrine banding (Q-banding) was the first staining method used to produce specific banding patterns. This method requires a fluorescence microscope and is no longer as widely used as Giemsa banding (G-banding). Reverse banding, or R-banding, requires heat treatment and reverses the usual black-and-white pattern that is seen in G-bands and Q-bands. This method is particularly helpful for staining the distal ends of chromosomes. Other staining techniques include C-banding and nucleolar organizing region stains (NOR stains). These latter methods specifically stain certain portions of the chromosome. C-banding stains the constitutive heterochromatin, which usually lies near the centromere, and NOR staining highlights the satellites and stalks of acrocentric chromosomes. High-resolution banding involves the staining of chromosomes during prophase or early metaphase (prometaphase), before they reach maximal condensation.
This causes a slow accumulation of mutations and results in the development of cancers. An example of such a hereditary cancer syndrome is xeroderma pigmentosum, which causes the development of skin cancers in response to even minimal exposure to ultraviolet light.
Sources: en.wikipedia.org
== Pharmacology == The antibody component of inotuzumab ozogamicin binds to CD22 receptors, which are expressed mostly on B cells. The whole conjugate is then drawn into the cell, where the ozogamicin is cleaved from the antibody by the acidic environment of the lysosome. The ozogamicin eventually travels to the nucleus where it breaks up DNA, causing the cell to die.
===== Acrididae ===== Locust swarming is initiated but not maintained by serotonin, with release being triggered by tactile contact between individuals. This transforms social preference from aversion to a gregarious state that enables coherent groups. Learning in flies and honeybees is affected by the presence of serotonin.
=== Regeneration === Earthworm adults have the ability to regenerate lost segments, but this ability varies between species and the extent of damage as well as genetic factors within the same species. Earthworm regeneration is known from the 17th century, but the cellular mechanisms in play remain incompletetly understood. Regeneration involves epimorphosis, i.e. dedifferentiation of extant tissues followed by generation of new body tissues. The first stage of regeneration after an injury (mostly caused by a predator or agricultural machinery) is wound healing, followed by cell death, formation of a blastema and stem cell proliferation while mechanisms help the newly regenerated segments to determine polarity and positional identity within the body. It has been shown that regeneration takes place only in the presence of an intact clitellum. Earthworms are able to regenerate both anterior (head with brain included) and posterior segments, the intestine participating in head regeneration. Earthworm extracts have been used for thousand of years as a traditional Chinese medicine for wound healing, and their efficacy has been attested by a recent meta-analysis of 16 published human and animal model studies.
One of the earliest patents for a "chain sawing machine" comprising a chain of links carrying saw teeth was granted to Frederick L. Magaw of Flatlands, New York, in 1883, apparently for the purpose of producing boards by stretching the chain between grooved drums. A later patent incorporating a guide frame was granted to Samuel J. Bens of San Francisco on January 17, 1905, his intent being to fell giant redwoods. The first portable chainsaw was developed and patented in 1918 by Canadian millwright James Shand. After he allowed his rights to lapse in 1930, his invention was further developed by what became the German company Festo in 1933. The company, now operating as Festool, produces portable power tools. Other important contributors to the modern chainsaw are Joseph Buford Cox and Andreas Stihl; the latter patented and developed an electric chainsaw for use on log bucking sites in 1926 and a gasoline-powered chainsaw in 1929, and founded a company to mass-produce them. In 1927, Emil Lerp, the founder of Dolmar, developed the world's first gasoline-powered chainsaw and mass-produced them. World War II interrupted the supply of German chainsaws to North America, so new manufacturers sprang up, including Industrial Engineering Ltd (IEL) in 1939, the forerunner of Pioneer Saws Ltd and part of Outboard Marine Corporation, the oldest manufacturer of chainsaws in North America. The first one-man chainsaw was introduced in 1950, though it was relatively heavy.
Powdered alcohol is made by a process called micro-encapsulation. An auxiliary material for a capsule may be any readily water-soluble substance (e.g. carbohydrate such as dextrins (starch hydrolyzate), protein such as gelatin). For powdered alcohol, maltodextrin (a type of dextrin) was chosen. For the process to encapsulate, a method called spray drying was selected. In this process, a mixture of dextrin and the alcoholic drink is subjected to simultaneous spraying and heating. The spraying converts the liquid to small drops (up to several hundred μm (micrometers) in diameter), and the heat causes the hydrous dextrin to form a film. When the film dries, the drop becomes a microcapsule containing a dehydrated alcoholic drink and dextrin. Drying removes about 90% of the water and 10% of the ethanol from the initial liquid. An explanation for this preferential loss of water over volatile organics like ethanol is called "selective diffusion": a carbohydrate (in this case, maltodextrin) film forms during spray-drying on each droplet. The film allows smaller molecules like water to go through, but not larger ones like ethanol. As a result, more water is lost. The film is formed in about 0.1 second from the creation of the droplet by spraying. There is no time for the internal convection in each drop or capsule to occur. The end result of spray-drying is large amounts of microcapsules with the appearance of a powder. This is powdered alcohol. According to Sato's web page, powdered alcohol contains 30.5% ethyl alcohol by volume in the state of powder.
Sources: en.wikipedia.org
== Regulation == eNOS expression and activity are carefully controlled by multiple interconnected mechanisms of regulation present at the transcriptional, posttranscriptional, and posttranslational levels. Binding of transcription factors such as Sp1, Sp3, Ets-1, Elf-1, and YY1 to the NOS3 promoter and DNA methylation represents an important mechanism of transcriptional regulation. Posttranscriptionally, eNOS is regulated by modifications of the primary transcript, mRNA stability, subcellular localization, and nucleocytoplasmatic transport. Posttranslational modifications of eNOS include fatty acid acylation, protein-protein interactions, substrate, and co-factor availability, and degree of phosphorylation. Importantly, eNOS is attached by myristoylation and palmitoylation to caveolae, a pocket-like invagination on the membrane rich in cholesterol and sphingolipids. With the binding of eNOS to caveolae, the enzyme is inactivated due to the strong and direct interaction of eNOS with caveolin-1. The binding of calcium-activated calmodulin to eNOS displaces caveolin-1 and activates eNOS. However, more recent studies have questioned the hypothesis that caveolin-1 directly binds to eNOS, as the region of the caveolin-1 protein proposed to bind to eNOS may be inaccessible due to its location in the plasma membrane. As a result, the specifics of how caveolin-1 interacts with eNOS to regulate eNOS activity are still unclear. Moreover, eNOS activation is dynamically regulated by multiple phosphorylation sites at tyrosine, serine, and threonine residues.
Basketball is one of the most popular sports in Hong Kong, with the A1 Division Championship serving as the city's top-tier amateur league since 1954. Historically, the sport gained regional prominence through the success of clubs like Regal, which won the 1997 ABC Champions Cup, and more recently, Hong Kong Eastern.
Rock salt has been mined at Lake Afrera, and the surrounding part of the Afar Depression, for centuries. Lt. Lefebvre recorded some of the hazards of mining salt from the Depression, which he heard from one of the miners himself:
== Chemistry == ETH-LAD, also known as 9,10-didehydro-N,N,6-triethylergoline-8β-carboxamide or as 6-ethyl-6-nor-LSD, is a substituted lysergamide derivative related to lysergic acid diethylamide (LSD; also known as METH-LAD). It is the 6-ethyl derivative of nor-LSD (6-nor-LSD; H-LAD) and is the derivative of LSD with an ethyl group instead of methyl group at the 6 position of the ergoline ring system.
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.