A practical reference on reversed-phase HPLC: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
Reviewed 2025-12-02. Anything still debated is marked as such rather than presented as settled.
The four residues give epitalon a molecular formula of C14H22N4O9 and a molecular weight near 390.35 daltons. The presence of two acidic residues, glutamate and aspartate, makes the free peptide strongly acidic, while the alanine and glycine ends provide neutral, nonpolar character. This combination produces a molecule with substantial water solubility. Because there are no cysteine, methionine, or tryptophan residues, the peptide lacks the most common oxidation-sensitive side chains, which simplifies handling compared with many longer peptides.
The proposed relationship between epitalon and pineal function is a central part of its background. Khavinson's group reported that short peptides corresponding to regions of larger pineal proteins could influence gene expression in cells. Epitalon was framed as a synthetic analogue of an active fragment rather than a direct isolation product. Whether the tetrapeptide reproduces the effects of the parent extract is an open question, because comparative studies are limited and the parent extract itself is not a single defined substance.
Interest in epitalon is usually discussed within the broader field of short peptide bioregulators, a category that includes other synthetic di-, tri-, and tetrapeptides studied by the same research group. These compounds share a common rationale: that small fragments of tissue-derived proteins can retain biological activity and can be produced reproducibly. The category as a whole remains outside mainstream pharmacological consensus, and epitalon specifically has a limited presence in independent, non-Russian research literature, which shapes how its evidence base is described.
Laboratory handling begins with dissolution of the lyophilized powder in water or a suitable aqueous buffer. The dry solid is the more stable form, so stock solutions are generally prepared only when required and kept cold afterwards. Repeated freezing and thawing of a solution is avoided because it encourages aggregation and gradual loss of the intact chain. Diluents and containers are selected to limit adsorption of a short peptide onto plastic surfaces and to reduce microbial growth in aqueous preparations.
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 |
|---|---|---|
| Amino acid sequence | Ala-Glu-Asp-Gly | Tetrapeptide, often abbreviated AEDG |
| Molecular formula | C14H22N4O9 | Free peptide, unmodified termini |
| Molecular weight | ~390.35 Da | Calculated for the free acid form |
| Appearance | White to off-white powder | Typical lyophilized product form |
| Solubility class | Freely soluble in water | Two acidic residues dominate ionic character |
Epitalon is a synthetic four-amino-acid peptide with the sequence alanine-glutamate-aspartate-glycine, commonly abbreviated AEDG. Its molecular formula is C14H22N4O9, and its calculated molar mass is approximately 390.35 grams per mole. The compound is a short fragment related to a peptide fraction isolated from bovine pineal gland extracts, and it is normally supplied as a lyophilised powder intended for laboratory research. It is not a registered pharmaceutical product in most countries.
The peptide emerged from research carried out in Saint Petersburg from the late 1980s onward, where investigators searched for shorter active fragments of a pineal preparation known as epithalamin. The name epitalon was chosen to reflect that parent extract. Early reports described effects on neuroendocrine markers and on the lifespan of laboratory animals. Much of that work appeared in Russian-language journals, with English translations following later, which affects how readily the original protocols can be assessed by outside groups.
Published studies on epitalon are dominated by a small number of research groups, and independent replication in other laboratories remains limited. Proposed mechanisms include activation of telomerase and modulation of melatonin rhythms, but the evidence for either rests mainly on cell cultures and animal models. Whether the peptide produces comparable effects in humans is an open question, and the absence of large controlled trials means the literature is best read as exploratory rather than settled.
Reference material is normally supplied as a lyophilised powder in a sealed vial. Product literature typically recommends storage at minus twenty degrees Celsius or colder, protected from light and moisture. Freeze-thaw cycling is usually avoided because repeated condensation can introduce water into the vial. Working solutions are commonly prepared fresh, aliquoted, and kept cold for short periods rather than stored at ambient temperature. Labelling the date of opening helps track how long a vial has been in use.
Solubility is high in water, phosphate-buffered saline and normal saline, a pattern that follows from the two acidic residues in the chain. The peptide dissolves poorly in non-polar solvents such as hexane or chloroform. Stock solutions are often prepared in water first and then diluted into the buffer of interest. Because the molecule is small and hydrophilic, filtration through a low-protein-binding membrane is usually straightforward, and visible particulates are uncommon in freshly made solutions.
（TG:@pojiaai）Epitalon is a synthetic linear tetrapeptide with the sequence alanine-glutamate-aspartate-glycine, abbreviated AEDG. It emerged from work on epithalamin, a peptide fraction prepared from bovine pineal tissue, and was designed as a short, chemically defined analogue of that extract. Early publications came mainly from Russian laboratories studying pineal peptides and aging-related endpoints. The compound appears in the literature under several spellings, including epithalon and epithalone, which complicates systematic searching. Its small size makes solid-phase assembly and routine analytical characterization straightforward.
Chemically, the molecule consists of four amino acid residues joined by three peptide bonds, with a free N-terminal amino group and a free C-terminal carboxyl group. Its molecular formula is C14H22N4O9, and its monoisotopic mass is approximately 390 daltons. The acidic glutamate and aspartate side chains give the peptide a net negative charge near neutral pH, a property that shapes its chromatographic behaviour and solubility profile. No disulfide bridges or other post-translational modifications are present, so the primary sequence alone defines the structure.
Gerald Kaufman (21 June 1930 – 26 February 2017) politician, journalist, broadcaster and author who served as a minister throughout the Labour government of 1974 to 1979; elected as member of parliament (MP) at the 1970 general election, he became Father of the House and served until 2017; served as chair of the Culture, Media and Sport Committee; was knighted in 2004; was assistant general secretary of Fabian Society; was leader writer on Daily Mirror and journalist on New Statesman; also worked as television writer, contributing to BBC Television's satirical programme That Was The Week That Was; was member of Poale Zion (later the Jewish Labour Movement) but became disillusioned with Israel because of its treatment of the Palestinian territories. Michael Kauffmann FBA (5 February 1931 – 30 June 2023), art historian and author of numerous scholarly monographs and academic publications; Director of the Courtauld Institute, London and Fellow of the British Academy; held posts at the Warburg Institute, Manchester City Art Gallery, and the Victoria and Albert Museum; was son of noted art historian, art dealer and scholar Arthur Kauffmann, both of German Jewish ancestry; died on 30 June 2023, at the age of 92. Adam Kay (writer) (born 12 June 1980) comedy writer, author, comedian and former doctor. His television writing credits include Crims, Mrs. Brown's Boys and Mitchell and Webb. He is best known as author of the number-one bestselling book This Is Going to Hurt.
=== Chronic wounds === A 2015 review found that the evidence supporting the use of electrotherapy in healing pressure ulcers was of low quality, and a 2015 Cochrane review found no evidence that electromagnetic therapy, a subset of electrotherapy, was effective in healing pressure ulcers. Earlier reviews found that, because of low-quality evidence, it was unclear whether electrotherapy increases healing rates of pressure ulcers. By 2014 the evidence supported electrotherapy's efficacy for ulcer healing. Another 2015 Cochrane review found no evidence supporting the use of electrotherapy for venous stasis ulcers.
=== Other films about Soviet Union–United States fears and rivalry === The Third Man (1949) – A major subplot deals with the refugee status of a Czechoslovak woman, and the Russian attempts to deport her back to Czechoslovakia. The Russians Are Coming the Russians Are Coming (1966) – A film about a Soviet submarine that accidentally runs aground near a small New England town. Russian Roulette (1975) – A film starring George Segal about a Canadian Mounty attempting to stop a KGB plot to assassinate a Soviet premier in Vancouver. Telefon (1977) – A film starring Charles Bronson and Donald Pleasence about the net of deep-cover sleeper agents in the US who are being activated by the deserted KGB agent. The Return of Godzilla (1984) — In the 16th installment of the Toho Godzilla franchise, a Soviet nuclear submarine is destroyed by the titular creature, causing tensions between the Soviet Union & America until it is proven by the Japanese government that Godzilla was responsible for its destruction. Later in the movie, a Russian nuclear missile is accidentally fired at Godzilla from a space satellite until an American missile detonates it in the stratosphere long before it can strike Godzilla in Tokyo. Rocky IV (1985) – In this installment of the Rocky saga, Rocky Balboa has to fight Ivan Drago, an extremely powerful boxer from the Soviet Union. Spies Like Us (1985) – A comedy film starring Dan Aykroyd and Chevy Chase as decoy agents send to infiltrate the Soviet Union.
Sources: en.wikipedia.org
== Credits == Band members Udo Dirkschneider – lead vocals, harmony vocals (4, 9, 10), backing vocals (1, 8), finger snapping (8) Wolf Hoffmann – lead & rhythm guitars (all except 9), rhythm guitar (9), acoustic guitar (1, 10), backing vocals (1, 6, 7, 10), electric sitar (1) Jörg Fischer – rhythm guitar (all except 4, 9), lead & rhythm guitars (4, 9), 8-string bass (3), backing vocals (1, 6, 7, 10), finger snapping (8) Peter Baltes – bass, Moog Taurus (1, 5, 7, 10), 8-string bass (1, 8, 10), backing vocals (1, 6, 7, 10), harmony vocals (2, 5), acoustic bass guitar (8) Stefan Kaufmann – drums, backing vocals (1, 6, 7, 10), timpani (1, 8, 10), cymbals and gongs (1), drum effects and gang vocals (3) Production Dieter Dierks – producer, arrangements Gerd Rautenbach – engineer Mike Kashnitz, Peter Brandt – assistant engineers Bob Ludwig – mastering at Masterdisk, New York Gaby "Deaffy" Hauke – management, cover concept Dirksen & Sohn Modellwerkstâtten, Stahl, Werbefotografie – cover art
NRgize Lifestyle Cafe (United States) Planet Smoothie – a chain of smoothie restaurants with stores in Alabama, Arizona, Arkansas, California, Florida, Georgia, Maryland, Massachusetts, Nebraska, New York, North Carolina, Pennsylvania, South Carolina, Texas and Virginia. Pinkberry – a chain of frozen dessert restaurants with locations in Canada, Chile, Egypt, India, Indonesia, Japan, Nigeria, Saudi Arabia, Jordan, Panama, Peru, Oman, Qatar, United Arab Emirates, United States, Philippines and Thailand. Ranch One – a chain of restaurants specializing in grilled chicken breast sandwiches, with locations in Kuwait and the United States. Rollerz (California, D.C., Illinois, Nevada and Texas) Samurai Sam's Teriyaki Grill (Kuwait and United States) Surf City Squeeze – a chain of smoothie restaurants with stores in Canada, Saudi Arabia, Curaçao/Netherlands Antilles and United States. Sweet Frog - a chain of frozen yogurt restaurants with stores in the United States (East Coast, South, Mideast, Midwest, West Coast only) and the Dominican Republic. Taco Time (Canada, Kuwait, Curaçao/Netherlands Antilles; and United States, except locations primarily in western Washington state operated by Taco Time Northwest) Tasti D-Lite – a New York-based fast food company which mainly sells frozen dessert products, it has locations in Florida, Maryland, Nevada, New Jersey, New York and Texas.
== Blood levels == Blood levels are in the pmol/L or fmol/mL range. Both active and total ghrelin can be measured. Circulating ghrelin concentrations rise before eating and fall afterward, more strongly in response to protein and carbohydrate than to lipids. The plasma ghrelin-like immunoreactivity concentration measured with a particular radioimmunoassay in a typical human is 166.0 + 10.1 fmol/mL. Serum ghrelin concentrations tend to increase in age and vary throughout the day, with values peaking while one is asleep.
Sources: en.wikipedia.org
=== Bacteria and viruses === Some hepatitis C viral glycoproteins may attach to host-produced C-type lectins on the liver cell surface to initiate infection. Mannose-binding lectin (MBL), a component of the innate immune system, paradoxically enhances Ebola cell entry. Some viruses, including influenza and several viruses in the Paramyxoviridae family, use a lectin (see Hemagglutinin § Viruses) to attach to tissue-specific glycans on host cell-surface glycoproteins and glycolipids. This allows them to gain entry into target cells. Pathogenic bacteria express surface lectins known as adhesins, similarly tuned to recognize target cells. These proteins help the bacteria adhere to its victim and establish a foodhold. Bacterial adhesins/lectins also play a role in keeping the bacterium attached to the biofilm, which typically has a carbohydrate framework.
== Prognosis == Androgenic alopecia is typically experienced as a "moderately stressful condition that diminishes body image satisfaction". However, although most men regard baldness as an unwanted and distressing experience, they usually can cope and retain integrity of personality. Although baldness is not as common in women as in men, the psychological effects of hair loss tend to be much greater. Typically, the frontal hairline is preserved, but the density of hair is decreased in all areas of the scalp. Previously, it was believed to be caused by testosterone, just as in male baldness, but most women who lose hair have normal testosterone levels.
=== Myomesin 1 === Myomesin 1 is the most researched of the forms of myomesin due to its presence in all striated muscles and that it is the largest of the myomesin class. It is sometimes just simply called myomesin because of it widespread expression. Myomesin 1 is found in mainly on the M4/M4' lines of the M-band. It is encoded by the MYOM1 gene. There are two variants of myomesin 1, one located between the My6 and My7 domains, and the other at the end of the C-terminal after the My13 domain. The prior is known as the embryonic heart (EH)-sequence and the latter, which has only been found in birds, is called the H or S splice variant (H is for heart and S is for skeletal). EH-myomesin can be found during embryonic development of the human heart (later replaced by myomesin 2). As the muscle matures, EH-myomesin is downregulated in favor of myomesin 1 with no genetic variations.
Sources: en.wikipedia.org
Epitalon is a synthetic tetrapeptide composed of four amino acids: alanine, glutamate, aspartate, and glycine. It is written as Ala-Glu-Asp-Gly. The free peptide has a molecular weight of about 390 daltons and is normally supplied as a lyophilized powder.
No. Epitalon is chemically synthesized, not extracted. It was designed as a short synthetic fragment conceptually related to larger pineal peptides studied in the same research tradition, particularly the extract known as epithalamin. The two are distinct materials with different compositions.
The term bioregulator is used in this research tradition for short peptides proposed to influence gene expression or cell function. Epitalon is grouped with other synthetic short peptides under this label. The term reflects a proposed mechanism rather than an established drug classification.
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.