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 2026-04-14. Numbers and descriptions here follow the published literature rather than marketing material.
（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.
Most experimental work has been carried out in cell culture and animal models. Several reports describe changes in telomerase activity and proliferation in cultured cells, while rodent studies have examined lifespan, melatonin rhythm and reproductive endpoints. Human data remain limited, and much of the published clinical material consists of small trials with incomplete reporting of methods and controls. Whether the cell and animal findings translate into measurable effects in people is an open question, and the mechanistic basis of the reported telomerase changes is not fully established.
Epitalon emerged from research conducted in Saint Petersburg by Vladimir Khavinson and colleagues, who studied short peptides as potential regulators of aging. The work built on epithalamin, a pineal gland extract reported to influence neuroendocrine function. Epitalon was designed as a synthetic counterpart with a defined sequence, allowing reproducible experiments that extracts could not support. Early publications described effects on melatonin rhythms and lifespan in animal models. These findings circulated mainly in Russian-language journals during the 1990s, which limited their visibility among English-speaking researchers.
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.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Linear tetrapeptide | Four residues joined by three peptide bonds |
| Sequence | Ala-Glu-Asp-Gly | Commonly abbreviated AEDG |
| Molecular formula | C14H22N4O9 | Free acid form |
| Monoisotopic mass | Approximately 390 Da | Matches values reported from mass spectrometry |
| Net charge near neutral pH | Negative | Contributed by glutamate and aspartate side chains |
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.
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.
Nitrogen compounds have a very long history, ammonium chloride having been known to Herodotus. They were well known by the Middle Ages. Alchemists knew nitric acid as aqua fortis (strong water), as well as other nitrogen compounds such as ammonium salts and nitrate salts. The mixture of nitric and hydrochloric acids was known as aqua regia (royal water), celebrated for its ability to dissolve gold, the king of metals. The discovery of nitrogen is attributed to the Scottish physician Daniel Rutherford in 1772, who called it noxious air. Though he did not recognise it as an entirely different chemical substance, he clearly distinguished it from Joseph Black's "fixed air", or carbon dioxide. The fact that there was a component of air that does not support combustion was clear to Rutherford, although he was not aware that it was an element. Nitrogen was also studied at about the same time by Carl Wilhelm Scheele, Henry Cavendish, and Joseph Priestley, who referred to it as burnt air or phlogisticated air. French chemist Antoine Lavoisier referred to nitrogen gas as "mephitic air" or azote, from the Greek word άζωτικός (azotikos), "no life", because it is asphyxiant. In an atmosphere of pure nitrogen, animals died and flames were extinguished. Though Lavoisier's name was not accepted in English since it was pointed out that all gases but oxygen are either asphyxiant or outright toxic, it is used in many languages (French, Italian, Portuguese, Polish, Russian, Albanian, Turkish, etc.; the German Stickstoff and Dutch stikstof similarly refer to the same characteristic, viz.
=== Solubility === Carboxylic acids are polar. Because they are both hydrogen-bond acceptors (the carbonyl −C(=O)−) and hydrogen-bond donors (the hydroxyl −OH), they also participate in hydrogen bonding. Together, the hydroxyl and carbonyl group form the functional group carboxyl. Carboxylic acids usually exist as dimers in nonpolar media due to their tendency to "self-associate". Smaller carboxylic acids (1 to 5 carbons) are soluble in water, whereas bigger carboxylic acids have limited solubility due to the increasing hydrophobic nature of the alkyl chain. These longer chain acids tend to be soluble in less-polar solvents such as ethers and alcohols. Aqueous sodium hydroxide and carboxylic acids, even hydrophobic ones, react to yield water-soluble sodium salts. For example, enanthic acid has a low solubility in water (0.2 g/L), but its sodium salt is very soluble in water.
With security largely under the purview of the BPC, corporate control of the park has meant that Bryant Park received passive-recreation amenities, while excluding active sports that might cater to a broader urban public. The BPC added a custom-built carousel in 2002 and revived the tradition of an open-air library, the Reading Room, in 2003. In July 2002, the park launched a public wireless network, making the park the first in New York City to formally offer free Wi-Fi access to visitors. The Wi-Fi system was subsequently upgraded in 2008. Furthermore, the Pond, a free-admission ice skating rink, opened in the park in 2005. The park's public restrooms were renovated in 2006 and in 2017. The dramatic rise in real estate values in the area around Bryant Park, as well as new construction in adjacent areas, was a consequence of the park's improvements. By 1993, the surrounding region had become a highly desirable office area, and formerly vacant office space around the park was being filled quickly. By the first decade of the 21st century, nearby buildings and businesses were also using names that referred to the park. This was shown by the then-new Bank of America Tower skyscraper at the park's northeast corner using the address "One Bryant Park", as well as the growing trend of Bryant Park vanity addresses, including 3, 4, 5, and 7 Bryant Park. National Public Radio, located just south of the park, also named a now-defunct talk show the "Bryant Park Project" upon the show's 2007 launch.
Sources: en.wikipedia.org
==== Regulation of sports drinks ==== In July 2024, the FDA revoked its authorization for the use of brominated vegetable oil (BVO), which is a stabilizer for fruity and citrus-flavored food and beverages. BVO has been found to have potential negative consequences for human health. In some studies BVO has been shown to cause an increase in bromide triglycerides level in the heart, lungs and fat tissue. In 2024, few beverages in the U.S. contained BVO, with many companies having phased out BVO in the 21st century, including PepsiCo with Gatorade in 2013, and Coca-Cola with Powerade in 2014. BVO was most commonly found in citrus-flavored drinks.
In 1930, the Grand Coalition fell apart. Heinrich Brüning, from the moderate-conservative wing of the party, was appointed as Chancellor with a cabinet that, apart from the missing Social Democrats, was virtually unchanged. Brüning was confronted with economic crises exacerbated by the Great Depression and had to tackle the difficult tasks of consolidating both budget and currency when faced with rising unemployment, and of also negotiating changes to the war reparations payments. His course of strict budget discipline, with severe cuts in public expenditure, and tax increases made him extremely unpopular among the lower and middle classes as well as among the Prussian Junkers. In 1930, Brüning's failure to gain a majority for his policies in parliament prompted him to call early elections, in which the four parties of the former Grand coalition lost their majority. After this, Brüning based his administration entirely on the support of the presidential decrees ("Notverordnung") through article 48 of the Constitution. This allowed him to circumvent parliament, as long as the Social Democrats - who feared another election - tolerated this practice. For this way of government based on both the President and cooperation of parliament, Brüning coined the term "authoritarian democracy". By this time, the party had become increasingly ambivalent toward democracy. Many elements of the party, including Kaas, had come to believe that only an authoritarian regime could protect the position of the Church.
Another challenge facing efforts to control transmission is the fact that although long-term care facilities have been heavily indicated as the primary centers for incidence, amplification, and spread of CRE, studies that have controlled for this transmission have still found CRE spreading in other affiliated hospitals, indicating that long-term acute-care facilities are likely not the sole culprit in the spread of CRE and other multidrug-resistant organisms. One method found effective is to screen and isolate incoming patients from other facilities, and renew focus on hand washing. No new drugs for the bacteria are in development and the bacteria's rapid adaptation to new drugs makes investment in their development unprofitable, as the new drug would quickly become useless. Studies have found that CRE incidence and prevalence can be reduced by applying targeted interventions including increased hygiene measures and equipment sterilization, even in populations where the prevalence of infection exceeds 50% of patients. However, additional environmental cleaning to control transmission has not been verified by controlled trials. The involvement of local and national public health authorities will likely be critical to ensure broader and more sustainable implementation of these measures. Prevention is a top priority for reducing person-to-person transmission of CRE. This is especially true because limited treatment options are available to use after carbapenem resistance develops.
Sources: en.wikipedia.org
=== Other countries === Legislation has been implemented by Japan, Singapore, and Australia that offers subsidies and other incentives to encourage the development of drugs that treat orphan diseases.
==== Nephrotoxicity ==== The extent of nephrotoxicity for vancomycin remains controversial. In the 1980s, vancomycin with a purity > 90% was available, and kidney toxicity defined by an increase in serum creatinine of at least 0.5 mg/dL occurred in only about 5% of patients. But dosing guidelines from the 1980s until 2008 recommended vancomycin trough concentrations between 5 and 15 μg/mL. Concern for treatment failures prompted recommendations for higher dosing (troughs 15 to 20 μg/mL) for serious infection, and acute kidney injury (AKI) rates attributable to the vancomycin increased. Importantly, the risk of AKI increases with co-administration of other known nephrotoxins, in particular aminoglycosides. Furthermore, the sort of infections treated with vancomycin may also cause AKI, and sepsis is the most common cause of AKI in critically ill patients. Finally, studies in humans are mainly associations studies, where the cause of AKI is usually multifactorial. Animal studies have demonstrated that higher doses and longer duration of vancomycin exposure correlates with increased histopathologic damage and elevations in urinary biomarkers of AKI.37-38 Damage is most prevalent at the proximal tubule, which is further supported by urinary biomarkers, such as kidney injury molecule-1 (KIM-1), clusterin, and osteopontin (OPN). In humans, insulin-like growth factor binding protein 7 (IGFBP7) as part of the nephrocheck test.
=== Pharmacodynamics === Oxprenolol is a beta blocker. In addition, it has been found to act as an antagonist of the serotonin 5-HT1A and 5-HT1B receptors with respective Ki values of 94.2 nM and 642 nM in rat brain tissue.
Sources: en.wikipedia.org
It is a synthetic tetrapeptide with the sequence alanine-glutamate-aspartate-glycine, often abbreviated AEDG. The molecule is linear and contains no modified residues, so it is fully described by its sequence.
The compound came out of work on epithalamin, a peptide preparation derived from pineal tissue, conducted largely in Russian laboratories. Later studies in other countries examined it mainly in cell cultures and animal models.
The tetrapeptide sequence is a synthetic construct rather than a described circulating peptide. It was derived by analogy to peptide fractions obtained from tissue extracts, not isolated from blood or tissue as such.
Vladimir Khavinson and colleagues at research institutes in Saint Petersburg developed and studied the peptide. Their program examined short peptides as regulators of aging and neuroendocrine function. Epitalon was one of several compounds produced by that group.