This is a working overview of telomerase, written for readers who want more than a one-paragraph summary but less than a textbook.
This page was last updated on 2025-09-26 and is reviewed periodically as new material appears.
Stability of the tetrapeptide follows ordinary peptide chemistry rather than any unusual structural feature. The aspartate-glycine pair is prone to aspartimide formation under mildly basic or neutral conditions, and deamidation can follow, altering both mass and chromatographic retention. Dry lyophilised powder kept at or below minus twenty degrees Celsius is the usual handling recommendation, with repeated freeze-thaw cycles avoided. Once dissolved in neutral aqueous buffer, degradation proceeds over days to weeks depending on pH and temperature, while acidic conditions generally slow the aspartimide route. A formal stability-indicating study has not been published in the indexed literature.
Because epitalon has no pharmacopoeial monograph, quality assessment depends on supplier documentation and independent testing. Certificates of analysis typically report a purity figure from a single chromatographic run, a measured mass and sometimes an appearance description, but methods and acceptance criteria are not harmonised across vendors. Third-party laboratories can repeat identity and purity measurements, and mismatches between labelled and measured peptide content have been described for research peptides generally. What constitutes adequate identity confirmation for a molecule of this size stays an open question, since mass agreement alone does not separate closely related sequences.
Identity testing for epitalon relies on reversed-phase high-performance liquid chromatography for purity and mass spectrometry for mass confirmation. Because the sequence contains no tryptophan or tyrosine, ultraviolet detection at 280 nanometres is insensitive, so chromatographic methods usually monitor absorbance near 214 nanometres, where the peptide backbone absorbs. Electrospray ionisation or matrix-assisted laser desorption/ionisation then checks the intact mass against the expected value near 390 daltons. Peptide mapping or amino acid analysis after acid hydrolysis can supplement these measurements, although such confirmatory work is seldom reported on commercial certificates of analysis.
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.
Epitalon is a synthetic tetrapeptide with the amino acid sequence alanine-glutamate-aspartate-glycine, abbreviated Ala-Glu-Asp-Gly or AEDG. It was developed by the Russian researcher Vladimir Khavinson and colleagues during work on peptide bioregulators derived from the pineal gland. The compound is short enough to be produced by standard solid-phase peptide synthesis and is typically handled as a lyophilized white powder. Its small size distinguishes it from larger pineal peptides such as epithalamin, a complex extract from which the tetrapeptide was conceptually derived.
| Property | Value | Notes |
|---|---|---|
| Analytical method | Reversed-phase HPLC | Purity determination, typically 214 nm |
| Mass confirmation | ESI or MALDI mass spectrometry | Compared with mass near 390 Da |
| Common synonyms | Epitalon, epithalon, AEDG | Naming differs between suppliers |
| Storage temperature | −20 °C or lower | Lyophilised powder, kept desiccated |
| Solution stability | Limited in neutral aqueous buffer | Aspartimide and hydrolysis pathways |
Analytical characterization of epitalon relies on standard peptide methods. Reverse-phase high-performance liquid chromatography is used to assess purity, and mass spectrometry confirms identity by checking the observed mass against the expected value near 390 daltons. Amino acid analysis can verify composition. Because the peptide is short and hydrophilic, it elutes early on many reverse-phase columns, so method development often requires ion-pairing reagents to achieve adequate retention and resolution from related impurities.
Storage and handling follow conventional peptide practice. Lyophilized epitalon is typically kept refrigerated or frozen, protected from moisture and light, and allowed to equilibrate to room temperature before opening to avoid condensation. Once dissolved, aqueous solutions are usually stored cold and used within a short period, since dilute peptide solutions can support microbial growth and may slowly degrade. The absence of cysteine and methionine reduces, but does not eliminate, oxidation concerns during long-term storage.
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.
Animal and clinical reports appear mainly in Russian-language journals from the 1990s and 2000s, covering endpoints such as melatonin rhythm, lifespan in aged rodents, and retinal function. Many of these papers involve small groups, lack blinding or placebo comparison, and are difficult to retrieve through indexed databases. Review articles published in English generally summarise the claims without reanalysing the underlying data. Because no large randomised trial exists, the clinical importance of these reported effects stays unresolved and is properly described as an open question.
No national medicines regulator has approved epitalon as a therapeutic product. It is generally distributed as a research chemical, and in some jurisdictions selling peptides for human consumption without approval is restricted or prohibited. Certificates of analysis accompanying commercial material vary in which tests are performed, and independent verification of identity and purity is uncommon. Statements about anti-ageing or disease-prevention benefits on vendor pages are marketing claims rather than regulatory findings, a distinction that shapes how the compound is discussed in scientific and popular sources alike.
The most frequently cited laboratory finding is that AEDG increased telomerase activity and extended telomere length in cultured human somatic cells. That work used fetal fibroblast strains and reported changes in enzyme activity alongside altered division counts. Replication by unrelated groups has been limited, and the published record is largely a single-laboratory series rather than a multi-centre programme. The result supports a hypothesis about peptide influence on gene expression in cell culture; it does not by itself establish an effect on telomere length in living animals or in people.
Published evidence comes mainly from Russian-language journals and from a single research group, with small sample sizes and limited independent replication. A few laboratories outside that group have examined related peptides and reported weaker or absent telomerase effects, so the central claim is best described as contested rather than settled. Rodent studies report modest changes in some ageing markers and in survival, but designs vary and control conditions are often sparse. No large randomised trial in humans has been published, and long-term safety data in healthy populations are correspondingly thin.
Epitalon is a synthetic tetrapeptide with the sequence alanine-glutamate-aspartate-glycine, commonly abbreviated AEDG. It was designed at the St. Petersburg Institute of Bioregulation and Gerontology as a short, chemically defined analogue of epithalamin, a fraction obtained from bovine pineal tissue. Small peptide bioregulators of this type formed a long-running line of work there from the 1980s onward. Because the molecule is produced by solid-phase synthesis rather than extraction, its composition is exact and its purity can be measured directly.
== Healthcare == UPMC Children's Hospital of Pittsburgh Community Health Partnerships, Scotland Certified Health Physicist, United States, a specialist in radiation protection and safety Centre for Health Protection, an agency of Hong Kong Cricohyoidopexy, a surgical procedure
Ipamorelin (INN; development code NNC 26-0161) is a peptide selective agonist of the ghrelin/growth hormone secretagogue receptor (GHS) and a growth hormone secretagogue. It is a pentapeptide with the amino acid sequence Aib-His-D-2-Nal-D-Phe-Lys-NH2 that was derived from GHRP-1. Ipamorelin significantly increases plasma growth hormone (GH) levels in both animals and humans. In addition, ipamorelin stimulates body weight gain in animals. In rats, ipamorelin has also been reported to induce longitudinal bone growth. Like pralmorelin and GHRP-6, ipamorelin does not affect prolactin, follicle-stimulating hormone (FSH), luteinizing hormone (LH), or thyroid-stimulating hormone (TSH) levels. However, unlike pralmorelin (GHRP-2) and GHRP-6, but similarly to growth hormone-releasing hormone (GHRH), ipamorelin does not stimulate the secretion of adrenocorticotropic hormone (ACTH), or cortisol, and is highly selective for inducing the secretion only of GH. Ipamorelin was originally developed by Novo Nordisk, and was investigated in phase II clinical trials by Helsinn Therapeutics for the treatment of postoperative ileus, but was discontinued due to lack of efficacy. Ipamorelin has been used by athletes as a performance-enhancing drug. Currently, Ipamorelin is commonly marketed as a research peptide rather than as an approved pharmaceutical drug.
=== Sarcopenia === Sarcopenia is the degenerative loss of skeletal muscle mass, quality, and strength associated with aging. This involves muscle atrophy, reduction in number of muscle fibers and a shift towards "slow twitch" or type I skeletal muscle fibers over "fast twitch" or type II fibers. The rate of muscle loss is dependent on exercise level, co-morbidities, nutrition and other factors. There are many proposed mechanisms of sarcopenia, such as a decreased capacity for oxidative phosphorylation, cellular senescence or an altered signaling of pathways regulating protein synthesis, and is considered to be the result of changes in muscle synthesis signalling pathways and gradual failure in the satellite cells which help to regenerate skeletal muscle fibers, specifically in "fast twitch" myofibers. Sarcopenia can lead to reduction in functional status and cause significant disability but is a distinct condition from cachexia although they may co-exist. In 2016 an ICD code for sarcopenia was released, contributing to its acceptance as a disease entity.
==== 2300–2399 ==== Sandwell Borough Council (Patent Shaft/Moorcroft Infrastructure) (Walsall Canal Bridge) Scheme 1993 Confirmation Instrument 1993 (S.I. 1993/2302) Civil Aviation (Canadian Navigation Services) (Fourth Amendment) Regulations 1993 (S.I. 1993/2320) Highlands and Islands Rural Enterprise Programme (Revocation) Regulations 1993 (S.I. 1993/2325) Value Added Tax (Reverse Charge) Order 1993 (S.I. 1993/2328) Telecommunications (Leased Lines) Regulations 1993 (S.I. 1993/2330) Coal Mines (Owner's Operating Rules) Regulations 1993 (S.I. 1993/2331) Combined Probation Areas (East Sussex) Order 1993 (S.I. 1993/2332) Plant Health Fees (Scotland) Amendment Order 1993 (S.I. 1993/2344) Environmentally Sensitive Areas (Cairngorms Straths) Designation Order 1993 (S.I. 1993/2345) Act of Sederunt (Enforcement of Judgments under the Civil Jurisdiction and Judgments Act 1982) (Authentic Instruments and Court Settlements) 1993 (S.I. 1993/2346) Haydon Natural Gas Pipe–lines Order 1993 (S.I. 1993/2347) Croydon, Merton and Sutton (London Borough Boundaries) Order 1993 (S.I. 1993/2350) Angola (United Nations Sanctions) Order 1993 (S.I. 1993/2355) Angola (United Nations Sanctions) (Dependent Territories) Order 1993 (S.I. 1993/2356) Angola (United Nations Sanctions) (Channel Islands) Order 1993 (S.I. 1993/2357) Angola (United Nations Sanctions) (Isle of Man) Order 1993 (S.I. 1993/2358) Exempt Charities Order 1993 (S.I. 1993/2359) Clinical Thermometers (EEC Requirements) Regulations 1993 (S.I. 1993/2360) Ionising Radiations (Outside Workers) Regulations 1993 (S.I.
=== Other === In April 2017 MGX Minerals reported it had received independent confirmation of its rapid lithium extraction process to recover lithium and other valuable minerals from oil and gas wastewater brine.
Sources: en.wikipedia.org
Their intention was to protect Raleigh from the destruction inflicted on other cities by Union troops. Graham and Swain departed to meet the advancing Federal forces on the morning of April 12, 1865, and were to return by that evening. The evening struck, but Graham and Swain had not returned due to train delays and their temporary capture by Sherman. Governor Vance left the evening after Graham and Sherman failed to return, leaving behind a letter giving Mayor William H. Harrison the authority to surrender. On the morning of April 13, Mayor Harrison among others went to the southern Wake County area to meet General Hugh Judson Kilpatrick and propose surrender. Kenneth Rayner, a long-time resident of Raleigh, delivered the proposal including a promise of no resistance. Kilpatrick agreed to accept the surrender and protect Raleigh from destruction. Kilpatrick's cavalry occupied Raleigh and removed the flagpole from the state capitol, replacing it with a United States Flag above the dome. Sherman arrived shortly after and established his headquarters in the governor's mansion. The city was spared significant destruction during the war. As Confederate cavalry retreated west, Union soldiers followed, leading to the Battle of Morrisville nearby. Due to the economic and social problems of the postwar period and Reconstruction, with a state economy still heavily dependent on agriculture, the city grew little over the next several decades. Shaw University, the South's first African American college, began classes in 1865 and was chartered in 1875.
=== "In the Hepatitis B Camp" === "In the Hepatitis B Camp" is a popular website for hepatitis B carriers' human rights in China. Its online forum is the world's biggest such forum with over 300,000 members. The website was first shut down by the Chinese government in November 2007. Lu Jun, the head of the rights group, managed to reopen the website by moving it to an overseas server, but the authorities in May 2008 began blocking access to the website within China, only 10 days after government officials participated in an event for World Hepatitis Day at the Great Wall of China. An official had told the head of the rights group, Lu Jun, at the time that the closure was due to the Beijing Olympic Games.
=== Excessive hair growth === Finasteride has been found to be effective in the treatment of hirsutism (excessive facial or body hair growth) in women. In a study of 89 women with hyperandrogenism due to persistent adrenarche syndrome, finasteride produced a 93% reduction in facial hirsutism and a 73% reduction of bodily hirsutism after 2 years of treatment. Other studies using finasteride for hirsutism have also found it to be effective.
PRCL's Role in Economic Development The role of PRCL in economic development of Pakistan is significant. PRCL awareness of increasing requirements of insurance and reinsurance of a progressive economy is making great efforts in coming up to national expectations. This progress signifies the consolidation of the position, both at home and abroad, encouraging further expansion.
Nalin Chandra Wickramasinghe (born 20 January 1939) is a Sri Lankan-born British mathematician and astronomer. His research interests include the interstellar medium, infrared astronomy, light scattering theory, applications of solid-state physics to astronomy, the early Solar System, comets, astrochemistry, the origin of life and astrobiology. A student and collaborator of Fred Hoyle, the pair worked jointly for over 40 years as the most famous proponents of a non-mainstream version of panspermia, the proposal that life was seeded (or continues to be seeded) on Earth through space-based processes. In 1974 they proposed that some dust in interstellar space matched the spectral characteristics of freeze-dried bacteria, which was largely ignored at its publishing while the ubiquity of polycyclic aromatic hydrocarbons explains the apparent match. Wickramasinghe has advanced numerous fringe claims, including the argument that various outbreaks of illnesses on Earth are of extraterrestrial origins, including the 1918 flu pandemic and certain outbreaks of polio and mad cow disease. For the 1918 flu pandemic they proposed that cometary dust brought the virus to Earth simultaneously at multiple locations—a view dismissed by experts on this pandemic. Claims connecting terrestrial disease and extraterrestrial pathogens have been rejected by the scientific community. Wickramasinghe has written more than 40 books about astrophysics and related topics; he has made appearances on radio, television and film, and he writes online blogs and articles.
Sources: en.wikipedia.org
Sample preparation is a critical step in imaging spectroscopy. Scientists take thin tissue slices mounted on conductive microscope slides and apply a suitable MALDI matrix to the tissue, either manually or automatically. Next, the microscope slide is inserted into a MALDI mass spectrometer. The mass spectrometer records the spatial distribution of molecular species such as peptides, proteins or small molecules. Suitable image processing software can be used to import data from the mass spectrometer to allow visualization and comparison with the optical image of the sample. Recent work has also demonstrated the capacity to create three-dimensional molecular images using MALDI imaging technology and comparison of these image volumes to other imaging modalities such as magnetic resonance imaging (MRI).
Although they live and work in Hong Kong, these workers are not treated as ordinary residents and do not have the right of abode in the territory. The Joint Declaration guarantees the Basic Law of Hong Kong for 50 years after the handover. According to legal scholar Albert Chen, the Basic Law does not have an expiry date and is, unless amended, of continuing validity. In response to large-scale protests in 2019 and 2020, the Standing Committee of the National People's Congress passed the controversial Hong Kong national security law. The law criminalises secession, subversion, terrorism and collusion with foreign elements and establishes the Office for Safeguarding National Security of the CPG in the HKSAR, an investigative office under Central People's Government authority immune from HKSAR jurisdiction. Some of the aforementioned acts were previously considered protected speech under Hong Kong law. The United Kingdom considers the law to be a serious violation of the Joint Declaration. In October 2020, the Hong Kong Police arrested seven pro-democracy politicians over tussles with pro-Beijing politicians in the Legislative Council in May. They were charged with contempt and with interfering with council members, while none of the pro-Beijing lawmakers were detained. Annual commemorations of the 1989 Tiananmen Square protests and massacre were also cancelled amidst fears of violating the national security law.
=== Wealth === According to the Salvadoran government's transparency website, Bukele's monthly presidential salary was $5,181 in July 2019. According to the website, he had a net worth of $2,548,967 at that time. Bukele acquired most of his wealth through business ventures before entering politics. Bukele owns a coffee farm. In July 2024, he began donating coffee beans grown on his farm to local businesses and launched the Bean of Fire coffee brand. Through Bean of Fire, Bukele became one of El Salvador's largest coffee producers. In 2024, the Redacción magazine published the second of its two investigations against him, which found that his family land holding increased 12-fold during his first five years as president and that his family's wealth had increased considerably.
=== Thai Sang Thai Party === Thai Sang Thai was reduced to a single party-list seat. On 12 February Sudarat Keyuraphan announced that she would resign as party leader, saying that "there is no place for idealists" in Thai politics.
There have been proposals for reactors that consume nuclear waste and transmute it to other, less-harmful or shorter-lived, nuclear waste. In particular, the integral fast reactor was a proposed nuclear reactor with a nuclear fuel cycle that produced no transuranic waste and, in fact, could consume transuranic waste. It proceeded as far as large-scale tests but was eventually canceled by the U.S. Government. Another approach, considered safer but requiring more development, is to dedicate subcritical reactors to the transmutation of the left-over transuranic elements. An isotope that is found in nuclear waste and that represents a concern in terms of proliferation is Pu-239. The large stock of plutonium is a result of its production inside uranium-fueled reactors and of the reprocessing of weapons-grade plutonium during the weapons program. An option for getting rid of this plutonium is to use it as a fuel in a traditional light-water reactors (LWR). Several fuel types with differing plutonium destruction efficiencies are under study. Transmutation was banned in the United States in April 1977 by U. S. President Carter due to the danger of plutonium proliferation, but President Reagan rescinded the ban in 1981. Due to economic losses and risks, the construction of reprocessing plants during this time did not resume. Due to high energy demand, work on the method has continued in the European Union (EU). This has resulted in a practical nuclear research reactor called Myrrha in which transmutation is possible.
Sources: en.wikipedia.org
The molecule lacks aromatic residues, so it absorbs weakly near 280 nanometres, the wavelength applied to many other peptides. The peptide bond absorbs strongly below 220 nanometres, making 214 nanometres a practical compromise. Gradient methods must therefore use mobile phases with low ultraviolet absorbance to keep the baseline clean.
Neutral and slightly basic aqueous conditions promote aspartimide formation at the aspartate-glycine step, often followed by deamidation. Elevated temperature and repeated freeze-thaw cycles accelerate the loss. Acidic solutions and dry lyophilised powder are comparatively stable over short periods.
No monograph exists in the United States Pharmacopeia or the European Pharmacopoeia, and no widely distributed certified reference standard is available. Purity and identity therefore rest on supplier methods that are not harmonised. This absence is the main reason reported purities are difficult to compare between sources.
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.