The short version of reversed-phase HPLC fits in a sentence. The long version — which is the one that helps — is below.
Reviewed 2025-12-16. Anything still debated is marked as such rather than presented as settled.
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.
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.
Storage practice centres on limiting moisture, oxygen, and repeated temperature cycling. Freeze-dried powder is generally held desiccated at minus twenty degrees Celsius or colder and protected from light. Reconstituted solutions are markedly less stable, and the aspartate-glycine junction is prone to succinimide formation at neutral to mildly alkaline pH. Portioning material into single-use aliquots reduces degradation compared with repeated freeze-thaw cycles. Stability data specific to this tetrapeptide remain scarce, so most handling guidance is extrapolated from general peptide chemistry rather than measured directly.
Documentation accompanying research peptides usually includes a certificate of analysis listing the batch number, purity figure, and test methods applied. Buyers comparing suppliers should check whether the reported purity refers to chromatographic area or to a mass-balance calculation, because the two are not equivalent. Counter-ion content, residual solvents, and water content are sometimes omitted from such certificates even though they affect the actual peptide mass present. Independent verification through a second laboratory is the most direct way to confirm that a supplied material matches its label.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C14H22N4O9 | Derived from the four-residue sequence |
| Molar mass | About 390.35 g/mol | Free peptide, counter-ion not included |
| Appearance | White to off-white powder | Lyophilised solid from aqueous solution |
| Water solubility | Freely soluble | Short, polar peptide chain |
| Common synonyms | AEDG; epithalone | Catalogues use the names interchangeably |
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.
The most frequently cited proposed action is induction of telomerase, the enzyme that adds repeat sequences to chromosome ends. Cell-culture work from the originating group reported higher telomerase reverse transcriptase expression and measurable telomere elongation in human somatic cells after exposure. How a four-residue peptide would reach nuclear gene regulation is not established, and no cell-surface receptor or uptake route has been identified. Additional reports describe changes in melatonin secretion, antioxidant enzyme activity and lipid peroxidation in aged animals, but these findings remain mechanistically unconnected to the telomerase observation.
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.
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.
Epitalon is a synthetic tetrapeptide whose four residues are alanine, glutamate, aspartate and glycine, commonly abbreviated AEDG. Its molecular formula is C14H22N4O9 and its monoisotopic mass is near 390.35 daltons. The peptide carries two acidic side chains, so it is neutral to negatively charged in most aqueous buffers. Published reference summaries usually list it under both spellings, epitalon and epithalon, and treat the two names as the same material.
The compound is generally described as a synthetic analogue of a fragment isolated from a pineal gland extract. Researchers associated with the Saint Petersburg Institute of Bioregulation and Gerontology introduced it during the 1980s and 1990s while studying short peptides from animal tissue. The original extract, called epithalamin, is a heterogeneous mixture, whereas epitalon is a single defined sequence. That distinction matters because findings reported for the extract are not automatically findings about the pure tetrapeptide, and claims about broader biological effects remain a separate question from the chemical identity described here.
Residue composition is the property that most cleanly separates verified material from mislabelled samples. Alanine, glutamate, aspartate and glycine appear in that order from the N-terminus, and the two acidic residues sit in the middle of the chain. Because the peptide is short, it can be produced by solid-phase synthesis and characterised by mass spectrometry without ambiguity. Any reported sample whose measured mass departs substantially from 390 daltons is a different compound or a degraded mixture rather than epitalon.
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.
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.
Little People of the World Organization Archived 2021-05-10 at the Wayback Machine [Hub for all International Organizations; services/advocacy/know your rights/support] Little People of America (Includes a list of International support groups) Little People of Canada (Includes a list of Canadian Provincial support groups) Little People UK Dwarf Sports Association UK Restricted Growth Association UK
== Usage == Deltamethrin is a highly effective insecticide. It is used, among other applications, for the production of long-lasting insecticidal nets (LLINs), which, along with indoor residual spraying (IRS), are the main vector control strategies recommended by the World Health Organization (WHO) for the management of malaria. Deltamethrin plays a key role in controlling malaria vectors, and is used in the manufacture of long-lasting insecticidal mosquito nets. It is used as one of a battery of pyrethroid insecticides in control of malarial vectors, particularly Anopheles gambiae, and whilst being the most employed pyrethroid insecticide, can be used in conjunction with, or as an alternative to, permethrin, cypermethrin and organophosphate-based insecticides, such as malathion and fenthion. Resistance to deltamethrin (and its counterparts) is now extremely widespread and threatens the success of worldwide vector control programmes.
===== Conjugates ===== In addition to LNPs, RNAi therapeutics have targeted delivery through siRNA conjugates (e.g., GalNAc, carbohydrates, peptides, aptamers, antibodies). Therapeutics using siRNA conjugates have been developed for rare or genetic diseases such as acute hepatic porphyria (AHP), hemophilia, primary hyperoxaluria (PH) and hereditary ATTR amyloidosis as well as other cardiometabolic diseases such as hypertension and non-alcoholic steatohepatitis (NASH).
Sources: en.wikipedia.org
During the years that followed, Gaddafists adopted quotes from The Green Book, such as "Representation is Fraud", as slogans. Meanwhile, in September 1975, Gaddafi implemented further measures to increase popular mobilization, introducing objectives to improve the relationship between the Councils and the ASU. In 1975, Gaddafi's government declared a state monopoly on foreign trade. Its increasingly radical reforms, coupled with the large amount of oil revenue being spent on foreign causes, generated discontent in Libya, particularly among the country's merchant class. In 1974, Libya saw its first civilian attack on Gaddafi's government when a Benghazi army building was bombed. Much of the opposition centred around RCC member Umar Muhayshi. With fellow RCC members Bashir Saghir al-Hawaadi and Awad Ali Hamza, he began plotting a coup against Gaddafi. In 1975, their plot was exposed and Muhayshi fled to Tunisia, eventually receiving asylum from Sadat's Egypt. Hawaadi, Hamza, and Omar El-Hariri were arrested. Most of the other conspirators were executed in March 1976. Another RCC member, foreign minister Abdul-Munim al-Huni, also fled to Egypt. In the aftermath, only five RCC members remained: Gaddafi, Jalloud, Abu-Bakr Yunis Jabr, Mustafa Kharubi, and Kweldi al-Hamidi. Thus, power was further concentrated in Gaddafi's hands. This ultimately led to the RCC's official abolition in March 1977. In September 1975, Gaddafi purged the army, arresting around 200 senior officers, and in October he founded the clandestine Office for the Security of the Revolution.
Nobel Prize in Physiology or Medicine (1929) Bernard Horecker (1914–2010). American biochemist at Cornell University known for elucidation of the pentose phosphate pathway. Member Natl. Acad. Sci. USA. Linda Hsieh-Wilson (PhD 1996). American chemist known for work in chemical neurobiology and the structure and function of carbohydrates in the nervous system Wayne L. Hubbell (b. 1943). American biochemist at UCLA, pioneer of site-directed spin labelling. Member Natl. Acad. Sci. USA. Hugh Huxley (1924–2013). British molecular biologist at University College London and Brandeis University noted for discovery the underlying principle of muscle movement.
The energy released by the Hiroshima bomb explosion (about 15 kt TNT equivalent, or 6×1013 J) is often used by geologists as a unit when describing the energy of earthquakes, volcanic eruptions, and asteroid impacts. Prior to the detonation of the Hiroshima bomb, the size of the Halifax Explosion (about 3 kt TNT equivalent, or 1.26×1013 J), was the standard for this type of relative measurement. Each explosion had been the largest known artificial detonation to date.
Sources: en.wikipedia.org
== See also == Phragmen's voting rules – a ballot load balancing method analogous to the idea of Archimedes' principle. Ship stability – Archimedes's theory of displacement of fluid is a core principle of ship stability. List of eponymous laws
The epithelial cells of the parathyroid glands are richly supplied with blood from the Inferior thyroid artery and superior thyroid artery. Parathyroid hormone acts on bone, the kidneys, and the GI tract to increase calcium reabsorption and phosphate excretion. In addition, it also stimulates the conversion of vitamin D to its most active variant, 1,25-dihydroxyvitamin D3, which further stimulates calcium absorption in the GI tract. The pancreas contains nearly 1 to 2 million pancreatic islets the organ's endocrine cells that secrete hormones, and acini. The acini secrete digestive enzymes. The pancreatic endocrine cells include alpha cells that produce and secrete the glucagon to maintain homeostatic blood sugar. In response to low blood sugar levels, the release of glucagon stimulates glycogen stores in the liver to release sugar into the bloodstream to raise blood sugar to normal levels. Pancreatic beta cells make up 60% of the cells in the islets. Along with alpha cells, beta cells help to maintain glucose levels in the body. In response to high blood sugar, beta cells secrete insulin, a hypoglycemic hormone. Insulin decreases blood glucose level by helping cells to take up and metabolize glucose, and by stopping the liver from releasing more glucose. Insulin also performs other metabolic functions: causing muscle cells to take up amino acids, and inhibiting the breakdown and release of fats. Delta cells (5%) in the islets produce regulatory somatostatin.
== Prevention == Cara Myer, the author of "The Tea and Toast Syndrome: Psychosocial Aspects of Congregate Dining" suggests that congregate dining for older adults may be an excellent strategy to prevent tea and toast syndrome. Myer mentions that social service interventions for malnutrition, including congregate dining, are often under-utilized and could provide a stimulating environment that may improve the quality of life of many older adults. Further, general preventative measures focus on evaluating the nutrition of older adults, including keeping a record of weight patterns, helping with meal plans focusing on nutrient-rich foods, and using local services such as a meal delivery program. Additional strategies include:
The foundation charged the new project with development, testing, licensure and mass introduction of a meningococcal conjugate vaccine. In 2002, the collaboration supported reinforced meningitis surveillance activities in 12 countries in Africa: Benin, Burkina Faso, Cameroon, Central African Republic, Chad, Ethiopia, Ghana, Ivory Coast, Mali, Niger, Nigeria and Togo. The surveillance indicated an increased risk of outbreaks in the future and the continued need for a vaccine. MenAfriVac became available for widespread use in African meningitis belt countries in 2010. Distribution in Mali and Niger was assisted by Médecins Sans Frontières.
Sources: en.wikipedia.org
It is a synthetic tetrapeptide built from alanine, glutamate, aspartate and glycine. The four residues are joined by standard peptide bonds, giving a linear chain rather than a branched structure.
The name derives from epithalamin, a pineal gland extract studied in the former Soviet Union. Researchers proposed that short fragments of that extract carried the biological activity of interest.
No major regulatory agency has approved it as a medicine. It is handled as a research chemical, and products sold under this name are not standardised drugs with defined clinical labelling.
Reversed-phase high-performance liquid chromatography with ultraviolet detection at 214 nanometres is the usual approach. Peak area percentage provides a purity figure relative to other components in the sample. Mass spectrometry is then applied to confirm identity.