This is a working overview of epithalamin, written for readers who want more than a one-paragraph summary but less than a textbook.
Reviewed 2025-11-14. Anything still debated is marked as such rather than presented as settled.
Identity is normally established by reversed-phase high-performance liquid chromatography combined with mass spectrometry, a pairing that separates components and confirms molecular mass at once. Purity is quoted as a percentage from the chromatogram, and figures above ninety-five percent are a frequent commercial specification. Amino acid analysis or sequencing supplies further confirmation when required. Because many short peptides behave similarly under chromatography, retention time alone does not establish sequence; the mass measurement is what separates one tetrapeptide from another, and certificates should report both.
Short peptides such as AEDG are normally supplied as a freeze-dried solid and are kept dry, cold, and shielded from light. Holding at minus twenty degrees Celsius is common for the long term, while a refrigerator suffices for brief periods before use. The material takes up moisture to some degree, so containers should stay sealed and be allowed to reach room temperature before opening, which limits condensation on the contents. Repeated warming and cooling of a single container is discouraged because it admits water and can lower the amount of intact peptide.
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.
Discussions in the literature often conflate three distinct entities: the pineal extract epithalamin, the isolated tetrapeptide AEDG, and commercial preparations sold under similar names. Reviews citing older Russian-language studies sometimes omit detail on purity, route of administration and control groups, which makes cross-study comparison difficult. Researchers working with the compound generally note the need for independent replication, standardized enzyme assays, and clearer reporting of peptide identity. These caveats are relevant when weighing claims that appear in secondary sources rather than in primary reports.
| Property | Value | Notes |
|---|---|---|
| Sequence | Ala-Glu-Asp-Gly | Written in three-letter amino acid code |
| Single-letter code | AEDG | Form used in most catalogue entries |
| Typical purity specification | 95 percent or higher | Value read from the HPLC chromatogram |
| Storage, dry solid | Minus 20 degrees Celsius, desiccated | Sealed container, protected from light |
| Handling, solution | Divide into single-use portions | Limits losses from freeze-thaw cycling |
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.
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.
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.
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.
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.
Sitagliptin works to competitively inhibit the enzyme dipeptidyl peptidase 4 (DPP-4). This enzyme breaks down the incretins GLP-1 and GIP, gastrointestinal hormones released in response to a meal. By preventing breakdown of GLP-1 and GIP, they are able to increase the secretion of insulin and suppress the release of glucagon by the alpha cells of the pancreas. This drives blood glucose levels towards normal. As the blood glucose level approaches normal, the amounts of insulin released and glucagon suppressed diminishes, thus tending to prevent an "overshoot" and subsequent low blood sugar (hypoglycemia), which is seen with some other oral hypoglycemic agents. Sitagliptin has been shown to lower HbA1c level by about 0.7% points versus placebo. It is slightly less effective than metformin when used as a monotherapy. It does not cause weight gain and has less hypoglycemia compared to sulfonylureas. Sitagliptin is recommended as a second-line drug (in combination with other drugs) after the combination of diet/exercise and metformin fails.
Nicotine dependence pathophysiology in heavy smokers suggests less efficient network architecture in the brain and disruptions in the topological organization of brain networks, with the altered brain network metrics correlated with the duration of cigarette use and the severity of nicotine dependence. Some long-term effects of nicotine may be irreversible because "it is entirely possible that doses of nicotine achieved in the brains of human smokers can damage or kill mHb [medial habenula] neurons that regulate nicotine avoidance behaviors", but more studies are needed to elucidate this underlying mechanism of nicotine-induced degeneration of the mHb-IPn circuit . A 2026 Nature study revealed that nicotine mimics endogenous acetylcholine in the nucleus accumbens, artificially triggering dopamine release to biologically "tag" behaviors as valuable, high-effort achievements regardless of actual difficulty. During active use, this chemical shortcut causes salience dysregulation and "false productivity," as the brain assigns intense reward signals to trivial tasks independent of outcome quality while displacing ambition for a meaningful achievement.
The trials were conducted in Europe, South America, the United States, Asia Pacific, Africa, and Mexico. It was approved for use in the European Union in February 2020. In June 2020, imipenem/cilastatin/relebactam was approved for the indication to treat hospital-acquired bacterial pneumonia and ventilator-associated bacterial pneumonia (HABP/VABP) in adults 18 years of age and older. The safety and efficacy of imipenem/cilastatin/relebactam for the treatment of HABP/VABP were evaluated in a randomized, controlled clinical trial of 535 hospitalized adults with HABP/VABP due to Gram-negative bacteria (a type of bacteria) in which 266 participants were treated with imipenem/cilastatin/relebactam and 269 participants were treated with piperacillin-tazobactam, another antibacterial drug. Overall, 16% of participants who received imipenem/cilastatin/relebactam and 21% of participants who received piperacillin-tazobactam died through day 28 of the study. In September 2026, Merck withdrew it from the US market.
=== Laboratory synthesis === As early as the 1860s, experiments demonstrated that biologically relevant molecules can be produced from interaction of simple carbon sources with abundant inorganic catalysts. The spontaneous formation of complex polymers from abiotically generated monomers under the conditions posited by the "soup" theory is not straightforward. Besides the necessary basic organic monomers, compounds that would have prohibited the formation of polymers were also formed in high concentration during the Miller–Urey experiment and Joan Oró experiments. Biology uses essentially 20 amino acids for its coded protein enzymes, representing a very small subset of the structurally possible products. Since life tends to use whatever is available, an explanation is needed for why the set used is so small. Formamide is attractive as a medium that potentially provided a source of amino acid derivatives from simple aldehyde and nitrile feedstocks.
== Characteristics == Elastin is a very long-lived protein, with a half-life of over 78 years in humans. However, its long lifespan does not imply that its functional properties remain unchanged throughout life. In human skin, ageing is associated with changes in the amount, organisation and integrity of dermal elastic fibres. An in vivo multiphoton tomography study reported age-related reductions in the measured elastin and collagen content of the human dermis. More recent three-dimensional imaging of human dermal elastin has shown that the number of elastic fibres decreases with age and that the remaining network becomes more fragmented and less interconnected. Finite-element modelling based on these structural observations associated age-related changes in elastin-fibre architecture with reduced skin firmness.
Sources: en.wikipedia.org
=== Genesis of the Israelite people === Biblically, the Israelites referred to the descendants of Israel, a view that was reinforced by Second Temple Judaism, although gentiles could fully assimilate into the Israelite community. They referred to themselves as the sons of Israel, which could possibly refer to peoplehood rather than blood descent, especially after Israel's biological family transitioned from a clan to a nation (Exodus 1:9). The Israelite identity is alternatively interpreted as being based on religious allegiance, especially through worship of Yahweh or 'covenantal circumcision'. There's also contentious evidence of Israelite tribal status being acquired through self-declared allegiance, residency within assigned tribal territory (Ezekiel 47:21–23) or forceful absorption by a greater Israelite tribe. Jason A. Staples argues that the Israelites referred to the northern Israelite tribes, especially in the Nevi'im, although it's also inclusive of the other tribes in other contexts. The Israelites trace their ancestors to Jacob, who in turn descended from Abraham. Abraham was formerly a native of Ur Kaśdim (Genesis 11:31), whose location is unknown. Some scholars argue that it is located in lower Mesopotamia whilst others locate it further north in upper Mesopotamia, around northern Syria or southeastern Turkey. Theologians suggest that Canaan always belonged to the Israelites but was initially usurped by the descendants of Canaan, resulting in their conquest by Israel as divine punishment.
== Therapeutic use(s) == When patients with blood cancers (leukemia and lymphoma) receive high dose chemotherapy and radiation therapy to undergo bone marrow transplantation, they usually get severe oral mucositis. Palifermin reduces the incidence and duration of severe oral mucositis by protecting those cells and stimulating the growth of new epithelial cells to build up the mucosal barrier. Palifermin is also being studied in the prevention and treatment of oral mucositis and dysphagia (difficulty swallowing) in other types of cancer.
==== Re-sentencing of death row inmates ==== The amendments of the law also offered a chance for all current death row inmates to have their cases to be reviewed for re-sentencing. Some death row inmates declined to be re-sentenced, including Tang Hai Liang and Foong Chee Peng. The below cases are known cases where death row inmates applied for re-sentencing.
Cytogenetics is essentially a branch of genetics, but is also a part of cell biology/cytology (a subdivision of human anatomy), that is concerned with how the chromosomes relate to cell behaviour, particularly to their behaviour during mitosis and meiosis. Techniques used include karyotyping, analysis of G-banded chromosomes, other cytogenetic banding techniques, as well as molecular cytogenetics such as fluorescence in situ hybridization (FISH) and comparative genomic hybridization (CGH).
Tasipimidine (INNTooltip International Nonproprietary Name, USANTooltip United States Adopted Name; developmental code names ODM-105 and ORM-19695), sold under the brand name Tessie, is an α2-adrenergic receptor agonist which is approved for the short-term treatment of fear and anxiety in dogs. It is also under development for the treatment of insomnia in humans. The drug is used as an oral solution in dogs, whereas its route of administration for humans is unspecified. The drug acts as a potent and selective full agonist of the human α2A-adrenergic receptor. Conversely, it is a much weaker agonist of the rodent α2B-, α2C-, and α2D-adrenergic receptors. In addition, it shows only low affinity for α1-adrenergic receptors, where it appears to act as a partial agonist. Tasipimidine produces anxiolytic, sedative, hypolocomotor, hypotensive, and bradycardic effects in animals. Tasipimidine is under development for use in humans by Orion Corporation. As of October 2024, it is in phase 2 clinical trials for this indication. The drug is or was also under development for the treatment of psychiatric disorders in humans, but no recent development for this indication has been reported. It has reached phase 1 trials for psychiatric disorders. Tasipimidine was approved for treatment of fear and anxiety in dogs in the European Union in 2021.
Sources: en.wikipedia.org
==== Oligonucleotide therapeutics ==== Unlike small-molecule drugs, approved RNAi-based therapeutics such as siRNA drugs do not significantly induce or inhibit cytochrome P450 (CYP) enzymes, and therefore require distinct frameworks for evaluating drug–drug interactions (DDIs). Several interaction mechanisms relevant to oligonucleotide drugs have been identified:
March 14 – Marvin Scott died on March 14, 2021, in police custody at a correctional facility in McKinney, Texas. March 14–15 – A blizzard in Colorado brings over 24.1 inches (61 cm) of snow, passing a record of 23.8 inches (60 cm) set in 1982, to become the fourth largest recorded snowfall in Denver history and the largest since 2003 when the city received 31.8 inches (81 cm). It also leaves tens of thousands of people without power and some stranded in their cars after roads are closed. In Wyoming, over 31 inches (79 cm) were received in Cheyenne, and 52.5 inches (133 cm) in the Laramie Range. March 15 – Three people are killed and one injured when a small plane crashes in Pembroke Pines, Florida. March 16 COVID-19 pandemic: Massachusetts confirms its first case of the Lineage P.1 variant that originated in Brazil. 2021 Atlanta spa shootings – Eight people are killed and one is injured in a trio of shootings at spas in the Metro Atlanta, Georgia area. A suspect is arrested 150 miles south of Atlanta later that day and charged with eight counts of murder and one count of attempted murder two days later, March 18. March 17 The IRS announces that the deadline for Tax Day will be postponed to May 17. COVID-19 pandemic: North Dakota confirms its first four cases of the California variant of SARS-CoV-2. Additionally, seven cases of the UK variant are also confirmed. March 18–19 – The U.S. and China hold talks in Alaska to discuss relations, with topics ranging from Taiwanese security to Black Lives Matter.
=== Manufacturing === HPLC has many applications in both laboratory and clinical science. It is a common technique used in pharmaceutical development, as it is a dependable way to obtain and ensure product purity. While HPLC can produce extremely high quality (pure) products, it is not always the primary method used in the production of bulk drug materials. According to the European pharmacopoeia, HPLC is used in only 15.5% of syntheses. However, it plays a role in 44% of syntheses in the United States pharmacopoeia. This could possibly be due to differences in monetary and time constraints, as HPLC on a large scale can be an expensive technique. An increase in specificity, precision, and accuracy that occurs with HPLC unfortunately corresponds to an increase in cost.
Most bacteria have a single circular chromosome that can range in size from only 160,000 base pairs in the endosymbiotic bacteria Carsonella ruddii, to 12,200,000 base pairs (12.2 Mbp) in the soil-dwelling bacteria Sorangium cellulosum, to 16.0 Mbp in another soil-dwelling bacteria, Minicystis rosea. There are many exceptions to this; for example, some Streptomyces and Borrelia species contain a single linear chromosome, while some bacteria including species of Vibrio contain more than one chromosome. Some bacteria contain plasmids, small extra-chromosomal molecules of DNA that may contain genes for various useful functions such as antibiotic resistance, metabolic capabilities, or various virulence factors. Whether they have a single chromosome or more than one, almost all bacteria have a haploid genome. This means that they have only one copy of each gene encoding proteins. This is in contrast to eukaryotes, which are diploid or polyploid, meaning they have two or more copies of each gene. This means that unlike humans, who may still be able to create a protein if the gene becomes mutated (since the human genome has an extra copy in each cell), a bacterium will be completely unable to create the protein if its gene incurs an inactivating mutation. Bacterial genomes usually encode a few hundred to a few thousand genes. The genes in bacterial genomes are usually a single continuous stretch of DNA. Although several different types of introns do exist in bacteria, these are much rarer than in eukaryotes.
Sources: en.wikipedia.org
Reversed-phase high-performance liquid chromatography is run alongside mass spectrometry. The chromatogram separates components and gives a purity figure, while the mass spectrum confirms that the measured molecular mass matches the expected sequence. Neither measurement on its own is treated as sufficient.
Long-term holding is usually at minus twenty degrees Celsius in a sealed, desiccated container. A refrigerator is adequate for short intervals before use. Light exposure is normally avoided as well. Allowing a cold container to warm before opening reduces moisture condensation on the contents.
Repeated cycles are generally avoided. Each freeze and thaw can promote aggregation or loss of peptide to container surfaces, which reduces the amount available for later work. Dividing a solution into single-use portions at the outset is the usual way to limit this problem.
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.