Everything below concerns AEDG. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Last reviewed on 2026-04-04. Where a claim depends on a specific study, the study is described rather than over-claimed.
Literature searches for this compound must account for several spelling variants. Indexing databases contain epitalon, epithalon, epithalone, and AEDG, and relevant records are scattered across Russian-language and English-language journals that do not consistently cross-cite. Early publications describe the parent extract as a mixture of many peptides, whereas later work addresses the single synthetic tetrapeptide. That shift in nomenclature complicates comparison between studies, because extract data and tetrapeptide data are sometimes cited interchangeably. A search strategy omitting the alternate spellings will return an incomplete set of references.
Reported biological findings come mainly from cell culture and rodent experiments. Those studies describe changes in telomerase catalytic subunit expression, melatonin rhythm amplitude, and antioxidant enzyme activity after peptide exposure. Human data are sparse and consist of small trials with limited blinding and inconsistent endpoints. The proposed mechanisms remain hypotheses rather than established facts, and there is no consensus on whether effects observed in animals carry over to people. Independent replication outside the original research groups is limited, which is a recognised gap in the published literature.
The parent extract epithalamin was characterised as a low-molecular-weight fraction of pineal tissue rather than a single defined chemical entity. Researchers fractionated it and tested successive fragments for activity, a screening approach typical of peptide discovery work in that era. Epitalon emerged from that process as one of the shorter sequences of interest. Because the original extract was never fully resolved into individual components, claims about which constituent drives a given effect rest on inference. This distinction matters when reading older reports that attribute extract observations to the tetrapeptide itself.
Laboratory-grade epitalon is typically supplied as a lyophilized powder. Purity is commonly assessed with reverse-phase high-performance liquid chromatography, often paired with mass spectrometry to confirm molecular identity. Amino acid analysis and peptide mapping can provide additional confirmation of sequence. Certificates of analysis for research materials frequently report purity above 95 percent, although the methods behind such figures vary between suppliers. The absence of a pharmacopeial monograph means that no single standardized assay defines the compound, so reported results depend on the analytical protocol chosen.
Storage recommendations center on limiting moisture, heat, and light. The dry powder is generally kept at minus 20 degrees Celsius, and some suppliers recommend minus 80 degrees for long-term archival. Once dissolved, solutions are usually aliquoted and frozen to avoid repeated freeze-thaw cycles, which can promote aggregation or degradation. Aqueous stability depends on pH and concentration, and buffered saline is often preferred over plain water for biological work. Stability data specific to epitalon remain limited, so general peptide-handling practices are applied by analogy rather than from product-specific validation.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic tetrapeptide | Four amino acid residues |
| Residue sequence | Ala-Glu-Asp-Gly | Abbreviated AEDG |
| Approximate mass | 390.35 Da | Monoisotopic, free base form |
| Parent preparation | Epithalamin extract | Derived from pineal tissue |
| Common spelling variants | Epithalon, epithalone, AEDG | Affects literature retrieval |
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.
The published literature is dominated by a small number of research groups, much of it in Russian-language journals, and independent replication outside those groups is limited. Studies are typically small, use cultured cells or rodent models, and report endpoints that differ between papers, which makes comparison difficult. Large randomised human trials have not appeared in the indexed literature. Questions about absorption, distribution and clearance are therefore still treated as open in reviews that mention the compound.
Epitalon is a synthetic tetrapeptide with the sequence alanine–glutamate–aspartate–glycine, commonly abbreviated AEDG. Its design traces to epithalamin, a peptide fraction prepared from bovine pineal gland extracts that researchers in Saint Petersburg began investigating in the 1970s. The compound has a molecular formula of C14H22N4O9 and a nominal molecular mass near 390 daltons. It holds no approved drug status in the United States or the European Union, and material sold under this name is generally offered as a research chemical rather than a finished pharmaceutical product.
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.
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.
Potency is the amount of drug needed to give a certain therapeutic effect. It is affected by the drug's affinity to the receptors and the number of receptors available. For antagonists, half maximal inhibitory concentration (IC50) is used to measure the potency of antagonists. IC50 means the concentration of antagonist needed to give a 50% inhibition. It can be directly compared with EC50, which is commonly used to measure the potency of an agonist. EC50 means the concentration of agonist needed to give a 50% response. IC50 is significant in determining the optimal dose of antagonist. A high concentration of an antagonist in the body may result in toxicity in the cell and damage the cell membrane. A lower IC50 means the inhibitory effect can be met with a lower concentration of antagonist and, therefore a lower risk of toxicity. For example, the IC50 of antagonists on cancer cell growth is essential for determining the optimal dose which inhibits cancer cells while inducing less harmful systemic effects in the body.
=== Industrial and chemical === Technetium-99 decays almost entirely by beta decay, emitting beta particles with consistent low energies and no accompanying gamma rays. Moreover, its long half-life means that this emission decreases very slowly with time. It can also be extracted to a high chemical and isotopic purity from radioactive waste. For these reasons, it is a U.S. National Institute of Standards and Technology (NIST) standard beta emitter, and is used for equipment calibration. Technetium-99 has also been proposed for optoelectronic devices and nanoscale nuclear batteries. Like rhenium and palladium, technetium can serve as a catalyst. In processes such as the dehydrogenation of isopropyl alcohol, it is a far more effective catalyst than either rhenium or palladium. However, its radioactivity is a major problem in safe catalytic applications. When steel is immersed in water, adding a small concentration (55 ppm) of potassium pertechnetate(VII) to the water protects the steel from corrosion, even if the temperature is raised to 250 °C (523 K). For this reason, pertechnetate has been used as an anodic corrosion inhibitor for steel, although technetium's radioactivity poses problems that limit this application to self-contained systems. While (for example) CrO2−4 can also inhibit corrosion, it requires a concentration ten times as high. In one experiment, a specimen of carbon steel was kept in an aqueous solution of pertechnetate for 20 years and was still uncorroded.
== History == Precursor drugs to repaglinide were invented in late 1983 by scientists at Dr Karl Thomae GmbH, a German drug manufacturer located at Biberach an der Riß in southern Germany which was acquired by Boehringer Ingelheim in 1990. The drug that became repaglinide was later licensed by Boehringer to Novo Nordisk, which filed an Investigational New Drug application for the compound with the Food and Drug Administration (FDA) in April 1992. Novo Nordisk filed its New Drug Application (NDA) for Prandin in July 1997 and it was quickly approved, gaining FDA approval in December 1997. The drug was the first of the meglitinide class. It was branded Prandin because its quick onset and short duration of action concentrates its effect around meal time (the prandium was the Roman meal which is comparable to the modern lunch).
==== Anionic: sulfate, sulfonate, and phosphate, carboxylate derivatives ==== Anionic surfactants contain anionic functional groups at their head, such as sulfate, sulfonate, phosphate, and carboxylates. Prominent alkyl sulfates include ammonium lauryl sulfate, sodium lauryl sulfate (sodium dodecyl sulfate, SLS, or SDS), and the related alkyl-ether sulfates sodium laureth sulfate (sodium lauryl ether sulfate or SLES), and sodium myreth sulfate.
Sources: en.wikipedia.org
"Impact of metformin and rosiglitazone treatment on glucose transporter 4 mRNA expression in women with polycystic ovary syndrome". European Journal of Endocrinology. 158 (6): 793–801. doi:10.1530/EJE-07-0857. PMID 18322300. Jensterle, Mojca; Janez, Andrej; Vrtovec, Bojan; Meden-Vrtovec, Helena; Pfeifer, Marija; Prezelj, Janez; Kocjan, Tomaz (2007). "Decreased Androgen Levels and Improved Menstrual Pattern after Angiotensin II Receptor Antagonist Telmisartan Treatment in Four Hypertensive Patients with Polycystic Ovary Syndrome: Case Series". Croatian Medical Journal. 48 (6): 864–70. doi:10.3325/cmj.2007.6.864. PMC 2213810. PMID 18074422. Silič, Anja; Janež, Andrej; Tomažič, Janez; Karner, Primož; Vidmar, Ludvik; Sharma, Prem; Matičič, Mojca (2007). "Effect of Rosiglitazone and Metformin on Insulin Resistance in Patients Infected with Human Immunodeficiency Virus Receiving Highly Active Antiretroviral Therapy Containing Protease Inhibitor: Randomized Prospective Controlled Clinical Trial". Croatian Medical Journal. 48 (6): 791–9. doi:10.3325/cmj.2007.6.791. PMC 2213797. PMID 18074413. Steiner, Charles A.; Janez, Andrej; Jensterle, Mojca; Reisinger, Katrin; Forst, Thomas; Pfützner, Andreas (2007). "Impact of treatment with rosiglitazone or metformin on biomarkers for insulin resistance and metabolic syndrome in patients with polycystic ovary syndrome". Journal of Diabetes Science and Technology. 1 (2): 211–7. doi:10.1177/193229680700100212. PMC 2771474. PMID 19888409. Mlinar, B; Marc, J; Janez, A; Pfeifer, M (2007).
The juice forms the basis for various squashes, juice drinks, and smoothies. In Britain, 95% of the blackcurrants grown are used to manufacture Ribena (a brand of fruit juice whose name is derived from Ribes nigrum) and similar fruit syrups and juices. Macerated blackcurrants are also the primary ingredient in the apéritif, crème de cassis, which in turn is added to white wine to produce a Kir or to champagne to make a Kir Royal. In the UK, a blackcurrant squash may be mixed with beer or alcoholic cider to make drinks including "cider and black", "lager and black", or "snakebite and black".
Delayed stomach emptying creates especially favorable conditions for the shock lactic acidosis, because the digestive system may meanwhile still inhibit fatty acid release and oxidation, helping more muscles to run out of glycogen in those persons, who are otherwise still able to maintain its stores between meals. It has been experimentally demonstrated, that delayed gastric emptying prolongs the duration of the GLP-1 signal. Notably, a small quantity of dietary fructose does not produce this effect (the lactic acidosis), as it is captured by liver and may be fully expended for replenishing liver glycogen. Once all AMP has been recharged to ATP, and glycogen stores allowed to replenish, the cell transitions back to the unmodified original state. If carbohydrate-rich food is not consumed in this state, AMP elimination from the cell eventually completes, glycogen stores can be replenished again, and the cell transitions back to the original state but with reduced ATP pool and an up-regulated citric acid cycle. It may be especially important to have adequate dietary iodine in the glycogen-less state, so that stomach emptying is not excessively delayed, the up-regulation of the citric acid cycle in muscle cells in response to a load increment is not too slow, and the muscles can each time accept a bigger load increment relative to the perceived effort.
The officials further add that the PAF conducted airstrikes at 46 locations inside Afghanistan. The officials also released footage that they said showed Pakistani troops crossing into Afghanistan from North Waziristan and capturing a border outpost belonging to Afghan Taliban. Elsewhere, Pakistan's security forces claimed to have taken control of 32 square kilometres (12 sq mi) of strategic Afghan territory south of the Zhob sector. This strategic territory, near the Kandahar Province, is known as the Ghudwana enclave. At night, local resident in Herat province said that fighter jets were patrolling the skies of the province. In Islam Qala, residents reported hearing two explosions as aircraft flew over. At the same time, armed clashes resumed between Taliban and Pakistan border guards along the border area of Angoor Adda. On 2 March, the PAF conducted airstrikes in Kabul which were confirmed by Taliban officials. According to Afghan local sources, the PAF also carried out airstrikes in parts of Panjshir, Kapisa, and Nangarhar provinces. In the provinces of Panjshir and Kapisa, local sources reported that, for the third consecutive night, they had heard aircraft, explosions, and ground-to-air gunfire. According to residents, scattered gunfire was also heard in the area known as Darband Mountain, which connects Panjshir, Kapisa, and Parwan. While in Nangarhar province, Pakistan's warplane bombed a Taliban-led Afghan armed forces' border brigade near the provincial capital Jalalabad.
The clitoris develops from a phallic outgrowth in the embryo called the genital tubercle. In the absence of testosterone, the genital tubercle allows for the formation of the clitoris; the initially rapid growth of the phallus gradually slows and the body and glans of the clitoris are formed along with its other structures.
Sources: en.wikipedia.org
It is based on epithalamin, a peptide-rich preparation obtained from pineal gland tissue and studied in the former Soviet Union. Researchers later identified the tetrapeptide AEDG as a constituent fragment of that material. Modern supplies are produced by chemical synthesis rather than tissue extraction.
No. Epithalamin is a heterogeneous extract containing many peptides, while epitalon is a single synthesised tetrapeptide. Publications sometimes treat findings from the two as equivalent, which is a common source of confusion. Their compositions differ and they are not interchangeable in analytical terms.
Most published work uses cell cultures or rodents because those models are faster and less costly to run. The few human trials that have been reported are small, and several lack control groups or blinding. This restricts what can reasonably be concluded about effects in people.
Epitalon is a synthetic tetrapeptide built from four amino acids: alanine, glutamate, aspartate, and glycine. It is not extracted from a natural source but made in the laboratory by chemical synthesis. Its short length makes it relatively straightforward to produce at high purity.