Everything below concerns lyophilised powder. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Updated 2025-09-17. Numbers and descriptions here follow the published literature rather than marketing material.
Laboratory work has examined effects on telomerase activity in cultured cells, on melatonin rhythms in animals, and on markers of oxidative stress. Some experiments report measurable changes while others show none, and the reported findings rest largely on small studies. The absence of large independent trials means the generality of these results is unresolved rather than settled. Review articles occasionally apply the label geroprotector, a term that reflects a research hypothesis about ageing rather than an established clinical finding.
Epitalon is the common name for a synthetic tetrapeptide with the sequence alanine-glutamate-aspartate-glycine, usually abbreviated AEDG. All four residues are proteinogenic amino acids, and the free peptide has a calculated mass near 390 grams per mole. Because the chain is short and carries no modifications, it is assembled readily by solid-phase synthesis and is distributed mainly as a freeze-dried solid for laboratory work. Catalogue listings use the spellings epitalon, epithalone, and simply AEDG, and the three refer to the same sequence.
The compound is generally presented as a synthetic fragment of epithalamin, a pineal gland extract investigated in the former Soviet Union from the 1970s onward. Vladimir Khavinson and colleagues in Saint Petersburg developed short peptides modelled on such extracts, and epitalon became the most widely cited of those sequences. Most primary reports appeared in Russian-language journals or in proceedings with limited international circulation. Independent replication in laboratories outside that network remains sparse, and much repeated secondary material traces back to a small number of originating groups.
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.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C14H22N4O9 | Computed for the free acid of Ala-Glu-Asp-Gly |
| Molecular mass | About 390.35 g/mol | Free peptide; salt forms shift the value |
| Appearance | White to off-white solid | Typical of short peptides after freeze-drying |
| Solubility class | Freely soluble in water | Aqueous buffers are also commonly used |
| Common synonyms | Epitalon, epithalone, AEDG | AEDG is the single-letter sequence |
In its supplied form epitalon is a white to off-white powder, usually lyophilized and often hygroscopic. It dissolves readily in water and in aqueous buffers, and it is commonly handled as the acetate or trifluoroacetate salt to improve stability during purification and drying. The amide backbone is labile in aqueous media, so solutions are less durable than the dry solid. Handling notes in the chemical literature therefore emphasize keeping the powder dry, cool and shielded from light until it is dissolved.
Epitalon is a synthetic tetrapeptide whose sequence is alanine-glutamate-aspartate-glycine, written in single-letter code as AEDG. The four residues are joined by three peptide bonds, giving a linear backbone with no branching and no disulfide bridges. Its calculated molecular mass for the free form is approximately 390.3 daltons, a figure that rises when the compound is supplied as an acetate or trifluoroacetate salt. Because the chain is short, the molecule is defined entirely by its residue order rather than by any folded three-dimensional structure.
Proposed mechanisms centre on cell-culture observations rather than a defined receptor interaction. Several reports describe increased expression of the telomerase catalytic subunit after exposure of cultured human cells, and the authors attributed the effect to short peptide fragments entering the nucleus and influencing gene transcription. No receptor for the tetrapeptide has been identified, and the free peptide is expected to be degraded rapidly by plasma peptidases. Whether any measurable fraction reaches intact tissues after administration remains an unresolved question rather than an established finding.
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.
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.
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.
==== Amphibians ==== Some salamanders can extrude sharp venom-tipped ribs. Two frog species in Brazil have tiny spines around the crown of their skulls which, on impact, deliver venom into their targets.
Many bird species migrate to take advantage of global differences of seasonal temperatures, therefore optimising availability of food sources and breeding habitat. These migrations vary among the different groups. Many landbirds, shorebirds, and waterbirds undertake annual long-distance migrations, usually triggered by the length of daylight as well as weather conditions. These birds are characterised by a breeding season spent in the temperate or polar regions and a non-breeding season in the tropical regions or opposite hemisphere. Before migration, birds substantially increase body fats and reserves and reduce the size of some of their organs. Migration is highly demanding energetically, particularly as birds need to cross deserts and oceans without refuelling. Landbirds have a flight range of around 2,500 km (1,600 mi) and shorebirds can fly up to 4,000 km (2,500 mi), although the bar-tailed godwit is capable of non-stop flights of up to 10,200 km (6,300 mi). Some seabirds undertake long migrations, with the longest annual migrations including those of Arctic terns, which were recorded travelling an average of 70,900 km (44,100 mi) between their Arctic breeding grounds in Greenland and Iceland and their wintering grounds in Antarctica, with one bird covering 81,600 km (50,700 mi), and sooty shearwaters, which nest in New Zealand and Chile and make annual round trips of 64,000 km (39,800 mi) to their summer feeding grounds in the North Pacific off Japan, Alaska and California. Other seabirds disperse after breeding, travelling widely but having no set migration route.
Malaysia is a country in Southeast Asia. A federal constitutional monarchy, it consists of 13 states and three federal territories, separated by the South China Sea into two regions: Peninsular Malaysia on Mainland Southeast Asia and East Malaysia on the island of Borneo. Peninsular Malaysia shares land and maritime borders with Thailand, as well as maritime borders with Singapore, Vietnam, and Indonesia; East Malaysia shares land borders with Brunei and Indonesia, and maritime borders with the Philippines and Vietnam. Kuala Lumpur is the country's national capital, largest city, and the seat of the legislative branch of the federal government, while Putrajaya is the federal administrative capital, representing the seat of both the executive branch and the judicial branch of the federal government. With a population of over 34 million, it is the world's 43rd-most populous country. The country has its origins in the Malay kingdoms, which, from the 18th century on, became subject to the British Empire, along with the British Straits Settlements protectorate. During World War II, British Malaya, along with other nearby British and American colonies, was occupied by the Empire of Japan. Following three years of occupation, Malaya was briefly unified as the Malayan Union in 1946 until 1948 when it was restructured as the Federation of Malaya. The country achieved independence on 31 August 1957. On 16 September 1963, independent Malaya united with the then British crown colonies of North Borneo, Sarawak, and Singapore to become Malaysia.
=== Forestry === In commercial forestry, the transplanting of crop trees to new locations often requires an accompanying ectomycorrhizal partner. This is especially true of trees that have a high degree of specificity for their mycobiont, or trees that are being planted far from their native habitat among novel fungal species. This has been repeatedly shown in plantations involving obligate ectomycorrhizal trees, such as Eucalyptus and Pinus species. Mass planting of these species often requires an inoculum of native EcM fungi for the trees to prosper. Sometimes ectomycorrhizal plantation species, such as pine and eucalyptus, are planted and promoted for their ability to act as a sink for atmospheric carbon. However, the ectomycorrhizal fungi of these species also tend to deplete soil carbon, making this use of plantations controversial.
Sources: en.wikipedia.org
When herbivores are moved around leaves of wild type plants, they reach similar masses to herbivores that consume only mutant plants, implying the effects of JAs are localized to sites of herbivory. Studies have shown that there is significant crosstalk between defense pathways.
It was a pragmatic system based on the primacy of the strong – a "trusteeship of the powerful", as he then called it, or, as he put it later, "the Four Policemen". The concept was, as [Senator Arthur H.] Vandenberg noted in his diary in April 1944, "anything but a wild-eyed internationalist dream of a world state. ... It is based virtually on a four-power alliance." Eventually this proved to be both the potential strength and the actual weakness of the future UN, an organization theoretically based on a concert of great powers whose own mutual hostility, as it turned out, was itself the greatest potential threat to world peace.
=== Famotidine === Famotidine is a specific, long-acting H2 antagonist that decreases gastric acid secretion. It is used in the treatment of peptic ulcer disease, GERD, and pathological hypersecretory conditions, like Zollinger–Ellison syndrome. (14,15) H2-receptor antagonists affect hormone metabolism, but their effect on glucose metabolism is not well established. (16) A study has revealed a glucose-lowering effect for famotidine. The study of famotidine binding to the enzyme has showed that famotidine can be docked within the binding pocket of GSK-3β making significant interactions with key points within the GSK-3β binding pocket. Strong hydrogen bond interactions with the key amino acids PRO-136 and VAL -135 and potential hydrophobic interaction with LEU-188 were similar to those found in the ligand binding to the enzyme (AR-A014418). Furthermore, famotidine showed high GSK-3β binding affinity and inhibitory activity due to interactions that stabilize the complex, namely hydrogen bonding of guanidine group in famotidine with the sulfahydryl moiety in CYS-199; and electrostatic interactions between the same guanidine group with the carboxyl group in ASP-200, the hydrogen bond between the terminal NH2 group, the OH of the TYR-143, and the hydrophobic interaction of the sulfur atom in the thioether with ILE-62. In vitro studies showed that famotidine inhibits GSK-3β activity and increases liver glycogen reserves in a dose dependent manner. A fourfold increase in the liver glycogen level with the use of the highest dose of famotidine (4.4 mg/kg) was observed.
The War of 1812 coincided with the War of the Sixth Coalition. Historians in the United States and Canada see it as a war in its own right, while Europeans often see it as a minor theatre of the Napoleonic Wars. The United States declared war on Britain due to a variety of reasons, including British support for Native Americans resisting US settler expansion, interference with American merchant shipping, the impressment of Royal Navy deserters from US merchantmen, and expansionist American desires to occupy Canada. France had interfered with American shipping as well, and the United States had considered declaring war on France. The war ended in a military stalemate under the Treaty of Ghent, which took effect in early 1815 when Napoleon was still in Elba and returned the pre-war boundaries.
=== Reductive half === The action of GR proceeds through two distinct half reactions, a reductive half mechanism followed by an oxidative half. In the first half, NADPH reduces FAD present in GSR to produce a transient FADH− anion. This anion then quickly breaks a disulfide bond of Cys58 - Cys63, forming a short lived covalent bond a stable charge-transfer complex between the flavin and Cys63. The now oxidized NADP+ is released and is subsequently replaced by a new molecule of NADPH. This is the end of the so-called reductive half of the mechanism.
Sources: en.wikipedia.org
It is a four-amino-acid peptide with the sequence alanine-glutamate-aspartate-glycine. The chain is unmodified and contains only standard proteinogenic residues, which makes it straightforward to produce by solid-phase synthesis and to characterise by standard peptide methods.
Epitalon and epithalon both circulate, and the difference reflects transliteration of a name coined in Russian-language publications. Reference to the extract it derives from, epithalamin, explains the shared stem. Databases and suppliers are inconsistent, so a search for one spelling alone may miss relevant entries.
No. Epithalamin is a multi-component preparation obtained from pineal tissue, and its exact composition is not fully characterised. Epitalon is a single defined tetrapeptide described as a short synthetic counterpart of that extract, so the two are related in origin but not interchangeable in identity.
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.