The short version of Khavinson fits in a sentence. The long version — which is the one that helps — is below.
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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.
=== Governmental districts (Regierungsbezirke) === The large states of Baden-Württemberg, Bavaria, Hesse, and North Rhine-Westphalia are divided into governmental districts, or Regierungsbezirke. In Rhineland-Palatinate, these districts were abolished or re-organized on 1 January 2000, in Saxony-Anhalt on 1 January 2004, and in Lower Saxony on 1 January 2005. From 1990 until 2012, Saxony was divided into three districts (called Direktionsbezirke since 2008). In 2012, these districts' authorities were merged into one central authority, the Landesdirektion Sachsen.
However, Karachi-based K-Electric and Water and Power Development Authority (WAPDA) generate much of the electricity used in Pakistan and collect revenue nationwide. In 2023, Pakistan's installed electricity generation capacity was ~45,885 MWt. Pakistan produced 1,135 megawatts of renewable energy for the month of October 2016. Pakistan expects to produce 10,000 megawatts of renewable energy by 2025.
The more recent x-ray crystal structure of 1-aza-3,5,7-trimethyladamantan-2-one is a good model for cationic tetrahedral intermediate. The C1-N1 bond is rather long [155.2(4) pm], and C1-O1(2) bonds are shortened [138.2(4) pm]. The protonated nitrogen atom N1 is a great amine leaving group.
The upper town is composed of three parts: the "coast", the suburban districts of the plateau, and large peripheral housing estates. The neighbourhoods on the "coast" (the Dead Cliff) are residential – more prosperous in the western part (Les Ormeaux, Rue Felix Faure) and more modest to the east (St. Cecilia, Aplemont). The Jenner tunnel passes under the "coast" and connects the upper town to the lower town. It is also on the coast that there are two fortifications of the city, Forts Sainte-Adresse and Tourneville, and the main cemetery (Sainte-Marie cemetery). With the demise of the military functions of the city, the forts are gradually being converted: Fort Sainte-Adresse houses the Hanging Gardens and Fort Tourneville hosted the Tetris project in 2013 – an axis of contemporary music with concert halls and rehearsal studios. To the north of the "coast" suburban districts such as Rouelles, Sainte-Cecile, la Mare au Clerc, Sanvic, Bleville, and Dollemard were developed during the first half of the 19th century. In their extension North-west between Bleville and Octeville airport a new area is being developed: "Les Hauts de Bleville". This eco-district made up of housing units to HQE standards, a Joint Development Area (ZAC), and a school should have a total of 1,000 housing units. The peripheral suburbs of the commune grew in the postwar period. These are large housing estates in Caucriauville, Bois de Bleville, Mont-Gaillard, and Mare-rouge where a disadvantaged population is concentrated.
Sources: en.wikipedia.org
=== Contraction === Neuromuscular junctions are the focal point where a motor neuron attaches to a muscle. Acetylcholine, (a neurotransmitter used in skeletal muscle contraction) is released from the axon terminal of the nerve cell when an action potential reaches the microscopic junction called a synapse. A group of chemical messengers across the synapse and stimulate the formation of electrical changes, which are produced in the muscle cell when the acetylcholine binds to receptors on its surface. Calcium is released from its storage area in the cell's sarcoplasmic reticulum. An impulse from a nerve cell causes calcium release and brings about a single, short muscle contraction called a muscle twitch. If there is a problem at the neuromuscular junction, a very prolonged contraction may occur, such as the muscle contractions that result from tetanus. Also, a loss of function at the junction can produce paralysis. Skeletal muscles are organized into hundreds of motor units, each of which involves a motor neuron, attached by a series of thin finger-like structures called axon terminals. These attach to and control discrete bundles of muscle fibers. A coordinated and fine-tuned response to a specific circumstance will involve controlling the precise number of motor units used. While individual muscle units' contract as a unit, the entire muscle can contract on a predetermined basis due to the structure of the motor unit. Motor unit coordination, balance, and control frequently come under the direction of the cerebellum of the brain.
Other natural materials occasionally confused with or used in lieu of turquoise include: variscite and faustite; chrysocolla (especially when impregnating quartz); lazulite; smithsonite; hemimorphite; wardite; and a fossil bone or tooth called odontolite or "bone turquoise", coloured blue naturally by the mineral vivianite. While rarely encountered today, odontolite was once mined in large quantities—specifically for its use as a substitute for turquoise—in southern France. These fakes are detected by gemologists using a number of tests, relying primarily on non-destructive, close examination of surface structure under magnification; a featureless, pale blue background peppered by flecks or spots of whitish material is the typical surface appearance of natural turquoise, while manufactured imitations will appear radically different in both colour (usually a uniform dark blue) and texture (usually granular or sugary). Glass and plastic will have a much greater translucency, with bubbles or flow lines often visible just below the surface. Staining between grain boundaries may be visible in dyed imitations. Some destructive tests may be necessary; for example, the application of diluted hydrochloric acid will cause the carbonates odontolite and magnesite to effervesce and howlite to turn green, while a heated probe may give rise to the pungent smell so indicative of plastic. Differences in specific gravity, refractive index, light absorption (as evident in a material's absorption spectrum), and other physical and optical properties are also considered as means of separation.
=== Further clinical studies of radiolabeled somatostatin receptor antagonists === Ga-NODAGA-JR11 had entered further clinical studies as an imaging agent, while Lu-DOTA-JR11 had similar research done as a therapeutic agent, as JR11 has a high binding affinity for ssrt2 subtype receptors which are highly expressed on the surface of tumor cells. Gallium-containing agonists had already been established as an imaging agent. Lutetium-containing agonists were used as a therapeutic agent in peptide receptor radionuclide therapy, due to the lower energy electrons emitted, and γ-emission causing easier dose adjustment to patient characteristics to avoid renal damage. The NODAGA chelator was used over DOTA in Gallium antagonists due to higher binding affinity, while no Lu-NODAGA compounds were developed due to established usage of Lu-DOTA derivative agonist drugs, and poor uptake compared to DOTA, which is reverse that of the gallium-containing antagonists.
In November 1968, dismay gripped the United States Central Intelligence Agency when a successful satellite destruction simulation was successfully orchestrated by the Soviet Union. As a part of the Istrebitel Sputnikov anti-satellite weapons research programme, the Kosmos 248 Soviet satellite was successfully destroyed by Kosmos 252 which was able to intercept within the 5 km 'kill radius' and destroyed Kosmos 248 by detonating its onboard warhead. This wasn't the beginning of the programme, years earlier intercept attempts had begun with maneuvering test of the Polyot satellites in 1964.
Pakistan was ranked 99th in the Global Innovation Index by 2025. The 1960s marked the rise of Pakistan's space program, led by SUPARCO, yielding advancements in rocketry, electronics, and aeronomy. Notably, Pakistan launched its first rocket into space, pioneering South Asia's space exploration. In 1990, it successfully launched its first satellite, becoming the first Muslim nation and second in South Asia to achieve this milestone.
Sources: en.wikipedia.org
Due to use of the drug for date rape and recreation, in 1998 Roche modified the formulation to give lower doses, make it less soluble, and add a blue dye for easier detection in drinks. It was never marketed in the United States, and by 2016 had been withdrawn from the markets in Spain, France, Norway, Germany, and the United Kingdom.
=== Heptapeptide backbone synthesis === The heptapeptide backbone of teicoplanin is assembled by the nonribosomal peptide synthetases (NRPSs) TeiA, TeiB, TeiC and TeiD. Together these comprise seven modules, each containing a number of domains, with each module responsible for the incorporation of a single amino acid. Modules 1, 4, and 5 activate L-4-Hpg as the aminoacyl-AMP, modules 2 and 6 activate L-Tyr, and modules 3 and 7 activate L-3,5-Dpg. The activated amino acids are covalently bound to the NRPS as thioesters by a phosphopantetheine cofactor, which is attached to the peptidyl carrier protein (PCP) domain. The enzyme bound amino acids are then joined by amide bonds by the action of the condensation (C) domain. The heptapetide of teicoplanin contains 4 D-amino acids, formed by epimerization of the activated L-amino acids. Modules 2, 4 and 5 each contain an epimerization (E) domain which catalyzes this change. Module 1 does not contain an E domain, and epimerization is proposed to be catalysed by the C domain. In all, six of the seven total amino acids of the teicoplanin backbone are composed of nonproteinogenic or modified amino acids. Eleven enzymes are coordinatively induced to produce these six required residues. Teicoplanin contains two chlorinated positions, 2 (3-Cl-Tyr) and 6 (3-Cl-β-Hty). The halogenase Tei8* has been acts to catalyze the halogenation of both tyrosine residues.
In electrospray ionization, a liquid is pushed through a very small, charged and usually metal, capillary. This liquid contains the substance to be studied, the analyte, dissolved in a large amount of solvent, which is usually much more volatile than the analyte. Volatile acids, bases or buffers are often added to this solution as well. The analyte exists as an ion in solution either in its anion or cation form. Because like charges repel, the liquid pushes itself out of the capillary and forms an aerosol, a mist of small droplets about 10 μm across. The aerosol is at least partially produced by a process involving the formation of a Taylor cone and a jet from the tip of this cone. An uncharged carrier gas such as nitrogen is sometimes used to help nebulize the liquid and to help evaporate the neutral solvent in the droplets. As the solvent evaporates, the analyte molecules are forced closer together, repel each other and break up the droplets. This process is called Coulombic fission because it is driven by repulsive Coulombic forces between charged molecules. The process repeats until the analyte is free of solvent and is a bare ion. The ions observed are created by the addition of a proton (a hydrogen ion) and denoted [M + H]+, or of another cation such as sodium ion, [M + Na]+, or the removal of a proton, [M − H]−. Multiply charged ions such as [M + 2H]2+ are often observed. For macromolecules, there can be many charge states, occurring with different frequencies; the charge can be as great as [M + 24H]24+, for example.
=== Benefactor and corporate members === Benefactor and corporate members can be companies, universities, national, regional or international organisations, laboratories, associations or any other structure active in or connected to the refrigeration industry or IIR activities.
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.