This is a working overview of AEDG, written for readers who want more than a one-paragraph summary but less than a textbook.
Reviewed 2026-01-18. Anything still debated is marked as such rather than presented as settled.
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.
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.
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.
The four residues give epitalon a molecular formula of C14H22N4O9 and a molecular weight near 390.35 daltons. The presence of two acidic residues, glutamate and aspartate, makes the free peptide strongly acidic, while the alanine and glycine ends provide neutral, nonpolar character. This combination produces a molecule with substantial water solubility. Because there are no cysteine, methionine, or tryptophan residues, the peptide lacks the most common oxidation-sensitive side chains, which simplifies handling compared with many longer peptides.
The proposed relationship between epitalon and pineal function is a central part of its background. Khavinson's group reported that short peptides corresponding to regions of larger pineal proteins could influence gene expression in cells. Epitalon was framed as a synthetic analogue of an active fragment rather than a direct isolation product. Whether the tetrapeptide reproduces the effects of the parent extract is an open question, because comparative studies are limited and the parent extract itself is not a single defined substance.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C14H22N4O9 | Calculated from the four residues with three water losses |
| Molecular mass | About 390.35 g/mol | Monoisotopic mass near 390.14, used for mass-spectrometric identification |
| Peptide sequence | Ala-Glu-Asp-Gly | Single-letter form AEDG; no disulfide bonds or modified residues |
| Appearance | White to off-white solid | Supplied as a dried powder |
| Isoelectric point | Around 4 | Estimated from aspartate and glutamate side-chain pKa values |
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.
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.
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.
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.
Connective tissue in skeletal muscle Dorsal artery of the penis (example of integument enclosing an internal organ) Flensing Flesh (generic use of plural "integuments") Herzog & de Meuron (figurative usage) Integumentary system (senses related to vertebrate skin and medical aspects) Integumental muscles Mosasaur Seed
Since the details regarding such variables as test species, receptor source, route of administration, drug concentration, and stereochemical composition are important but often incomplete in other Reviews and Abstracts of research publications, many are provided in the more technical review below, in order to support as fully as possible the broad statements made in this Synopsis.
Amino acid replacement is a change from one amino acid to a different amino acid in a protein due to point mutation in the corresponding DNA sequence. It is caused by a nonsynonymous missense mutation which changes the codon sequence to code for a different amino acid than the original sequence.
=== Chromatography === Internal standards are used in GC/MS and LC/MS to control for variability introduced by injection, sample preparation and other matrix effects. The ratio of peak areas between the internal standard and analyte is calculated to determine analyte concentration. A common type of internal standard is an isotopically labeled analogue of the analyte, which incorporates one or more atoms of 2H, 13C, 15N and 18O into its structure.
Sources: en.wikipedia.org
Plant cells have cell walls composed of cellulose, hemicelluloses, and pectin that are constructed outside the cell membrane. In sclerenchyma tissue lignin is secreted to form a secondary wall inside the primary cell wall. Cutin is secreted outside the primary cell wall and into the outer layers of the secondary cell wall of the epidermal cells of leaves, stems and other above-ground organs to form the plant cuticle. Cell walls perform many essential functions, they provide shape to form the tissue and organs of the plant, and play an important role in intercellular communication and plant-microbe interactions. Specialized cell-to-cell communication pathways known as plasmodesmata, occur in the form of pores in the primary cell wall through which the cell membrane and endoplasmic reticulum of adjacent cells are continuous. Organelles in plant cells, include pigment-containing plastids, especially chloroplasts that contain chlorophyll (also found in algae), large water-storage vacuoles, and two types of peroxisome. Chloroplasts capture the sun's energy to make carbohydrates through photosynthesis. Chromoplasts contain fat-soluble carotenoid pigments such as orange carotene and yellow xanthophylls which helps in synthesis and storage. Leucoplasts are non-pigmented plastids and helps in storage of nutrients. Plastids divide by binary fission. The vacuoles are larger than those in animal cells, and their membrane transports ions against concentration gradients. One type of peroxisome is in the leaves where it takes part in photorespiration.
==== Spina bifida ==== MTRR requires vitamin B12 for maintenance of the methyl synthase reaction whilst folate is needed for normal synthesis of nucleotide precursors. These ensure normal DNA synthesis and cellular methylation reactions. Chronic folate or methyl deficiencies are thereby linked to abnormal DNA methylation. The 66A>G polymorphism is up-regulated in neural tube defects and increases the risk of spina bifida by two-fold. Homozygosis for this mutation is an established maternal risk factor for spina bifida especially with low intracellular vitamin B12 in the circulation or amniotic fluid. Vitamin B12 is reflected by plasma methylmalonic acid (MMA), an elevation in which indicates impaired B12 uptake or metabolism. A raised MMA combined with the MTRR mutation corresponds to a 5-fold increase in spina bifida. The mechanism of action of this polymorphism is through the mother, hence there is no preferential transmission of this mutation from parent to child. Abnormal MTRR binding to the MTR-cob(I)alamin-enzyme complex down regulates the rate of homocysteine methylation. Consequent decreases in methionine and S-adenosylmethionine negatively affect DNA, gene and protein methylation, all of which are involved in neural tube closure. Increased proliferation during neurulation decreases the availability of DNA nucleotides. As these are unable to be replaced due to impaired DNA methylation and nucleotide formation, consequent disturbed neurulation results in the formation of neural tube defects.
Nuclear export of SENP2 additionally downregulates endothelial nitric oxide synthase, eNOS while it upregulates inflammatory adhesion molecules. As eNOS is required for healthy vascular physiology, pathological oxidative stress ensues in vascular endothelial cells. With the oxidative stress comes subsequent accumulation of cellular lipids; this results in the inflammatory foamy cell state that is typified by atherosclerosis as well as the similarly inflammatory myelin-laden macrophages known to produce chronic inflammation in SCI. In cardiovascular disease, many proteins are subject to SUMOylation. To say SUMOylation itself is bad or good regarding this or any other class of disease is to overlook the role of the multiple proteins in question. One common denominator among many conditions is fibrosis; in myocardial fibrosis, PPARγ1 is understood to have a role in regulating expression of some key genes, and its transcriptional activity is generally inhibited by SUMOylation. Therefore, one possible therapeutic intervention in the case of cardiac hypertrophy may be countering the SUMOylation of PPARγ1. In neurodegenerative disease, we often observe pathological accumulation of proteins. Inclusion bodies form when for example, the Huntington's disease protein, aptly named Huntingtin, accumulates and folds into a form which is impervious to the proteasome.
== Site-directed mutagenesis == This method use DNA recombinant technology and it gives an actual measurement of protein stability. In his detailed site-directed mutagenesis studies, Utani and his coworkers substituted 19 amino acids at Trp49 of the tryptophan synthase and he measured the free energy of unfolding. They found that the increased stability is directly proportional to increase in hydrophobicity up to a certain size limit. The main disadvantage of site-directed mutagenesis method is that not all the 20 naturally occurring amino acids can substitute a single residue in a protein. Moreover, these methods have cost problems and is useful only for measuring protein stability.
Court docket: United States v. Carvajal-Barrios (S.D.N.Y.), 1:11-cr-00205; second superseding indictment against Maduro and others "Crisis in Venezuela". Frontline. Season 44. Episode 9. 10 February 2026. PBS. WGBH. Retrieved 25 February 2026.
Sources: en.wikipedia.org
The first MP, installed at Yale in 1963, operated consistently at 10–11 megavolts; a later installation at Strasbourg reached 18. At these energies, electron stripping becomes highly efficient. A uranium ion passing through the terminal can lose more than 20 electrons, enabling heavy-ion fusion experiments impossible with earlier machines. Advances in gamma-ray spectroscopy combined with MP tandems enabled precision measurements of nuclear structure. HVEC manufactured 10 MP units between 1965 and 1973 for institutions including the University of Minnesota, Chalk River, and the Max Planck Institute in Heidelberg. The XTU ("Holy Roman Emperor") was designed for superheavy element synthesis. Theoretical models predicted an "island of stability" beyond element 110 where nuclei would resist rapid decay. The XTU's 20-megavolt rating would accelerate uranium ions to nearly one billion electron volts—enough to overcome Coulomb barriers in heavy-element fusion. Two prototypes operated solely on a test basis at Burlington before the project was cancelled. One later sold to Italy's national laboratory at Legnaro in 1979.
== Legal status == Ketazolam is a List 3 drug under the Betäubungsmittelgesetz, like almost all benzodiazepines in Germany. Ketazolam is a List II drugs of the Opium Law in the Netherlands. Ketazolam is a Schedule IV drug under the Controlled Substances Act in the US.
Military rations, operational rations, or military provisions are goods issued to sustain the needs of military personnel. As their name suggests, military rations have historically been, and often still are, subject to rationing, with each individual receiving specific amounts from available supplies. Military-issued goods and the rationing of such goods have existed since the beginnings of organized warfare. Though commonly referring to food and drink rations, "military ration" may also refer to other types of items that are rationed for military personnel, such as fuel, alcohol, expensive items, or consumer goods. Ration acquisition may be managed using allowances or a ration card, or they may be issued without charge. Military rations are a key component of military nutrition, the field and study of nutrition in the military. Significant research goes into creating military rations, including the nutrition and energy of rations, food spoilage prevention, what meals should be offered, the amount of food each ration should contain, and the exact specifications of each meal and ingredient.
==== Magnetic droplets in non-traditional systems ==== In traditional, droplet-based microfluidic systems, that is to say, a droplet in a channel which contains an immiscible oil that separates the droplets, movement of the droplets is achieved through differences in pressure or surface tension. In non-traditional, droplet-based microfluidic systems, such as those herein, other mechanisms of control are needed to manipulate the droplets. Application of a magnetic field to a microfluid array containing magnetic droplets allows for easily achieved sorting and arrangement of the droplets into useful patterns and configurations. These types of manipulations can be achieved via static or dynamic application of a magnetic field which allows for a high degree of control over magnetic droplets. Characterization of the degree of control over magnetic droplets includes measurements of the magnetic susceptibility of the ferrofluid, measurement of the change in droplet in substrate interface area in the presence of an applied magnetic field, and measurement of the "roll-off angle" or the angle at which the droplet would move in the presence of a magnetic field when the surface was tilted. Interactions between the water droplet and the surface can be manipulated by adjusting the structure of the microfluidic system itself by applying a magnetic field to iron-doped poly[dimethylsiloxane] (PDMS), a common material for microfluidic devices.
Sources: en.wikipedia.org
No. Epithalamin is a peptide-containing extract of bovine pineal glands, while epitalon is a single synthetic tetrapeptide. The extract contains many peptides and other tissue components, so its composition varies between batches in ways that a synthesised sequence does not.
It is not recognised as an endogenous peptide hormone. The four-residue sequence can appear inside larger proteins and in digestive fragments of dietary protein, but no dedicated pathway producing it as a signalling molecule has been identified.
Several cell-culture reports describe increased telomerase activity after treatment, measured by enzyme assays or by transcript levels. Results differ between cell types and laboratories, and measured telomere lengthening has been reported in some studies but not in others, which leaves the physiological relevance open.
Epitalon is a synthetic tetrapeptide composed of four amino acids: alanine, glutamate, aspartate, and glycine. It is written as Ala-Glu-Asp-Gly. The free peptide has a molecular weight of about 390 daltons and is normally supplied as a lyophilized powder.