Everything below concerns AEDG peptide. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Updated 2025-11-30. Numbers and descriptions here follow the published literature rather than marketing material.
The compound is described in the literature as a derivative of epithalamin, a preparation obtained from bovine pineal tissue. Work on this peptide family was carried out mainly by a research group in Saint Petersburg beginning in the 1980s, and the substance was later registered for clinical use in Russia under the name Epitalon. Outside that region it is generally treated as a research chemical rather than an approved medicine. Statements about its biological activity rest on a relatively small number of studies, and independent replication remains limited.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic tetrapeptide | Four residues, linear chain |
| Residue sequence | Ala-Glu-Asp-Gly | Single-letter form AEDG |
| Calculated mass | 390.3 daltons | Value for the free, uncharged form |
| Appearance | White to off-white powder | Usually supplied lyophilized |
| Solubility | Freely soluble in water | Often handled as a salt form |
（TG:@pojiaai）Epitalon is a synthetic linear tetrapeptide with the sequence alanine-glutamate-aspartate-glycine, abbreviated AEDG. It emerged from work on epithalamin, a peptide fraction prepared from bovine pineal tissue, and was designed as a short, chemically defined analogue of that extract. Early publications came mainly from Russian laboratories studying pineal peptides and aging-related endpoints. The compound appears in the literature under several spellings, including epithalon and epithalone, which complicates systematic searching. Its small size makes solid-phase assembly and routine analytical characterization straightforward.
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.
Published work on this compound consists mainly of in vitro experiments, animal studies, and small clinical investigations, a substantial share of which appeared in Russian-language journals. Sample sizes are generally small, control conditions differ between studies, and several endpoints rely on markers whose clinical meaning is itself debated. Reviews of the longevity field treat the peptide as an early example of telomerase-directed research rather than an established intervention. Regulatory treatment varies by country: some jurisdictions place it under prescription controls, others treat it as a laboratory material, and importation may be restricted regardless of local status.
Epitalon is a synthetic tetrapeptide whose sequence is alanine–glutamate–aspartate–glycine, commonly abbreviated AEDG. It was developed in Russia during the 1980s and 1990s by investigators associated with the St. Petersburg Institute of Bioregulation and Gerontology, who studied short peptides as regulators of gene expression and tissue function. The alternative spelling epithalon appears interchangeably in the literature, and the two names refer to the same molecule. Outside Russia it is encountered chiefly as a research chemical rather than a licensed medicine, and it holds no approval from the United States Food and Drug Administration or the European Medicines Agency.
The most frequently cited proposed action is induction of telomerase, the enzyme that adds repeat sequences to chromosome ends. Cell-culture work from the originating group reported higher telomerase reverse transcriptase expression and measurable telomere elongation in human somatic cells after exposure. How a four-residue peptide would reach nuclear gene regulation is not established, and no cell-surface receptor or uptake route has been identified. Additional reports describe changes in melatonin secretion, antioxidant enzyme activity and lipid peroxidation in aged animals, but these findings remain mechanistically unconnected to the telomerase observation.
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.
=== mRNA Degradation === Degradation of mRNA also plays an important part in regulating the translation process. To explore mechanisms of decay, genome-wide mapping of uncapped and cleaved transcripts (GMUCT), parallel analysis of RNA ends (PARE), and degradome sequencing use the T4 ligase of the Illumina sequencing platform to sequence decapped mRNAs. T4 ligase ligates to RNA with a free 5' monophosphate. As mature mRNAs have a 5' cap, they are not bound as substrates, leaving decapped and degrading mRNAs to be bound. 5′-monophosphorylated ends sequencing (5Pseq) captures both capped and decapped sequences to allow sequencing of both mature mRNA and degraded products. This helps identify mRNA degradation products and has uses in studying ribosome stalling. These methods study 5' to 3' degradation, miRNA-mediated cleavage, and nonsense-mediated mRNA decay, but cannot measure 3' to 5' degradation and other degradation mechanisms.
The administration of reboxetine with food delayed the absorption rate by approximately 2 hours while not affecting the extent of absorption. The absolute bioavailability is approximately 94%. Plasma concentrations of reboxetine fell in one exponential phase (monoexponential) with a half-life of about 12 hours. Steady-state is seen within 5 days. Reboxetine is 97% protein bound in young people and 92% in the elderly and is distributed into total body water. Radioactivity excreted in the urine corresponds to 78% of the dose. Even though the drug is mainly unchanged in blood circulation (70% of total radioactivity, as the area under the concentration curve (AUC)), only about 10% of the dose is excreted unchanged in the urine. Reboxetine is almost fully metabolised after oral administration. The drug is mainly metabolised through o-dealkylation and oxidation of the morpholine ring and hydroxylation of the ethoxyphenoxy ring. In vitro studies indicate that the CYP450(3A4) enzyme is primarily responsible for the metabolism of reboxetine. The drug is available as a racemic compound. The RR enantiomer is 10 times less potent than the SS enantiomer. The SS enantiomer (more potent) has a plasma level that is two times lower than the urinary excretion. Elimination of reboxetine is mainly via hepatic metabolism (by cytochrome P450 3A4) with a mean terminal half-life of about 12 hours. No significant difference was observed in the terminal half-lives of the RR and SS diastereomers. About 10% of the dose of reboxetine is cleared renally.
In summary, between 2003 and 2006, 11.3% of children and adolescents were obese and 16.3% were overweight. A slight increase was observed in 2007 and 2008 when the recorded data shows that 11.9% of the children between 6 and 19 years old were obese and 16.9% were overweight. The data recorded in the first survey was obtained by measuring 8,165 children over four years and the second was obtained by measuring 3,281 children. "More than 80 percent of affected children become overweight adults, often with lifelong health problems." Children are not only highly at risk of diabetes, high cholesterol and high blood pressure but obesity also takes a toll on the child's psychological development. Social problems can arise and have a snowball effect, causing low self-esteem which can later develop into eating disorders.
=== Regeneration === After the last solute has been eluted, it is necessary to strip the displacer from the column. Since the displacer was chosen for high affinity, this can pose a challenge. On reverse-phase materials, a wash with a high percentage of organic solvent may suffice. Large pH shifts are also often employed. One effective strategy is to remove the displacer by chemical reaction; for instance if hydrogen ion was used as displacer it can be removed by reaction with hydroxide, or a polyvalent metal ion can be removed by reaction with a chelating agent. For some matrices, reactive groups on the stationary phase can be titrated to temporarily eliminate the binding sites, for instance weak-acid ion exchangers or chelating resins can be converted to the protonated form. For gel-type ion exchangers, selectivity reversal at very high ionic strength can also provide a solution. Sometimes the displacer is specifically designed with a titratable functional group to shift its affinity. After the displacer is washed out, the column is washed as needed to restore it to its initial state for the next run.
=== Evaluating similarity === Often the purpose of seeking a structural superposition is not so much the superposition itself, but an evaluation of the similarity of two structures or a confidence in a remote alignment. A subtle but important distinction from maximal structural superposition is the conversion of an alignment to a meaningful similarity score. Most methods output some sort of "score" indicating the quality of the superposition. However, what one actually wants is not merely an estimated "Z-score" or an estimated E-value of seeing the observed superposition by chance but instead one desires that the estimated E-value is tightly correlated to the true E-value. Critically, even if a method's estimated E-value is precisely correct on average, if it lacks a low standard deviation on its estimated value generation process, then the rank ordering of the relative similarities of a query protein to a comparison set will rarely agree with the "true" ordering. Different methods will superimpose different numbers of residues because they use different quality assurances and different definitions of "overlap"; some only include residues meeting multiple local and global superposition criteria and others are more greedy, flexible, and promiscuous. A greater number of atoms superposed can mean more similarity but it may not always produce the best E-value quantifying the unlikeliness of the superposition and thus not as useful for assessing similarity, especially in remote homologs.
Sources: en.wikipedia.org
Gas chromatography–mass spectrometry (GC–MS) is an analytical method that combines the features of gas-chromatography and mass spectrometry to identify different substances within a test sample. Applications of GC–MS include drug detection, fire investigation, environmental analysis, explosives investigation, food and flavor analysis, and identification of unknown samples, including that of material samples obtained from planet Mars during probe missions as early as the 1970s. GC–MS can also be used in airport security to detect substances in luggage or on human beings. Additionally, it can identify trace elements in materials that were previously thought to have disintegrated beyond identification. Like liquid chromatography–mass spectrometry, it allows analysis and detection even of tiny amounts of a substance. GC–MS has been regarded as a "gold standard" for forensic substance identification because it is used to perform a 100% specific test, which positively identifies the presence of a particular substance. A nonspecific test merely indicates that any of several in a category of substances is present. Although a nonspecific test could statistically suggest the identity of the substance, this could lead to false positive identification. However, the high temperatures (300°C) used in the GC–MS injection port (and oven) can result in thermal degradation of injected molecules, thus resulting in the measurement of degradation products instead of the actual molecule(s) of interest.
The most common dashi stocks for miso soup are made of niboshi (dried baby sardines), kombu (dried kelp), katsuobushi (thin shavings of fermented, dried, and smoked bonito), or hoshi-shiitake (dried shiitake). The kombu can also be used with katsuobushi or hoshi-shiitake. Kelp or shiitake dashi give a vegetarian soup stock. When the soup includes clams such as asari, shijimi, or hamaguri, prepared dashi is often not used. Outside Japan, American- or European-style miso soup is sometimes made by dissolving miso in a Western vegetable stock. It can also be made with chicken broth. The stock might include ingredients such as negi, carrot, potato and daikon radish. In some versions of the dish, chicken stock, Western-style fish stock, and other non-dashi bases can even be used, but there is some debate over whether or not miso soups made using these non-traditional bases count as true miso soup.
This procedure can induce ovulation, typically leads to a single pregnancy, but other risks may be higher compared to medication. The procedure might lead to lower chance of live births compared to medication alone. Ovarian wedge resection is no longer used as much due to complications such as adhesions and the presence of frequently effective medications. As a final treatment option, in vitro fertilisation (IVF) can be considered. IVF does increase the risk of ovarian hyperstimulation syndrome. Using a 'freeze all' strategy makes it easier to transfer a single embryo and provides time for the ovaries to recover from hyperstimulation. A less effective alternative, but with much lower risks of ovarian hyperstimulation syndrome, is in vitro maturation instead of full IVF. This option avoids high-dose gonadotropin therapy.
Progesterone ( ; P4) is an endogenous steroid and progestogen sex hormone involved in the menstrual cycle, pregnancy, and embryogenesis of humans and other species. It belongs to a group of steroid hormones called the progestogens and is the major progestogen in the body. Progesterone has a variety of important functions in the body. The hormone is also an important metabolic intermediate in the production of other endogenous steroids, including the sex hormones and the corticosteroids, and acts in the brain as a neurosteroid. In addition to its role as a natural hormone, progesterone is also used as a medication, such as in combination with estrogen for contraception, to reduce the risk of uterine or cervical cancer, in hormone replacement therapy, and in feminizing hormone therapy. It was first prescribed in 1934.
Sources: en.wikipedia.org
The peptide contains four residues in the order alanine, glutamate, aspartate and glycine, abbreviated AEDG. The chain is linear and held together by three peptide bonds. Its calculated mass for the uncharged free form is about 390.3 daltons.
Epithalamin refers to a crude preparation derived from bovine pineal tissue, which contains many components. Epitalon is a single synthetic tetrapeptide identified from that material and produced by chemical synthesis. The two names are sometimes confused because early reports treated the synthetic peptide as an active fragment of the extract.
It has been registered for clinical use in Russia, where it is associated with a small family of short peptides. In most other jurisdictions it is not an approved medicine and is traded as a research chemical. Regulatory status varies by country and changes over time.
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.