This is a working overview of AEDG, written for readers who want more than a one-paragraph summary but less than a textbook.
Reviewed 2026-03-29. Anything still debated is marked as such rather than presented as settled.
Identity and purity of epitalon samples are normally established by reversed-phase high-performance liquid chromatography with ultraviolet detection near 214 nanometres, combined with mass spectrometry. The mass spectrum confirms the expected molecular ion and can reveal truncated or oxidised by-products. Amino acid analysis after acid hydrolysis verifies that the four residues are present in the expected ratio. Certificates typically report a purity figure taken from chromatographic peak area, expressed as a percentage of total integrated signal.
Lyophilised epitalon is generally held at minus twenty degrees Celsius in a sealed container kept dry and dark. Cooler conditions are sometimes recommended for long-term archives. The solid takes up moisture readily enough that repeated opening of a vial introduces water, so dividing a batch into smaller portions before storage lowers degradation risk. Aqueous solutions are less durable than the dry powder and are usually prepared shortly before use, then kept cold and shielded from light to slow hydrolysis and oxidation.
The peptide is a synthetic analogue of epithalamin, a preparation extracted from bovine pineal glands. Investigators sought a short, chemically defined molecule that would reproduce some of the endocrine and gerontological observations attributed to the glandular extract. Proposed mechanisms centre on induction of telomerase activity, an effect reported in cultured human somatic cells in the early 2000s, together with influences on melatonin secretion and neuroendocrine regulation. Those mechanisms remain incompletely characterised, and the reported telomerase response has not been consistently reproduced by independent groups working in comparable systems.
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.
| Property | Value | Notes |
|---|---|---|
| Typical purity specification | 95 percent or higher by HPLC area | Higher grades are also offered |
| Primary analytical method | Reversed-phase HPLC, UV detection | Frequently paired with mass spectrometry |
| Confirmatory technique | Electrospray mass spectrometry | Observed mass compared with theory |
| Storage temperature | Minus 20 degrees Celsius, dry powder | Sealed, desiccated, protected from light |
| Solution handling | Prepare fresh before use | Hydrolysis proceeds in aqueous media |
Laboratory handling begins with dissolution of the lyophilized powder in water or a suitable aqueous buffer. The dry solid is the more stable form, so stock solutions are generally prepared only when required and kept cold afterwards. Repeated freezing and thawing of a solution is avoided because it encourages aggregation and gradual loss of the intact chain. Diluents and containers are selected to limit adsorption of a short peptide onto plastic surfaces and to reduce microbial growth in aqueous preparations.
Stability depends strongly on pH, temperature and the presence of oxygen and trace metals. Cleavage of the backbone proceeds faster under neutral to alkaline conditions, whereas acidic solutions tend to slow that reaction. The aspartate and glutamate side chains can undergo deamidation or imide formation over time, generating closely related impurities. Published stability data specific to epitalon are sparse, so the usable life of a given solution is best regarded as an open question that depends on buffer composition, concentration and storage temperature.
Identity and purity are usually assessed by reversed-phase high-performance liquid chromatography with ultraviolet detection, frequently near 214 nanometers where the peptide bond absorbs. Mass spectrometry, most often with electrospray ionization, confirms the observed molecular mass and helps separate the intact peptide from truncated or modified forms. Amino acid analysis or tandem mass spectrometry can establish residue order. Purity is commonly quoted as an area percentage, yet such values are method-dependent, and comparisons between laboratories require matching column, gradient and detection wavelength.
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.
=== Retinoblastoma === More recent studies have identified ITGA1 as a potential therapeutic target in retinoblastoma (Rb). ITGA1 promotes Rb progression by activating the FAK/STAT3 signaling pathway. Restoration of STAT3 partially reverses the effects of ITGA1 inhibition, supporting the role of this pathway in ITGA1-mediated tumor growth. Genetic knockdown or pharmacological inhibition of ITGA1 suppresses retinoblastoma cell proliferation, migration, colony formation, and growth in vivo. Inhibition of the α1β1 integrin receptor using genetic approaches or the α1β1 inhibitor obtustatin reduces tumor progression, suggesting that ITGA1-targeted therapies may represent a potential strategy for treating high-risk retinobloastoma. However, further research and testing are needed to confirm the safety and efficacy of ITGA1 inhibition before it is used as a clinical treatment.
A platelet function assay may give an abnormal collagen/epinephrine closure time, and in most cases, a normal collagen/ADP time. Type 2N may be considered if factor VIII levels are disproportionately low, but confirmation requires a "factor VIII binding" assay. Additional laboratory tests that help classify sub-types of VWD include von Willebrand multimer analysis, modified ristocetin induced platelet aggregation assay and VWF propeptide to VWF propeptide antigen ratio. In cases of suspected acquired von Willebrand syndrome, a mixing study (analysis of patient plasma along with pooled normal plasma/PNP and a mixture of the two tested immediately, at one hour, and at two hours) should be performed. Detection of VWD is complicated by VWF being an acute-phase reactant with levels rising in infection, pregnancy, and stress. The testing for VWD can be influenced by laboratory procedures. Numerous variables exist in the testing procedure that may affect the validity of the test results and may result in a missed or erroneous diagnosis. The chance of procedural errors are typically greatest during the preanalytical phase (during collecting storage and transportation of the specimen) especially when the testing is contracted to an outside facility and the specimen is frozen and transported long distances. Diagnostic errors are not uncommon, and the rate of testing proficiency varies amongst laboratories, with error rates ranging from 7 to 22% in some studies to as high as 60% in cases of misclassification of VWD subtype.
== Chemistry == Indium has 49 electrons, with an electronic configuration of [Kr]4d105s25p1. In compounds, indium most commonly donates the three outermost electrons to become indium(III), In3+. In some cases, the pair of 5s-electrons are not donated, resulting in indium(I), In+. The stabilization of the monovalent state is attributed to the inert pair effect, in which relativistic effects lowers the energy of the 5s-orbital, observed in heavier elements. Thallium (indium's heavier homolog) shows an even stronger effect, manifested by the pervasiveness of thallium(I) vs thallium(III), Gallium (indium's lighter homolog) is only rarely observed in the +1 oxidation state. Thus, although thallium(III) is a moderately strong oxidizing agent, indium(III) is not, and many indium(I) compounds are powerful reducing agents. While the energy required to include the s-electrons in chemical bonding is lowest for indium among the group 13 metals, bond energies decrease down the group so that by indium, the energy released in forming two additional bonds and attaining the +3 state is not always enough to outweigh the energy needed to involve the 5s-electrons. Indium(I) oxide and hydroxide are more basic and indium(III) oxide and hydroxide are more acidic. A number of standard electrode potentials, depending on the reaction under study, are reported for indium, reflecting the decreased stability of the +3 oxidation state:
== Side effects == Rasburicase administration can cause anaphylaxis (incidence unknown); methemoglobinemia may occur in susceptible individuals such as those with G6PDH deficiency due to the production of hydrogen peroxide in the urate oxidase reaction. Testing patients for G6PDH deficiency prior to starting a course of rasburicase has been recommended.
Sources: en.wikipedia.org
The fundamental function of platelets is to clump together to stop acute bleeding. This process is complex, as more than 193 proteins and 301 interactions are involved in platelet dynamics. Despite much overlap, platelet function can be modeled in three steps:
A herbarium is a collection of preserved plant specimens and associated data used for scientific study. Originally, the word "herbarium" referred to books about medicinal plants. In 1700, French botanist Joseph Pitton de Tournefort used the word to describe a collection of dried plants and Carl Linnaeus continued to use this term in his work which is where the term caught on. Initially, herbarium collections were bound in volumes instead of on individual sheets as it is done today. It is not exactly known how long dry plant specimens last in storage, but with proper conservation, they have been able to last many centuries. Specimens collected by Linnaeus in the eighteenth century and by Banks and Solander on the Endeavour voyage in 1788 are still excellently preserved. The specimens may be whole plants or plant parts. These will usually be dried and pressed and mounted on a sheet of paper but, depending upon the material, may also be stored in boxes or kept in alcohol or other preservatives.
=== Liver fatty acid storage === In a high-fat diet-induced obesity model of fatty liver disease (i.e., excessive buildup of fat in the liver), mice fed a diet that increased intestinal levels of SC-FAs showed reductions in their livers' synthesis of lipids, triglyceride levels, and weights. These reductions did not occur in Ffar3 gene knockout mice but did occur in Ffar2 gene knocked-out mice. These results indicate that the SC-FA-induced activation of FFAR3 suppresses the liver's accumulation of fatty acids that underlies the development of fatty liver disease in this mouse model. Other studies have found that Ffar3 gene knockout mice showed less weight gain than wild-type mice under standard laboratory conditions, but this difference was lost in mice reared under germ-free conditions (i.e., which causes the mice to have lower intestinal and tissue levels of SC-FAs). These findings indicated that the activation of FFAR3 but not FFAR2 by SC-FAs protects against developing fatty liver disease in mice.
Sources: en.wikipedia.org
The usual approach is reversed-phase HPLC with ultraviolet detection, reported as a percentage of total peak area. Mass spectrometry is used alongside chromatography to confirm identity rather than purity alone.
The dry powder is commonly kept at minus twenty degrees Celsius, desiccated and away from light. Solutions are generally prepared fresh because they break down faster than the solid form.
Tandem mass spectrometry or enzymatic peptide mapping can establish residue order. A single intact mass value indicates composition and molecular weight but not always the precise arrangement of residues.
Epitalon is a synthetic four-amino-acid peptide with the sequence alanine–glutamate–aspartate–glycine, also written AEDG. It was developed in Russian gerontology research and is studied for proposed effects on telomerase, melatonin regulation, and neuroendocrine function. It is not an approved pharmaceutical in the United States or the European Union.