Aspartimide raises a handful of sensible questions. This page answers them in order, starting with the fundamentals and moving to applications.
This page was last updated on 2026-08-01 and is reviewed periodically as new material appears.
Dissolution is usually performed in water or a suitable aqueous buffer, and the resulting liquid is divided into single-use portions before freezing. Freeze-thaw cycling is a recognised source of loss for short peptides, since each cycle can encourage aggregation or adsorption onto container walls. Working solutions are generally kept cold and used within a short window, although published stability data specific to epitalon are thin. Containers should be marked with concentration and date, and solutions examined for cloudiness before use.
Identity is normally established by reversed-phase high-performance liquid chromatography combined with mass spectrometry, a pairing that separates components and confirms molecular mass at once. Purity is quoted as a percentage from the chromatogram, and figures above ninety-five percent are a frequent commercial specification. Amino acid analysis or sequencing supplies further confirmation when required. Because many short peptides behave similarly under chromatography, retention time alone does not establish sequence; the mass measurement is what separates one tetrapeptide from another, and certificates should report both.
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 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.
| Property | Value | Notes |
|---|---|---|
| Sequence | Ala-Glu-Asp-Gly | Written in three-letter amino acid code |
| Single-letter code | AEDG | Form used in most catalogue entries |
| Typical purity specification | 95 percent or higher | Value read from the HPLC chromatogram |
| Storage, dry solid | Minus 20 degrees Celsius, desiccated | Sealed container, protected from light |
| Handling, solution | Divide into single-use portions | Limits losses from freeze-thaw cycling |
Because epitalon has no pharmacopoeial monograph, quality assessment depends on supplier documentation and independent testing. Certificates of analysis typically report a purity figure from a single chromatographic run, a measured mass and sometimes an appearance description, but methods and acceptance criteria are not harmonised across vendors. Third-party laboratories can repeat identity and purity measurements, and mismatches between labelled and measured peptide content have been described for research peptides generally. What constitutes adequate identity confirmation for a molecule of this size stays an open question, since mass agreement alone does not separate closely related sequences.
Identity testing for epitalon relies on reversed-phase high-performance liquid chromatography for purity and mass spectrometry for mass confirmation. Because the sequence contains no tryptophan or tyrosine, ultraviolet detection at 280 nanometres is insensitive, so chromatographic methods usually monitor absorbance near 214 nanometres, where the peptide backbone absorbs. Electrospray ionisation or matrix-assisted laser desorption/ionisation then checks the intact mass against the expected value near 390 daltons. Peptide mapping or amino acid analysis after acid hydrolysis can supplement these measurements, although such confirmatory work is seldom reported on commercial certificates of analysis.
The compound is generally described as a synthetic analogue of a fragment isolated from a pineal gland extract. Researchers associated with the Saint Petersburg Institute of Bioregulation and Gerontology introduced it during the 1980s and 1990s while studying short peptides from animal tissue. The original extract, called epithalamin, is a heterogeneous mixture, whereas epitalon is a single defined sequence. That distinction matters because findings reported for the extract are not automatically findings about the pure tetrapeptide, and claims about broader biological effects remain a separate question from the chemical identity described here.
Residue composition is the property that most cleanly separates verified material from mislabelled samples. Alanine, glutamate, aspartate and glycine appear in that order from the N-terminus, and the two acidic residues sit in the middle of the chain. Because the peptide is short, it can be produced by solid-phase synthesis and characterised by mass spectrometry without ambiguity. Any reported sample whose measured mass departs substantially from 390 daltons is a different compound or a degraded mixture rather than epitalon.
Epitalon is a synthetic tetrapeptide whose four residues are alanine, glutamate, aspartate and glycine, commonly abbreviated AEDG. Its molecular formula is C14H22N4O9 and its monoisotopic mass is near 390.35 daltons. The peptide carries two acidic side chains, so it is neutral to negatively charged in most aqueous buffers. Published reference summaries usually list it under both spellings, epitalon and epithalon, and treat the two names as the same material.
Among the British firms that dominated the colony in the late 19th century was the Belize Estate and Produce Company, which eventually acquired half of all privately held land and eventually eliminated peonage. Belize Estate's influence accounts in part for the colony's reliance on the mahogany trade throughout the rest of the 19th century and the first half of the 20th century. The Great Depression of the 1930s caused a near-collapse of the colony's economy as British demand for timber plummeted. The effects of widespread unemployment were worsened by a devastating hurricane that struck the colony in 1931. Perceptions of the government's relief effort as inadequate were aggravated by its refusal to legalize labour unions or introduce a minimum wage. Economic conditions improved during World War II, as many Belizean men entered the armed forces or otherwise contributed to the war effort.
Indigenous people traded obsidian throughout the Americas. Each volcano and in some cases each volcanic eruption produces a distinguishable type of obsidian allowing archaeologists to use methods such as non-destructive energy dispersive X-ray fluorescence to select minor element compositions from both the artifact and geological sample to trace the origins of a particular artifact. Obsidian cores and blades were traded far inland from the coast. A particularly distant examples of traded obsidian are pieces from the Yellowstone Region found at Hopewell sites, such as Hopewell Culture National Historical Park, Ohio, over 1500 miles away.
== Regulation == Some of the strategies for regulating retinal dehydrogenases are only now becoming more clear after in vivo regulation remained mysterious for some time, though much of the current research on regulation has focused on the modulation of gene expression rather than direct protein regulation. Dendritic cells in the gut help in modulating immune tolerance through the activity of retinal dehydrogenase; expression in these cells may be driven by a TNF receptor, 4-1-BB. It was also shown that the expression of a certain retinal dehydrogenase found in humans, retinal short-chain dehydrogenase/reductase (retSDR1), is increased by tumor-suppressor proteins p53 and p63, suggesting that retSDR1 may have tumor-preventing activities. Expression of retinal dehydrogenase types 1 and 2 genes is enhanced by the addition of cholesterol or cholesterol derivatives. Disulfiram is a drug used to artificially regulate aldehyde dehydrogenase activity in patients with alcoholism by inhibiting the activity of aldehyde dehydrogenases, though it is not specific to retinal dehydrogenase. Other exogenous molecules have also been found to inhibit retinal dehydrogenase activity including nitrofen, 4-biphenyl carboxylic acid, bisdiamine, and SB-210661.
=== Amyloid formation === Although ELPs generally form reversible spherical aggregates due to their proline and glycine content, there is a possibility that, under certain conditions such as exceedingly high temperatures, ELPs will form amyloids, or irreversible aggregates of insoluble protein. It is also believed that changes in the ELP backbone leading to a reduction in the proline and glycine content may lead to ELPs with a greater propensity for the amyloid state. As amyloids are implicated in the progression of Alzheimer's disease as well as in prion-based diseases, such as Creutzfeldt-Jakob disease (CJD), modeling of ELP amyloid formation may be useful from a biomedical standpoint.
This results in the Fe2+ ion switching to a low-spin configuration, resulting in a 20% decrease in ionic radius so that now it can fit into the porphyrin ring, which becomes planar. (Additionally, this hydrogen bonding results in the tilting of the oxygen molecule, resulting in a Fe–O–O bond angle of around 120° that avoids the formation of Fe–O–Fe or Fe–O2–Fe bridges that would lead to electron transfer, the oxidation of Fe2+ to Fe3+, and the destruction of hemoglobin.) This results in a movement of all the protein chains that leads to the other subunits of hemoglobin changing shape to a form with larger oxygen affinity. Thus, when deoxyhemoglobin takes up oxygen, its affinity for more oxygen increases, and vice versa. Myoglobin, on the other hand, contains only one heme group and hence this cooperative effect cannot occur. Thus, while hemoglobin is almost saturated with oxygen in the high partial pressures of oxygen found in the lungs, its affinity for oxygen is much lower than that of myoglobin, which oxygenates even at low partial pressures of oxygen found in muscle tissue. As described by the Bohr effect (named after Christian Bohr, the father of Niels Bohr), the oxygen affinity of hemoglobin diminishes in the presence of carbon dioxide.
Sources: en.wikipedia.org
=== Role of transformation === H. influenzae mutants defective in their rec1 gene (a homolog of recA) are very susceptible to being killed by the oxidizing agent hydrogen peroxide. This finding suggests that rec1 expression is important for H. influenzae survival under conditions of oxidative stress. Since it is a homolog of recA, rec1 likely plays a key role in recombinational repair of DNA damage. Thus, H. influenzae may protect its genome against the reactive oxygen species produced by the host's phagocytic cells through recombinational repair of oxidative DNA damages. Recombinational repair of a damaged site of a chromosome requires, in addition to rec1, a second homologous undamaged DNA molecule. Individual H. influenzae cells are capable of taking up homologous DNA from other cells by the process of transformation. Transformation in H. influenzae involves at least 15 gene products, and is likely an adaptation for repairing DNA damage in the resident chromosome.
Supervised injection sites are legally sanctioned, medically supervised facilities designed to provide a safe, hygienic, and stress-free environment for people who use substances. The facilities provide sterile injection equipment, information about substances and basic health care, treatment referrals, and access to medical staff. Opioid agonist therapy (OAT) is the medical procedure of using a harm-reducing opioid that produces significantly less euphoria, such as methadone or buprenorphine to reduce opioid cravings in people who use illegal opioids, such as heroin; buprenorphine and methadone are taken under medical supervision. Another approach is heroin assisted treatment, in which medical prescriptions for pharmaceutical heroin (diacetylmorphine) are provided to people who are dependent on heroin. Media campaigns inform drivers of the dangers of driving drunk. Most people who recreationally consume alcohol are now aware of these dangers and safe ride techniques like 'designated drivers' and free taxicab programmes are reducing the number of drunk-driving crashes. Many schools now provide safer sex education to teen and pre-teen students, who may engage in sexual activity. Since some adolescents are going to have sex, a harm-reductionist approach supports a sexual education which emphasizes the use of protective devices like condoms and dental dams to protect against unwanted pregnancy and the transmission of STIs. Since 1999, some countries have legalized or decriminalized prostitution, such as Germany (2002) and New Zealand (2003).
Like many other anemones, S. helianthus can serve as a “hub” for mutualistic networks of species and has been documented to live in symbiosis with other organisms. Symbiosis refers to the close association between organisms of two different species, whereas at least one organism benefits. These symbiont organisms vary substantially and can include algal endosymbionts, such as zooxanthellae, anemone crabs and anemone shrimp. In specific, Symbiodinium spp. is zooxanthellae that has been investigated to establish complex relationships with sun anemones, even to the extent of coordinating cell cycles with hosts. Another endosymbiont is the Clibanarius tricolor, or the blue-legged hermit crab, which has been recorded to live in symbiosis in the Caribbean and Indo-Pacific Regions. This crab uses the surface of the anemone as a “microhabitat” and is protected from the anemone's harmful toxins by removable coverings on the surface of their bodies. Another largely-studied endosymbiont is the anemone shrimp. Hayes et al. reported cohabitation of sun anemones by Periclimenes rathbunae, also called sun anemone shrimp, in a random manner that may be directly influenced by anemone size in the West Indies. In a further study, Periclimenes yucatanicus, or spotted cleaner shrimp, were additionally observed in symbiosis with S. helianthus in the Florida Bay.
linker DNA 1. A short, synthetic DNA duplex containing the recognition sequence for a particular restriction enzyme. In molecular cloning, linkers are often deliberately included in recombinant molecules in order to make them easily modifiable by permitting cleavage and insertion of foreign sequences at precise locations. A segment of an engineered plasmid containing many such restriction sites is sometimes called a polylinker. 2. A section of chromosomal DNA connecting adjacent nucleosomes by binding to histone H1.
== Censorship == In December 2025, the Lukashenko regime added the book to the List of printed publications containing information materials, the distribution of which could harm the national interests of Belarus.
Sources: en.wikipedia.org
Reversed-phase high-performance liquid chromatography is run alongside mass spectrometry. The chromatogram separates components and gives a purity figure, while the mass spectrum confirms that the measured molecular mass matches the expected sequence. Neither measurement on its own is treated as sufficient.
Long-term holding is usually at minus twenty degrees Celsius in a sealed, desiccated container. A refrigerator is adequate for short intervals before use. Light exposure is normally avoided as well. Allowing a cold container to warm before opening reduces moisture condensation on the contents.
Repeated cycles are generally avoided. Each freeze and thaw can promote aggregation or loss of peptide to container surfaces, which reduces the amount available for later work. Dividing a solution into single-use portions at the outset is the usual way to limit this problem.
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.