This is a working overview of Tetrapeptide, written for readers who want more than a one-paragraph summary but less than a textbook.
Reviewed 2026-06-09. Anything still debated is marked as such rather than presented as settled.
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 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.
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.
| 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 |
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.
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.
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.
== History == Three scientists were involved in the discovery of lutetium: French scientist Georges Urbain, Austrian mineralogist Baron Carl Auer von Welsbach, and American chemist Charles James. They found lutetium as an impurity in ytterbia, which was thought by Swiss chemist Jean Charles Galissard de Marignac to consist entirely of ytterbium. Of the three, Urbain was the first to publish, followed by Welsbach; James was about to publish when he learned of Urbain's work, and thereafter gave up his claim and did not publish. Despite staying out of the priority argument, James worked on a much larger scale and possessed the largest supply of lutetium at the time. Urbain and Welsbach proposed different names. Urbain chose neoytterbium for ytterbium and lutecium for the new element. Welsbach chose aldebaranium and cassiopeium (after Aldebaran and Cassiopeia). Both authors accused the other man of publishing results based on their work. The International Commission on Atomic Weights, which was then responsible for the attribution of new element names, settled the dispute in 1909 by granting priority to Urbain and adopting his choice for a name, one derived from the Latin Lutetia (Paris). This decision was based on the fact that the separation of lutetium from Marignac's ytterbium was first described by Urbain. Welsbach had achieved the separation before Urbain, but Urbain had published 44 days earlier.
== Legal status == para-Chloroisobutyrylfentanyl has been a Schedule I controlled drug in the United States since 1 February 2018. It was banned in Finland in September 2017, and in Sweden in October 2017.
== External links == Media related to Romanian Revolution of 1989 at Wikimedia Commons Article on justice failing for 942 killed in Revolution on eve of 20th anniversary Video of Nicolae Ceaușescu's final speech in Republican Square Anonymous Photo Essay about the Romanian Revolution of 1989 TV broadcasts from 22 and 23 December 1989 Live TV Broadcast from 22 December 1989 on Hungarian TV (with English subtitles) The Romanian Revolution of December 1989 Academic Article on Feature Films about 1989 Academic Article on Documentaries about 1989
Glucose concentrations in the atmosphere are detected via collection of samples by aircraft and are known to vary from location to location. For example, glucose concentrations in atmospheric air ranges from 0.8 to 20.1 pg/L in inland China, to 10.3 to 142 pg/L in East coastal China.
Metabolic. The thyroid hormones increase the basal metabolic rate and have effects on almost all body tissues. Appetite, the absorption of substances, and gut motility are all influenced by thyroid hormones. They increase the absorption in the gut, generation, uptake by cells, and breakdown of glucose. They stimulate the breakdown of fats, and increase the number of free fatty acids. Despite increasing free fatty acids, thyroid hormones decrease cholesterol levels, perhaps by increasing the rate of secretion of cholesterol in bile. Cardiovascular. The hormones increase the rate and strength of the heartbeat. They increase the rate of breathing, intake and consumption of oxygen, and increase the activity of mitochondria. Combined, these factors increase blood flow and the body's temperature. Developmental. Thyroid hormones are important for normal development. They increase the growth rate of young people, and cells of the developing brain are a major target for the thyroid hormones T3 and T4. Thyroid hormones play a particularly crucial role in brain maturation during fetal development and first few years of postnatal life Other. The thyroid hormones also play a role in maintaining normal sexual function, sleep, and thought patterns. Increased levels are associated with increased speed of thought generation but decreased focus. Sexual function, including libido and the maintenance of a normal menstrual cycle, are influenced by thyroid hormones. After secretion, only a very small proportion of the thyroid hormones travel freely in the blood.
Sources: en.wikipedia.org
Gold- or silver-decorated lacquerwares had been popular in the Edo period but fell out of favor in the early nineteenth-century due to economic hardship. The Meiji era saw a renewed interest in lacquer as artists developed new designs and experimented with new textures and finishes. Foremost among these was Shibata Zeshin, who has been called "Japan's greatest lacquerer". The appeal of his highly original style was in the choice of motifs and subject matter rather than embedded gold and silver. He placed lacquer panels in frames, imitating Western oil paintings. Other notable lacquer artists of the 19th century include Nakayama Komin and Shirayama Shosai, both of whom, in contrast with Zeshin, maintained a classical style that owed a lot to Japanese and Chinese landscape art. Maki-e, decorating the lacquer in gold or silver dust, was the most common technique for quality lacquerware in this period. Lacquer from Japanese workshops was recognized as technically superior to what could be produced anywhere else in the world.
== Immunity == The D. melanogaster immune system can be divided into two responses: humoral and cell-mediated. The former is a systemic response mediated in large part through the toll and Imd pathways, which are parallel systems for detecting microbes. Other pathways including the stress response pathways JAK-STAT and P38, nutritional signalling via FOXO, and JNK cell death signalling are all involved in key physiological responses to infection. D. melanogaster has an organ called the "fat body", which is analogous to the human liver. The fat body is the primary secretory organ and produces key immune molecules upon infection, such as serine proteases and antimicrobial peptides (AMPs). AMPs are secreted into the hemolymph and bind infectious bacteria and fungi, killing them by forming pores in their cell walls or inhibiting intracellular processes. The cellular immune response instead refers to the direct activity of blood cells (hemocytes) in Drosophila, which are analogous to mammalian monocytes/macrophages. Hemocytes also possess a significant role in mediating humoral immune responses such as the melanization reaction. The immune response to infection can involve up to 2,423 genes, or 13.7% of the genome. Although the fly's transcriptional response to microbial challenge is highly specific to individual pathogens, Drosophila differentially expresses a core group of 252 genes upon infection with most bacteria.
Transactions typically use Bitcoin for payment, sometimes combined with tumblers for added anonymity and PGP to secure communications between buyers and vendors from being stored on the site itself. Many sites use Bitcoin multisig transactions to improve security and reduce dependency on the site's escrow. The discontinued Helix Bitcoin tumbler offered direct anonymized marketplace payment integrations. On making a purchase, the buyer must transfer cryptocurrency into the site's escrow, after which a vendor dispatches their goods then claims the payment from the site. On receipt or non-receipt of the item users may leave feedback against the vendor's account. Buyers may "finalize early" (FE), releasing funds from escrow to the vendor prior to receiving their goods in order to expedite a transaction, but leave themselves vulnerable to fraud if they choose to do so. Following Operation Onymous, there was a substantial increase in PGP support from vendors, with PGP use on two marketplaces near 90%. This suggests that law enforcement responses to cryptomarkets result in continued security innovations, thereby making markets more resilient to undercover law enforcement efforts.
== D == dactinomycin - dalton - decarboxylation reaction - delta opioid receptor - denaturation (biochemistry) - dendrite - dendritic cell - dendritic spine - deoxyribonucleoprotein - deoxyribose - desmopressin - deuterium - developmental biology - dialysis (chemical) - diffusion - dimer - dinucleotide repeat - diploid - disaccharide - dissociation constant - disulfide bond - disulfide bridge - DNA - DNA fragmentation - DNA replication - DNA sequence - DNA topology - DNA transposable element - DNA virus - DNA-binding protein - dopamine D1 receptor - dopamine D2 receptor - dopamine receptor - double helix - Drosophila - drugs - dynorphin
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.
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.