The short version of AEDG tetrapeptide fits in a sentence. The long version — which is the one that helps — is below.
This page was last updated on 2026-03-09 and is reviewed periodically as new material appears.
Storage and handling follow conventional peptide practice. Lyophilized epitalon is typically kept refrigerated or frozen, protected from moisture and light, and allowed to equilibrate to room temperature before opening to avoid condensation. Once dissolved, aqueous solutions are usually stored cold and used within a short period, since dilute peptide solutions can support microbial growth and may slowly degrade. The absence of cysteine and methionine reduces, but does not eliminate, oxidation concerns during long-term storage.
Regulatory status varies by country and is not harmonized. Epitalon is not an approved drug in major Western jurisdictions. In some countries it is sold as a research chemical, and in others it has appeared in products marketed for other categories. This inconsistent status means that purity, labeling accuracy, and documentation differ widely between suppliers, and verification of identity and purity through independent analysis is the usual way buyers assess a given lot.
Proposed mechanisms centre on cell-culture observations rather than a defined receptor interaction. Several reports describe increased expression of the telomerase catalytic subunit after exposure of cultured human cells, and the authors attributed the effect to short peptide fragments entering the nucleus and influencing gene transcription. No receptor for the tetrapeptide has been identified, and the free peptide is expected to be degraded rapidly by plasma peptidases. Whether any measurable fraction reaches intact tissues after administration remains an unresolved question rather than an established finding.
The published literature is dominated by a small number of research groups, much of it in Russian-language journals, and independent replication outside those groups is limited. Studies are typically small, use cultured cells or rodent models, and report endpoints that differ between papers, which makes comparison difficult. Large randomised human trials have not appeared in the indexed literature. Questions about absorption, distribution and clearance are therefore still treated as open in reviews that mention the compound.
Epitalon is a synthetic tetrapeptide with the sequence alanine–glutamate–aspartate–glycine, commonly abbreviated AEDG. Its design traces to epithalamin, a peptide fraction prepared from bovine pineal gland extracts that researchers in Saint Petersburg began investigating in the 1970s. The compound has a molecular formula of C14H22N4O9 and a nominal molecular mass near 390 daltons. It holds no approved drug status in the United States or the European Union, and material sold under this name is generally offered as a research chemical rather than a finished pharmaceutical product.
| Property | Value | Notes |
|---|---|---|
| Purity assessment | RP-HPLC | Reported as percent area, often ≥95% |
| Identity confirmation | Mass spectrometry | Observed mass compared with ~390 Da |
| Typical storage temperature | -20 °C or below | Lyophilized powder, desiccated |
| Reconstitution solvent | Sterile water or buffer | Acidic residues aid dissolution |
| Common synonyms | AEDG; epithalon | Spelling varies in literature |
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.
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.
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.
Material sold for research use varies widely in documented quality. A useful verification package includes a certificate of analysis that states peptide content rather than only net weight, the chromatographic method and column used, and a mass spectrum consistent with the expected mass. Independent testing by a third-party laboratory is occasionally reported. Statements of identity resting only on a supplier label provide little assurance, and the gap between nominal mass and actual peptide content can be substantial once counterions and residual water are counted.
Peptides of this size are generally stable as dry solids but degrade in solution over time. The principal routes are hydrolysis of the peptide backbone and oxidation, with hydrolysis favoured by elevated temperature and extreme pH. Aqueous solutions held at room temperature can show measurable loss of purity within days, while frozen aliquots are considerably more durable. Because the sequence contains neither cysteine nor methionine, oxidation is less of a concern than for many other peptides, but pH control during handling still matters.
Southern Rhodesia was represented in the Dodecanese Campaign of September–November 1943 by the Long Range Desert Group, which was withdrawn from the North African front in March 1943. After retraining for mountain operations in Lebanon, the LRDG moved in late September to the Dodecanese island of Kalymnos, north-west of Kos and south-east of Leros, off the coast of south-west Turkey. In the fall-out from the Armistice of Cassibile between Italy and the Allies, which had been concluded in the first week of September, the Allies were attempting to capture the Dodecanese so the islands could be used as bases against the German-occupied Balkans. Most of the Italian forces had changed sides; the LRDG found itself in an infantry role, acting as a mobile reserve for Italian troops. The Germans swiftly mobilised to expel the Allied forces and launched heavy air assaults on Kos and Leros. Without fighter support, the islands' defence was soon precarious; the LRDG and the rest of the troops on Kalymnos were withdrawn to Leros on 4 October after the Germans won the Battle of Kos. German air assaults on Leros intensified during late October, and at dawn on 12 November 1943 the Germans attacked Leros by sea and air. During the ensuing Battle of Leros, the LRDG Rhodesians at Point 320, commanded by Rhodesian Captain J R Olivey, spiked their position's guns and withdrew before counter-attacking and retaking the point the next day. They held that position for three more days, during which they learned that the Germans were winning the battle.
This measurement is made after each amplification cycle, and this is the reason why this method is called real time PCR (that is, immediate or simultaneous PCR). Quantitative PCR and DNA microarray are modern methodologies for studying gene expression. Older methods were used to measure mRNA abundance: differential display, RNase protection assay and northern blot. Northern blotting is often used to estimate the expression level of a gene by visualizing the abundance of its mRNA transcript in a sample. In this method, purified RNA is separated by agarose gel electrophoresis, transferred to a solid matrix (such as a nylon membrane), and probed with a specific DNA or RNA probe that is complementary to the gene of interest. Although this technique is still used to assess gene expression, it requires relatively large amounts of RNA and provides only qualitative or semi quantitative information of mRNA levels. Estimation errors arising from variations in the quantification method can be the result of DNA integrity, enzyme efficiency and many other factors. For this reason a number of standardization systems (often called normalization methods) have been developed. Some have been developed for quantifying total gene expression, but the most common are aimed at quantifying the specific gene being studied in relation to another gene called a normalizing gene, which is selected for its almost constant level of expression. These genes are often selected from housekeeping genes as their functions related to basic cellular survival normally imply constitutive gene expression.
For services to 31 Squadron Royal Air Force Association. Henry Ashley Edwards, Consultant Anaesthetist, Ysbyty Gwynedd. For services to the Welsh Medical Committee. The Reverend John Gisborne Charteris Eldrid. For services to the Samaritans. Geoffrey Kenyon Elliott. For services to Forestry and to Wood Science. Robert William Elliott, Chairperson and Director, Wiltshire & Swindon Users' Network, and Chairperson, The Jumbulance Group. For services to disabled people in Wiltshire. David John Ellis, Grade 6, Ministry of Defence. Andrew James Erving, Grade 7, Foreign and Commonwealth Office. George Stanley Etchells, Member, Rotherham Metropolitan Borough Council. For services to Local Government. Eric Magnus Eunson, lately General Manager, Power System Development, National Grid Company plc. For services to the Electricity Industry. David Roger Evans. For services to Agriculture in Wales. Gwynne Howard Neill Evans, lately Grade 6, Department for Education and Employment. David Roger Evans. For services to Agriculture in Wales. John Ivan Ellis Farmer, Honorary Show Director, All England Jumping Course, Hickstead. For services to Show Jumping. William Harold Faulkner, Headteacher, Montrose Academy. For services to Education. David Alan Fawcett. For humanitarian services in the Caribbean. Ronald Paul Feeney, Governor 2, Her Majesty's Prison Stafford. Professor Christine Elizabeth Fell, Professor of Early English Studies, University of Nottingham. For services to Early English. John Ronald Fenner, Chairman, British Urban Regeneration Association.
=== Pre-cigarette === Texts on the harmful effects of smoking tobacco were recorded in the Timbuktu manuscripts. James I wrote a book that denounced tobacco smoking as: "loathsome to the eye, hateful to the nose, harmful to the brain, dangerous to the lungs". Pipe smoking gradually became generally accepted as a cause of mouth cancers following work done in the 1700s. "An association between a variety of cancers and tobacco use was repeatedly observed from the late 1800s into the early 1920s." Gideon Lincecum, an American naturalist and practitioner of botanical medicine, wrote in the early 19th century on tobacco: "This poisonous plant has been used a great deal as a medicine by the old school faculty, and thousands have been slain by it. ... It is a very dangerous article, and use it as you will, it always diminishes the vital energies in exact proportion to the quantity used – it may be slowly, but it is very sure." The 1880s invention of automated cigarette-making machinery in the American South made it possible to mass-produce cigarettes at low cost, and smoking became common. This led to a backlash and a tobacco prohibition movement, which challenged tobacco use as harmful and brought about some bans on tobacco sale and use. In 1912, American Dr. Isaac Adler was the first to strongly suggest that lung cancer is related to smoking. In 1924, economist Irving Fisher wrote an anti-smoking article for Reader's Digest which said "tobacco lowers the whole tone of the body and decreases its vital power and resistance ...
Sources: en.wikipedia.org
== Partial EMT or a hybrid E/M phenotype == Not all cells undergo a complete EMT, i.e. losing their cell-cell adhesion and gaining solitary migration characteristics. Instead, most cells undergo partial EMT, a state in which they retain some epithelial traits such as cell-cell adhesion or apico-basal polarity, and gain migratory traits, thus cells in this hybrid epithelial/mesenchymal (E/M) phenotype are endowed with special properties such as collective cell migration. Single-cell tracking contributes to enabling the visualization of morphological transitions during EMT, the discernment of cell migration phenotypes, and the correlation of the heritability of these traits among sister cells. Two mathematical models have been proposed, attempting to explain the emergence of this hybrid E/M phenotype, and its highly likely that different cell lines adopt different hybrid state(s), as shown by experiments in MCF10A, HMLE and H1975 cell lines. Although a hybrid E/M state has been referred to as 'metastable' or transient, recent experiments in H1975 cells suggest that this state can be stably maintained by cells.
Guanylate cyclase (EC 4.6.1.2, also known as guanyl cyclase, guanylyl cyclase, or GC; systematic name GTP diphosphate-lyase (cyclizing; 3′,5′-cyclic-GMP-forming)) is a lyase enzyme that converts guanosine triphosphate (GTP) to cyclic guanosine monophosphate (cGMP) and pyrophosphate:
The Independent Office for Police Conduct launches an investigation into the incident the following day. The UK government publishes an updated list of 214 schools and colleges in England affected by reinforced autoclaved aerated concrete. 20 October – 2023 Mid Bedfordshire by-election: Labour MP Alistair Strathern wins the constituency of Mid Bedfordshire, with the Conservatives' share of the vote falling by 28.7%, one of the largest swings of the post-war era. 2023 Tamworth by-election: Labour MP Sarah Edwards wins the constituency of Tamworth, with the Conservatives' share of the vote falling by 25.6%. Leeds Bradford Airport is closed, causing delays to flights, after a TUI plane skids on the runway during landing as a result of heavy rainfall caused by Storm Babet. The airport reopens again the following day. Scotland Yard has reported an increase in the number of antisemitic crimes in London since the start of the Israel–Hamas conflict, with 218 incidents reported between 1 and 18 October; the number of incidents reported over the same period in 2022 was 15. 21 October – The UK government announces reforms to recycling in England that will see the majority of households receive a weekly collection of food waste by 2026, and a designated list of items councils must recycle. Police and Transport for London officials are investigating after video emerged online of a tube driver on the Central Line chanting pro-Palestinian slogans on a train. The driver is subsequently suspended pending an investigation by TfL.
Sources: en.wikipedia.org
== Development and patents == D-Ribose-L-cysteine was developed by Herbert T. Nagasawa, a medicinal chemist formerly affiliated with the United States Department of Veterans Affairs and the University of Minnesota, whose research focused on sulfur amino acid metabolism and hepatic toxicology. The compound and its use as a glutathione-enhancing agent are protected by multiple patents, including United States Patent US 9,173,917 B2, assigned to Max International and the U.S. Department of Veterans Affairs. D-Ribose-L-cysteine has since been incorporated into dietary supplement formulations marketed by Max International, Inc. and LiveMax, LLC.
Quinazolinones are also a class of drugs that function as hypnotics/sedatives that contain a 4-quinazolinone core. Examples of quinazolinones include cloroqualone, diproqualone, etaqualone (Aolan, Athinazone, Ethinazone), mebroqualone, afloqualone (Arofuto), mecloqualone (Nubarene, Casfen), and methaqualone (Quaalude). This class of drugs has been largely discontinued and is no longer used clinically.
== See also == mRNA, the nucleic acid messenger that serves as the middleman in the Central Dogma of Biology Ribosome, the molecular machine responsible for protein synthesis Translation, the process of peptide synthesis
Sources: en.wikipedia.org
Identity is normally confirmed by mass spectrometry, which checks the measured mass against the expected value near 390 daltons. Reverse-phase high-performance liquid chromatography is used alongside it to assess purity. Amino acid analysis can provide additional composition data.
The powder is generally kept refrigerated or frozen, protected from light and moisture. Vials should reach room temperature before opening to prevent condensation. Reconstituted solutions are usually stored cold and used within a limited window because dilute solutions can degrade or support microbial growth.
Epitalon is not an approved drug in major Western regulatory jurisdictions. Its legal status differs between countries, and it is often distributed as a research chemical. This means product documentation and purity vary considerably between suppliers.
No. Epithalamin is a heterogeneous peptide fraction obtained from pineal gland extract and contains many components. Epitalon is a single synthetic tetrapeptide with the sequence Ala-Glu-Asp-Gly. Researchers synthesised the shorter peptide while attempting to identify active sequences within the extract.