The short version of tetrapeptide fits in a sentence. The long version — which is the one that helps — is below.
Reviewed 2025-09-25. Anything still debated is marked as such rather than presented as settled.
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.
Storage recommendations center on limiting moisture, heat, and light. The dry powder is generally kept at minus 20 degrees Celsius, and some suppliers recommend minus 80 degrees for long-term archival. Once dissolved, solutions are usually aliquoted and frozen to avoid repeated freeze-thaw cycles, which can promote aggregation or degradation. Aqueous stability depends on pH and concentration, and buffered saline is often preferred over plain water for biological work. Stability data specific to epitalon remain limited, so general peptide-handling practices are applied by analogy rather than from product-specific validation.
Epitalon is a synthetic tetrapeptide with the sequence alanine-glutamate-aspartate-glycine, abbreviated AEDG. Its molecular formula is C14H22N4O9 and its calculated monoisotopic mass is approximately 390.35 daltons. The compound does not occur naturally as a free peptide; it is produced by solid-phase peptide synthesis. Because it contains two acidic residues and no basic residues, the neutral form carries a net negative charge at physiological pH. This charge profile influences how the peptide behaves in solution and during chromatographic analysis.
| 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 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 supplied for laboratory use is normally a lyophilised white to off-white powder that dissolves readily in water and in isotonic saline. Lyophilised cakes are hygroscopic and should be equilibrated to room temperature before opening to limit condensation on the solid. Solutions are typically prepared at milligram-per-millilitre concentrations and divided into single-use aliquots, because repeated freeze–thaw cycles degrade short peptides. Aqueous solutions are far less stable than the dry powder, and identity is usually verified by mass spectrometry alongside purity estimation from reversed-phase high-performance liquid chromatography.
Epitalon is a synthetic linear tetrapeptide with the sequence alanine–glutamate–aspartate–glycine, abbreviated AEDG. Its molecular formula is C14H22N4O9 and the calculated mass is approximately 390.35 g/mol. The compound is made by solid-phase peptide synthesis rather than extracted from tissue, although early work described it as a short fragment of a peptide fraction obtained from bovine pineal extract. In the research literature the spelling epitalon and the variant epithalone both appear, while AEDG is the standard code used in peptide nomenclature.
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.
Most experimental work has been carried out in cell culture and animal models. Several reports describe changes in telomerase activity and proliferation in cultured cells, while rodent studies have examined lifespan, melatonin rhythm and reproductive endpoints. Human data remain limited, and much of the published clinical material consists of small trials with incomplete reporting of methods and controls. Whether the cell and animal findings translate into measurable effects in people is an open question, and the mechanistic basis of the reported telomerase changes is not fully established.
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.
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 diagnostic tests of ptaquiloside inside cells include gene mutation detection, immunohistochemical detection of tumor biomarkers, chromosomal aberrations, oxidative stress for EBH, PCR, real-time PCR and DNase-SISPA (sequence-independent single primer amplification).
Hertz (1939), operations research scholar known for pioneering the Monte Carlo methods in finance Victor Wouk (1939), pioneer in the development of electric and hybrid vehicles Julius Ashkin (1940), nuclear physicist, brother of Arthur Ashkin '47 Jeremiah Stamler (1940), epidemiologist, expert in the field of preventive cardiology, professor emeritus at Northwestern University Ulrich P. Strauss (1941), chemist at Rutgers University, 1971 Guggenheim Fellow Bruce Wallace (1941), geneticist, professor at Virginia Tech Robert S. Wallerstein (1941), psychoanalyst and former president of the International Psychoanalytical Association and director of the Langley Porter Psychiatric Institute, brother of political scientist Immanuel Wallerstein '51 Kimball Chase Atwood III (1942), geneticist, professor at Columbia University Medical School Leon Davidson (1942), chemical engineer known for his work in the Manhattan Project and the study of Unidentified Flying Objects Karl Koopman (1943), chiropterologist and curator at the American Museum of Natural History Robert G.
== History == In the United States, the profession began in the 1950s due to a shortage of medical technologists in rural areas and physician owned laboratories. MLA positions were more prevalent prior to laboratory automation, but have made a comeback due to the ongoing laboratory staffing shortage.
The relatively recent emergence of Salvia divinorum in modern Western culture, in comparison to its long continuing traditions of Indigenous use, contrasts widely differing attitudes on the subject. Opinions range from veneration of the plant as a spiritual sacrament or "a gift from the gods" to a "threat to society," to be banned as quickly as possible in order to "spare countless families the horror of losing a loved one to the relentless tentacles of drug abuse".
In pharmacokinetics, the drug accumulation ratio (Rac) is the ratio of accumulation of a drug under steady state conditions (i.e., after repeated administration) as compared to a single dose. The higher the value, the more the drug accumulates in the body. An Rac of 1 means no accumulation.
Sources: en.wikipedia.org
It also announces that it will no longer grant blanket immunity to politicians who use its service, especially if their posts are deemed to be deceptive or abusive. District Judge Roger Benitez overturns California's ban on assault weapons. A letter to Apple's Tim Cook is made public, in which staff request more flexibility over remote work, following the company's decision to return its 150,000 employees to the office. The FDA approves the first new medication since 2014, semaglutide (Wegovy), for chronic weight management. June 5 – Aftermath of the January 6 United States Capitol attack – The Department of Justice says that over 465 people have been arrested since the January 6 attack. It is also seeking information on 250 other suspects. June 6 Aftermath of the January 6 United States Capitol attack – Rep. Eric Swalwell (D–CA) announces he sued Mo Brooks (R–AL) for being responsible for inciting January 6. COVID-19 vaccination in the United States: The U.S. surpasses 300 million COVID-19 vaccine doses administered. Floyd Mayweather fights in an exhibition bout against YouTuber Logan Paul. The United States defeats Mexico 3–2 after extra time in the final to become the first champions of the CONCACAF Nations League. June 7 Twitter suspensions: Twitter announces that they have suspended the account of former Florida Department of Health dashboard manager Rebekah Jones for spamming and "platform manipulation" after she paid other users to follow her. Aducanumab (Aduhelm), the first new medication for Alzheimer's disease in 20 years, is approved by the FDA.
Size-exclusion chromatography (SEC) separates polymer molecules and biomolecules based on differences in their molecular size (actually by a particle's Stokes radius). The separation process is based on the ability of sample molecules to permeate through the pores of gel spheres, packed inside the column, and is dependent on the relative size of analyte molecules and the respective pore size of the absorbent. The process also relies on the absence of any interactions with the packing material surface. There are 2 main types of SEC:
== Clinical significance == Mutations of the CELA1 gene were suspected to be associated with diffuse nonepidermolytic palmoplantar keratoderma (diffuse NEPPK). However the suspected sequence variant was fully functional and did not strongly associate with the disease. More recently, a specific mutation in the KRT6C gene has been linked to some cases of diffuse NEPPK. A possible polymorphism of the CELA1 gene coding this protein was found. On a secondary structure level, this polymorphism manifests itself in an excision of a short sequence of CELA1. The disappeared sequence carries the key amino acid residues Val-227 and Thr-239, which contribute to the substrate specificity of elastase I (highlighted in Figure 3), as well as five of the eight amino acids involved in the primary contact of the elafin(inhibitor)/elastase complex formation. These observations imply that the sequence variant might modify the substrate specificity of the enzyme and abolish the inhibitor binding capability. Though there were no obvious pathogenic epidermal abnormalities associated with the truncated ELA1 variant, it is possible that carriers of the polymorphism may be at greater risk of developing the common skin diseases such as psoriasis and eczema (genetic and histologic studies will be required to investigate the role of ELA1 in these common epidermal disorders.).
== How it works == GPC is a type of chromatography in which analytes are separated, based on their size or hydrodynamic volume (radius of gyration). This differs from other chromatographic techniques, which depend upon chemical or physical interactions between the mobile and stationary phases to separate analytes. Separation occurs via the use of porous gel beads packed inside a column (see stationary phase (chemistry)). The principle of separation relies on the differential exclusion or inclusion of the macromolecules by the porous gel stationary phase. Larger molecules are excluded from entering the pores and elute earlier, while smaller molecules can enter the pores, thus staying longer inside the column. The entire process takes place without any interaction of the analytes with the surface of the stationary phase. The smaller analytes relative to the pore sizes can permeate these pores and spend more time inside the gel particles, increasing their retention time. Conversely, larger analytes relative to the pores sizes spend little if any time inside the column, hence they elute sooner. Each type of column has a range of molecular weights that can be separated, according to their pores sizes. If an analyte is too large relative to the column's pores, it will not be retained at all and will be totally excluded; conversely, if the analyte is small relative to the pores sizes, it will be totally permeating.
Sources: en.wikipedia.org
All records, in any form (including, but not limited to, written, electronic, magnetic, and optical records; and scans, x-rays, and electrocardiograms) that describe or record the methods, conduct, and/or results of a trial, the factors affecting a trial, and the actions taken. (ICH E6) Dose
=== Mediterranean area === The soybean was first cultivated in Italy by 1760 in the Botanical Garden of Turin. During the 1780s, it was grown in at least three other botanical gardens in Italy. The first soybean product, soy oil, arrived in Anatolia during 1909 under Ottoman Empire. The first clear cultivation occurred in 1931. This was also the first time that soybeans were cultivated in Middle East. By 1939, soybeans were cultivated in Greece.
chelation A type of bonding involving the formation of two separate coordinate covalent bonds between a polydentate ligand and a single central metal ion. The ligand is usually an organic compound called a chelant or chelating agent.
25 June – Astronomers report the discovery and confirmation of two unusually low-density exoplanets, TOI-791 b and TOI-791 c, orbiting the star TOI-791 about 1,113 light-years from Earth. Detected using NASA's Transiting Exoplanet Survey Satellite, the Jupiter-sized "super-puff" planets have densities of 0.038 and 0.047 g/cm3, respectively, making them among the lowest-density giant planets known and the largest planets yet found with densities below 0.05 g/cm3. 29 June – Palaeontologists identify a fossil vertebra collected on James Ross Island in 1985 as the earliest-known dinosaur bone collected in Antarctica. The specimen, stored for 40 years in the British Antarctic Survey collections, is confirmed to be a tail bone from a titanosaur, a group of long-necked sauropod dinosaurs. The animal is estimated to have lived about 82 million years ago, during the Late Cretaceous, when Antarctica was covered in forest. 30 June – Astronomers report a revised orbit and mass for the nearby habitable zone super-Earth GJ 3378 b. Combining radial velocity data from the Habitable-zone Planet Finder, NEID, CARMENES and SPIRou spectrometers, the team finds that the planet has an orbital period of 21.45 days and a minimum mass of 2.3 Earth masses, rather than earlier estimates of 24.73 days and 5.26 Earth masses. The revision leaves the planet within the conservative liquid-water habitable zone of its red dwarf host star, increases the likelihood that it has a terrestrial composition, and suggests that it may have retained an atmosphere despite high X-ray and ultraviolet exposure.
== Classification == Wounds can be broadly classified as either acute or chronic based on time from initial injury and progression through normal stages of wound healing. Both wound types can further be categorized by cause of injury, wound severity/depth, and sterility of the wound bed. Several classification systems have been developed to describe wounds and guide their management. Some notable classification systems include the CDC's Surgical Wound Classification, the International Red Cross Wound Classification, the Tscherne classification, the Gustilo-Anderson classification of open fractures, and the AO soft tissue grading system.
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 built from four amino acids: alanine, glutamate, aspartate, and glycine. It is not extracted from a natural source but made in the laboratory by chemical synthesis. Its short length makes it relatively straightforward to produce at high purity.