AEDG is one of those subjects where the details matter more than the headlines. This page pulls together the background, the mechanisms, and the practical points readers ask about most.
Updated 2025-12-17. Numbers and descriptions here follow the published literature rather than marketing material.
Regulatory treatment differs by country. No formulation of epitalon holds a marketing authorisation as a medicine in the United States or the European Union, where material sold for laboratory use is handled as a research chemical and is not intended for human consumption. In Russia, several short peptide preparations from the same institute's peptide series are registered medicinal products, and epitalon appears in that national context. Elsewhere it is frequently offered as a cosmetic ingredient, a category with lighter requirements. Advertising claims about longevity or disease prevention are restricted in most jurisdictions, which limits how sellers describe the compound.
Freeze-dried epitalon is normally kept at minus twenty degrees Celsius in a sealed, desiccated container, protected from light. Short excursions at ambient temperature during shipping are generally tolerated, but repeated warming and cooling cycles encourage moisture uptake, which shortens shelf life. Once dissolved, the peptide is far less stable than the solid: aqueous solutions are subject to hydrolysis and to deamidation at the aspartate and glutamate residues. Working solutions are therefore held refrigerated and used within days, and repeated freezing and thawing of the same vial is best avoided.
Identity and purity are checked by reversed-phase high-performance liquid chromatography, usually with ultraviolet detection near 214 nanometres, where the peptide bond absorbs. Mass spectrometry confirms the expected mass and reveals whether truncation products or adducts are present. Acid hydrolysis followed by amino acid analysis gives the residue ratio, which should approximate one alanine, one glutamate, one aspartate and one glycine. Counter-ions such as acetate or trifluoroacetate remain in the dried product and lower net peptide content, so a stated purity figure on a label does not by itself describe how much peptide a vial holds.
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.
| Property | Value | Notes |
|---|---|---|
| Storage temperature, solid | Approximately -20 C | Sealed, desiccated, protected from light |
| Typical identity method | Electrospray mass spectrometry | Protonated ion expected near 391 |
| Typical purity method | Reversed-phase HPLC | Ultraviolet detection near 214 nm |
| Common synonyms | Epithalon, epithalone, AEDG | Spelling variants appear in supplier catalogues |
| Solution stability | Days at 2-8 C | Hydrolysis and deamidation limit shelf life |
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.
Stability of the tetrapeptide follows ordinary peptide chemistry rather than any unusual structural feature. The aspartate-glycine pair is prone to aspartimide formation under mildly basic or neutral conditions, and deamidation can follow, altering both mass and chromatographic retention. Dry lyophilised powder kept at or below minus twenty degrees Celsius is the usual handling recommendation, with repeated freeze-thaw cycles avoided. Once dissolved in neutral aqueous buffer, degradation proceeds over days to weeks depending on pH and temperature, while acidic conditions generally slow the aspartimide route. A formal stability-indicating study has not been published in the indexed literature.
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.
== Burning mirror == The chronicler Inca Garcilaso de la Vega described the use of a burning mirror as part of the annual "Inti Raymi" (sun festival): "The fire for that sacrifice had to be new, given by the hand of the sun, as they said. For which they took a large bracelet, which they call Chipana (similar to others that the Incas commonly wore on the left wrist) which the high priest had; it was large, larger than the common ones, it had for a medallion a concave vessel, the shape of a half orange and brightly polished, they put it against the sun, and at a certain point where the rays that came out of the vessel hit each other, they put a bit of finely unravelled cotton (they did not know how to make tinder), which caught fire naturally in a short space of time. With this fire, thus given by the hand of the sun, the sacrifice was burned and all the meat of that day was roasted."
=== Bioplastics === Various polymers can be created from algae, which can be especially useful in the creation of bioplastics. These include hybrid plastics, cellulose-based plastics, poly-lactic acid, and bio-polyethylene. Several companies have begun to produce algae polymers commercially, including for use in flip-flops and in surf boards. Even algae is also used to prepare various polymeric resins suitable for coating applications.
There is no scientific evidence that HCG is effective in the treatment of obesity. The meta-analysis found insufficient evidence supporting the claims that HCG is effective in altering fat-distribution, hunger reduction, or in inducing a feeling of well-being. The authors stated "…the use of HCG should be regarded as an inappropriate therapy for weight reduction…" In the authors opinion, "Pharmacists and physicians should be alert on the use of HCG for Simeons therapy. The results of this meta-analysis support a firm standpoint against this improper indication. Restraints on physicians practicing this therapy can be based on our findings." According to the American Society of Bariatric Physicians, no new clinical trials have been published since the definitive 1995 meta-analysis. The scientific consensus is that any weight loss reported by individuals on an "HCG diet" may be attributed entirely to the fact that such diets prescribe calorie intake of between 500 and 1,000 calories per day, substantially below recommended levels for an adult, to the point that this may risk health effects associated with malnutrition.
=== Religious views on circumcision === Circumcision is commonly practiced in the Jewish, Islamic, and Druze faiths, and among the members of Coptic Church, the Ethiopian Orthodox Church and the Eritrean Orthodox Tewahedo Church. In contrast, other religions, such as Mandaeism, Hinduism and Sikhism, strongly prohibit the practice of routine circumcision.
=== Flavin-independent ene-reductases === Flavin-independent ERs are able to reduce their substrates directly using the NAD(P)H cofactor that can be regenerated. Two families of this group are the medium-chain dehydrogenases/reductases (MDR; EC 1.3.1), and the short-chain dehydrogenases/reductases (SDR; EC 1.1.1.207−8). The typical substrates reduced by those enzymes include aromatic and monocyclic alkenes containing aldehydes or ketones as activating groups.
Sources: en.wikipedia.org
==== Documentaries without words ==== Films in the documentary form without words have been made. Listen to Britain, directed by Humphrey Jennings and Stuart McAllister in 1942, is a wordless meditation on wartime Britain. From 1982, the Qatsi trilogy and the similar Baraka could be described as visual tone poems, with music related to the images, but no spoken content. Koyaanisqatsi (part of the Qatsi trilogy) consists primarily of slow motion and time-lapse photography of cities and many natural landscapes across the United States. Baraka tries to capture the great pulse of humanity as it flocks and swarms in daily activity and religious ceremonies. Bodysong was made in 2003 and won a British Independent Film Award for "Best British Documentary." The 2004 film Genesis shows animal and plant life in states of expansion, decay, sex, and death, with some, but little, narration.
Upon heating a dilute potassium hydroxide solution with glucose to 100 °C, a strong reddish browning and a caramel-like odor develops. Concentrated sulfuric acid dissolves dry glucose without blackening at room temperature forming sugar sulfuric acid. In a yeast solution, alcoholic fermentation produces carbon dioxide in the ratio of 2.0454 molecules of glucose to one molecule of CO2. Glucose forms a black mass with stannous chloride. In an ammoniacal silver solution, glucose (as well as lactose and dextrin) leads to the deposition of silver. In an ammoniacal lead acetate solution, white lead glycoside is formed in the presence of glucose, which becomes less soluble on cooking and turns brown. In an ammoniacal copper solution, yellow copper oxide hydrate is formed with glucose at room temperature, while red copper oxide is formed during boiling (same with dextrin, except for with an ammoniacal copper acetate solution). With Hager's reagent, glucose forms mercury oxide during boiling. An alkaline bismuth solution is used to precipitate elemental, black-brown bismuth with glucose. Glucose boiled in an ammonium molybdate solution turns the solution blue. A solution with indigo carmine and sodium carbonate destains when boiled with glucose.
=== Other conditions === Catatonia is also seen in many medical disorders, including encephalitis, meningitis, autoimmune disorders, focal neurological lesions (including strokes), alcohol withdrawal, abrupt or overly rapid benzodiazepine withdrawal, cerebrovascular disease, neoplasms, head injury, and some metabolic conditions (e.g.,homocystinuria, diabetic ketoacidosis, hepatic encephalopathy, and hypercalcaemia).
By 9 April 2026, there was no sign that the agreement to lift the Iranian blockade of Strait of Hormuz was being implemented, ships once again being prevented from moving through the Strait, and Israel and the United States being accused by Iran of violating the ceasefire with the recent attacks in Lebanon. However, no new attacks were reported in the Gulf that day either. Indian media sources reported that the Pakistan Air Force had mobilised its JF-17 and F-16 fighters, as well as IL-78 tankers and C-130 cargo planes. The fighters are expected to fly an escort mission for the Iranian representatives and the PAF set up a protective shield over Iran and the Persian Gulf for the Iranian delegation to travel to Islamabad. Iranian aircraft were also escorted by AEWACS, JF-17s and J-10C aircraft and flew with their transponders switched off. According to one report, Iran lost track of mines it planted in the Strait of Hormuz, and it was therefore unable to fully open the Strait. The US began a naval operation to clear the Strait from mines.
Based on their interpretation of scriptures such as Acts 15:28, 29 ("Keep abstaining...from blood."), many Jehovah's Witnesses neither consume blood nor accept transfusions of whole blood or its major components: red blood cells, white blood cells, platelets (thrombocytes), and plasma. Members may personally decide whether they will accept medical procedures that involve their own blood or substances that are further fractionated from the four major components.
Sources: en.wikipedia.org
=== Symptoms === Consumption of atractyloside (ATR) in plants will oftentimes also contain carboxyatractyloside (CATR), a highly toxic glycoside. Ingestion of A. gummifera, C. laureola, Xanthium, or their extracts, may result in symptoms of gastrointestinal pain, nausea, diarrhea, and vomiting. Also possible is respiratory depression which may cause hypoxemia, leading to tissue hypoxia, spasms, stiffness, and convulsions. In several cases, these symptoms are followed by coma. Postmortem analysis may indicate hepatocellular damage and renal failure. More recent literature has described sustained application of ATR on skin causing the symptoms described above, including hepatorenal injury.
== Causes == Dominant genetic disorders can be caused by just a single copy of an abnormal gene. This abnormal gene can be the result of being inherited from either parent or be a new mutation. Most cases are caused by a de novo (new) mutation in the gene that occurs during the formation of the egg or sperm. These cases occur when there is no history of the disorder in the family. The COL11A2 gene is responsible for providing instructions on making one component of the type XI collagen. Type XI collagen is a complex molecule that helps give structure and strength to the connective tissues. Collagen is found in bone. It is also found in cartilage that makes up most of the skeleton during early development. The mutation of COL11A2 in Weissenbacher-Zweymüller syndrome disrupts the assembly of the type XI collagen molecules. The malfunctioning collagen weakens the connective tissue causing impaired bone development. COL11A2 is also associated with autosomal dominant non-syndromic hearing loss (ADNSHL). All mutations of COL11A2 in ADNSHL are missense mutations.
It is a flat tax up to the cap, but regressive overall as it is not applied to higher incomes. The Medicare portion is also paid by employer and employee each at 1.45% and is not capped. Starting in 2013, an additional 0.9 percent more in Medicare taxes was applied to income of more than $200,000 ($250,000 for married couples filing jointly), making it a progressive tax overall. For calendar years 2011 and 2012, the employee's portion of the payroll tax was reduced to 4.2% as an economic stimulus measure; this expired for 2013. Approximately 65% percent of tax return filers pay more in payroll taxes than income taxes.
== Contributions in protein structural biology == The three-dimensional structures of various proteins including lactoperoxidase, peptidoglycan recognition protein, lactoferrin from several species, ribosome inactivating proteins, bifunctional inhibitor proteins from plant seeds and various serine proteases and their inhibitors have been determined by his group. The elaborate structural studies of proteins from several important systems as potential drug targets such as phospholipase A2, cyclooxygenase, lipoxygenase, endothelin receptor, endothelin converting enzyme, breast cancer regression proteins and matrix metanosomal proteins as well as their complexes with natural and designed synthetic ligands have been carried out. He had developed the rules of peptide design with alpha, beta – dehydro – amino acids through extensive studies using syntheses, and X-ray and NMR structure determinations. These design rules are being exploited for making specific peptides to act as tight inhibitors of target enzymes and potent antagonists of target receptors for eventually leading to useful therapeutic agents. He initiated a new programme on Clinical Proteomics at the All India Institute of Medical Sciences in which it is intended to characterize all the proteins that are expressed during various patho/physiological conditions. The newly identified proteins will either be useful as biomarkers or they may be associated with the progression of diseases making them important targets for drug design.
Sources: en.wikipedia.org
The solid is kept cold, dry and dark, typically at minus twenty degrees Celsius, in a sealed container with desiccant. Dissolved material is kept refrigerated and used promptly. Freezing and thawing a solution repeatedly is avoided because it accelerates degradation.
Reversed-phase chromatography with ultraviolet detection gives a purity percentage, while mass spectrometry confirms identity. Amino acid analysis checks the residue composition. Buyers typically request a certificate of analysis showing these measurements for the specific lot.
It is not authorised as a medicine in the United States or the European Union. Material is sold there as a research chemical or cosmetic ingredient. Some related short peptides are registered drugs in Russia, which is a distinct national situation rather than a general approval.
It is a synthetic tetrapeptide. Its sequence was derived from research on peptide fractions of bovine pineal extract, and the intact AEDG sequence has not been demonstrated as an abundant free peptide in human tissue.