Everything below concerns reversed-phase HPLC. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Updated 2025-11-07. Numbers and descriptions here follow the published literature rather than marketing material.
Several names circulate for the same molecule, including epitalon, epithalone, epithalamin tetrapeptide, and the sequence code AEDG. A CAS registry number, 307297-39-8, is commonly cited for it, though catalogue entries should be checked against supplier documentation because mislabelled records occur. In its usual form the peptide carries free amino and carboxyl termini and is neither glycosylated nor lipidated. Researchers distinguish the defined tetrapeptide from epithalamin itself, a crude pineal preparation containing many peptides that is not chemically characterised.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Amino acid sequence | Ala-Glu-Asp-Gly | Linear tetrapeptide, also written AEDG |
| Molecular mass | About 390.35 g/mol | Value calculated from the sequence |
| Appearance | White to off-white powder | Lyophilised material forms a loose cake |
| Solubility | Freely soluble in water | Also dissolves in isotonic saline |
| Storage | -20 °C, desiccated | Aliquot solutions to avoid freeze–thaw cycling |
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.
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.
Identity confirmation uses mass spectrometry, usually electrospray ionisation in positive mode or matrix-assisted laser desorption. The protonated free peptide produces a signal near three hundred and ninety-one daltons, while salt adducts shift that value slightly. Tandem mass spectrometry or amino acid analysis supplies sequence-level confirmation, which a single mass measurement cannot. Peptides containing aspartate can cyclise into succinimide intermediates that hydrolyse to isoaspartate isomers of identical mass. Because those isomers are difficult to separate chromatographically, identity and purity results carry more weight when interpreted together.
Storage practice centres on limiting moisture, oxygen, and repeated temperature cycling. Freeze-dried powder is generally held desiccated at minus twenty degrees Celsius or colder and protected from light. Reconstituted solutions are markedly less stable, and the aspartate-glycine junction is prone to succinimide formation at neutral to mildly alkaline pH. Portioning material into single-use aliquots reduces degradation compared with repeated freeze-thaw cycles. Stability data specific to this tetrapeptide remain scarce, so most handling guidance is extrapolated from general peptide chemistry rather than measured directly.
Autism: Oxytocin may play a role in autism and may be an effective treatment for autism's repetitive and affiliative behaviors. Relationship counseling: The use of oxytocin in relationship counseling for well-being has been suggested. Post-traumatic stress disorder: It has been suggested that oxytocin may be a safer option than MDMA for the treatment of PTSD, although oxytocin has less evidence of efficacy.
== Treatment == For newborn infants starved of oxygen during birth, there is now evidence that hypothermia therapy for neonatal encephalopathy applied within 6 hours of cerebral hypoxia effectively improves survival and neurological outcome. In adults, however, the evidence is less convincing and the first goal of treatment is to restore oxygen to the brain. The method of restoration depends on the cause of the hypoxia. For mild-to-moderate cases of hypoxia, removal of the cause of hypoxia may be sufficient. Inhaled oxygen may also be provided. In severe cases, treatment may also involve life support and damage control measures. A deep coma will interfere with the body's breathing reflexes even after the initial cause of hypoxia has been dealt with; mechanical ventilation may be required. Additionally, severe cerebral hypoxia causes an elevated heart rate, and in extreme cases the heart may tire and stop pumping. CPR, defibrilation, epinephrine, and atropine may all be tried in an effort to get the heart to resume pumping. Severe cerebral hypoxia can also cause seizures, which put the patient at risk of self-injury, and various anti-convulsant drugs may need to be administered before treatment.
The courts give the EU a wide discretion to implement policy, so judicial review is possible only if agricultural measures are 'manifestly inappropriate'. EU law does not yet have a systematic plan or subsidies to rewild depleted environments, and to move to complete clean energy infrastructure.
The soft tissue in the oral cavity is classified as either keratinized or nonkeratinized based on the presence of keratin in the epithelium. In health, the soft tissue immediately around the teeth is keratinized and is referred to as keratinized tissue or gingiva. Alveolar mucosa is non keratinized oral epithelium and is located apical to the keratinized tissue, delineated by the mucogingival junction (MGJ). It should also be pointed out that mucosa can surround a tooth in health. Nonkeratinized tissue also lines the cheeks (buccal mucosa), underside of the tongue and floor of the mouth. The lips contain both non-keratinized tissue (on the inside) and keratinized tissue on the outside, demarcated by the vermillion border. The dorsum of the tongue is keratinized and features many papillae, some of which contain taste buds. Exposure of the tooth root due to loss of keratinized tissue around the neck of a tooth is referred to as gingival recession. This can result in sensitivity or pain from the exposed tooth root surface (dentin is more permeable and soft compared to enamel and dentin is what makes up the tooth root). Recession may also cause an unasthetic appearance especially if located in the anterior dentition (front teeth). While not all cases of gingival recession require surgical correction, there are various options if that is what the patient desires. It should be reinforced that recession left untreated will not result in tooth loss, contrary to popular belief.
The evidence for brain-derived neurotrophic factor (BDNF) in mediating some of the neurobiological effects of physical exercise was noted in one review which hypothesized that increased BDNF signaling is responsible for the antidepressant effect. A meta-analysis of 15 studies published in 2022 suggested a curvilinear dose-response relationship between exercise and depression risk, with low levels of exercise showing the best dose-response.
Sources: en.wikipedia.org
As numerous ASSRs declared sovereignty and self-promotion to Soviet Socialist Republics, Art. 71 and 72 of the Constitution of the RSFSR were amended on May 24, 1991 to recognize its autonomous republics as SSRs; it was further amended on July 3 to promote all its autonomous oblasts other than Jewish Autonomous Oblast to SSRs. This decision came into conflict with Art. 85 of the Constitution of the USSR.
== Use in medicine and technology == In medicine several nucleoside analogues are used as antiviral or anticancer agents. The viral polymerase incorporates these compounds with non-canonical bases. These compounds are activated in the cells by being converted into nucleotides. They are administered as nucleosides since charged nucleotides cannot easily cross cell membranes. In molecular biology, several analogues of the sugar backbone exist. Due to the low stability of RNA, which is prone to hydrolysis, several more stable alternative nucleoside/nucleotide analogues that correctly bind to RNA are used. This is achieved by using a different backbone sugar. These analogues include locked nucleic acids (LNA), morpholinos and peptide nucleic acids (PNA). In sequencing, dideoxynucleotides are used. These nucleotides possess the non-canonical sugar dideoxyribose, which lacks 3' hydroxyl group (which accepts the phosphate). DNA polymerases cannot distinguish between these and regular deoxyribonucleotides, but when incorporated a dideoxynucleotide cannot bond with the next base and the chain is terminated.
Umami peptides are a family of small to medium length polypeptides found in a variety of savoury foods, which impart an umami taste. They are best known from Asian condiments and foods such as soy sauce, fish sauce, oyster sauce, and miso, but are also found in a diverse range of other foods including cheese, stewed or preserved meat products, and Bolete mushrooms. One of the best characterised umami peptides is beefy meaty peptide, originally isolated from beef soup, an eight amino acid peptide with the sequence Lys-Gly-Asp-Glu-Glu-Ser-Leu-Ala which is thought to interact with the T1R1/T1R3 taste receptor complex. There are dozens if not hundreds of umami peptides known, most of which have been little studied in isolation as they typically occur in complex mixtures, which can vary significantly between different foods, brands, and even different batches made the same way. Not all peptides isolated from such mixtures have umami flavour, with some closely related peptides tasting sweet, sour, salty, bitter or kokumi, and often a change in only a single amino acid can be enough to change the flavour entirely. However, the majority of peptides isolated from fermented foods or cooked or preserved meat products tend to have an umami flavour, with trace amounts of peptides with other flavours contributing to the overall flavour profile of the food.
== Clinical trials == The drug was reported to improve motivation and reduce apathy in people with Parkinson's disease in a phase 2a clinical trial. As of September 2024, pirepemat is in phase 2 clinical trials for Parkinson's disease. A phase 3 trial is being planned. The drug was also under development for the treatment of "behavioral disorders" and attention deficit hyperactivity disorder (ADHD). However, no recent development for the former indication has been reported and development for ADHD was discontinued. In August 2020, pirepemat received an INNTooltip International Nonproprietary Name with a novel suffix reflecting its reputedly new and unique mechanism of action. Pirepemat is under development by Integrative Research Laboratories (IRLAB).
Sources: en.wikipedia.org
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.
AEDG is the one-letter code for the four amino acids alanine, glutamate, aspartate and glycine in that order. The same molecule is written in three-letter form as Ala-Glu-Asp-Gly.
Identity is normally confirmed by mass spectrometry against the calculated mass of roughly 390.35 g/mol. Purity is then estimated by reversed-phase high-performance liquid chromatography with ultraviolet detection.
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.