epitalon comes up often in conversation and rarely with the context attached. Here we lay out the basics in order, then work through the practical considerations.
Last reviewed on 2026-01-08. Where a claim depends on a specific study, the study is described rather than over-claimed.
Documentation accompanying research peptides usually includes a certificate of analysis listing the batch number, purity figure, and test methods applied. Buyers comparing suppliers should check whether the reported purity refers to chromatographic area or to a mass-balance calculation, because the two are not equivalent. Counter-ion content, residual solvents, and water content are sometimes omitted from such certificates even though they affect the actual peptide mass present. Independent verification through a second laboratory is the most direct way to confirm that a supplied material matches its label.
Purity assessment of peptide reagents normally relies on reversed-phase high-performance liquid chromatography. A gradient of acetonitrile in water with trifluoroacetic acid, paired with a C18 stationary phase, separates the target tetrapeptide from truncated sequences and deletion analogues. Detection at 214 nanometres exploits absorbance of the peptide backbone, since the molecule contains no aromatic residue. Results are expressed as a percentage of total peak area. Values above ninety-five percent are typical for research-grade material, although reporting conventions vary between suppliers.
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.
| Property | Value | Notes |
|---|---|---|
| Appearance | White to off-white powder | Freeze-dried solid |
| Solubility class | Freely soluble in water | Aqueous buffers also suitable |
| Typical storage temperature | Minus 20 degrees Celsius or colder | Desiccated and light protected |
| Typical analytical method | RP-HPLC with UV detection | 214 nm on C18 column |
| Identity confirmation | Electrospray mass spectrometry | Sequence verified separately |
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.
Residue composition is the property that most cleanly separates verified material from mislabelled samples. Alanine, glutamate, aspartate and glycine appear in that order from the N-terminus, and the two acidic residues sit in the middle of the chain. Because the peptide is short, it can be produced by solid-phase synthesis and characterised by mass spectrometry without ambiguity. Any reported sample whose measured mass departs substantially from 390 daltons is a different compound or a degraded mixture rather than epitalon.
Epitalon is a synthetic tetrapeptide whose four residues are alanine, glutamate, aspartate and glycine, commonly abbreviated AEDG. Its molecular formula is C14H22N4O9 and its monoisotopic mass is near 390.35 daltons. The peptide carries two acidic side chains, so it is neutral to negatively charged in most aqueous buffers. Published reference summaries usually list it under both spellings, epitalon and epithalon, and treat the two names as the same material.
The compound is generally described as a synthetic analogue of a fragment isolated from a pineal gland extract. Researchers associated with the Saint Petersburg Institute of Bioregulation and Gerontology introduced it during the 1980s and 1990s while studying short peptides from animal tissue. The original extract, called epithalamin, is a heterogeneous mixture, whereas epitalon is a single defined sequence. That distinction matters because findings reported for the extract are not automatically findings about the pure tetrapeptide, and claims about broader biological effects remain a separate question from the chemical identity described here.
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.
=== List of resources === PhosphoSitePlus – A database of comprehensive information and tools for the study of mammalian protein post-translational modification ProteomeScout – A database of proteins and post-translational modifications experimentally Human Protein Reference Database – A database for different modifications and understand different proteins, their class, and function/process related to disease causing proteins PROSITE – A database of Consensus patterns for many types of PTM's including sites RESID – A database consisting of a collection of annotations and structures for PTMs. iPTMnet– A database that integrates PTM information from several knowledgbases and text mining results. dbPTM – A database that shows different PTM's and information regarding their chemical components/structures and a frequency for amino acid modified site Uniprot has PTM information although that may be less comprehensive than in more specialized databases. The O-GlcNAc Database - A curated database for protein O-GlcNAcylation and referencing more than 14 000 protein entries and 10 000 O-GlcNAc sites.
Kruja, headquartered at the tekke of Fushë-Krujë Elbasan, headquartered at the tekke of Krastë, Dibër Korça, headquartered at the tekke of Melçan Gjirokastra, headquartered at the tekke of Asim Baba Prishta, representing Berat and part of Përmet Vlora, headquartered at the tekke of Frashër National headquarters in other countries are located in:
In the Georgian period, many excellent examples of the period's houses were built in Billericay. One of those remaining today is Burghstead Lodge in High Street, which used to house the library. The Town Hall was built in 1830 at 94 High Street. The Billericay Poor Law Union was created in 1835 to serve the town and several surrounding parishes. It built a workhouse in 1840 on Norsey Road. Parts of this building were later incorporated into St Andrew's Hospital. The population of the town in the 1841 census was 1,824. The railway arrived in Billericay in 1889; the station is situated on a branch line from the Great Eastern Main Line between Shenfield and Southend-on-Sea. In 1899, Billericay's market, the reason for the town's establishment is recorded for the last time, though there were short-lived revivals.
Vitamin K: CID 5280483 from PubChem Vitamin K1 (phylloquinone, phytomenadione): CID 5284607 from PubChem Vitamin K2 (menaquinone 6): CID 5283547 from PubChem Vitamin K3 (menadione): CID 4055 from PubChem
Midtown Raleigh is a relatively new term used to describe the residential and commercial area lying on the northside of the I-440 Beltline and is part of North Raleigh. It is roughly framed by Glenwood/Six Forks Road to the West, Wake Forest Road to the East, and Millbrook Road to the North. It includes shopping centers such as North Hills and Crabtree Valley Mall. It also includes North Hills Park and part of the Raleigh Greenway System. The term was coined by the Greater Raleigh Chamber of Commerce, developer John Kane and planning director Mitchell Silver. The News & Observer newspaper started using the term for marketing purposes only. The Midtown Raleigh Alliance was founded on July 25, 2011, as a way for community leaders to promote the area. The center of the area, especially around the North Hills development at the junction of Six Forks Road and the Beltline, is experiencing rapid urbanization as several high-rise buildings have been built since 2010.
Sources: en.wikipedia.org
=== Prevalence === Of the 350 million to 400 million individuals worldwide infected with the hepatitis B virus (HBV), one-third reside in China, with 130 million carriers and 30 million chronically infected. Since the Expanded Program on Immunization (EPI) beginning 1992, the prevalence of HBV has declined, especially among children 3 to 12 years old. During a 5-year period, 10.0% of patients with chronic hepatitis developed cirrhosis, and 20.3% of the cases with compensated cirrhosis progressed to decompensated cirrhosis. 6.5% of the people with cirrhosis and chronic hepatitis progressed to hepatocellular carcinoma (HCC). 5-year survival for compensated cirrhosis is 55%, that for decompensated cirrhosis is 14%, and that for HCC is less than 5%. Every year, 300,000 people die from HBV-related diseases in China, including 180,000 patients with HCC. However, the incidence of hepatitis B is still increasing, from 21.9 in 100,000 people in 1990 to 53.3 in 100,000 in 2003. That increase has occurred despite a vaccination program for newborn babies since the 1990s, which showed good effectiveness for reducing chronic HBV infection in children.
== Veterinary use == Fentanyl is commonly used for analgesia and as a component of balanced sedation and general anesthesia in small animal patients. The short-acting nature, wide safety profile, lower rate of adverse effect compared to other opioids, and high potency make fentanyl one of the most effective and common analgesics in veterinary medicine; the ability to reduce the minimum alveolar concentration leads to fentanyl being commonly used in dogs that are elderly or have cardiovascular issues. Due to its short duration and quick onset, fentanyl is commonly used as a constant rate infusion or as a transdermal patch, with the latter being able to last 3 to 4 days. Fentanyl can provide sedation for dogs. Fentanyl is less common and has more adverse effects in livestock and equine compared to cats and dogs. In horses at analgesic doses tachycardia, restlessness, and excitement occur. Subcutaneous administration often causes pain, but a bicarbonate solution exists which does not cause pain when given subcutaneously. Fentanyl is highly lipophilic, about 1000 times more than morphine. In dogs it has low protein binding of 15.6% and a half-life of 2–6 hours. In cats the half-life is 2.5 hours. Fentanyl has poor oral bio-availability due to it being metabolized by the liver. Transdermal and transmucosal formulations are common for out-patients, although the latter's efficacy is not well supported by evidence.
O-GlcNAc has been found to slow protein aggregation, though the generality of this phenomenon is unknown. Solid-phase peptide synthesis was used to prepare full-length α-synuclein with an O-GlcNAc modification at T72. Thioflavin T aggregation assays and transmission electron microscopy demonstrated that this modified α-synuclein does not readily form aggregates. Treatment of JNPL3 tau transgenic mice with an OGA inhibitor was shown to increase microtubule-associated protein tau O-GlcNAcylation. Immunohistochemistry analysis of the brainstem revealed decreased formation of neurofibrillary tangles. Recombinant O-GlcNAcylated tau was shown to aggregate slower than unmodified tau in an in vitro thioflavin S aggregation assay. Similar results were obtained for a recombinantly prepared O-GlcNAcylated TAB1 construct versus its unmodified form.
Poppy straw (also known as opium straw, mowed opium straw, crushed poppy capsule, poppy chaff, or poppy husk) is derived from opium poppies (Papaver somniferum) that are harvested when fully mature and dried by mechanical means. Opium poppy straw is what remains after the seed pods have been harvested — that is, the dried stalks, stem and leaves of poppies grown for their seeds. The field-dried leaves, stalk, and seed pod are then used in commercial manufacture of morphine or other poppy-alkaloid derived drugs, by first processing the material, separating the seeds, and then making concentrate of poppy straw where no extraction using the traditional methods of latex extraction has been made. The straw was originally considered an agricultural by-product of the mechanised poppy seed harvest, which was primarily grown for its edible and oil-producing seed. This changed in 1927 when János Kabay developed a chemical process to extract morphine from the crushed capsule. Concentrated poppy straw, consisting mainly of the crushed capsule without the seeds, soon became a valuable source of morphine. Today, concentrate of poppy straw is a major source of many opiates and other alkaloids. It is the source of 90% of the world supply of legal morphine (for medical and scientific use) and in some countries it also is a source of illegal morphine, which could be processed into illegal heroin. The 1961 Single Convention on Narcotic Drugs defines poppy straw as "all parts (except the seeds) of the opium poppy, after mowing".
HIV infection In October 2016, scientists from Emory University and National Institute of Allergy and Infectious Diseases (NIAID) published a paper which claimed that they applied daily ART (antiretroviral therapy) of 90 days followed by simianized (rhesus macaques) anti α4β7 antibody on SIV+ rhesus macaques for 23 weeks. Twenty three months after stopping both ART and anti-α4β7 antibody treatment, the in vivo SIV level still remained undetectable. Therefore, treating HIV+ people with ART and anti-α4β7 simultaneously may be a new therapy that could potentially lead to an HIV infection cure. In mice, vedolizumab was not able to prevent or control HIV-infections. Phase 1 clinical trial of that therapy has been initialized by NIAID since May 2016. For each of the participants, they will get vedolizumab infusions every four weeks for 30 weeks. Before the 23rd week of vedolizumab infusions, cART (combination ART) is kept. During the 30 weeks, blood draws are repeated for baseline tests. After the 22-week-cART is stopped, both viral load and CD4 count will be monitored biweekly. If HIV viral load goes high or their CD4 cell counts decrease by too much when vedolizumab is used alone, cART will be brought back on the participants. The published results from this clinical trial suggest "that blockade of α4β7 may not be an effective strategy for inducing virological remission in HIV-infected individuals after ART interruption" because only one patient showed prolonged virus suppression.
Sources: en.wikipedia.org
=== AI Growth Zones and Compute Roadmap === Following the Action Plan, the government published its AI Growth Zones policy paper in November 2025, designating specific sites, with streamlined planning approvals and accelerated power connections. The policy aims to reduce the time to power for new data centres by up to five years and save a 500 MW data centre up to £80 million annually. In July 2025, the UK government published its UK Compute Roadmap outlining up to £2 billion for a modern public compute ecosystem and a 20-fold expansion of the AI Research Resource by 2030, alongside AI Growth Zones.
=== Endoscopy === After Edlich learned about endoscopes in Asia, he received an endoscope for gastroscopic visualization of the patient's stomach. As a surgical resident, Edlich was the first physician to do a gastroscopy at the University of Minnesota Medical Center. Edlich's picture was featured on the cover of Postgraduate Medicine, the Journal of Applied Medicine, in November 1968. His experiences with gastroscopy led to the first minimally invasive surgical procedure at the University of Minnesota Hospital, an endoscopic gastrostomy. Edlich soon realized the limitations of the thick, narrow-diameter latex Ewald tubes that were being used to evacuate blood clots from the patient's stomach before endoscopic examination. Edlich devised a thin-walled, transparent, plastic tube for evacuation of blood clots from a patient's stomach.
MS2 tagging is a technique based upon the natural interaction of the MS2 bacteriophage coat protein with a stem-loop structure from the phage genome, which is used for biochemical purification of RNA-protein complexes and partnered to GFP for detection of RNA in living cells. More recently, the technique has been used to monitor the appearance of RNA in living cells, at the site of transcription, or simply by observing the changes in RNA number in the cytoplasm. This has revealed that transcription of both prokaryotic and eukaryotic genes occurs in a discontinuous fashion with bursts of transcription separated by irregular intervals.
David J. Brayden is a pharmaceutical scientist, researcher, and academic. He is a full professor of advanced drug delivery at the University College Dublin (UCD). Brayden's research has focused on peptide delivery across intestinal and buccal epithelia, utilizing nanoparticle and permeation enhancer constructs for oral peptide administration, evaluating high-content toxicology in cells, and developing nanoparticle formulations for intra-articular injection for arthritis. Brayden is a fellow of the Controlled Release Society and a member of the Royal Irish Academy.
== Sources == L. S. Ettre (2004) American Laboratory, May 2004, pages 4-6 In memoriam: Csaba Horváth A. Guttman (2000) American Laboratory, June 2000, pages 6-10 Archived 2022-05-20 at the Wayback Machine Happy Birthday Csaba Horváth The Hungary Page Nobel Prize Winners and Famous Hungarians: Science, Mathematics & Technology Yale news of his death at the Wayback Machine (archived June 17, 2004) "Speeches at his remembrance Service". Archived from the original on June 18, 2004. Retrieved September 13, 2007. Claudia Flavell-White The Chemical Engineer October 2010 pp 54–55 "Degrees of Separation: Chemical Engineers who Changed the World - Csaba Horváth" An Introduction to Separation Science, (1973) B.L. Karger, Cs. Horváth and L.R. Snyder, Wiley
Sources: en.wikipedia.org
Reversed-phase high-performance liquid chromatography with ultraviolet detection at 214 nanometres is the usual approach. Peak area percentage provides a purity figure relative to other components in the sample. Mass spectrometry is then applied to confirm identity.
Aspartate can cyclise into a succinimide intermediate that later hydrolyses back as isoaspartate. Both forms share the same molecular mass, so mass spectrometry alone cannot tell them apart. This shapes how purity data should be interpreted.
Freeze-dried material is normally kept desiccated below minus twenty degrees Celsius and shielded from light. Solutions are prepared shortly before use and held cold. Repeated thawing is avoided because it accelerates aggregation and degradation.
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.