The short version of Aspartimide fits in a sentence. The long version — which is the one that helps — is below.
Reviewed 2025-09-03. Anything still debated is marked as such rather than presented as settled.
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.
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 |
|---|---|---|
| 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 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.
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.
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.
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.
Sitagliptin, sold under the brand name Januvia among others, is an anti-diabetic medication used to treat type 2 diabetes. It is in the dipeptidyl peptidase-4 (DPP-4) inhibitor class and works by increasing the production of insulin and decreasing the production of glucagon by the pancreas. In the United Kingdom it is listed as less preferred than metformin or a sulfonylurea. It is taken by mouth. It is also available in the fixed-dose combination medication sitagliptin/metformin (Janumet, Janumet XR). Common side effects include headaches, swelling of the legs, and upper respiratory tract infections. Serious side effects may include angioedema, low blood sugar, kidney problems, pancreatitis, and joint pain. Whether use in pregnancy or breastfeeding is safe is unclear. Sitagliptin was developed by Merck & Co. and approved for medical use in the United States in 2006. In 2023, it was the 123rd most commonly prescribed medication in the United States, with more than 5 million prescriptions. It is available as a generic medication, but not in the United States.
It can be difficult to tell whether a trait has been lost and then re-evolved convergently, or whether a gene has simply been switched off and then re-enabled later. Such a re-emerged trait is called an atavism. From a mathematical standpoint, an unused gene (selectively neutral) has a steadily decreasing probability of retaining potential functionality over time. The time scale of this process varies greatly in different phylogenies; in mammals and birds, there is a reasonable probability of a gene's remaining in the genome in a potentially functional state for around 6 million years.
This aircraft was so successful in this mission that the Army ordered two F-51Ds from Cavalier in 1968 for use at Fort Rucker. They were assigned the serials 68-15795 and 68-15796. These F-51s had wingtip fuel tanks and were unarmed. Following the end of the Cheyenne program, these two chase aircraft were used for other projects. One of them (68-15795) was fitted with a 106 mm recoilless rifle for evaluation of the weapon's value in attacking fortified ground targets. Cavalier Mustang 68-15796 survives at the Air Force Armament Museum, Eglin AFB, Florida, displayed indoors in World War II markings. The F-51 was adopted by many foreign air forces and continued to be an effective fighter into the mid-1980s with smaller air arms. The last Mustang ever downed in battle occurred during Operation Power Pack in the Dominican Republic in 1965, with the last aircraft finally being retired by the Dominican Air Force in 1984.
=== Circadian rhythm sleep disorders === Melatonin receptor agonists like melatonin and tasimelteon are considered to be effective in regulating sleep–wake cycles and in the treatment of circadian rhythm sleep disorders like delayed sleep phase disorder. Ramelteon has been assessed in only a few studies in the treatment of circadian rhythm sleep disorders, including jet lag disorder, shift work disorder, and non-24-hour sleep–wake disorder. These studies have been of varying quality and their findings in terms of effectiveness have been mixed. Ramelteon is approved only for treatment of insomnia and is not approved for treatment of circadian rhythm sleep disorders. It was previously under development for treatment of circadian rhythm sleep disorders, but development for these indications was discontinued. Some clinical trials since 2020 have found that dosages much lower than the standard 8 mg tablet may be more effective at advancing the circadian rhythm.
=== Psychiatry === Phosphorylation of tyrosine hydroxylase at Ser31 or Ser40 can increase dopamine biosynthesis; therefore an increase in pSer31 or pSer40 elevates dopamine synthesis in DA neurons. Excessive dopamine in the mesolimbic pathways of the brain produces psychotic symptoms. Antipsychotic medications block dopamine D2 receptors in the caudate and putamen as well as in limbic target areas, they can also block or partially block serotonin. Therapy with AMPT could prove to be more specific to dopamine and therefore eliminate some of the negative side effects of antipsychotic drugs. Metirosine is used as an off-label treatment for psychosis due to DiGeorge syndrome. The dopamine transporter (DAT) is a principal site of action for cocaine. Cocaine inhibits DAT function and vesicular dopamine transport (VMAT). Cocaine administration abruptly and reversibly increases both the Vmax of dopamine uptake and the Bmax of vesicular monoamine transporter 2 (VMAT-2) ligand (dihydrotetrabenazine) binding. Dopamine depletion resulting from administration of AMPT had similar neuropharmacological effects as cocaine. Administration of methamphetamine, a dopamine-releasing agent, rapidly decreased vesicular uptake. A relationship between cytoplasmic dopamine concentration and VMAT activity was established using cocaine, methamphetamines, and AMPT. Although it is not well understood, this relationship allows for AMPT’s inhibitory property, which blocks tyrosine hydroxylase, to increase dopamine transport by the vesicle monoamine transporter-2.
Sources: en.wikipedia.org
Components of the RNAi pathway are used in many eukaryotes in the maintenance of the organization and structure of their genomes. Modification of histones and associated induction of heterochromatin formation serves to downregulate genes pre-transcriptionally; this process is referred to as RNA-induced transcriptional silencing (RITS), and is carried out by a complex of proteins called the RITS complex. In fission yeast this complex contains Argonaute, a chromodomain protein Chp1, and a protein called Tas3 of unknown function. As a consequence, the induction and spread of heterochromatic regions requires the Argonaute and RdRP proteins. Indeed, deletion of these genes in the fission yeast S. pombe disrupts histone methylation and centromere formation, causing slow or stalled anaphase during cell division. In some cases, similar processes associated with histone modification have been observed to transcriptionally upregulate genes. The mechanism by which the RITS complex induces heterochromatin formation and organization is not well understood. Most studies have focused on the mating-type region in fission yeast, which may not be representative of activities in other genomic regions/organisms. In maintenance of existing heterochromatin regions, RITS forms a complex with siRNAs complementary to the local genes and stably binds local methylated histones, acting co-transcriptionally to degrade any nascent pre-mRNA transcripts that are initiated by RNA polymerase.
==== Prokaryotic pathway ==== In prokaryotes such as bacteria, diphosphatidylglycerol synthase catalyses a transfer of the phosphatidyl moiety of one phosphatidylglycerol to the free 3'-hydroxyl group of another, with the elimination of one molecule of glycerol, via the action of an enzyme related to phospholipase D. The enzyme can operate in reverse under some physiological conditions to remove cardiolipin.
The bill reduced the number of elected trustees to a minimum of 12, changed the responsibilities of trustees, and introduced the position of school board chief executive officer. To reduce student absenteeism among secondary school students, the bill makes attendance and participation part of students' final marks and introduces written final exams.
GeneDx is an American biotechnology company specializing in genomic diagnostics, with a focus on whole genome sequencing (WGS) and whole exome sequencing (WES) for the diagnosis of rare and inherited disorders. The company provides genetic testing services to healthcare providers, hospitals, and health systems, and contributes to advancements in genomic medicine through research, biopharma partnerships, and advocacy. The company is headquartered in Stamford, Connecticut, with its clinical laboratory in Gaithersburg, Maryland, and is publicly traded on the Nasdaq under the ticker symbol WGS. GeneDx was founded in 2000 by Sherri Bale and John Compton, scientists from the National Institutes of Health (NIH), to provide diagnostic services for patients with rare and ultra-rare disorders. The company was acquired by BioReference Laboratories in 2006 and subsequently by Sema4 in 2022, after which it underwent a strategic transformation refocusing on whole exome and genome sequencing in pediatrics and changed its name to GeneDx. Since launching exome testing in 2011, the company has built GeneDx Infinity, a large and diverse rare disease dataset including more than one million clinically sequenced exomes and genomes, more than 2.5 million tests, and more than 8 million phenotypic datapoints. In 2024, GeneDx reported revenue of $302.3 million, representing 56% year-over-year growth, and announced its first profitable quarter. For full-year 2025, the company reported revenue of approximately $427 million.
Sources: en.wikipedia.org
The atheroma ("lump of gruel", from Greek ἀθήρα (athera) 'gruel'), which is the nodular accumulation of a soft, flaky, yellowish material at the center of large plaques, composed of macrophages nearest the lumen of the artery Underlying areas of cholesterol crystals Calcification at the outer base of older or more advanced lesions. Atherosclerotic lesions, or atherosclerotic plaques, are separated into two broad categories: Stable and unstable (also called vulnerable). The pathobiology of atherosclerotic lesions is very complicated, but generally, stable atherosclerotic plaques, which tend to be asymptomatic, are rich in extracellular matrix and smooth muscle cells. On the other hand, unstable plaques are rich in macrophages and foam cells, and the extracellular matrix separating the lesion from the arterial lumen (also known as the fibrous cap) is usually weak and prone to rupture. Ruptures of the fibrous cap expose thrombogenic material, such as collagen, to the circulation and eventually induce thrombus formation in the lumen. Upon formation, intraluminal thrombi can occlude arteries outright (e.g., coronary occlusion), but more often they detach, move into the circulation, and eventually occlude smaller downstream branches, causing thromboembolism. Apart from thromboembolism, chronically expanding atherosclerotic lesions can cause complete closure of the lumen. Chronically expanding lesions are often asymptomatic until the lumen stenosis is so severe (usually over 80%) that blood supply to downstream tissue(s) is insufficient, resulting in ischemia.
Californiconus J. K. Tucker & Tenorio, 2009 Conasprella Thiele, 1929 † Conilithes Swainson, 1840 † Contraconus Olsson & Harbison, 1953 Conus Linnaeus, 1758 † Eoconus J. K. Tucker & Tenorio, 2009 † Hemiconus Cossmann, 1889 † Herndliconus Petuch & Drolshagen, 2015 Kenyonia Brazier, 1896 Lilliconus G. Raybaudi Massilia, 1994 Malagasyconus Monnier & Tenorio, 2015 † Papilliconus Tracey & Craig, 2017 Profundiconus Kuroda, 1956 Pseudolilliconus J. K. Tucker & Tenorio, 2009 Pygmaeconus Puillandre & Tenorio, 2017 † Tequestaconus Petuch & Drolshagen, 2015 † The authors grouped 85% of all known cone snail species under Conus. They recognized 57 subgenera within Conus, and 11 subgenera within the genus Conasprella.
Russia is pursuing deals to supply its vaccine abroad. According to the Russian Direct Investment Fund, they had received orders for more than 1.2 billion doses of the vaccine as of December 2020. Over 50 countries had made requests for doses, with supplies for the global market being produced by partners in India, Brazil, China, South Korea, Hungary, and other countries. In August 2020, according to the Russian authorities, there were at least 20 countries that wanted to obtain the vaccine. The Israeli Hadassah Medical Center signed a commercial memorandum of understanding to obtain 1.5–3 million doses. Argentina agreed to buy 25 million doses of Russia's COVID-19 vaccine, subject to its clearing clinical trials; the vaccine was registered and approved in Argentina in late December 2020. The Brazilian state of Bahia signed an agreement to conduct Phase III clinical trials of the Sputnik V vaccine and planned to buy 50 million doses to market in northeastern Brazil. On 21 January 2021, Argentine president Alberto Fernández became the first Latin American leader to be inoculated with Sputnik V, shortly after it was approved for use in the country. Two months after being vaccinated he developed fever and headache, and tested positive for COVID-19. He was asymptomatic ten days later, was discharged from medical treatment subject to medical follow-up as usual for former COVID-19 patients, and resumed his normal activities.
=== Drug trafficking cases === 1981: Ong Ah Chuan, a Singaporean national, hanged on 20 February 1981 for the trafficking of 209 grams of pure heroin. 1981: Low Hong Eng and her accomplice Tan Ah Tee, both Singaporean nationals, hanged on 9 October 1981 for the joint enterprise of trafficking 459g of heroin. Low was the first woman to be hanged for drug offences in Singapore. 1989: Lau Chi Sing, Hong Kong national, hanged on 17 November 1989 for smuggling 242 grams of heroin. Lau was the first drug mule to be sentenced to death for trafficking narcotics via Changi Airport 1992: Lim Joo Yin and his accomplice Ronald Tan Chong Ngee were both hanged on 3 April 1992 for smuggling heroin. 1994: Cheuk Mei Mei and her accomplice Tse Po Chung, Hongkongers, were hanged on 4 March 1994 for smuggling 2 kg of heroin each. 1994: Johannes van Damme, a Dutch engineer and the first European to be executed in modern-day Singapore, hanged on 23 September 1994 for smuggling 4.32 kg of pure heroin. 1994: Elke Tsang Kai-mong, Hong Kong National, was hanged on 16 December 1994 for smuggling 4 kg of heroin. 1995: Angel Mou Pui Peng, a Macau national hanged on 6 January 1995 for smuggling 4 kg of heroin. 1995: Daniel Chan Chi-pun, Hong Kong national, hanged on 10 March 1995 for smuggling of 464 grams of heroin. 1995: Tong Ching Man and her boyfriend Lam Cheuk Wang, both Hong Kong nationals, hanged on 21 April 1995 for smuggling 1.6 kg and 1.4 kg of heroin respectively. 1995: Poon Yuen Chung, Hong Kong national, hanged on 21 April 1995 for smuggling 3 kg of heroin.
== Mission and Research Strategy == The mission of TBRI is targeted towards the control, the diagnosis and management of endemic diseases and their complications especially those affecting the liver, the gastrointestinal and the urinary tracts, mainly as result of schistosomiasis and viral hepatitis, this is to meet the social, economic and technological needs of Egypt and the regional area. The Institute adopts an integrated strategy based on six research programs that can cope with and fulfill this objective:
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.
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.