The short version of tetrapeptide fits in a sentence. The long version — which is the one that helps — is below.
Reviewed 2025-10-11. Anything still debated is marked as such rather than presented as settled.
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.
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.
Epitalon is a synthetic tetrapeptide whose sequence is alanine–glutamate–aspartate–glycine, commonly abbreviated AEDG. It was developed in Russia during the 1980s and 1990s by investigators associated with the St. Petersburg Institute of Bioregulation and Gerontology, who studied short peptides as regulators of gene expression and tissue function. The alternative spelling epithalon appears interchangeably in the literature, and the two names refer to the same molecule. Outside Russia it is encountered chiefly as a research chemical rather than a licensed medicine, and it holds no approval from the United States Food and Drug Administration or the European Medicines Agency.
| 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 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 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.
=== Patentability issues === As indicated above, some mammals typically used for food production (such as goats, sheep, pigs, and cows) have been modified to produce non-food products, a practice sometimes called pharming. Use of genetically modified goats has been approved by the FDA and EMA to produce ATryn, i.e. recombinant antithrombin, an anticoagulant protein drug. These products "produced by turning animals into drug-manufacturing 'machines' by genetically modifying them" are sometimes termed biopharmaceuticals. The patentability of such biopharmaceuticals and their process of manufacture is uncertain. Probably, the biopharmaceuticals themselves so made are unpatentable, assuming that they are chemically identical to the preexisting drugs that they imitate. Several 19th-century United States Supreme Court decisions hold that a previously known natural product manufactured by artificial means cannot be patented. An argument can be made for the patentability of the process for manufacturing a biopharmaceutical, however, because genetically modifying animals so that they will produce the drug is dissimilar to previous methods of manufacture; moreover, one Supreme Court decision seems to hold open that possibility. On the other hand, it has been suggested that the recent Supreme Court decision in Mayo v.
== Partnerships and Agreements == Licensing agreements for Biomatrica technologies were signed with Qiagen in 2007 and 2009. Following the launch of DNAstable, the company gained the interest of law enforcement organizations, such as the California Department of Justice, which sought to stabilize DNA samples from crime scenes for forensics purposes. Other law enforcement organizations, including sheriffs’ departments in Orange County, CA Los Angeles, CA, and Palm Beach, FL, have adopted ambient temperature forensic sample management systems based on Biomatrica's technologies. Also in 2010, Biomatrica signed a collaborative research and development agreement (CRADA) with United States Army Medical Research Institute for Infectious Diseases (USAMRIID) to develop and test new technologies for ambient temperature stabilization of clinical and biological samples. The same year, Biomatrica began a partnership agreement with the U.S. National Cancer Institute (NCI) for biomarker stabilization and SAIC-Frederick to improve molecular analysis of tumors. In 2011, the company announced a partnership agreement with In-Q-Tel, an investment firm that identifies technologies to support the mission of the U.S. intelligence community. In 2014, Biomatrica and American Type Tissue Culture (ATCC) signed a licensing agreement for Biomatrica to supply its DNA & RNA stabilization reagents to the ATCC for use in the latter company's DNA and RNA standards. In the same year, Biomatrica and Sigma-Aldrich signed an agreement for the worldwide distribution of Biomatrica's stabilization reagents.
Automated insulin delivery systems are automated (or semi-automated) systems designed to assist people with insulin-requiring diabetes, by automatically adjusting insulin delivery in response to blood glucose levels. Currently available systems (as of October 2020) can only deliver (and regulate delivery of) a single hormone—insulin. Other systems currently in development aim to improve on current systems by adding one or more additional hormones that can be delivered as needed, providing something closer to the endocrine functionality of the pancreas. The endocrine functionality of the pancreas is provided by islet cells which produce the hormones insulin and glucagon. Artificial pancreatic technology mimics the secretion of these hormones into the bloodstream in response to the body's changing blood glucose levels. Maintaining balanced blood sugar levels is crucial to the function of the brain, liver, and kidneys. Therefore, for people with diabetes, it is necessary that the levels be kept balanced when the body cannot produce insulin itself. Automated insulin delivery (AID) systems are often referred to using the term artificial pancreas, but the term has no precise, universally accepted definition. For uses other than automated insulin delivery, see Artificial pancreas (disambiguation).
=== Discontinued === AS-601811 – oral – male pattern baldness – 5α-reductase inhibitor ATI-501 (A-201; ATI-50001) – oral – alopecia areata – Janus kinase 1 inhibitor, Janus kinase 3 inhibitor Brepocitinib (PF-06700841) – oral – alopecia, alopecia areata – Janus kinase 1 inhibitor, TYK2 kinase inhibitor Cioteronel (CPC-10997; Cyoctol, X-Andron) – topical – alopecia – androgen receptor antagonist Diazoxide – topical – alopecia – potassium channel opener Denileukin diftitox (Lymphirtm, Ontak, Remitoro; LY-335348; DAB389 interleukin-2) – unknown – alopecia – protein synthesis inhibitor Epristeride (Aipuliete; ONO-9302, SKF-105657) – oral – alopecia – 5α-reductase inhibitor Etrasimod (Verespiti, Velspity; APD-334, PF-07915503) – oral – alopecia areata – sphingosine 1 phosphate receptor modulator Farudodstat (ASLAN-003, LAS-186323) – oral – alopecia areata – dihydroorotate dehydrogenase inhibitor HST-001 (HSC-660) – intradermal – alopecia – intercellular signalling peptide and protein replacement Ifidancitinib (A-301, ATI-50002, ATI-502) – topical – alopecia, alopecia areata – Janus kinase 1 inhibitor, Janus kinase 3 inhibitor MK-434 (MK-0434) – oral – alopecia – 5α-reductase inhibitor Naminidil (BMS-234303) – topical – alopecia – potassium channel opener NEOSH–101 – topical – alopecia – undefined mechanism of action P-1075 – unknown – alopecia – potassium channel opener Piliel – topical – alopecia – undefined mechanism of action Research programme: androgen receptor antagonists - Endoceutics (EM-4350, EM-6537) – unknown – male pattern baldness – androgen receptor antagonists Research programme: oligonucleotide therapeutics for alopecia - OliPass – unknown – alopecia – androgen receptor antagonists RU-58841 (PSK-3841, HMR-3841) – topical – alopecia – androgen receptor antagonist Secukinumab (Cosentyx) – injection – alopecia areata – IL17A protein inhibitor Setipiprant (ACT-129968, KYTH-105) – oral – alopecia – prostaglandin D2 receptor antagonist Timbetasin (thymosin β4) – unknown – alopecia – various mechanisms of action Tralokinumab (Adbry, Adtralza; CAT-354, LP-0162) – subcutaneous injection – alopecia areata – interleukin-13 inhibitor TU-2100 – topical – hair disorders – undefined mechanism of action Viprostol (CL-115347) – topical – alopecia – synthetic prostaglandin E2 analogue
Ketoconazole shampoo in conjunction with an oral 5α-reductase inhibitor such as finasteride or dutasteride has been used off label to treat androgenic alopecia. It was speculated that antifungal properties of ketoconazole reduce scalp microflora and consequently may reduce follicular inflammation that contributes to alopecia. Limited clinical studies suggest ketoconazole shampoo used either alone or in combination with other treatments may be useful in reducing hair loss in some cases. However, one study found that applying a 2% Topical Ketoconazole solution on the balding scalps of women found comparable regrowth to 2% Minoxidil, albeit with a longer onset of action.
Sources: en.wikipedia.org
Bush, after receiving a phone call from Boris Yeltsin, delivers a Christmas Day speech acknowledging the end of the Cold War. December 26: The Council of the Republics of the Supreme Soviet of the USSR dissolves the Soviet Union. The United States became the world's only superpower.
At the biochemical level, YAP is part of and regulated by the Hippo signaling pathway where a kinase cascade results in its “inactivation”, along with that of TAZ. In this signaling cascade, TAO kinases phosphorylate Ste20-like kinases, MST1/2, at their activation loops (Thr183 for MST1 and Thr180 for MST2). Active MST1/2 then phosphorylate SAV1 and MOB1A/B which are scaffold proteins that assist in the recruitment and phosphorylation of LATS1/2. LATS1/2 can also be phosphorylated by two groups of MAP4Ks. LATS1/2 then phosphorylate YAP and TAZ which causes them to bind with 14-3-3, resulting in cytoplasmic sequestration of YAP and TAZ. The result of the activation of this pathway is the restriction of YAP/TAZ from entering the cell nucleus. Once inside the nucleus, physical association of YAP with binding partners such as beta-catenin mediates the recruitment of SWI/SNF complexes, which in turn generate DNA accessibility needed to activate enhancers.
== Mechanism == Blockage of the cystic duct by a gallstone causes a buildup of bile in the gallbladder and increased pressure within the gallbladder. Concentrated bile, pressure, and sometimes bacterial infection irritate and damage the gallbladder wall, causing inflammation and swelling of the gallbladder. Inflammation and swelling of the gallbladder can reduce normal blood flow to areas of the gallbladder, which can lead to cell death due to inadequate oxygen.
==== Monazite identification and mapping ==== Monazite grains are identified by a backscattered electron imaging survey or/and electron microprobe analysis (EMPA) by mapping the concentration of distinctive Ce in monazite. The two images are usually superimposed to reflect sample texture and monazite locations at the same time.
Sources: en.wikipedia.org
The primary operational ration used by the Hellenic Armed Forces is the Merida Eidikon Dynameon (Special Forces' Ration, also known as a 4B-ration), a 24-hour ration pack inside a cardboard box measuring 240 mm × 140 mm × 130 mm (9.4 in × 5.5 in × 5.1 in) and weighing 1 kg (2.2 lb). Most items are commercially procured, with the main meals in round pull-ring cans. Typical contents include: a 200 g canned meat ("SPAM"); 280 g can of meat with vegetables (beef and potatoes, etc.) (termed Prepared Food With Meat or ΠΦΜΚ); a 280 g can of cooked vegetables (green peas, etc.) (Prepared Food Without Meat or ΠΦΑΚ); an 85 g can of cheese; 6 hard biscuits; 40 g honey; three 50 g packages of raisins or chocolate; 30 g sugar; 1.5 g black tea, 2 g instant coffee; 19 g instant milk powder; two small packets of salt; a multivitamin tablet; 4 water purification tablets; a pack of tissues; a disposable ration heater with 5 fuel tablets; and a box of matches. In wartime, packs of locally commandeered cigarettes may also be issued.
=== Other types === Various types are distinguished by the domain of life to which they belong. Physical well-being concerns the domain of the body, including the capacity to engage in physical activity and the absence of illness and bodily pain. It includes general health considerations and the ability to perform one's social role without being hindered by physical limitations. Psychological well-being, also called mental health, is a state of mind characterized by internal balance. It involves the absence or successful management of disorders and disturbances, together with the abilities to cope with challenging situations, maintain positive relationships, and cultivate personal growth. It is closely linked to intellectual, spiritual, and emotional well-being. Intellectual well-being encompasses well-functioning cognitive abilities and traits, such as critical thinking, problem-solving, and curiosity. Spiritual well-being is a state in which people find purpose in life and have inner peace, self-confidence, and a sense of identity. Emotional well-being involves the capacities to comprehend, articulate, and regulate emotions, together with an overall positive mood. Hedonic well-being refers to a life rich in pleasurable experiences and devoid of suffering. Eudaimonic well-being is a form of personal fulfillment in which an individual flourishes by striving for excellence and actualizing their innate potential.
Triiodothyronine, also known as T3, is a thyroid hormone. It affects almost every physiological process in the body, including growth and development, metabolism, body temperature, and heart rate. Production of T3 and its prohormone thyroxine (T4) is activated by thyroid-stimulating hormone (TSH), which is released from the anterior pituitary gland. This pathway is part of a closed-loop feedback process: Elevated concentrations of T3, and T4 in the blood plasma inhibit the production of TSH in the anterior pituitary gland. As concentrations of these hormones decrease, the anterior pituitary gland increases production of TSH, and by these processes, a feedback control system stabilizes the level of thyroid hormones in the bloodstream. At the cellular level, T3 is the body's more active and potent thyroid hormone. T3 helps deliver oxygen and energy to all of the body's cells, its effects on target tissues being roughly four times more potent than those of T4. Of the thyroid hormone that is produced, just about 20% is T3, whereas 80% is produced as T4. Roughly 85% of the circulating T3 is later formed in the liver and anterior pituitary by removal of the iodine atom from the carbon atom number five of the outer ring of T4. In any case, the concentration of T3 in the human blood plasma is about one-fortieth that of T4. The half-life of T3 is about 2.5 days. The half-life of T4 is about 6.5 days. T3 levels start to rise 45 minutes after administration and peak at about 2.5 hours.
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.
Epitalon is a synthetic four-amino-acid peptide with the sequence alanine–glutamate–aspartate–glycine, also written AEDG. It was developed in Russian gerontology research and is studied for proposed effects on telomerase, melatonin regulation, and neuroendocrine function. It is not an approved pharmaceutical in the United States or the European Union.