The short version of tetrapeptide fits in a sentence. The long version — which is the one that helps — is below.
Reviewed 2026-01-29. Anything still debated is marked as such rather than presented as settled.
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.
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 |
|---|---|---|
| Molecular formula | C14H22N4O9 | Derived from the four constituent residues |
| Molecular mass | About 390.35 Da | Monoisotopic value, confirmed by mass spectrometry |
| Residue sequence | Ala-Glu-Asp-Gly | Read from the N-terminus to the C-terminus |
| Common synonyms | Epithalon; AEDG | Both forms appear in reference catalogues |
| Net charge near neutral pH | Negative | Two acidic side chains give a low isoelectric point |
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.
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.
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.
==== General ==== Lower Saxony has clear regional divisions that manifest themselves geographically, as well as historically and culturally. In the regions that used to be independent, especially the heartlands of the former states of Brunswick, Hanover, Oldenburg and Schaumburg-Lippe, a marked local regional awareness exists. By contrast, the areas surrounding the Hanseatic cities of Bremen and Hamburg are much more oriented towards those centres.
William Field and colleagues found a 50% increased lung cancer risk even at the protracted exposures at the EPA's action level of 4 pCi/L. North American and European pooled analyses further support these findings. However, the conclusion that exposure to low levels of radon leads to elevated risk of lung cancer has been disputed, and analyses of the literature point towards elevated risk only when radon accumulates indoors and at levels above 100 Bq/m3. Thoron (220Rn) is less studied than 222Rn in regards to domestic exposure due to its shorter half-life. However, it has been measured at comparatively high concentrations in buildings with earthen architecture, such as traditional half-timbered houses and modern houses with clay wall finishes, and in regions with thorium- and monazite-rich soil and sand. Thoron is a minor contributor to the overall radiation dose received due to indoor radon exposure, and can interfere with 222Rn measurements when not taken into account.
== Tissue distribution == CRF1 is expressed widely throughout both the central and peripheral nervous systems. In the central nervous system, CRF1 is particularly found in the cortex, cerebellum, amygdala, hippocampus, olfactory bulb, ventral tegmental area, brainstem areas, paraventricular hypothalamus, and pituitary. In the pituitary, CRF1 stimulation triggers the activation of the POMC gene, which in turn causes the release of ACTH and β-endorphins from the anterior pituitary. In the peripheral nervous system, CRF1 is expressed at low levels in a wide variety of tissues, including the skin, spleen, heart, liver, adipose tissue, placenta, ovary, testis, and adrenal gland. In CRF1 knockout mice, and mice treated with a CRF1 antagonist, there is a decrease in anxious behavior and a blunted stress response, suggesting that CRF1 mechanisms are anxiogenic. However, the effect of CRF1 appears to be regionally specific and cell-type specific, likely due to the wide variety of cascades and signaling pathways activated by the binding of CRF or CRF-agonists. In mice, offspring born to CRF1 -/- knockout mothers typically die within a few days of birth from lung dysplasia, likely due to low glucocorticoid levels. In the central nervous system, CRF1 activation mediates fear learning and consolidation in the extended amygdala, stress-related modulation of memory formation in the hippocampus, and brainstem regulation of arousal.
Owen Chadwick was born in Bromley in 1916. He was awarded the Order of Merit, was Vice Chancellor of University of Cambridge, Master of Selwyn Cambridge, Regius Professor of Modern History, Dixie Professor of Ecclesiastical History, Chancellor of University of Anglia, President of the British Academy, and was a Rugby Union International. Other writers from Bromley include Captain W.E. Johns (author of the Biggles adventures), David Nobbs (author of The Fall and Rise of Reginald Perrin and writer for Les Dawson and The Two Ronnies), and Enid Blyton who wrote children's fiction. A blue historical plaque can be found on the external wall of her former home on Shortlands Road, Bromley. Other notable people who lived in Bromley include David Bowie; Jane Downs, (actress); Talbot Rothwell, (screenwriter of twenty Carry On films); actress Justine Lord; Peter Howitt; Richmal Crompton; Pixie Lott; Matt Terry; Christopher Tennant; Hanif Kureishi; Peter Frampton; Aleister Crowley; Fatboy Slim; Jack Dee; Tom Allen; D. Bernard Amos; Rob Beckett; actor Alexander Molony; Gary Rhodes; Pete Sears; singer Poly Styrene; Billy Idol; Brian Poole (of The Tremoloes); Billy Jenkins; Alex Clare; cricketer Jill Cruwys; the anarchist Peter Kropotkin; the former Clash drummer Topper Headon; illustrator Charles Keeping, children's writer Andrew Murray; tenor Roland Cunningham; actor Michael York, who attended Bromley Grammar School for Boys; and clarinetist Chris Craker. The musical conducting brothers Stephen and Nicholas Cleobury were born in Bromley, as was suffragette Marie du Sautoy Newby.
Iron-pyrite FeS2 represents the prototype compound of the crystallographic pyrite structure. The structure is cubic and was among the first crystal structures solved by X-ray diffraction. It belongs to the crystallographic space group Pa3 and is denoted by the Strukturbericht notation C2. Under thermodynamic standard conditions the lattice constant
Sources: en.wikipedia.org
== Dynamical features == Alpha-helices in proteins may have low-frequency accordion-like motion as observed by the Raman spectroscopy and analyzed via the quasi-continuum model. Helices not stabilized by tertiary interactions show dynamic behavior, which can be mainly attributed to helix fraying from the ends.
== External links == Kristin Tillotson, "Minnesota Opera co-commissions Cold Mountain, Minneapolis Star Tribune (Artcetera blog), 6 May 2014 Heidi Waleson, "Creating Cold Mountain: Student Singers Help to Shape a Major Modern Opera", Overtones (Curtis Institute of Music), Spring 2014 Cold Mountain, Opera Philadelphia page "Cold Mountain makes East Coast Premiere February 5–14, 2016, at the Academy of Music." Opera Philadelphia press release, 5 January 2016 Tom Huizenga, "Great Expectations: A New Season Of New Music". National Public Radio (Deceptive Cadence blog), 3 September 2014 "Jennifer Higdon writes an opera", The Musicalist podcast, 12 February 2014 Jim Cotter, "Jennifer Higdon on Cold Mountain". WRTI, 90.1 FM, 16 November 2012 Mark Gresham, "Jennifer Higdon completes her new opera, Cold Mountain". EarRelevant blog, 17 September 2013 Pentatone Records page on Cold Mountain Peter Dobrin, "Cold Mountain scores", The Philadelphia Inquirer, Blogs the Arts, 16 May 2016
There was a mass solanine poisoning incident in 1979 in the U.K., when 78 adolescent boys at a boarding school exhibited symptoms after eating potatoes that had been stored improperly over the summer. Seventeen of them ended up hospitalized, but they all recovered. The potatoes were determined to have between 0.25 and 0.3 mg of solanine per gram of potato. Another mass poisoning was reported in Canada in 1984, after 61 schoolchildren and teachers showed symptoms of solanine toxicity after consuming baked potatoes with 0.5 mg of solanine per gram of potato.
In May 2013 the Criminal Cases Review Commission confirmed it was re-examining the Norris case in the light of new medical and scientific evidence contradictory to that submitted to the jury during the original trial. However, in 2014, the son of victim Vera Wilby, John Barrie Wilby, said that he was "sad and upset" about the claims that Norris may be innocent, and said that he was still convinced of his guilt. In the same year there was outrage amongst elderly residents when a benefit concert was held for Norris in Dundee, with a spokesperson of the Dundee Pensioners' Forum stating: "Having a party for someone convicted of murdering all these elderly, vulnerable people is disgraceful. It's a slap in the face doing it, with all those families still grieving their loved ones". The Times declared he was one of "the 11 most evil staff in the NHS". In January 2015 the foreman of the jury that convicted Norris, after being shown the evidence in the BBC programme, said that he now believes him to be innocent; apparently the second member of the jury to do so (although this would still leave enough jury members to convict him, 10). He said that "the evidence shows a murder wasn't committed at all" (although in 2021 the CCRC concluded that Hall's case at least was indeed a clear murder).
Sources: en.wikipedia.org
=== Political === The company and its founders are major contributors, via the Outback Steakhouse PAC, to the Republican Party, contributing $303,015 and $334,197 for the 2000 and 2004 election cycles, respectively. The PAC remains active, giving $428,000 to federal candidates in the 2017–2018 cycle and raising $464,074 in the 2019–2020 cycle. Since the 2022 cycle its activity has substantially decreased. The PAC gave $93,000 to 37 federal candidates in 2022, and only $12,700 in contributions were recorded from the company in the 2024 cycle. The Outback Steakhouse PAC itself is historically one of the largest donors in the food and beverage sector, second only to the National Restaurant Association, which itself represents 300,000 restaurants.
found itself on unstable ground as their offices were raided by federal authorities on January 3, 2003 in connection with Kenneth McGriff. Thirteen days later; an unidentified gunman opened fire at the offices of Violator Management, no individuals were injured, but the attack was widely believed to be a retaliatory act attributed to the recent raid on Murder Inc.'s offices. The roles in the feud began to shift rapidly as 50 Cent would go on to release his highly anticipated major label debut Get Rich or Die Tryin' on February 6, 2003. The album was established as both a critical and commercial juggernaut as it debuted at #1 on the Billboard 200 chart and became the highest selling record of 2003, while each of the album's singles sold several million copies apiece. One key track; Back Down became the most pivotal diss track in the feud up to that point, verbally dissecting both Ja Rule and Murder Inc's ability to maintain their flawed image as 50 Cent managed significantly greater commercial success in a far shorter span of time. The legal complications involving Murder Inc. ultimately delayed and reduced Ja Rule's response. Most of his initial responses involved remixing tracks released by 50 Cent, and re recording verses attacking him thereafter. DMX later took involvement with Eminem and Obie Trice as he had an ongoing feud with Ja Rule dating back to 1999 after his failed super group with Ja Rule and Jay Z. The three rappers attacked Ja Rule on the track Go to Sleep for the Cradle 2 the Grave soundtrack on February 18, 2003.
=== Roads === The A34 road, which links Salford and Winchester, by-passes the town centre to the east; this was later extended around neighbouring Alderley Edge. It joins the A555 at Handforth Dean, which has been extended to Manchester Airport.
Sources: en.wikipedia.org
It is a four-amino-acid peptide built from alanine, glutamate, aspartate and glycine in that order. Its formula is C14H22N4O9, and it is made by chemical synthesis rather than extracted from tissue. The synthetic peptide is a single defined molecule, unlike the pineal extracts it is often compared with.
No. The two spellings refer to the same tetrapeptide, and the difference reflects transliteration from Russian. Laboratories and catalogues use both forms interchangeably. The material is also indexed as AEDG, taken from the one-letter codes of its residues.
Epithalamin is a mixed preparation derived from animal pineal tissue and contains many peptides. Epitalon is one synthetic sequence chosen for study from that broader mixture. Statements about one do not transfer directly to the other.
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.