If you have been reading about AEDG and want a single page that covers the useful parts, this is it: definitions, context, how it is studied, and the questions that come up repeatedly.
Last reviewed on 2026-08-01. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
Reversed-phase high-performance liquid chromatography is the standard approach for assessing purity, usually with ultraviolet detection near 214 nm, where the peptide bond absorbs. Mass spectrometry, most often with electrospray ionization, confirms the molecular mass and helps reveal truncation or deletion byproducts. Amino acid analysis can verify composition, and counterion content is sometimes measured because peptides purified with trifluoroacetic acid retain variable amounts of that salt. Purity figures reported without a stated method and detection wavelength are difficult to interpret.
Material sold for research use varies widely in documented quality. A useful verification package includes a certificate of analysis that states peptide content rather than only net weight, the chromatographic method and column used, and a mass spectrum consistent with the expected mass. Independent testing by a third-party laboratory is occasionally reported. Statements of identity resting only on a supplier label provide little assurance, and the gap between nominal mass and actual peptide content can be substantial once counterions and residual water are counted.
| 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 |
Chemically, the molecule consists of four amino acid residues joined by three peptide bonds, with a free N-terminal amino group and a free C-terminal carboxyl group. Its molecular formula is C14H22N4O9, and its monoisotopic mass is approximately 390 daltons. The acidic glutamate and aspartate side chains give the peptide a net negative charge near neutral pH, a property that shapes its chromatographic behaviour and solubility profile. No disulfide bridges or other post-translational modifications are present, so the primary sequence alone defines the structure.
Most experimental work has been carried out in cell culture and animal models. Several reports describe changes in telomerase activity and proliferation in cultured cells, while rodent studies have examined lifespan, melatonin rhythm and reproductive endpoints. Human data remain limited, and much of the published clinical material consists of small trials with incomplete reporting of methods and controls. Whether the cell and animal findings translate into measurable effects in people is an open question, and the mechanistic basis of the reported telomerase changes is not fully established.
Discussions in the literature often conflate three distinct entities: the pineal extract epithalamin, the isolated tetrapeptide AEDG, and commercial preparations sold under similar names. Reviews citing older Russian-language studies sometimes omit detail on purity, route of administration and control groups, which makes cross-study comparison difficult. Researchers working with the compound generally note the need for independent replication, standardized enzyme assays, and clearer reporting of peptide identity. These caveats are relevant when weighing claims that appear in secondary sources rather than in primary reports.
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.
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.
=== 22 March === The SAF retook the Corinthia Hotel and the headquarters of the Central Bank of Sudan and the General Intelligence Service in Khartoum from the RSF. It also retook Tuti Island, situated at the confluence of the Blue Nile and the White Nile, after advancing through the Tuti Bridge. Forty-eight people were killed in ethnically motivated attacks by the RSF in Al-Malha.
The NO can then contribute to two suggested pathways. Under typical conditions, nitric oxide (NO) interacts non-covalently with the heme and copper (Cu) subunits of CCO, competing with oxygen molecules and inhibiting cellular respiration, leading to reduced production of adenosine triphosphate (ATP). Low energy light can revise the mitochondrial inhibition of cellular respiration by photodissociating of NO from CCO, and thereby increasing ATP synthesis. The second pathway proposes that released nitric oxide (NO) will boost Cytochrome c Oxidase (CCO) activity, as an enzyme nitrite reductase. This mechanism includes the transfer of electrons to oxygen molecules, resulting in the production of water and reactive oxygen species (ROS). The ROS then activates enzymes necessary for producing vital cellular components like nucleic acids and proteins. LED therapy may also increase ROS, which may activate transcription factors that manage genes important for cell growth, cytokine production, and making growth factors for cell repair and proliferation.
It was thought appropriate to choose a name to dissociate nicotinic acid from nicotine, to avoid the perception that vitamins or niacin-rich food contains nicotine, or that cigarettes contain vitamins. The resulting name niacin was derived from nicotinic acid + vitamin. Carpenter found in 1951, that niacin in corn is biologically unavailable, and can be released only in very alkaline lime water of pH 11. This explains why a Latin-American culture that used alkali-treated cornmeal to make tortilla was not at risk for niacin deficiency. The modern explanation is that alkali treatment enhances the bioavailability of tryptophan, not directly for any form of the vitamin. In 1955, Altschul and colleagues described large amounts of nicotinic acid as having a lipid-lowering property. As such, niacin is the oldest known lipid-lowering drug. Lovastatin, the first 'statin' drug, was first marketed in 1987.
In the 2021–22 season Freiburg reached the final of the DFB-Pokal for the first time. In the league Freiburg finished sixth to qualify to the next season's Europa League, where they reached the round of 16. In the following season, they finished fifth in the league to achieve another direct qualification to the Europa League group stage, despite being in the Champions League spots most of the season; however, two consecutive losses against rivals RB Leipzig and Union Berlin had them drop down in the league table with two games remaining. In the DFB-Pokal of the same season, defeated Bayern Munich 2–1 in the quarter-finals, in an away match for the first time in their history, before losing in the semi-finals at home 1–5 to RB Leipzig.
== Description == Buckwheat is a herbaceous annual flowering plant growing to about 60 centimetres (24 in), with red stems and pink and white flowers resembling those of knotweeds. The leaves are arrow-shaped and the fruits are achenes about 5–7 mm with 3 prominent sharp angles. Fagopyrum esculentum is native to south-central China and Tibet, and has been introduced into suitable climates across Eurasia, Africa and the Americas.
Sources: en.wikipedia.org
The therapeutic uses of puffer fish (tetraodon) eggs were mentioned in the first Chinese pharmacopoeia Pen-T'so Ching (The Book of Herbs, allegedly 2838–2698 BC by Shennong; but a later date is more likely), where they were classified as having "medium" toxicity, but could have a tonic effect when used at the correct dose. The principal use was "to arrest convulsive diseases". In the Pen-T'so Kang Mu (Index Herbacea or The Great Herbal by Li Shih-Chen, 1596) some types of the fish Ho-Tun (the current Chinese name for tetraodon) were also recognized as both toxic yet, at the right dose, useful as part of a tonic. Increased toxicity in Ho-Tun was noted in fish caught at sea (rather than river) after the month of March. It was recognized that the most poisonous parts were the liver and eggs, but that toxicity could be reduced by soaking the eggs. (Tetrodotoxin is slightly water-soluble, and soluble at 1 mg/ml in slightly acidic solutions.) The German physician Engelbert Kaempfer, in his "A History of Japan" (translated and published in English in 1727), described how well known the toxic effects of the fish were, to the extent that it would be used for suicide and that the Emperor specifically decreed that soldiers were not permitted to eat it. There is also evidence from other sources that knowledge of such toxicity was widespread throughout southeast Asia and India. The first recorded cases of TTX poisoning affecting Westerners are from the logs of Captain James Cook from 7 September 1774. The crew received a fish from the New Caledonia natives.
The A form occurs under non-physiological conditions in partly dehydrated samples of DNA, while in the cell it may be produced in hybrid pairings of DNA and RNA strands, and in enzyme-DNA complexes. Segments of DNA where the bases have been chemically modified by methylation may undergo a larger change in conformation and adopt the Z form. Here, the strands turn about the helical axis in a left-handed spiral, the opposite of the more common B form. These unusual structures can be recognized by specific Z-DNA binding proteins and may be involved in the regulation of transcription.
Potash is primarily a mixture of potassium salts because plants have little or no sodium content, and the rest of a plant's major mineral content consists of calcium salts of relatively low solubility in water. While potash has been used since ancient times, its composition was not understood. Georg Ernst Stahl obtained experimental evidence that led him to suggest the fundamental difference of sodium and potassium salts in 1702, and Henri Louis Duhamel du Monceau was able to prove this difference in 1736. The exact chemical composition of potassium and sodium compounds, and the status as chemical element of potassium and sodium, was not known then, and thus Antoine Lavoisier did not include the alkali in his list of chemical elements in 1789. For a long time the only significant applications for potash were the production of glass, bleach, soap and gunpowder as potassium nitrate. Potassium soaps from animal fats and vegetable oils were especially prized because they tend to be more water-soluble and of softer texture, and are therefore known as soft soaps. The discovery by Justus Liebig in 1840 that potassium is a necessary element for plants and that most types of soil lack potassium caused a steep rise in demand for potassium salts. Wood-ash from fir trees was initially used as a potassium salt source for fertilizer, but, with the discovery in 1868 of mineral deposits containing potassium chloride near Staßfurt, Germany, the production of potassium-containing fertilizers began at an industrial scale.
Villhauer at Novartis started to explore N-substituted glycinyl-cyanopyrrolidines based on the fact that DPP-4 identifies N-methylglycine as an N-terminal amino acid. This group of new cyanopyrrolidines became extremely popular field of research in the following years. Some trials with dual inhibitors of DPP-4 and vasopeptidase have been represented, since vasopeptidase inhibition is believed to enhance the antidiabetic effect of DPP-4 inhibition by stimulating insulin secretion. Vasopeptidase-inhibiting motif is connected to the DPP-4 inhibitor at the N-substituent.
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 powder is normally kept at −20 °C or below in a sealed, moisture-protected container. Letting the vial reach room temperature before opening helps prevent condensation on the contents.