A practical reference on tetrapeptide: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
This page was last updated on 2026-03-31 and is reviewed periodically as new material appears.
（TG:@pojiaai）Epitalon is a synthetic linear tetrapeptide with the sequence alanine-glutamate-aspartate-glycine, abbreviated AEDG. It emerged from work on epithalamin, a peptide fraction prepared from bovine pineal tissue, and was designed as a short, chemically defined analogue of that extract. Early publications came mainly from Russian laboratories studying pineal peptides and aging-related endpoints. The compound appears in the literature under several spellings, including epithalon and epithalone, which complicates systematic searching. Its small size makes solid-phase assembly and routine analytical characterization straightforward.
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.
Epitalon is a synthetic linear tetrapeptide with the sequence alanine–glutamate–aspartate–glycine, abbreviated AEDG. Its molecular formula is C14H22N4O9 and the calculated mass is approximately 390.35 g/mol. The compound is made by solid-phase peptide synthesis rather than extracted from tissue, although early work described it as a short fragment of a peptide fraction obtained from bovine pineal extract. In the research literature the spelling epitalon and the variant epithalone both appear, while AEDG is the standard code used in peptide nomenclature.
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.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Linear tetrapeptide | Four residues joined by three peptide bonds |
| Sequence | Ala-Glu-Asp-Gly | Commonly abbreviated AEDG |
| Molecular formula | C14H22N4O9 | Free acid form |
| Monoisotopic mass | Approximately 390 Da | Matches values reported from mass spectrometry |
| Net charge near neutral pH | Negative | Contributed by glutamate and aspartate side chains |
Epitalon is the common name for a synthetic tetrapeptide with the sequence alanine-glutamate-aspartate-glycine, usually abbreviated AEDG. All four residues are proteinogenic amino acids, and the free peptide has a calculated mass near 390 grams per mole. Because the chain is short and carries no modifications, it is assembled readily by solid-phase synthesis and is distributed mainly as a freeze-dried solid for laboratory work. Catalogue listings use the spellings epitalon, epithalone, and simply AEDG, and the three refer to the same sequence.
The compound is generally presented as a synthetic fragment of epithalamin, a pineal gland extract investigated in the former Soviet Union from the 1970s onward. Vladimir Khavinson and colleagues in Saint Petersburg developed short peptides modelled on such extracts, and epitalon became the most widely cited of those sequences. Most primary reports appeared in Russian-language journals or in proceedings with limited international circulation. Independent replication in laboratories outside that network remains sparse, and much repeated secondary material traces back to a small number of originating groups.
Epitalon is a synthetic tetrapeptide with the sequence alanine-glutamate-aspartate-glycine, abbreviated AEDG. Its molecular formula is C14H22N4O9 and its calculated monoisotopic mass is approximately 390.35 daltons. The compound does not occur naturally as a free peptide; it is produced by solid-phase peptide synthesis. Because it contains two acidic residues and no basic residues, the neutral form carries a net negative charge at physiological pH. This charge profile influences how the peptide behaves in solution and during chromatographic analysis.
Laboratory-grade epitalon is typically supplied as a lyophilized powder. Purity is commonly assessed with reverse-phase high-performance liquid chromatography, often paired with mass spectrometry to confirm molecular identity. Amino acid analysis and peptide mapping can provide additional confirmation of sequence. Certificates of analysis for research materials frequently report purity above 95 percent, although the methods behind such figures vary between suppliers. The absence of a pharmacopeial monograph means that no single standardized assay defines the compound, so reported results depend on the analytical protocol chosen.
== Medical uses == It has been proven to be effective in various inflammatory skin diseases, e.g., seborrheic dermatitis, cutaneous lupus erythematosus, oral lichen planus, vitiligo, and psoriasis. Tacrolimus and pimecrolimus are both calcineurin inhibitors and function as immunosuppressants.
During the summer of 1936, experiments were carried out at RAF Biggin Hill to examine what effect the presence of radar would have on an air battle. Assuming RDF would provide them 15 minutes' warning, they developed interception techniques putting fighters in front of the bombers with increasing efficiency. They found the main problems were finding their own aircraft's location, and ensuring the fighters were at the right altitude. In a similar test against the operational radar at Bawdsey in 1937, the results were comical. As Dowding watched the ground controllers scramble to direct their fighters, he could hear the bombers passing overhead. He identified the problem not as a technological one, but in the reporting. The pilots were being sent too many reports, often contradictory. This realization led to the development of the Dowding system, an extensive network of telephone lines reporting to a central "filter room" in London where the reports from the radar stations were collected and collated, and fed back to the pilots in a clear format. The system as a whole was enormously manpower intensive. By the outbreak of war in September 1939, there were 21 operational Chain Home stations. After the Battle of France in 1940 the network was expanded to cover the west coast and Northern Ireland. The Chain continued to be expanded throughout the war, and by 1940 it stretched from Orkney in the north to Weymouth in the south. This provided radar coverage for the entire Europe-facing side of the British Isles, able to detect high-flying targets well over France.
He is a co-founder and board member of the Institute for the Study of Panspermia and Astroeconomics, set up in Japan in 2014, and the Editor-in-Chief of the Journal of Astrobiology & Outreach. He was a Visiting By-Fellow, Churchill College, Cambridge, England 2015/16; Professor and Director of the Buckingham Centre for Astrobiology at the University of Buckingham, a post he has held since 2011; Affiliated Visiting Professor, University of Peradeniya, Sri Lanka; and a board member and research director at the Institute for the Study of Panspermia and Astroeconomics, Ogaki-City, Gifu, Japan. In 2017, Wickramasinghe was appointed adjunct professor in the Department of Physics, at the University of Ruhuna, Matara, Sri Lanka.
Sources: en.wikipedia.org
=== Gaming Control Board === While secretary of revenue, Kennedy was also appointed to the Louisiana Gaming Control Board, which is responsible for regulating legalized gambling. He criticized riverboat casino operators for failing to enforce the 21-year age restriction.
=== Prenatal diagnostic testing === The preferred prenatal diagnostic method is molecular analysis which requires a mutational analysis to measure BCKAD (branched-chain alpha-keto acid dehydrogenase) enzyme activity in chorion villus cells or amniocytes. Another measurement method is BCAA (branched-chain amino acid) concentration in amniotic fluids.
Venous insufficiency is the most common disorder of the venous system, and is usually manifested as either spider veins or varicose veins. Several treatments are available including endovenous thermal ablation (using radiofrequency or laser energy), vein stripping, ambulatory phlebectomy, foam sclerotherapy, laser, or compression. Postphlebitic syndrome is venous insufficiency that develops following deep vein thrombosis.
Sources: en.wikipedia.org
It is a synthetic tetrapeptide with the sequence alanine-glutamate-aspartate-glycine, often abbreviated AEDG. The molecule is linear and contains no modified residues, so it is fully described by its sequence.
The compound came out of work on epithalamin, a peptide preparation derived from pineal tissue, conducted largely in Russian laboratories. Later studies in other countries examined it mainly in cell cultures and animal models.
The tetrapeptide sequence is a synthetic construct rather than a described circulating peptide. It was derived by analogy to peptide fractions obtained from tissue extracts, not isolated from blood or tissue as such.
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.