Tetrapeptide raises a handful of sensible questions. This page answers them in order, starting with the fundamentals and moving to applications.
Reviewed 2026-07-06. Anything still debated is marked as such rather than presented as settled.
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.
Epitalon is a synthetic tetrapeptide with the sequence alanine–glutamate–aspartate–glycine, commonly abbreviated AEDG. Its design traces to epithalamin, a peptide fraction prepared from bovine pineal gland extracts that researchers in Saint Petersburg began investigating in the 1970s. The compound has a molecular formula of C14H22N4O9 and a nominal molecular mass near 390 daltons. It holds no approved drug status in the United States or the European Union, and material sold under this name is generally offered as a research chemical rather than a finished pharmaceutical product.
Proposed mechanisms centre on cell-culture observations rather than a defined receptor interaction. Several reports describe increased expression of the telomerase catalytic subunit after exposure of cultured human cells, and the authors attributed the effect to short peptide fragments entering the nucleus and influencing gene transcription. No receptor for the tetrapeptide has been identified, and the free peptide is expected to be degraded rapidly by plasma peptidases. Whether any measurable fraction reaches intact tissues after administration remains an unresolved question rather than an established finding.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C14H22N4O9 | Free acid form of the tetrapeptide |
| Molecular mass | About 390.35 Da | Calculated monoisotopic value |
| Appearance | White to off-white powder | Typical lyophilized presentation |
| Solubility | Soluble in water | Also dissolves in buffered saline |
| Storage temperature | Minus 20 degrees Celsius | Dry, dark conditions; avoid repeated thawing |
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.
RF(Arg-Phe)amide family 26 amino acid peptide, also known as P518, is a human protein. The 26-amino acid RF-amide peptide, P518 functions as a high-affinity ligand of GPR103. Both GPR103 and P518 precursor mRNA exhibited highest expression in brain. The 43-amino acid QRFP peptide, a longer form of the P518 peptide is necessary to exhibit full agonistic activity with GPR103. Intravenous administration QRFP caused release of aldosterone, suggesting that QRFP and GPR103 regulate adrenal function.
Chloroformates are a class of organic compounds with the formula ROC(O)Cl. They are formally esters of chloroformic acid. Most are colorless, volatile liquids that degrade in moist air. Important chloroformate esters include 4-nitrophenyl chloroformate, fluorenylmethyloxycarbonylchloride, benzyl chloroformate and ethyl chloroformate. A simple example is methyl chloroformate, which is also commercially available. Chloroformates are used as reagents in organic chemistry. For example, benzyl chloroformate is used to introduce the Cbz (carboxybenzyl) protecting group and fluorenylmethyloxycarbonyl chloride is used to introduce the FMOC protecting group. Chloroformates are popular in the field of chromatography as derivatization agents. They convert polar compounds into less polar more volatile derivatives. In this way, chloroformates enable relatively simple transformation of large array of metabolites (aminoacids, amines, carboxylic acids, phenols) for analysis by gas chromatography / mass spectrometry.
Young Atlantic cod or haddock prepared in strips for cooking is called scrod. In the United Kingdom, Atlantic cod is one of the most common ingredients in fish and chips, along with haddock and plaice. The cod's soft liver can be tinned (canned) and eaten.
Sources: en.wikipedia.org
In the development of gliflozins, the distal ring contains a thiophene ring instead of an aromatic ring. However, the final chemical structures of the marketed gliflozins do not contain this thiophene ring.
Throughout its history, the Hydropower corps has been involved in the construction of over 50 hydropower projects, including the Three Gorges Dam, Wan'an Dam and Longtan Dam, along with providing aid and rescue to many disasters, such as the 2014 Ludian earthquake and 2015 Shenzhen landslide. The Hydropower corps was deployed for search and rescue after the 2013 Qingdao oil pipeline explosion. After the 2014 Ludian earthquake, the 1st Hydropower Corps deployed 263 personnel to conduct an emergency demolition operation of Changhai Dam, which after the earthquake had huge risk of a dam failure. The Hydropower corps was officially disbanded on 30 August 2018, and was handed over to the China Anneng Construction Group in April 2019.
==== Abnormal tongue motion ==== Abnormal tongue motion of infants is commonly caused by nipple confusion. When infants are given a rubber nipple and pacifier, they may sip at the maternal nipple as if it was a rubber nipple. The tongue movements used in breastfeeding and bottle-feeding are different: infants use a wave-like motion to remove breast milk in breastfeeding and thrusting action against the latex nipple to control milk flow in bottle-feeding. If the infant pinches and presses the nipple with the gums repeatedly, it creates a large friction and results in nipple soreness and bruising.
Sources: en.wikipedia.org
Epitalon is a synthetic tetrapeptide built from four amino acids: alanine, glutamate, aspartate, and glycine. It is not extracted from a natural source but made in the laboratory by chemical synthesis. Its short length makes it relatively straightforward to produce at high purity.
No naturally occurring free form of the peptide has been described. The four-amino-acid sequence can appear as a fragment within larger proteins, but that is not the same as the intact compound being present as a circulating molecule. Materials used in research are synthetic.
Purity is usually checked by reverse-phase high-performance liquid chromatography, which separates the target peptide from related impurities. Mass spectrometry is commonly used alongside it to confirm molecular mass. Some suppliers also provide amino acid analysis for additional sequence confirmation.
No. Epithalamin is a heterogeneous peptide fraction obtained from pineal gland extract and contains many components. Epitalon is a single synthetic tetrapeptide with the sequence Ala-Glu-Asp-Gly. Researchers synthesised the shorter peptide while attempting to identify active sequences within the extract.