Epitalon raises a handful of sensible questions. This page answers them in order, starting with the fundamentals and moving to applications.
Reviewed 2026-02-17. Anything still debated is marked as such rather than presented as settled.
Reference material is normally supplied as a lyophilised powder in a sealed vial. Product literature typically recommends storage at minus twenty degrees Celsius or colder, protected from light and moisture. Freeze-thaw cycling is usually avoided because repeated condensation can introduce water into the vial. Working solutions are commonly prepared fresh, aliquoted, and kept cold for short periods rather than stored at ambient temperature. Labelling the date of opening helps track how long a vial has been in use.
Solubility is high in water, phosphate-buffered saline and normal saline, a pattern that follows from the two acidic residues in the chain. The peptide dissolves poorly in non-polar solvents such as hexane or chloroform. Stock solutions are often prepared in water first and then diluted into the buffer of interest. Because the molecule is small and hydrophilic, filtration through a low-protein-binding membrane is usually straightforward, and visible particulates are uncommon in freshly made solutions.
Identity and purity are established with reversed-phase high-performance liquid chromatography and mass spectrometry. The chromatogram shows the main peak and any truncated or oxidised by-products, while the mass spectrum confirms the expected 390 dalton mass. Amino acid analysis can corroborate composition when a sample's origin is uncertain. Counterion content, particularly residual trifluoroacetate from purification, is frequently reported alongside purity because it shifts the net mass of the solid.
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.
| Property | Value | Notes |
|---|---|---|
| Appearance | White to off-white powder | Lyophilised and often hygroscopic |
| Solubility class | Freely soluble in water | Poor solubility in non-polar solvents |
| Typical storage temperature | -20 degrees Celsius or colder | Sealed, desiccated, protected from light |
| Typical analytical method | Reversed-phase HPLC with mass spectrometry | Establishes purity and confirms mass |
| Common salt form | Trifluoroacetate or acetate | Counterion reported alongside purity values |
Stability depends strongly on pH, temperature and the presence of oxygen and trace metals. Cleavage of the backbone proceeds faster under neutral to alkaline conditions, whereas acidic solutions tend to slow that reaction. The aspartate and glutamate side chains can undergo deamidation or imide formation over time, generating closely related impurities. Published stability data specific to epitalon are sparse, so the usable life of a given solution is best regarded as an open question that depends on buffer composition, concentration and storage temperature.
Identity and purity are usually assessed by reversed-phase high-performance liquid chromatography with ultraviolet detection, frequently near 214 nanometers where the peptide bond absorbs. Mass spectrometry, most often with electrospray ionization, confirms the observed molecular mass and helps separate the intact peptide from truncated or modified forms. Amino acid analysis or tandem mass spectrometry can establish residue order. Purity is commonly quoted as an area percentage, yet such values are method-dependent, and comparisons between laboratories require matching column, gradient and detection wavelength.
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.
（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.
The most frequently cited laboratory finding is that AEDG increased telomerase activity and extended telomere length in cultured human somatic cells. That work used fetal fibroblast strains and reported changes in enzyme activity alongside altered division counts. Replication by unrelated groups has been limited, and the published record is largely a single-laboratory series rather than a multi-centre programme. The result supports a hypothesis about peptide influence on gene expression in cell culture; it does not by itself establish an effect on telomere length in living animals or in people.
Animal and clinical reports appear mainly in Russian-language journals from the 1990s and 2000s, covering endpoints such as melatonin rhythm, lifespan in aged rodents, and retinal function. Many of these papers involve small groups, lack blinding or placebo comparison, and are difficult to retrieve through indexed databases. Review articles published in English generally summarise the claims without reanalysing the underlying data. Because no large randomised trial exists, the clinical importance of these reported effects stays unresolved and is properly described as an open question.
No national medicines regulator has approved epitalon as a therapeutic product. It is generally distributed as a research chemical, and in some jurisdictions selling peptides for human consumption without approval is restricted or prohibited. Certificates of analysis accompanying commercial material vary in which tests are performed, and independent verification of identity and purity is uncommon. Statements about anti-ageing or disease-prevention benefits on vendor pages are marketing claims rather than regulatory findings, a distinction that shapes how the compound is discussed in scientific and popular sources alike.
=== Mechanism of action === Transamination catalyzed by aminotransferase occurs in two stages. In the first step, the α amino group of an amino acid is transferred to the enzyme, producing the corresponding α-keto acid and the aminated enzyme. During the second stage, the amino group is transferred to the keto acid acceptor, forming the amino acid product while regenerating the enzyme. The chirality of an amino acid is determined during transamination. For the reaction to complete, aminotransferases require participation of aldehyde containing coenzyme, pyridoxal-5'-phosphate (PLP), a derivative of Pyridoxine (Vitamin B6). The amino group is accommodated by conversion of this coenzyme to pyridoxamine-5'-phosphate (PMP). PLP is covalently attached to the enzyme via a Schiff Base linkage formed by the condensation of its aldehyde group with the ε-amino group of an enzymatic Lys residue. The Schiff base, which is conjugated to the enzyme's pyridinium ring, is the focus of the coenzyme activity.
The regulation of genetic engineering concerns approaches taken by governments to assess and manage the risks associated with the use of genetic engineering technology, and the development and release of genetically modified organisms (GMO), including genetically modified crops and genetically modified fish. There are differences in the regulation of GMOs between countries, with some of the most marked differences occurring between the US and Europe. Regulation varies in a given country depending on the intended use of the products of the genetic engineering. For example, a crop not intended for food use is generally not reviewed by authorities responsible for food safety. The European Union differentiates between approval for cultivation within the EU and approval for import and processing. While only a few GMOs have been approved for cultivation in the EU a number of GMOs have been approved for import and processing. The cultivation of GMOs has triggered a debate about the coexistence of GM and non-GM crops. Depending on the coexistence regulations, incentives for the cultivation of GM crops differ.
== Function == Enteroglucagon is a proglucagon-derived peptide or enteroendocrine cells derived peptide in the small intestine. Preproglucagon undergoes post translational modification to release glucagon-like peptides (GLP-1 and GLP-2) and other molecules derived from L-cells of intestine. GLP-1 is derived from a class of intestinal hormones called incretin and the molecule exists in two forms GLP-1(7-37) and GLP-1(7-36) amide. GLP-1 form of incretin starts circulating in response to a high blood glucose level. Incretin effect is a negative feedback loop between glucose and insulin level, it promotes insulin release from beta cells of pancreas islet and suppresses glucagon when the glucose level is high. In vertebrate mammals, GLP-2 sequences are highly conversed in the intestine. The molecule functions as a part of adaptive response, such that contributes intestinal growth, proliferation effect, intestinal dilation (increases the mucosal blood flow) and reduces the chance of apoptosis.
Sources: en.wikipedia.org
== History == Bovine pancreatic ribonuclease became a common model system in the study of proteins largely because it was extremely stable and could be purified in large quantities. In the 1940s Armour and Company purified a kilogram of protein - a very large quantity, particularly by the protein purification standards of the time - and offered samples at low cost to interested scientists. The ability to have a single lot of purified enzyme made it a predominant model system for protein studies. It remains commonly referred to as ribonuclease A or RNase A as the most prominent member of its protein family, known variously as pancreatic ribonuclease, ribonuclease A, or ribonuclease I. Christian Anfinsen's studies of the oxidative folding process of bovine pancreatic ribonuclease laid the groundwork for understanding the relationship between amino acid sequence and a protein's folded three-dimensional structure and solidified the thermodynamic hypothesis of protein folding, according to which the folded form of a protein represents its free energy minimum. RNase A was the first enzyme for which a correct catalytic mechanism was proposed, even before its structure was known. RNase A was the first protein for showing the effects of non-native isomers of peptide bonds preceding proline residues in protein folding.
== Applications == Capillary electrophoresis may be used for the simultaneous determination of the ions NH4+,, Na+, K+, Mg2+ and Ca2+ in saliva. One of the main applications of CE in forensic science is the development of methods for amplification and detection of DNA fragments using polymerase chain reaction (PCR), which has led to rapid and dramatic advances in forensic DNA analysis. DNA separations are carried out using thin CE 50-mm fused silica capillaries filled with a sieving buffer. These capillaries have excellent capabilities to dissipate heat, permitting much higher electric field strengths to be used than slab gel electrophoresis. Therefore, separations in capillaries are rapid and efficient. Additionally, the capillaries can be easily refilled and changed for efficient and automated injections. Detection occurs via fluorescence through a window etched in the capillary. Both single-capillary and capillary-array instruments are available with array systems capable of running 16 or more samples simultaneously for increased throughput. A major use of CE by forensic biologists is typing of STR from biological samples to generate a profile from highly polymorphic genetic markers which differ between individuals. Other emerging uses for CE include the detection of specific mRNA fragments to help identify the biological fluid or tissue origin of a forensic sample.
== Clinical significance == In vascular smooth muscle cell (VSMC), ADAMTS7 mediates VSMC migration, which plays an essential role during the development of atherosclerosis and restenosis. This proatherogenic effect has been demonstrated to specifically require the catalytic protease activity of ADAMTS7, as mice expressing a catalytically inactive mutant of the enzyme (E373Q) are similarly protected against atherosclerosis. Adamts7 deficiency in both the Ldlr−/– and Apoe−/– hyperlipidemic mouse models markedly attenuates formation of atherosclerotic lesions; furthermore, wire-injury experiments in the Adamts7−/– mouse show reduced neointima formation. The association of ADAMTS7 with atherosclerosis suggests that inhibition of ADAMTS7 should be atheroprotective in humans. A negative correlation between the expression levels of specific miRNAs and ADAMTS7 is observed in normal tissues but not in disease tissues, implying an altered miRNA-target interaction in the disease state. Accordingly, expression profiles of these miRNAs and ADAMTS7 may be useful diagnostic tools to differentiate cancer and lichen planus from normal tissues. ADAMTS7 has also been identified as a putative oncogene and reported to be mutated exclusively in Asians, which may have implications for the prevention and treatment of hepatocellular carcinoma. In addition, ADAMTS7 plays a crucial role in the pathogenesis of arthritis. For example, the FGF2/p65/miR-105/Runx2/ADAMTS axis is reportedly involved in osteoarthritis (OA) pathogenesis.
=== Academic career === William H. Stein began his higher education as a chemistry major at Harvard University in 1929. He spent one year as a graduate student at Harvard University before transferring to the Department of Biological Chemistry at the College of Physicians and Surgeons, Columbia University, in 1934 to focus on biochemistry. Hans Thatcher Clarke, the chairman of the department at the time, was collecting many talented graduate students who would become the distinguished biochemists of the early twentieth century. In 1937, Stein completed his thesis on the amino acid composition of elastin, earning his Ph.D. Stein was introduced to potassium trioxalatochromate and ammonium rhodanilate by Max Bergmann, a Jewish-German biochemist who fled to the United States in 1934 under threat of Nazi occupation and worked in a laboratory at the Rockefeller Institute. He used these two precipitating agents to isolate the amino acids glycine and proline, respectively, for his research on elastin. With the conclusion of his academic career, Stein went on to work under Bergmann.
Sources: en.wikipedia.org
Sealed lyophilised powder is normally kept at minus twenty degrees Celsius or below, away from light and moisture. Vials are allowed to reach room temperature before opening to limit condensation. Repeated warming and cooling of the same vial is discouraged.
Reversed-phase HPLC establishes purity and separation from related peptides, and mass spectrometry confirms the molecular mass. Amino acid analysis can verify residue composition. No single method proves identity on its own, so the results are read together.
Yes. Residual trifluoroacetate or acetate from purification adds mass and can shift the value obtained by certain assays. Purity figures are therefore meaningful only when the counterion form is stated. Reporting both peptide content and salt form gives a clearer picture.
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.