AEDG comes up often in conversation and rarely with the context attached. Here we lay out the basics in order, then work through the practical considerations.
Updated 2025-09-03. Numbers and descriptions here follow the published literature rather than marketing material.
Because epitalon has no pharmacopoeial monograph, quality assessment depends on supplier documentation and independent testing. Certificates of analysis typically report a purity figure from a single chromatographic run, a measured mass and sometimes an appearance description, but methods and acceptance criteria are not harmonised across vendors. Third-party laboratories can repeat identity and purity measurements, and mismatches between labelled and measured peptide content have been described for research peptides generally. What constitutes adequate identity confirmation for a molecule of this size stays an open question, since mass agreement alone does not separate closely related sequences.
Identity testing for epitalon relies on reversed-phase high-performance liquid chromatography for purity and mass spectrometry for mass confirmation. Because the sequence contains no tryptophan or tyrosine, ultraviolet detection at 280 nanometres is insensitive, so chromatographic methods usually monitor absorbance near 214 nanometres, where the peptide backbone absorbs. Electrospray ionisation or matrix-assisted laser desorption/ionisation then checks the intact mass against the expected value near 390 daltons. Peptide mapping or amino acid analysis after acid hydrolysis can supplement these measurements, although such confirmatory work is seldom reported on commercial certificates of analysis.
Stability of the tetrapeptide follows ordinary peptide chemistry rather than any unusual structural feature. The aspartate-glycine pair is prone to aspartimide formation under mildly basic or neutral conditions, and deamidation can follow, altering both mass and chromatographic retention. Dry lyophilised powder kept at or below minus twenty degrees Celsius is the usual handling recommendation, with repeated freeze-thaw cycles avoided. Once dissolved in neutral aqueous buffer, degradation proceeds over days to weeks depending on pH and temperature, while acidic conditions generally slow the aspartimide route. A formal stability-indicating study has not been published in the indexed literature.
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.
| Property | Value | Notes |
|---|---|---|
| Analytical method | Reversed-phase HPLC | Purity determination, typically 214 nm |
| Mass confirmation | ESI or MALDI mass spectrometry | Compared with mass near 390 Da |
| Common synonyms | Epitalon, epithalon, AEDG | Naming differs between suppliers |
| Storage temperature | −20 °C or lower | Lyophilised powder, kept desiccated |
| Solution stability | Limited in neutral aqueous buffer | Aspartimide and hydrolysis pathways |
Regulatory treatment differs by country. No formulation of epitalon holds a marketing authorisation as a medicine in the United States or the European Union, where material sold for laboratory use is handled as a research chemical and is not intended for human consumption. In Russia, several short peptide preparations from the same institute's peptide series are registered medicinal products, and epitalon appears in that national context. Elsewhere it is frequently offered as a cosmetic ingredient, a category with lighter requirements. Advertising claims about longevity or disease prevention are restricted in most jurisdictions, which limits how sellers describe the compound.
Freeze-dried epitalon is normally kept at minus twenty degrees Celsius in a sealed, desiccated container, protected from light. Short excursions at ambient temperature during shipping are generally tolerated, but repeated warming and cooling cycles encourage moisture uptake, which shortens shelf life. Once dissolved, the peptide is far less stable than the solid: aqueous solutions are subject to hydrolysis and to deamidation at the aspartate and glutamate residues. Working solutions are therefore held refrigerated and used within days, and repeated freezing and thawing of the same vial is best avoided.
Identity and purity are checked by reversed-phase high-performance liquid chromatography, usually with ultraviolet detection near 214 nanometres, where the peptide bond absorbs. Mass spectrometry confirms the expected mass and reveals whether truncation products or adducts are present. Acid hydrolysis followed by amino acid analysis gives the residue ratio, which should approximate one alanine, one glutamate, one aspartate and one glycine. Counter-ions such as acetate or trifluoroacetate remain in the dried product and lower net peptide content, so a stated purity figure on a label does not by itself describe how much peptide a vial holds.
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.
== Biodesulfurization implementation and pathways == It has been observed that there are sulfur-dependent bacteria that make use of the sulfur in sulfur-containing compounds in their life cycles (either in their growth or metabolic processes), producing molecules with lower/no content in sulfur. In particular, heteroaromatic compounds, namely thiophenes and their derivatives, were observed to constitute important substrates for bacteria. Biodesulfurization is an attractive alternative to sulfur removal, particularly in the crude oil fractions where there is an abundance of sulfur heterocycles. To date, pilot attempts for industrial applications have resorted to the use of whole bacterial systems, because biodesulfurization involves a sequential cascade of reactions by different enzymes and a large amount of cofactors participating in redox reactions either with the sulfur atom or molecular oxygen. However, they lacked the scalability desired for an industrial setup due to overall low enzyme efficiency, product feedback inhibition mechanisms and toxicity, or inadequate conditions for long-term bacterial growth. While cell-free recombinant enzymes would be desirable, known implementations are still well below the efficiency met for whole-cell ones. There are two main pathways through which bacteria remove sulfur from sulfur-containing compounds: ring destructive pathways and sulfur-specific pathways.
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Sources: en.wikipedia.org
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Demoxytocin (INN; brand names Sandopart, Odeax, Sandopral; also known as desaminooxytocin, deaminooxytocin, 1-(3-mercaptopropanoic acid)oxytocin, and [Mpa1]OT) is an oxytocic peptide drug that is used to induce labor, promote lactation, and to prevent and treat puerperal (postpartum) mastitis (breast inflammation). Demoxytocin is a synthetic analogue of oxytocin and has similar activities, but is more potent and has a longer half-life in comparison. Unlike oxytocin, which is given via intravenous injection, demoxytocin is administered as a buccal tablet formulation. The drug was first synthesized in 1960 and was introduced into clinical practice in 1971 by Sandoz. It is marketed in several European countries, including Italy, Czech Republic, and Poland. It has the amino acid sequence Mpa-Tyr-Ile-Gln-Asn-Cys-Pro-Leu-Gly-NH2 (Mpa = β-mercaptopropionic acid), and is an analogue of oxytocin wherein the leading cysteine is replaced with β-mercaptopropionic acid.
The Journal of Chromatography B is a peer-reviewed scientific journal publishing research papers in analytical chemistry, with a focus on chromatography techniques and methods in the biological and life sciences. According to the Journal Citation Reports, Journal of Chromatography B has a 2020 impact factor of 3.205, ranking it 36th out of 83 in the category of Chemistry, Analytical.
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Sources: en.wikipedia.org
Central obesity: waist circumference ≥102 cm (40 in) men; ≥88 cm (35 in) women Dyslipidaemia: TG ≥1.7 mmol/L (150 mg/dL) Dyslipidaemia: HDL-C <40 mg/dL (men), <50 mg/dL (women) Blood pressure ≥130/85 mmHg (or treated for hypertension) Fasting plasma glucose ≥6.1 mmol/L (110 mg/dL)
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Washington (Hb Lepore Washington, also known as Hb Lepore Boston or Hb Lepore Washington-Boston); most common in Italians from Southern Italy Baltimore (Hb Lepore Baltimore); first described in a family with African ancestry; most common in people from the Balkan countries, Albanians Croats, Serbs, Slovenes and Romanians. It has also been described in Turks and in regions of Spain and Portugal. A rare case of the Baltimore variety was discovered in an African American woman in the Bronx, New York and dubbed Hn Lepore-Bronx and another variety was discovered in the city of Saskatoon, Saskatchewan, Canada and dubbed Hb E-Lepore Saskatoon Hollandia (Hb Lepore Hollandia); identified in Papua New Guinea and Bangladesh.
Sources: en.wikipedia.org
The molecule lacks aromatic residues, so it absorbs weakly near 280 nanometres, the wavelength applied to many other peptides. The peptide bond absorbs strongly below 220 nanometres, making 214 nanometres a practical compromise. Gradient methods must therefore use mobile phases with low ultraviolet absorbance to keep the baseline clean.
Neutral and slightly basic aqueous conditions promote aspartimide formation at the aspartate-glycine step, often followed by deamidation. Elevated temperature and repeated freeze-thaw cycles accelerate the loss. Acidic solutions and dry lyophilised powder are comparatively stable over short periods.
No monograph exists in the United States Pharmacopeia or the European Pharmacopoeia, and no widely distributed certified reference standard is available. Purity and identity therefore rest on supplier methods that are not harmonised. This absence is the main reason reported purities are difficult to compare between sources.
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.