If you have been reading about Certificate of analysis 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 2025-11-21. Where a claim depends on a specific study, the study is described rather than over-claimed.
Literature searches for this compound must account for several spelling variants. Indexing databases contain epitalon, epithalon, epithalone, and AEDG, and relevant records are scattered across Russian-language and English-language journals that do not consistently cross-cite. Early publications describe the parent extract as a mixture of many peptides, whereas later work addresses the single synthetic tetrapeptide. That shift in nomenclature complicates comparison between studies, because extract data and tetrapeptide data are sometimes cited interchangeably. A search strategy omitting the alternate spellings will return an incomplete set of references.
Reported biological findings come mainly from cell culture and rodent experiments. Those studies describe changes in telomerase catalytic subunit expression, melatonin rhythm amplitude, and antioxidant enzyme activity after peptide exposure. Human data are sparse and consist of small trials with limited blinding and inconsistent endpoints. The proposed mechanisms remain hypotheses rather than established facts, and there is no consensus on whether effects observed in animals carry over to people. Independent replication outside the original research groups is limited, which is a recognised gap in the published literature.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic tetrapeptide | Four amino acid residues |
| Residue sequence | Ala-Glu-Asp-Gly | Abbreviated AEDG |
| Approximate mass | 390.35 Da | Monoisotopic, free base form |
| Parent preparation | Epithalamin extract | Derived from pineal tissue |
| Common spelling variants | Epithalon, epithalone, AEDG | Affects literature retrieval |
Interest in epitalon is usually discussed within the broader field of short peptide bioregulators, a category that includes other synthetic di-, tri-, and tetrapeptides studied by the same research group. These compounds share a common rationale: that small fragments of tissue-derived proteins can retain biological activity and can be produced reproducibly. The category as a whole remains outside mainstream pharmacological consensus, and epitalon specifically has a limited presence in independent, non-Russian research literature, which shapes how its evidence base is described.
Epitalon is a synthetic tetrapeptide with the amino acid sequence alanine-glutamate-aspartate-glycine, abbreviated Ala-Glu-Asp-Gly or AEDG. It was developed by the Russian researcher Vladimir Khavinson and colleagues during work on peptide bioregulators derived from the pineal gland. The compound is short enough to be produced by standard solid-phase peptide synthesis and is typically handled as a lyophilized white powder. Its small size distinguishes it from larger pineal peptides such as epithalamin, a complex extract from which the tetrapeptide was conceptually derived.
The four residues give epitalon a molecular formula of C14H22N4O9 and a molecular weight near 390.35 daltons. The presence of two acidic residues, glutamate and aspartate, makes the free peptide strongly acidic, while the alanine and glycine ends provide neutral, nonpolar character. This combination produces a molecule with substantial water solubility. Because there are no cysteine, methionine, or tryptophan residues, the peptide lacks the most common oxidation-sensitive side chains, which simplifies handling compared with many longer peptides.
Verification of research-grade material involves comparing a supplier chromatogram against an in-house reference, checking the observed mass against the calculated value, and where possible confirming residue order by tandem mass spectrometry or enzymatic peptide mapping. Purity claims should be read alongside the method used to obtain them, because detection wavelength and integration settings alter the result. Batch-specific data, rather than a generic grade statement, is the informative part of a certificate.
Identity and purity of epitalon samples are normally established by reversed-phase high-performance liquid chromatography with ultraviolet detection near 214 nanometres, combined with mass spectrometry. The mass spectrum confirms the expected molecular ion and can reveal truncated or oxidised by-products. Amino acid analysis after acid hydrolysis verifies that the four residues are present in the expected ratio. Certificates typically report a purity figure taken from chromatographic peak area, expressed as a percentage of total integrated signal.
Wakame Seaweed Archived 2016-04-21 at the Wayback Machine at About.com AlgaeBase link Undaria pinnatifida Archived 2019-09-24 at the Wayback Machine at the FAO Undaria pinnatifida at the Joint Nature Conservation Committee, UK Global Invasive species database Archived 2011-06-11 at the Wayback Machine Undaria Management at the Monterey Bay National Marine Sanctuary
==== Pancreatic extracts before insulin ==== The limit to early diabetes control was partly due to the common-sense assumption that the stomach was wholly responsible for nutrient metabolism. As physiologists came to better understand the metabolic role of other organs, they began to hypothesize alternative causes for the disease. Through accumulating evidence, it was established that the "cause" of diabetes could be localized to the pancreas, then to its internal secretion (see: History of diabetes#Pathophysiology#Role of the pancreas). These findings fueled attempts to treat diabetes in animals and humans with direct extracts from the pancreas, by no less than 400 researchers according to historian Michael Bliss. In the early 1900s, Georg Ludwig Zuelzer experimented extensively with pancreatic extracts. After initial tests on rabbits, he injected his extracts (which he called acomatol) on humans to clear but inconsistent success and severe side-effects. He nonetheless took out an American patent on his yet-problematic extracts. Unfortunately, Zuelzer was ultimately unable to purify the extract due to difficulty obtaining pancreases, a lack of funding, and interruption by World War I. Ernest Lyman Scott, studying at the University of Chicago between 1911 and 1912, also obtained some promising results but was discouraged from continuing. In 1913, John MacLeod, at the time several years into research in the area of carbohydrate metabolism and blood sugar behaviour, synthesized the state of research in Diabetes: Its Pathological Physiology.
=== Carbon nanotubes and related materials === The technique has been well utilized in studying carbon nanotubes to determine thermodynamic binding interactions with biological molecules and graphene composite interactions. Another notable use of ITC with carbon nanotubes is optimization of preparation of carbon nanotubes from graphene composite and polyvinyl alcohol (PVA). PVA assembly process can be measured thermodynamically as mixing of the two ingredients is an exothermic reaction, and its binding trend can be easily observed by ITC.
== Aftermath == An internal review estimated that the pursuit had cost the public £3 million and that vital scientific information had been missed. The criminal psychologist involved with the investigation was charged with professional misconduct by the British Psychological Society, but in 2002, in lieu of any substantial hearings, further action was dismissed due to the delay in bringing proceedings. André Hanscombe moved with his and Nickell's child to France. He was strongly critical of some of the reporters who tracked him and his son down to his "sanctuary" in the French countryside. In 1996 Hanscombe wrote a book titled The Last Thursday in July about his life with Nickell, coping with the homicide, how "media intrusion" drove him to move abroad, and life with their son afterwards. In 2017 Alex Hanscombe wrote a memoir, Letting Go: A True Story Of Murder, Loss & Survival, telling the story of his mother's murder and how he coped with his grief and trauma.
Sources: en.wikipedia.org
=== Sexual dysfunction === Sexual dysfunction, including erectile dysfunction, loss of libido, and reduced ejaculate, may occur in 3.4 to 15.8% of men treated with finasteride or dutasteride. This is linked to lower quality of life and can cause stress in relationships. There is also an association with lowered sexual desire. It has been reported that in a subset of men, these adverse sexual side effects may persist even after discontinuation of finasteride or dutasteride.
== Prognosis == While there is no cure for acrocyanosis, patients otherwise have excellent prognosis. Unless acrocyanosis results from another condition (e.g. malignancy, antiphospholipid syndrome, atherosclerosis, acute ischemic limb, bacterial endocarditis), there is no associated increased risk of disease or death, and there are no known complications. Aside from the discoloration, there are no other symptoms: no pain, and no loss of function. Patients can expect to lead normal lives. In secondary acrocyanosis treatment of the primary condition defines outcomes.
=== As a biochemical tool === Concanavalin A and other commercially available lectins have been used widely in affinity chromatography for purifying glycoproteins. In general, proteins may be characterized with respect to glycoforms and carbohydrate structure by means of affinity chromatography, blotting, affinity electrophoresis, and affinity immunoelectrophoreis with lectins, as well as in microarrays, as in evanescent-field fluorescence-assisted lectin microarray.
=== Platelet-rich plasma === Platelet-rich plasma is under preliminary research for its possible use in treating alopecia areata. A minimum of 3 treatments, once a month for 3 months are recommended, and afterwards a 3-6 month period of continual appointments for maintenance. Factors that determine efficacy include number of sessions, double versus single centrifugation, age and gender, and where the platelet-rich plasma is inserted. Future larger randomized controlled trials and other high-quality studies are still recommended to be carried out and published for a stronger consensus. Further development of a standardized practice for the procedure is also recommended.
== Regulation == Glycogenolysis is regulated hormonally in response to blood sugar levels by glucagon and insulin, and stimulated by epinephrine during the fight-or-flight response. Insulin potently inhibits glycogenolysis. In myocytes, glycogen degradation may also be stimulated by neural signals; glycogenolysis is regulated by epinephrine and calcium released by the sarcoplasmic reticulum. Glucagon has no effect on muscle glycogenolysis. Calcium binds with calmodulin and the complex activates phosphorylase kinase.
Sources: en.wikipedia.org
Today, scientific interest in snail and slug mucus has grown due to its potential biomedical and cosmetic applications. In the present day, slug slime is being studied for its antimicrobial properties and healing properties with research being done on drug delivery systems as well as cancer therapy. Scientific interest in snail and slug mucus has also grown in recent decades, particularly after glycosaminoglycans (GAGs), important compounds for skin health and repair, were first extracted from the African giant snail, Achatina fulica in 1996.
It is a flexible tool for creating ROC graphs, sensitivity/specificity curves, area under curve and precision/recall curve. The parametrization can be visualized by coloring the curve according to cutoff. WebCDK: A web interface for the CDK library which is used for predicting descriptors of chemicals. Pharmacokinetics: This data analysis determines the relationship between the dosing regimen and the body's exposure to the drug as measured by the drug's nonlinear concentration time curve. It includes a function to calculate area under this curve. It also includes functions for half-life estimation for a biexponential model, and a two phase linear regression.
"Whereas, for all time since the creation of mankind, no king whosoever had destroyed Armanum and Ebla, the god Nergal, by means of (his) weapons opened the way for Naram-Sin, the mighty, and gave him Armanum and Ebla. Further, he gave to him the Amanus, the Cedar Mountain, and the Upper Sea. By means of the weapons of the god Dagan, who magnifies his kingship, Naram-Sin, the mighty, conquered Armanum and Ebla."
After Charles's death, the former Austrian imperial family were soon to move again. Alfonso XIII of Spain had approached the British Foreign Office via his ambassador in London, and they agreed to allow Zita and her seven (soon to be eight) children to relocate to Spain. Alfonso duly sent the warship Infanta Isabel to Funchal and this took them to Cádiz. They were then escorted to the Pardo Palace in Madrid, where shortly after her arrival Zita gave birth to Archduchess Elisabeth. Alfonso XIII offered his exiled Habsburg relatives the use of Palacio Uribarren at Lekeitio on the Bay of Biscay. This appealed to Zita, who did not want to be a heavy burden to the state that harboured her. For the next six years Zita settled in Lekeitio, where she got on with the job of raising and educating her children. They lived with straitened finances, mainly living on income from private property in Austria, income from a vineyard in Johannisberg in the Rhine Valley, and voluntary collections. Other members of the exiled Habsburg dynasty, however, claimed much of this money, and there were regular petitions for help from former Imperial officials.
== Model organism in genetics == D. melanogaster remains one of the most studied organisms in biological research, particularly in genetics and developmental biology. It is also employed in studies of environmental mutagenesis.
Sources: en.wikipedia.org
It is based on epithalamin, a peptide-rich preparation obtained from pineal gland tissue and studied in the former Soviet Union. Researchers later identified the tetrapeptide AEDG as a constituent fragment of that material. Modern supplies are produced by chemical synthesis rather than tissue extraction.
No. Epithalamin is a heterogeneous extract containing many peptides, while epitalon is a single synthesised tetrapeptide. Publications sometimes treat findings from the two as equivalent, which is a common source of confusion. Their compositions differ and they are not interchangeable in analytical terms.
Most published work uses cell cultures or rodents because those models are faster and less costly to run. The few human trials that have been reported are small, and several lack control groups or blinding. This restricts what can reasonably be concluded about effects in people.
The solid is kept cold, dry and dark, typically at minus twenty degrees Celsius, in a sealed container with desiccant. Dissolved material is kept refrigerated and used promptly. Freezing and thawing a solution repeatedly is avoided because it accelerates degradation.