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Peptide Identity And Research Origin — Worked Examples

By Editorial Desk · published 2026-04-17 · last reviewed 2026-06-06 · Info

If you have been reading about Epithalamin 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.

Updated 2026-06-06. Numbers and descriptions here follow the published literature rather than marketing material.

Peptide Identity and Research Origin

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.

Analytical Characterization and Stability

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.

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.

Epitalon at a glance

PropertyValueNotes
Molecular formulaC14H22N4O9Synthetic tetrapeptide, four residues
Nominal massApproximately 390 DaFree peptide; salt forms differ
AppearanceWhite to off-white powderCommonly supplied lyophilised
Solubility classFreely soluble in waterAlso dissolves in aqueous buffer
Typical storage−20 °C, desiccatedCold packs used during transport

Epitalon Peptide Background and Structure

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.

The proposed relationship between epitalon and pineal function is a central part of its background. Khavinson's group reported that short peptides corresponding to regions of larger pineal proteins could influence gene expression in cells. Epitalon was framed as a synthetic analogue of an active fragment rather than a direct isolation product. Whether the tetrapeptide reproduces the effects of the parent extract is an open question, because comparative studies are limited and the parent extract itself is not a single defined substance.

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.

Related pages on this site

Epitalon in Research Literature and Handling

Epitalon appears in the literature primarily through a small number of research groups, most of them associated with the St. Petersburg Institute of Bioregulation and Gerontology. Publications describe cell culture experiments, animal studies, and a limited number of small human studies. Independent replication outside this network is sparse. As a result, reviews of the topic usually separate descriptive reports of observed effects from the question of whether those effects generalize, and they note the difficulty of comparing studies that use different preparations and endpoints.

Analytical characterization of epitalon relies on standard peptide methods. Reverse-phase high-performance liquid chromatography is used to assess purity, and mass spectrometry confirms identity by checking the observed mass against the expected value near 390 daltons. Amino acid analysis can verify composition. Because the peptide is short and hydrophilic, it elutes early on many reverse-phase columns, so method development often requires ion-pairing reagents to achieve adequate retention and resolution from related impurities.

Reference notes

== Mechanism == Seborrhoeic dermatitis is a complex condition with many interacting factors that are not yet fully explained. In general, the major factors that influence the development and severity include Malassezia yeast present on and in the skin, skin production of oily sebum, and a subsequent inflammatory response against Malassezia and their byproducts. Additional factors involved in the condition are a compromised skin barrier, the makeup and amount of sebum produced, the character of the immune response and inflammation, and the presence of other microbe species inhabiting the skin. A suggested series of events leading to seborrhoeic dermatitis is an initially damaged skin barrier and abnormal sebum production, which leads to a change in the microbiome of the skin that in turn elicits an immune response. An alternative explanation is an increase in sebum production feeding an increase in the Malassezia population that instigates inflammation; the inflammation then causes cellular changes that damage the skin barrier. This barrier disruption then encourages additional Malassezia growth and inflammation and again worsens skin barrier function.

nonilfenossipolietilenossietanolo (33 letters – chemical) pentagonododecaedrotetraedrico (30 letters – 3D geometric figure) esofagodermatodigiunoplastica (29 letters – surgery) elettroencefalograficamente (27 letters – medical adverb: electroencephalographically) diclorodifeniltricloroetano (27 letters – chemical: DDT)

Observational documentaries attempt to spontaneously observe their subjects with minimal intervention. Filmmakers who worked in this subgenre often saw the poetic mode as too abstract and the expository mode as too didactic. The first observational docs date back to the 1960s; the technological developments that made them possible include mobile lightweight cameras and portable sound-recording equipment for synchronized sound. Often, this mode of film eschewed voice-over commentary, post-synchronized dialogue and music, or re-enactments. The films aimed for immediacy, intimacy, and revelation of individual human character in ordinary life situations.

==== Fehling test ==== The Fehling test is a classic method for the detection of aldoses. Due to mutarotation, glucose is always present to a small extent as an open-chain aldehyde. By adding the Fehling reagents (Fehling (I) solution and Fehling (II) solution), the aldehyde group is oxidized to a carboxylic acid, while the Cu2+ tartrate complex is reduced to Cu+ and forms a brick red precipitate (Cu2O).

Sources: en.wikipedia.org

Notes from published material

== Broadcast == Matlock premiered with a sneak peek on September 22, 2024, before its timeslot premiere on October 17 on CBS. In Canada, the series airs on Global and is available to stream on StackTV. The second season premiered on October 12, 2025. In Australia, the show premiered on Channel Ten on the November 11, 2024 and has continued to air its second season through January 2026 and also airs on Paramount+. In Croatia, the show premiered on national HRT 1 starting with the first season on the 15th. June 2026.

The parietal serous pericardium, which lines the interior side of the superficial portion of the pericardial sac, is fused to and inseparable from the fibrous pericardium The visceral serous pericardium, also known as the epicardium, covers the myocardium of the heart and can be considered its serosa. It is largely made of a mesothelium overlying some elastin-rich loose connective tissue. During ventricular contraction, the wave of depolarization moves from the endocardial to the epicardial surface. Both of these layers function in lubricating the heart to prevent friction during heart activity. The visceral serous pericardium extends to the root of the great vessels and joins the parietal serous pericardium at the anatomical base of the heart. This junction occurs at two areas: the ventricular outflow tracts where the aorta and pulmonary trunk leave the heart, and the inflow tracts where the superior/inferior vena cava and pulmonary veins enter the heart. The root of the great vessels and the associated reflections of the serous pericardium creates various smaller sacs and tunnels known as pericardial sinuses, as well as radiographically significant pericardial recesses, where pericardial fluid can pool and mimic mediastinal lymphadenopathy.

This is a list of the fastest animals in the world, by types of animal. The peregrine falcon is the fastest bird, and the fastest member of the animal kingdom, with a diving speed of over 300 km/h (190 mph). The fastest land animal is the cheetah, capable of running at speeds of up to 93–104 km/h (58–65 mph). Among the fastest animals in the sea is the black marlin, with uncertain and conflicting reports of recorded speeds. When drawing comparisons between different classes of animals, an alternative unit is sometimes used for organisms: body length per second. On this basis the 'fastest' organism on earth, relative to its body length, is the Southern Californian mite, Paratarsotomus macropalpis, which has a speed of 322 body lengths per second. The equivalent speed for a human, running as fast as this mite, would be 1,300 mph (2,092 km/h), or approximately Mach 1.7. The speed of the P. macropalpis is far in excess of the previous record holder, the Australian tiger beetle Rivacindela eburneola, which is the fastest insect in the world relative to body size, with a recorded speed of 1.86 metres per second (6.7 km/h; 4.2 mph), or 171 body lengths per second. The cheetah, the fastest land mammal, scores at only 16 body lengths per second. Body mass can also be used to compare speed between species on a relative basis. Under this parameter the fastest animal for its body mass is the cheetah, followed by the pronghorn.

== Overdose == Overdoses of hydroxychloroquine are extremely rare, but extremely toxic. Eight people are known to have overdosed since the drug's introduction in the mid-1950s, of which three have died. Chloroquine has a risk of death in overdose in adults of about 20%, while hydroxychloroquine is estimated to be two or threefold less toxic. Serious signs and symptoms of overdose generally occur within an hour of ingestion. These may include sleepiness, vision changes, seizures, coma, stopping of breathing, and heart problems such as ventricular fibrillation and low blood pressure. Loss of vision may be permanent. Low blood potassium, to levels of 1 to 2 mmol/L, may also occur. Cardiovascular abnormalities such as QRS complex widening and QT interval prolongation may also occur. Treatment recommendations include early mechanical ventilation, heart monitoring, and activated charcoal. Supportive treatment with intravenous fluids and vasopressors may be required with epinephrine being the vasopressor of choice. Stomach pumping may also be used. Sodium bicarbonate and hypertonic saline may be used in cases of severe QRS complex widening. Seizures may be treated with benzodiazepines. Intravenous potassium chloride may be required, however this may result in high blood potassium later in the course of the disease. Dialysis does not appear to be useful.

Mikania micrantha is a widespread weed in the tropics. It grows very quickly (as fast as 80 to 90 millimetres (3.1 to 3.5 in) in 24 hours for a young plant) and covers other plants, shrubs and even trees. Mikania is a problem in Nepal, covering more than 20% of the Chitwan National Park. Various control measures against Mikania have been tried in many countries. It is moderately susceptible to the herbicides 2,4-D and 2,4,5-T and paraquat. Cuscuta, a parasitic plant, has been used in Assam and Sri Lanka to suppress the spread of Mikania from waste land to tea plantations. Other control measures include the rust fungus Puccinia spegazzinii and the thrips species Liothrips mikaniae. An example of its success can be seen in Hong Kong where first recorded in 1884, it has now spread throughout the region and invades its country parks. Economic gains due to Mikania are meager compared to the loss due to its infestation in various ecosystems. It is used as a fodder in many countries. Sheep preferentially grazed Mikania in Malaysia and other cattle also relish it. In Kerala, India, the weed is utilized as a fodder in some parts of the state, especially during summer when the availability of grass is scarce. However, Mikania is known to cause hepatotoxicity and liver damage in dairy cattle. The antibacterial effect of Mikania and its efficacy in wound healing has been reported. In Assam (NE India), Kabi tribes use the leaf juice of Mikania as an antidote for insect bite and scorpion sting. The leaves are also used for treating stomachache.

Sources: en.wikipedia.org

Further detail

=== In silico screening === T cell epitope content, which is one of the factors that contributes to the risk of immunogenicity can now be measured relatively accurately using in silico tools. Immunoinformatics algorithms for identifying T-cell epitopes are now being applied to triage protein therapeutics into higher risk and low risk categories. These categories refer to assessing and analyzing whether an immunotherapy or vaccine will cause unwanted immunogenicity. One approach is to parse protein sequences into overlapping nonamer (that is, 9 amino acid) peptide frames, each of which is then evaluated for binding potential to each of six common class I HLA alleles that "cover" the genetic backgrounds of most humans worldwide. By calculating the density of high-scoring frames within a protein, it is possible to estimate a protein's overall "immunogenicity score". In addition, sub-regions of densely packed high scoring frames or "clusters" of potential immunogenicity can be identified, and cluster scores can be calculated and compiled. Using this approach, the clinical immunogenicity of a novel protein therapeutics can be calculated. Consequently, a number of biotech companies have integrated in silico immunogenicity into their pre-clinical process as they develop new protein drugs.

As for the southern part of the street, Via Roma ends in Piazza Carlo Felice and in its Giardino Sambuy, a wide fenced garden right in the middle of the square. Across from Piazza Carlo Felice stands the monumental façade of Porta Nuova railway station, the central station of the city built between 1861 and 1868 by the architect Alessandro Mazzucchetti. The passengers building was renovated to host a shopping mall and more efficient passenger service offices. However, it is still an example of monumental architecture, with its stately foyer and some Baroque sights, such as the Sala Reale (the former Royal waiting room).

DNA can be twisted like a rope in a process called DNA supercoiling. With DNA in its "relaxed" state, a strand usually circles the axis of the double helix once every 10.4 base pairs, but if the DNA is twisted the strands become more tightly or more loosely wound. If the DNA is twisted in the direction of the helix, this is positive supercoiling, and the bases are held more tightly together. If they are twisted in the opposite direction, this is negative supercoiling, and the bases come apart more easily. In nature, most DNA has slight negative supercoiling that is introduced by enzymes called topoisomerases. These enzymes are also needed to relieve the twisting stresses introduced into DNA strands during processes such as transcription and DNA replication.

Andress, Jason. Winterfeld, Steve. (2011). Cyber Warfare: Techniques, Tactics and Tools for Security Practitioners. Syngress. ISBN 1-59749-637-5 Bodmer, Kilger, Carpenter, & Jones (2012). Reverse Deception: Organized Cyber Threat Counter-Exploitation. New York: McGraw-Hill Osborne Media. ISBN 0-07-177249-9, "ISBN 978-0-07-177249-5" Brenner, S. (2009). Cyber Threats: The Emerging Fault Lines of the Nation State. Oxford University Press. ISBN 0-19-538501-2 Carr, Jeffrey. (2010). Inside Cyber Warfare: Mapping the Cyber Underworld. O'Reilly. ISBN 978-0-596-80215-8 Conti, Gregory. Raymond, David. (2017). On Cyber: Towards an Operational Art for Cyber Conflict. Kopidion Press. ISBN 978-0-692-91156-3 Cordesman, Anthony H.; Cordesman, Justin G. (2002). Cyber-threats, Information Warfare, and Critical Infrastructure Protection: Defending the U.S. Homeland. Greenwood Publishing Group. ISBN 978-0-275-97423-7. Costigan, Sean S.; Perry, Jake (2012). Cyberspaces and global affairs. Farnham, Surrey: Ashgate. ISBN 978-1-4094-2754-4. Fritsch, Lothar & Fischer-Hübner, Simone (2019). Implications of Privacy & Security Research for the Upcoming Battlefield of Things. Journal of Information Warfare, 17(4), 72–87. Gaycken, Sandro. (2012). Cyberwar – Das Wettrüsten hat längst begonnen. Goldmann/Randomhouse. ISBN 978-3-442-15710-5 Geers, Kenneth. (2011). Strategic Cyber Security. NATO Cyber Centre.

== Scientific contributions == Potassium channels demonstrate a seemingly counterintuitive activity: they permit the passage of potassium ions, whereas they do not allow the passage of the much smaller sodium ions. Before MacKinnon's work, the detailed molecular architecture of potassium channels and the means by which they conduct ions were only generally known and indirectly inferred. In 1998, despite barriers to the structural study of integral membrane proteins that had thwarted most attempts for decades, MacKinnon and colleagues determined the three-dimensional molecular structure of a potassium channel from an actinobacterium, Streptomyces lividans, utilizing X-ray crystallography. With this structure and other biochemical experiments, MacKinnon and colleagues were able to explain the exact mechanism by which potassium channel selectivity occurs. His prize-winning research was conducted primarily at the Cornell High Energy Synchrotron Source (CHESS) of Cornell University, and at the National Synchrotron Light Source (NSLS) of Brookhaven National Laboratory. MacKinnon was elected to the American Philosophical Society in 2005. In 2007 he became a foreign member of the Royal Netherlands Academy of Arts and Sciences.

Sources: en.wikipedia.org

Frequently asked questions

Is epitalon the same as epithalamin?

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.

Does epitalon occur naturally in the human body?

No endogenous peptide with this exact sequence has been described as a circulating hormone or signalling molecule. The tetrapeptide was designed as a synthetic analogue based on fragments observed in pineal preparations. Any activity discussed in the literature therefore refers to administered material rather than to a natural pool of the compound.

What regulatory category does epitalon fall into?

It is not an approved medicine in major jurisdictions and does not appear in the major pharmacopoeias. Material is usually distributed as a research chemical or laboratory reagent. Such labelling places handling responsibility on the purchaser and does not indicate that a regulatory body has reviewed the substance.

Why is ultraviolet detection at 214 nanometres used?

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.

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