en · de · es · fr · pt
bench-notes.peptides8425.com › Blog › Structure, Naming And Discovery — Common Mistakes

Structure, Naming And Discovery — Common Mistakes

By Editorial Desk · published 2026-07-03 · last reviewed 2026-07-19 · Blog

The short version of AEDG fits in a sentence. The long version — which is the one that helps — is below.

This page was last updated on 2026-07-19 and is reviewed periodically as new material appears.

Structure, Naming and Discovery

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.

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 Background and Nomenclature

Laboratory work has examined effects on telomerase activity in cultured cells, on melatonin rhythms in animals, and on markers of oxidative stress. Some experiments report measurable changes while others show none, and the reported findings rest largely on small studies. The absence of large independent trials means the generality of these results is unresolved rather than settled. Review articles occasionally apply the label geroprotector, a term that reflects a research hypothesis about ageing rather than an established clinical finding.

Epitalon is the common name for a synthetic tetrapeptide with the sequence alanine-glutamate-aspartate-glycine, usually abbreviated AEDG. All four residues are proteinogenic amino acids, and the free peptide has a calculated mass near 390 grams per mole. Because the chain is short and carries no modifications, it is assembled readily by solid-phase synthesis and is distributed mainly as a freeze-dried solid for laboratory work. Catalogue listings use the spellings epitalon, epithalone, and simply AEDG, and the three refer to the same sequence.

The compound is generally presented as a synthetic fragment of epithalamin, a pineal gland extract investigated in the former Soviet Union from the 1970s onward. Vladimir Khavinson and colleagues in Saint Petersburg developed short peptides modelled on such extracts, and epitalon became the most widely cited of those sequences. Most primary reports appeared in Russian-language journals or in proceedings with limited international circulation. Independent replication in laboratories outside that network remains sparse, and much repeated secondary material traces back to a small number of originating groups.

Epitalon at a glance

PropertyValueNotes
Molecular formulaC14H22N4O9Derived from the four constituent residues
Molecular massAbout 390.35 DaMonoisotopic value, confirmed by mass spectrometry
Residue sequenceAla-Glu-Asp-GlyRead from the N-terminus to the C-terminus
Common synonymsEpithalon; AEDGBoth forms appear in reference catalogues
Net charge near neutral pHNegativeTwo acidic side chains give a low isoelectric point

Epitalon Background and Discovery

The peptide emerged from research carried out in Saint Petersburg from the late 1980s onward, where investigators searched for shorter active fragments of a pineal preparation known as epithalamin. The name epitalon was chosen to reflect that parent extract. Early reports described effects on neuroendocrine markers and on the lifespan of laboratory animals. Much of that work appeared in Russian-language journals, with English translations following later, which affects how readily the original protocols can be assessed by outside groups.

Published studies on epitalon are dominated by a small number of research groups, and independent replication in other laboratories remains limited. Proposed mechanisms include activation of telomerase and modulation of melatonin rhythms, but the evidence for either rests mainly on cell cultures and animal models. Whether the peptide produces comparable effects in humans is an open question, and the absence of large controlled trials means the literature is best read as exploratory rather than settled.

Related pages on this site

Chemical Identity and Research Background

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.

Notes from published material

== Medical uses == Patiromer is used for the treatment of hyperkalemia, but not as an emergency treatment for life-threatening hyperkalemia, as it acts relatively slowly. Such a condition needs other kinds of treatment, for example calcium infusions, insulin plus glucose infusions, salbutamol inhalation, and hemodialysis. Typical reasons for hyperkalemia are chronic kidney disease and application of drugs that inhibit the renin–angiotensin–aldosterone system (RAAS) – e.g. ACE inhibitors, angiotensin II receptor antagonists, or potassium-sparing diuretics – or that interfere with kidney function in general, such as nonsteroidal anti-inflammatory drugs (NSAIDs).

== Medical uses == Lercanidipine is used for the treatment of essential hypertension (high blood pressure). Lercanidipine seems to be a good agent in treating hypertensive patients who also have kidney issues.

== Quasi-enantiomers == Quasi-enantiomers are molecular species that are not strictly enantiomers, but behave as if they were. In quasi-enantiomers, the majority of the molecule is reflected; however, an atom or group within the molecule is changed to a similar atom or group. Quasi-enantiomers can also be defined as molecules that have the potential to become enantiomers if an atom or group in the molecule were replaced. An example of quasi-enantiomers is (S)-bromobutane and (R)-iodobutane. Under normal conditions, the enantiomers for (S)-bromobutane and (R)-iodobutane are (R)-bromobutane and (S)-iodobutane respectively. Quasi-enantiomers also produce quasi-racemates, which are similar to normal racemates (see racemic mixture) in that they form an equal mixture of quasi-enantiomers. Quasi-enantiomers have applications in parallel kinetic resolution.

== Overdose == A single oral dose of bicalutamide in humans that results in symptoms of overdose or that is considered to be life-threatening has not been established. Dosages of up to 600 mg/day have been well tolerated in clinical trials, and it is notable that there is a saturation of absorption with bicalutamide such that circulating levels of its active (R)-enantiomer do not further increase above a dosage of 300 mg/day. Overdose is considered unlikely to be life-threatening with bicalutamide or other first-generation NSAAs (i.e., flutamide and nilutamide). A massive overdose of nilutamide (13 grams, or 43 times the normal maximum 300 mg/day clinical dosage) in a 79-year-old man was uneventful, producing no clinical signs, symptoms, or toxicity. There is no specific antidote for bicalutamide or NSAA overdose, and treatment should be based on symptoms, if any are present.

=== National Assembly === Noboa was elected to the National Assembly in the 2021 legislative elections, representing Santa Elena, for the United Ecuadorian political movement. He was inaugurated on 14 May in the same year. In that same May, he was appointed chair of the Economic Development Commission. His political ideology in the National Assembly been described as both centrist and centre-right. Noboa was absent during President Lasso's impeachment trial, however a proxy voted in the affirmative. In March 2023, he was in favor of the muerte cruzada, in the face of the rejection and filing of the Investment Law, presented by the government of Guillermo Lasso. On 17 May 2023, Lasso invoked muerte cruzada, dissolving the National Assembly and ending Noboa's tenure as an assemblyman.

Sources: en.wikipedia.org

Background from the literature

== Mission statement == The association states that its vision is to drive quality and integrity through scientific research and development, through developing standards and facilitating knowledge sharing through: discussion, training, seminars, conferences, publications, partnership and cooperation. RQA holds over 40 face to face courses yearly in the UK and Mainland Europe on a variety of topics, including all major GxP's.

=== Phase 3 === Gepirone (Ariza; BMY-13805; Exxua; Gepirone ER; MJ-13805; Org-33062; TGFK-07AD; TGFK07AD; Travivo; Variza) – serotonin 5-HT1A receptor partial agonist [1] Lysergic acid diethylamide (LSD; lysergide; MM-120; MM120) – non-selective serotonin receptor agonist and psychedelic hallucinogen [2] [3] Toludesvenlafaxine extended release (4-methylbenzoate desvenlafaxine; ansofaxine; desvenlafaxine prodrug; LPM-570065; LY-03005; Ruoxinlin) – serotonin–norepinephrine–dopamine reuptake inhibitor (SNDRI) [4] Vilazodone (EMD-68843; SB-659746A; Viibryd) – serotonin reuptake inhibitor (SRI) and serotonin 5-HT1A receptor partial agonist [5]

== Ionization == The gastrointestinal tract is lined with epithelial cells. Drugs must pass through or permeate these cells to be absorbed into the bloodstream. Cell membranes may act as barriers to some drugs. They are essentially lipid bilayers which form semipermeable membranes. Pure lipid bilayers are generally permeable only to small, uncharged solutes. Hence, whether or not a molecule is ionized will affect its absorption, since ionic molecules are charged. Solubility favors charged species, and permeability favors neutral species. Some molecules have special exchange proteins and channels to facilitate movement from the lumen into the circulation. Ions cannot passively diffuse through the gastrointestinal tract because the epithelial cell membrane is made up of a phospholipid bilayer, comprising two layers of phospholipids in which the charged hydrophilic heads face outwards and the uncharged hydrophobic fatty acid chains are in the middle of the layer. The fatty acid chains repel ionized, charged molecules. This means that the ionized molecules cannot pass through the intestinal membrane and be absorbed. The Henderson-Hasselbalch equation offers a way to determine the proportion of a substance that is ionized at a given pH. In the stomach, drugs that are weak acids (such as aspirin) will be present mainly in their non-ionic form, and weak bases will be in their ionic form. Since non-ionic species diffuse more readily through cell membranes, weak acids will have a higher absorption in the highly acidic stomach.

where z is the number of positive or negative charges of the ion, e is the elementary charge and m is the mass of the ion. An electric excitation signal having a frequency f will therefore resonate with ions having a mass-to-charge ratio m/z given by

Sources: en.wikipedia.org

Reference notes

=== Pit vipers === The Crotalinae, commonly known as pit vipers, crotaline snakes (named for the Ancient Greek: κρόταλον krotalon castanet/rattle of a rattlesnake's tail), or pit adders, are a subfamily of venomous vipers found in Eurasia and the Americas. They are distinguished by the presence of a heat-sensing pit organ located between the eye and the nostril on both sides of the head. Currently, 22 genera and 151 species are recognized: These are also the only viperids found in the Americas. The groups of snakes represented here include rattlesnakes, lanceheads, and Asian pit vipers. The type genus for this subfamily is Crotalus, of which the type species is the timber rattlesnake, C. horridus.

The Parliament of Malaysia consists of the Yang di-Pertuan Agong (King) and two houses, the Dewan Rakyat (the House of Representatives) and Dewan Negara (the Senate). The term "members of Parliament" only refers to members of the Dewan Rakyat. In Malay, a member of Parliament is called Ahli Parlimen, or less formally wakil rakyat (people's representative). Members of Parliament are elected from population-based single-seat constituencies using first-past-the-post voting. The prime minister must be a member of Parliament. Members of Parliament are styled Yang Berhormat ("Honourable") with the initials Y.B. appended prenominally. A prince who is a member of Parliament is styled Yang Berhormat Mulia. The prime minister, deputy prime minister and Tuns who are members of Parliament are styled Yang Amat Berhormat ("Most Honourable"), abbreviated Y.A.B.

Wind direction plays a critical role in shaping the inland extent of X. parietina. Southwesterly winds in the warmer months carry marine aerosols further inland, while easterly storms contribute additional sea salt deposition through precipitation. The influence of these aerosols is evident in Maine cemeteries: X. parietina is more frequent in open cemeteries exposed to prevailing winds, compared to wooded cemeteries, which block or capture airborne sea salts, and have significantly lower frequencies of the lichen. In recent decades, inland populations of X. parietina have been discovered in southern Ontario, suggesting an expansion beyond its traditionally coastal range. Once considered extirpated from the region, the species was rediscovered growing on trees in several inland locations. This inland occurrence raises questions about whether the lichen has reestablished after a long absence or has persisted undetected for decades. The expansion may be linked to increasing nitrogen deposition from agricultural runoff and air pollution, which create conditions favorable for nitrophilous lichens like X. parietina. Another possible factor in its inland spread is the widespread use of road salt in Ontario over the past 50–70 years. Since X. parietina thrives in salt-rich coastal environments, roadside salt deposition may have provided an artificial habitat, mimicking the chemical conditions of maritime regions.

Sources: en.wikipedia.org

Frequently asked questions

What is epitalon made of?

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.

Are epitalon and epithalon different compounds?

No. The two spellings refer to the same tetrapeptide, and the difference reflects transliteration from Russian. Laboratories and catalogues use both forms interchangeably. The material is also indexed as AEDG, taken from the one-letter codes of its residues.

How does epitalon differ from epithalamin?

Epithalamin is a mixed preparation derived from animal pineal tissue and contains many peptides. Epitalon is one synthetic sequence chosen for study from that broader mixture. Statements about one do not transfer directly to the other.

What is epitalon made of?

It is a four-amino-acid peptide with the sequence alanine-glutamate-aspartate-glycine. The chain is unmodified and contains only standard proteinogenic residues, which makes it straightforward to produce by solid-phase synthesis and to characterise by standard peptide methods.

Network