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Peptide Identity And Laboratory Handling — Explained

By Editorial Desk · published 2026-03-07 · last reviewed 2026-03-23 · Faq

Lyophilized powder is one of those subjects where the details matter more than the headlines. This page pulls together the background, the mechanisms, and the practical points readers ask about most.

Last reviewed on 2026-03-23. Where a claim depends on a specific study, the study is described rather than over-claimed.

Peptide Identity and Laboratory Handling

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.

Structure, Naming and Discovery

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.

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 at a glance

PropertyValueNotes
Molecular formulaC14H22N4O9Free acid form of the tetrapeptide
Molecular massAbout 390.35 DaCalculated monoisotopic value
AppearanceWhite to off-white powderTypical lyophilized presentation
SolubilitySoluble in waterAlso dissolves in buffered saline
Storage temperatureMinus 20 degrees CelsiusDry, dark conditions; avoid repeated thawing

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.

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Notes from published material

== Substrate immobilization == Another widely used application of the immobilization approach together with enzymes has been the enzymatic reactions on immobilized substrates. This approach facilitates the analysis of enzyme activities and mimics the performance of enzymes on e.g. cell walls.

Therefore, an effective cure will require a sequential, integrated approach that combines adequate and safe immune interventions with beta cell regenerative approaches. It has also been demonstrated that alpha cells can spontaneously switch fate and transdifferentiate into beta cells in both healthy and diabetic human and mouse pancreatic islets, a possible future source for beta cell regeneration. In fact, it has been found that islet morphology and endocrine differentiation are directly related. Endocrine progenitor cells differentiate by migrating in cohesion and forming bud-like islet precursors, or "peninsulas", in which alpha cells constitute the peninsular outer layer and beta cells form later beneath them. Cryopreservation has shown promise to improve the supply chain of pancreatic islets for better transplantation outcomes.

Following his loss to Sylvia in May, Pudzianowski signed to face former heavyweight boxer and kickboxer Eric Esch, better known as 'Butterbean', at KSW 14 on 18 September. After several brief standup exchanges, Pudzianowski secured a takedown early in the fight and was then able to dominate Esch with ground and pound. Esch, unable to get back to his feet during the attack, tapped out to the strikes, making Pudzianowski the winner by submission at 1:15 of the first round. He came into the fight notably slimmer, having lost around 20 lbs from his previous fight. Many believe his large muscle mass to have caused his stamina problems in his earlier fights. On 21 May 2011 Pudzianowski fought James Thompson at KSW 16, losing by arm triangle. In September 2011 Mariusz Pudzianowski started professional training in the well known MMA camp in the USA – American Top Team. Pudzianowski fought on the KSW 17 event, which was held on 26 November 2011. He faced James Thompson in a rematch. He won the fight via majority decision. This decision caused controversy as Thompson had virtually full control in both rounds, and after the fight Thompson, who was clearly angered by the decision, took the microphone from the announcer and launched a verbal assault directed at the promotion in which he ranted: "F...g joke. Give Mariusz a big round of applause. Come on. What a f...g joke. I thought KSW was really trying to be serious.

Sources: en.wikipedia.org

Background from the literature

Carboxylation of the 2,3-enediolate results in the intermediate 3-keto-2-carboxyarabinitol-1,5-bisphosphate and Lys334 is positioned to facilitate the addition of the CO2 substrate as it replaces the third Mg2+-coordinated water molecule and add directly to the enediol. No Michaelis complex is formed in this process. Hydration of this ketone results in an additional hydroxy group on C3, forming a gem-diol intermediate. Carboxylation and hydration have been proposed as either a single concerted step or as two sequential steps. Concerted mechanism is supported by the proximity of the water molecule to C3 of RuBP in multiple crystal structures. Within the spinach structure, other residues are well placed to aid in the hydration step as they are within hydrogen bonding distance of the water molecule.

RCO2H → RH + CO2 Decarboxylation is one of the oldest known organic reactions. It is one of the processes assumed to accompany pyrolysis and destructive distillation. Overall, decarboxylation depends upon stability of the carbanion synthon R−, although the anion may not be a true chemical intermediate. Typically, carboxylic acids decarboxylate slowly, but carboxylic acids with an α electron-withdrawing group (e.g. β‑keto acids, β‑nitriles, α‑nitro acids, or arylcarboxylic acids) decarboxylate easily. Decarboxylation of sodium chlorodifluoroacetate generates difluorocarbene:

However, the "absolute zero" on the Kelvin temperature scale was originally defined in terms of the second law of thermodynamics, which Thomson himself described in 1852. Thomson did not assume that this was equal to the "zero-volume point" of Charles's law, merely said that Charles's law provided the minimum temperature which could be attained. The two can be shown to be equivalent by Ludwig Boltzmann's statistical view of entropy (1870). However, Charles also stated:

Sources: en.wikipedia.org

Reference notes

== Etymology == In a 1967 article in American Speech, linguists Edwin Eames and Howard Robboy identified thirteen different terms for the submarine sandwich in the United States in a survey of 100 American cities. The names, ranked by most widespread use, were: submarine, hoagie, poor boy, grinder, torpedo, Italian sandwich, hero, rocket, zeppelin, Garibaldi, bomber, musalatta, and Cuban sandwich. Eames and Robboy noted that "submarine" was the only term that was not regional in some way. Some of the least common of the names were identified in only one city, including Garibaldi in Madison, Wisconsin and musalatta (or muffuletta) in New Orleans.

== Procedure == This section covers livestock Cryo-branding. Since the 1960s, experimental work has been carried out on freeze brands for other animals. Around seventy species have been evaluated to date. These efforts are summarized in Freeze brand § Table of branding durations.

== Discovery == Jelleines were first isolated in 2004 by the research group of Professor Mario Sergio Palma at São Paulo State University, Brazil. First, he collected royal jelly from a group of honey bee larvae and purified the results by reverse phase, high-performance liquid chromatography. This purified royal jelly showed antimicrobial activity against different bacteria. So far, four peptides have been found in this family, each one containing the carboxamide C-terminal.

The CUX1 gene Alternatively Spliced Product was first reported in 1997. The CUX1 gene has up to 33 exons. CASP mRNA includes exons 1 through 14 and 25 through 33. The human CASP protein is predicted to contain 678 amino acids, of which 400 are shared with CUTL1. CASP protein is approximately 80 kD. It lacks the DNA binding region of CUTL1, but instead contains a trans-membrane domain that allows it to insert into lipid bilayers. It has been localized to the Golgi apparatus. CASP has been reported to be part of a complex with Golgin 84 that tethers COPI vesicles and is important for retrograde transport in the Golgi and between the Golgi and endoplasmic reticulum. The targeting of vesicles involves tethers and SNAREs.

Sources: en.wikipedia.org

Frequently asked questions

What is epitalon made of?

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.

Does epitalon occur naturally in the body?

No naturally occurring free form of the peptide has been described. The four-amino-acid sequence can appear as a fragment within larger proteins, but that is not the same as the intact compound being present as a circulating molecule. Materials used in research are synthetic.

How is epitalon purity checked?

Purity is usually checked by reverse-phase high-performance liquid chromatography, which separates the target peptide from related impurities. Mass spectrometry is commonly used alongside it to confirm molecular mass. Some suppliers also provide amino acid analysis for additional sequence confirmation.

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.

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