A practical reference on Tetrapeptide: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
Reviewed 2026-03-05. Anything still debated is marked as such rather than presented as settled.
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.
The published literature is dominated by a small number of research groups, much of it in Russian-language journals, and independent replication outside those groups is limited. Studies are typically small, use cultured cells or rodent models, and report endpoints that differ between papers, which makes comparison difficult. Large randomised human trials have not appeared in the indexed literature. Questions about absorption, distribution and clearance are therefore still treated as open in reviews that mention the compound.
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.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C14H22N4O9 | Derived from the four constituent residues |
| Molecular mass | About 390.35 Da | Monoisotopic value, confirmed by mass spectrometry |
| Residue sequence | Ala-Glu-Asp-Gly | Read from the N-terminus to the C-terminus |
| Common synonyms | Epithalon; AEDG | Both forms appear in reference catalogues |
| Net charge near neutral pH | Negative | Two acidic side chains give a low isoelectric point |
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.
Storage recommendations center on limiting moisture, heat, and light. The dry powder is generally kept at minus 20 degrees Celsius, and some suppliers recommend minus 80 degrees for long-term archival. Once dissolved, solutions are usually aliquoted and frozen to avoid repeated freeze-thaw cycles, which can promote aggregation or degradation. Aqueous stability depends on pH and concentration, and buffered saline is often preferred over plain water for biological work. Stability data specific to epitalon remain limited, so general peptide-handling practices are applied by analogy rather than from product-specific validation.
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.
== Function == Elastin, a protein in the extracellular matrix, provides elasticity and its soluble precursor is tropoelastin. When elastin cross links it produces desmosine and isodesmosine. When desmosine is mentioned, it is usually grouped with isodesmosine, the other tetrafunctional amino acid that is specific to elastin.
The chromatogram is then analyzed by integrating the peaks curves to get their area, then getting their retention time (RT) from the peak maximum to identify them, and then perform quantitative analysis, by comparing their area to those of samples whose concentrations are known, i.e., standards.
=== Culinary === Shallots are used in cooking. They may be pickled. Finely sliced, deep-fried shallots are used as a condiment in Asian cuisine, often served with porridge. Shallots taste similar to other cultivars of the common onion, but have a milder flavor. Like onions, when sliced, raw shallots release substances that irritate the human eye, resulting in production of tears. Fresh shallots can be stored in a cool, dry area (0 to 4 °C, 32 to 40 °F, 60 to 70% RH) for six months or longer. Chopped, dried shallots are available.
Travis personally confronts Barris, who tries to stab him, only for Travis to stop the blade with his bare hand. Shocked by his own actions, Barris allows Travis to beat him to a pulp. Only then does the door open, signaling the end of the experiment. The group emerges into bright sunlight and sits on the grass in silence until a bus arrives. Audio news snippets suggest that Archaleta is being tried for manslaughter in Benjy's death. Travis, having received his payment, travels to India to meet his girlfriend.
Ian McCartney, Labour Party chairman at the time, said Galloway was the only Labour MP who "incited foreign forces to rise up against British troops". Tony Benn questioned why Galloway strove to remain in the Labour Party despite calling its leadership a "blood-splattered, lying, crooked group of war criminals". Benn added, "It put me off George Galloway in a fairly fundamental way". Following the 7 July 2005 London bombings, which killed 52 civilians, Galloway linked the attack to Western policies in the Middle East. He said Tony Blair and George W. Bush had "far more blood on their hands" than the terrorists who carried out the bombings, and called President Bush the world's "biggest terrorist".
Sources: en.wikipedia.org
== Combination hemoglobinopathies == A combination hemoglobinopathy occurs when someone inherits two different abnormal hemoglobin genes. If these are different versions of the same gene, one having been inherited from each parent it is an example of compound heterozygosity. Some examples of clinically significant combinations involving beta thalassemia include:
== Prognosis == The prognosis for individuals with severe LNS is poor. Death is usually due to kidney failure or complications from hypotonia, in the first or second decade of life. Less severe forms have better prognosis.
When Augustus became sole ruler in 31 BC, he disbanded about half of the over 50 legions then in existence. The remaining 28 legions became the core of the early Imperial army of the Principate (27 BC – AD 284), most lasting over three centuries. Augustus and his immediate successors transformed legions into permanent units, staffed by entirely career soldiers on standard 25-year terms. During the Dominate period (near the end of the Empire, 284–476), legions were also professional, but are little understood due to scarcity of evidence compared to the Principate. What is clear is that late legions were radically different in size, structure, and tactical role from their predecessors, despite several retaining early period names. This was the result of the military reforms of Emperors Diocletian and Constantine I, and of further developments during the 4th century. The legions were identified by Roman numerals, though the spelling sometimes differed from the modern standard. For example, in addition to the spellings "IV", "IX", "XIV", "XVIII" and "XIX", the respective spellings "IIII", "VIIII", "XIIII", "XIIX" and "XVIIII" were commonly used. Legions also bore a cognomen or nickname. Neither a legion's number or cognomen were likely unique enough to identify it, so the combination of the two is usually needed to identify a specific legion. For example, both Legio III Cyrenaica and Legio III Gallica were distinct, long-standing legions of the late Republic and Imperial periods.
In a cohort of 20 suspected (19 confirmed) head-and-neck squamous cell carcinoma (HNSCC) cases, 68Ga-Trivehexin PET had a higher sensitivity (92.5%), positive predictive value (PPV, 100%), and accuracy (93%) than the standard 18F-FDG PET, for which sensitivity, PPV, and accuracy were 90%, 93.1%, and 84.3%, respectively. 68Ga-Trivehexin was furthermore applied in a case of tonsillar carcinoma metastasized to the brain (see image).
Sources: en.wikipedia.org
Also in the 4th century BCE, Herophilos and Erasistratus produced more accurate anatomical descriptions based on vivisection of criminals in Alexandria during the Ptolemaic period. In the 2nd century, Galen of Pergamum, an anatomist, clinician, writer, and philosopher, wrote the final and highly influential anatomy treatise of ancient times. He compiled existing knowledge and studied anatomy through the dissection of animals. He was one of the first experimental physiologists through his vivisection experiments on animals. Galen's drawings, based mostly on dog anatomy, became effectively the only anatomical textbook for the next thousand years. His work was known to Renaissance doctors only through Islamic Golden Age medicine until it was translated from Greek sometime in the 15th century.
=== Laboratory findings === Hormonal syndromes should be confirmed with laboratory testing. Laboratory findings in Cushing syndrome include increased serum glucose (blood sugar) and increased urine cortisol. Adrenal virilism is confirmed by the finding of an excess of serum androstenedione and dehydroepiandrosterone. Findings in Conn syndrome include low serum potassium, low plasma renin activity, and high serum aldosterone. Feminization is confirmed with the finding of excess serum estrogen.
In Berezovka, a memorial steel was erected in 1972. In Bychivka Station: A memorial plaque was dedicated in 1965. In Dubrova: a Monument was erected in 1979 commemorating the 1943 raid on the local German Garrison.
Sources: en.wikipedia.org
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.
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.
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.
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.