Tetrapeptide comes up often in conversation and rarely with the context attached. Here we lay out the basics in order, then work through the practical considerations.
Updated 2026-05-07. Numbers and descriptions here follow the published literature rather than marketing material.
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.
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.
The parent extract epithalamin was characterised as a low-molecular-weight fraction of pineal tissue rather than a single defined chemical entity. Researchers fractionated it and tested successive fragments for activity, a screening approach typical of peptide discovery work in that era. Epitalon emerged from that process as one of the shorter sequences of interest. Because the original extract was never fully resolved into individual components, claims about which constituent drives a given effect rest on inference. This distinction matters when reading older reports that attribute extract observations to the tetrapeptide itself.
Epitalon is a synthetic tetrapeptide with the residue sequence alanine-glutamate-aspartate-glycine, commonly abbreviated AEDG. Its monoisotopic mass is approximately 390.35 daltons, and it is usually supplied as a lyophilised trifluoroacetate or acetate salt. The compound was derived from a pineal gland extract called epithalamin, a heterogeneous preparation investigated in the former Soviet Union. Researchers associated with the Saint Petersburg Institute of Bioregulation and Gerontology described the tetrapeptide as a constituent fragment of that extract. Commercial material is offered as a laboratory reagent rather than as a finished pharmaceutical product.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C14H22N4O9 | Free acid form of the tetrapeptide |
| Molecular mass | About 390.35 Da | Calculated monoisotopic value |
| Appearance | White to off-white powder | Typical lyophilized presentation |
| Solubility | Soluble in water | Also dissolves in buffered saline |
| Storage temperature | Minus 20 degrees Celsius | Dry, dark conditions; avoid repeated thawing |
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.
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.
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.
== Alternative for specimen transport == One common alternative to dry shippers is using dry ice. This method reduces package weight and costs since there's no need for return shipping, unlike with dry shippers. However, at -80 °C (176 °F), dry ice might not provide a temperature low enough for all specimens. For instance, while cryopreserved mouse spermatozoa can handle this temperature for short periods without losing their fertilization capacity, cryopreserved mouse embryos require colder environments, such as those below -150 °C (302 °F) in dry shippers, to maintain their quality. Another method is shipping freeze-dried samples at ambient temperatures, as seen with freeze-dried mouse spermatozoa. This can be more cost-effective, but many samples, when freeze-dried, experience a notable decline in quality, limiting its applicability.
The actual Demilitarized Zone fence along the Southern Limit Line is completely off-limits to everyone except soldiers, and it is illegal to photograph it. Similarly, the whole estuary of the Han River in the Korean Peninsula is deemed a "Neutral Zone" and is officially off-limits to all civilian vessels. Only military vessels are allowed within this neutral zone. In recent years, Chinese fishing vessels have taken advantage of the tense situation in the Han River Estuary Neutral Zone and illegally fished in this area due to both North Korean and South Korean navies never patrolling this area due to the fear of naval battles breaking out. This has led to firefights and sinkings of boats between Chinese fishermen and South Korean Coast Guard. On 30 January 2019, North Korean and South Korean military officials signed a landmark agreement that would open the Han River Estuary to civilian vessels for the first time since the Armistice Agreement in 1953. The agreement was scheduled to take place in April 2019, but the failure of the 2019 Hanoi Summit indefinitely postponed these plans. The Green Line separating Southern Cyprus and Northern Cyprus is a demilitarised border zone operated by the United Nations Peacekeeping Force in Cyprus operate and patrol within the buffer zone. The buffer zone was established in 1974 due to ethnic tensions between Greek and Turkish Cypriots. The green line is similar in nature to the 38th parallel separating the Republic of Korea and North Korea.
== Early life and education == Alessio Ciulli was born in Florence on 22 July 1977. He attended University of Florence in his hometown with an undergraduate laurea in chemistry and graduated magna cum laude. Under the late Prof Ivano Bertini, his final year laurea project was in computational drug design and NMR spectroscopy of matrix metalloproteases. Awarded with a Gates Cambridge Scholarship, he did his PhD under the supervision of the late Professor Chris Abell at the University of Cambridge and in collaboration with Astex Technology (now Astex Pharmaceuticals) produced a thesis concerned with studying weak protein-ligand interactions using biophysical and structural methods.
Sources: en.wikipedia.org
=== Dicamba lawsuit === On 27 January 2020, the first-ever lawsuit concerning Dicamba-related products began in Cape Girardeau, Missouri. The lawsuit involved a peach farmer who alleged that Dicamba-based herbicides caused significant damage to his crops and trees. It had also been filed in November 2016, when Dicamba was still owned by Monsanto. On 14 February 2020, the jury involved in the lawsuit ruled against BASF and its co-defendant Bayer, which had acquired Monsanto and its products, and found in favor of the peach grower, Bader Farms owner Bill Bader. BASF and Bayer were also ordered to pay Bader $15 million in damages. On 15 February 2020, Monsanto and BASF were ordered to pay an additional $250 million in punitive damages.
=== Stereocilia === The stereocilia of the epididymis are long cytoplasmic projections that have an actin filament backbone. These filaments have been visualized at high resolution using fluorescent phalloidin that binds to actin filaments. The stereocilia in the epididymis are non-motile. These membrane extensions increase the surface area of the cell, allowing for greater absorption and secretion. It has been shown that the epithelial sodium channel ENaC that allows the flow of Na+ ions into the cell is localized on stereocilia. Because sperm are initially non-motile as they leave the seminiferous tubules, large volumes of fluid are secreted to propel them to the epididymis. The core function of the stereocilia is to resorb 90% of this fluid as the spermatozoa start to become motile. This absorption creates a fluid current that moves the immobile sperm from the seminiferous tubules to the epididymis. Spermatozoa only reach full motility when inside a vagina, where the alkaline pH is neutralized by acidic vaginal fluids.
=== Laboratory solvent === It is a common solvent for the Grignard reaction in addition to other reactions involving organometallic reagents. These uses exploit its basicity. Diethyl ether is a popular non-polar solvent in liquid-liquid extraction. As an extractant, it is immiscible with and less dense than water. Although immiscible, it has significant solubility in water (6.05 g/(100 ml) at 25 °C) and dissolves 1.5 g/(100 g) (1.0 g/(100 ml)) water at 25 °C.
Sources: en.wikipedia.org
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.
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.
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.
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.